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  • CN 31-1633/O6
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Synthesis of Pyrene-Based Two-Dimensional Polymer Film at Gas-Liquid Interface
HAN Xiangli, GUAN Jing, CHEN Le, ZHAO Pei, TAN Weiqiang, ZHENG Zhikun
 doi: 10.14133/j.cnki.1008-9357.20210125001
[Abstract](114) [FullText HTML](85) [PDF 1427KB](13)
Two-dimensional (2D) materials, such as 2D polymers (2DP) and 2D covalent organic frameworks (2D-COF), have arisen as promising materials because of their unique physicochemical properties and great potential in optoelectronics, sensing, catalysis, separation, and energy storage and conversion. Preparing 2DPs films with desirable structures is promising but remains a great challenge. Recently, vigorous efforts have been devoted to the synthesis of 2DPs films via different methods, such as interfacial synthesis at air-water or liquid-liquid. Here, by using surfactant-monolayer-assisted interfacial synthesis (SMAIS), a fluorescent pyrene-based 2D polyimine (2D-PI) thin film was prepared via Schiff-base condensation between 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetraaniline and 2,5-dihydroxyterephthalaldehyde with trifluoromethanesulfonic acid as catalyst at room temperature. The morphology, structure, crystallinity and fluorescence intensity of the film were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray diffraction (XRD), fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy, respectively. The results show that the thickness of the film was 70 nm, which could be controlled by changing the monomer concentration. The imine bond formation was confirmed by Raman and Fourier transform infrared spectroscopy. The crystallinity of the film depended on the diffusion rate of monomer and was significantly improved by the adding trifluoromethanesulfonic acid and surfactant monolayer which provides a confined 2D template for the polymerization. The fluorescence strength of the film was enhanced due to the existence of intramolecular hydrogen bonding in the framework structure. It provided a new idea for the preparation of 2DPs films with solid luminescent properties. The 2DPs thin film may be potentially applied to the detection of water content in organic solvents.
Drug Delivery Systems Based on Polymer Materials for Lowering Intraocular Pressure
HUANG Chang, ZHAO Yujin, XU Jianjiang, SUN Xinghuai, SUN Jianguo
 doi: 10.14133/j.cnki.1008-9357.20210225001
[Abstract](127) [FullText HTML](96) [PDF 1358KB](13)
Glaucoma drug therapy for lowering intraocular pressure suffers from some deficiencies, such as low bioavailability, discontinuous drug action, poor patient compliance and long-term tissue toxicity. To meet clinical needs more effectively, materials engineering technologies are gradually used for the development of novel intraocular pressure lowering drug delivery systems (DDSs), and some have been commercialized in clinical treatments. However, there is still a significant gap between commercial products and clinical needs in terms of safety and treatment efficacy. Based on our previous work and understanding of glaucoma treatment and novel ocular DDSs, we herein systematically summarize the recent research results of novel DDSs in lowering intraocular pressure. Initially, the physiological structure of the eye and the difficulties of drug therapy are introduced, then polymer materials used to develop drug delivery systems for intraocular antihypertensive therapy are summarized. New DDSs based on polymer materials, such as solid implants, gel-based DDSs and nanocarrier-based DDSs are reviewed. Furthermore, we briefly introduce the DDSs developed by our group for improving intraocular pressure. After simply analyzing the limitations of commercial ocular drug delivery systems in clinical applications, we prospect the future development of intraocular pressure lowering DDSs in the directions of more effective, more targeted and more intelligent DDSs.
Near-Infrared Light Induced Reverse Atom Transfer Radical Polymerization with the Assistance of Upconversion Particles
ZHANG Zhihui, ZHU Ye, LUO Jing, LIU Ren, LIU Xiaoya
 doi: 10.14133/j.cnki.1008-9357.20210208001
[Abstract](61) [FullText HTML](43) [PDF 1091KB](9)
Near-Infrared (NIR) induced reverse atom transfer radical polymerization (ATRP) was achieved by using upconversion particles (UCP), which can convert the NIR light into light with UV/vis wavelength, as the internal light source, phenyl bis(2, 4, 6-trimethylbenzoyl)-phosphine oxide (BAPO) as the initiator, copper bromide (CuBr2)/N, N, N', N', N"-pentamethyldiethylenetriamine (PMDETA) as the catalyst, methyl methacrylate (MMA) as the main monomer, N, N-dimethylformamide (DMF) as the solvent, reaction condition: [M]0/[PI]0/[CuBr2]0/[PMDETA]0=300/1/1/3, VMMA/VDMF=1/1, NIR laser power is 16.5 W/cm2. The UV/vis spectrum of BAPO and emission spectrum of UCP and photolysis of BAPO under irradiation of NIR light assisted by UCP indicated adaptability of BAPO and UCP. The process and reverse ATRP mechanism of this system were investigated by adjusting the conditions of polymerization system, including whether UCP or BAPO or catalyst exist. In addition, the energy source of this polymerization was investigated by simulating the temperature of this system under NIR light irradiation. The results confirmed the photoluminescence of UCP under irradiation of 980 nm NIR light and the polymerization initiated by fluorescence instead of thermal effect. UCP-assisted NIR induced reverse ATRP is capable for polymerization of various type of monomers including methyl methacrylate (MMA), methyl acrylate (MA) and styrene (St). The kinetics of the polymerization of MMA was investigated under UCP-assisted NIR induced reverse ATRP and a linear semilogarithmic plot of monomer concentration versus polymerization time was observed. The living character of the polymerization was confirmed by both the linear tendency of molecular weight evolution with conversion and a chain extension experiment. The UCP-assisted NIR induced reverse ATRP provided well-defined polymer with relative low dispersity and excellent chain-end fidelity.
Non-Aqueous Bioadhesive Based on Hyperbranched Polythioether
ZHANG Yifan, BAI Guanghang, LI Xiaojie, LIU Xiaoya
 doi: 10.14133/j.cnki.1008-9357.20210127001
[Abstract](73) [FullText HTML](76) [PDF 1266KB](21)
As a substitute of suture, bioadhesive attracts much attention in clinical application. However, the development of bioadhesive with excellent bonding performance for underwater usage remains a challenge. Herein, a non-aqueous bioadhesive with underwater bonding properties was manufactured based on hydrophobic hyperbranched polythioether (HBP). HBP with the surface containing abundant thiol groups was synthesized through a simple thiol-(meth)acrylate Michael addition polymerization of 2-(acryloyloxy)ethyl methacrylate (AA' monomer) and trimethylolpropane tris(3-mercaptopropionate) (B3 monomer). HBP was a liquid material under room temperature, thus enabling the manufacturing of non-aqueous adhesives (HBP-x) by the direct addition of poly(ethylene glycol) diacrylate. The properties of HBP-x were studied using vial-tilt method, rheological test, lap-shear adhesion test, swelling test, degradation test and in vitro cytotoxicity test. Results showed that the HBP-adhesive could bond porcine skin with an underwater adhesive strength of up to 43 kPa. Moreover, the HBP-adhesive minimally swelled (7.2%—17.3%) and was degradable. In vitro cell experiments showed that the HBP-adhesive showed very low cytotoxicity to L929 cells, and allowed the proliferation of L929 cells on the surface of the adhesive. This non-aqueous HBP-adhesive based on thiol-acrylate Michael addition reaction displayed an underwater bonding ability and excellent cytocompatibility, holding great potential for clinical applications.
Application of Heparin in Anti-Tumor Drug Delivery Systems
ZANG Jing, KE Xue, CI Tianyuan
 doi: 10.14133/j.cnki.1008-9357.20200824001
[Abstract](666) [FullText HTML](471) [PDF 1423KB](40)
Heparin is a kind of glycosaminoglycan with complex structure, which is composed of glucuronic acid and glucosamine. Even though heparin has been used as anticoagulant in clinic for long time, growing evidence have indicated its potent capability in anti-metastasis. In recent years, heparin-based anti-tumor drug delivery system has been widely reported. In these systems, heparin not only enhances the anti-tumor effect of anticancer drugs, but also exhibits its own anti-metastasis function, realizing synergistic anti-tumor and anti-metastasis effects between drugs and drug vesicles. Generally, the heparin-based drug delivery system can be divided into nano-based drug delivery system, micro-based drug delivery system and hydrogel. Here we review the rational design of these systems, and the potential challenges in this field are also discussed.
Design and Preparation of pH/Temperature Stimulated Responsive Core-Shell Mesoporous Silica Nanoparticles
CHEN Haowen, CHEN Miaoxin, LIU Yehong, ZHANG Yuhua, XU Shouhong
$v.latestStateEn  doi: 10.14133/j.cnki.1008-9357.20210402001
[Abstract](28) [FullText HTML](26) [PDF 1252KB](7)
Premature leakage of drugs into the bloodstream remains a problem in the process of drug delivery, resulting in higher toxic and side effects on normal tissue cells. Novel drug carriers enabling effective drug accumulation in the tumor site have got much attention of researchers. Poly (methyl acrylic acid diisopropyl amino ethyl ester) (PDPA) is a polymer with pH-sensitive response, the diisopropylamine in the side chains are protonated in an acidic environment, resulting in its changing from hydrophobic to hydrophilic. PDPA was grafted onto the surface of mesoporous silica nanoparticles (MSNs) by atom transfer radical polymerization (ATRP) reaction. Then folic acid (FA) was introduced onto PDPA as a targeting ligand for enabling the drug carrier to enter tumor cells effectively. Simultaneously P(MEO2MA90-co-OEGMA10)-b-PDPA10 (poly [di (ethylene glycol) methyl ether methacrylate-co-oligo (ethylene glycol) methacrylate]-b-poly[methyl acrylic acid diisopropyl amino ethyl ester]) with dual sensitivity of temperature and pH was synthesized and the lower critical solution temperatures (LCST) of the polymer was adjusted to 44 ℃ by adjusting the proportion of three monomers. A drug carrier with a core-shell structure was self-assembled through hydrophobic force by covering the later polymer on the surface of MSNs-PDPA-FA. Finally, the drug release kinetics of the carrier was studied by using doxorubicin(DOX) as a model drug, and the result showed that the total leakage of the model drug DOX was less than 10% after 48 h in normal physiological environment (pH=7.4, 37 ℃). However, when the pH was changed to 5.0 at 44 ℃, the shell was dissociated from the core and the drug was released. Then, the drug was released rapidly within 5 h and the cumulative drug release could reach to 65% in 48 h. Therefore, this research was expected to construct a shielding system based on the pH/temperature dual-responsive polymer, which could be used to avoid premature exposure of certain functional groups or molecules to the normal physiological environment, and it could also prevent the premature release of drugs in the normal tissues.
Photosensitive Polyurethane Resin with Self-Healing and Shape-Memory Functions
KONG Siyu, YANG Chongchong, ZHENG Zhen, WANG Xinling
 doi: 10.14133/j.cnki.1008-9357.20201223001
[Abstract](130) [FullText HTML](91) [PDF 1564KB](13)
A self-healing photosensitive polyurethane acrylate (PUTA), containing bulky urea bonds and crystalline soft segments, was designed and prepared based on the dynamic reversibility of the blocking agent. The UV-cured material presents high elasticity, good mechanical property, self-healing and shape memory functions. With the increase of soft segment content, the compatibility of soft and hard segments is improved. Combined with the thermal results of Dynamic Mechanical Analysis (DMA) and Differential Scanning Calorimetry (DSC), the best healing temperature of PUTA was 80 ℃, which was consistent with the glass transition temperature (Tg) of hard segment. After heat treatment, the healing efficiency of materials can reach 70% (the tensile strength and elongation are 3.58 MPa and 250%, respectively). The dynamic reversible characteristics of urea bond with large steric hindrance make the material better self-healing performance. After being thermal-stimulated, the urea bond molecules at the fracture place of the PUTA sample undergo dynamic exchange and reaction, thus completing the healing process of the material. The crystalline transformation of soft segment endows the material with properties of remolding and shape memory. Besides, the shape recovery can be completed quickly after heating. Specifically, for PUTA with polycaprolactone (PCL) 4000 as soft segment, the shape recovery can be completed within 5 min at 80 ℃. The prepared material has intelligent response characteristics in thermo-responsive behavior of self-healing and shape memory. Besides, the higher the content of soft segment is, the better the crystallinity and the stronger the shape memory ability are. Combined with UV curing 3D printing technology, it is expected to play a role in the field of customized intelligent wearable devices and biomedical materials.
Application of PVDF/TiO2 Electrospun Fiber Membrane in Photodegradation and Oil-Water Separation
GE Jun, FENG Yangyang, CHAI Peng, YAN Luke, CHEN Tao
 doi: 10.14133/j.cnki.1008-9357.
[Abstract](52) [FullText HTML](35) [PDF 1184KB](7)
Polyvinylidene fluoride (PVDF) and tetrabutyl titanate (TBOT) are dissolved in a mixed solvent of N, N'-dimethylformamide (DMF) and acetone to electrospun into a fiber membrane. Then, TBOT contained in the electrospun fiber membrane was reduced to titanium dioxide (TiO2) by a one-step hydrothermal method at 150 °C. The PVDF fiber membrane material with TiO2 grown in situ on the surface and inside of the fiber was obtained. The morphology and structure of TiO2 grown on PVDF fibers in situ was determined by scanning electron microscope (SEM), thermal weight loss instrument (TG), X-ray diffractometer (XRD) and Fourier infrared absorption spectroscopy (FT-IR). Then, the degradation effect of the composite film on the three organic dyes of rhodamine B, methyl orange and methylene blue was tested by UV-visible spectroscopy. Finally, the gravity-driven method is used to separate the oil-water mixture and the contact angle of the composite membrane to water and oil is tested to explore the oil-water separation effect of the composite membrane. Results show that the composite membrane has a good degradation effect on organic dyes such as rhodamine B, methyl orange, methylene blue. The composite membrane also has good lipophilic and hydrophobic properties. It is separated by the mixture of carbon tetrachloride and water. The composite membrane can effectively realize oil-water separation, and the oil-water separation effect can be as high as 98%.
Preparation of Polypyrrole/MnO2 Paper Electrode and Its Photothermal Effect Enhanced Capacitor Performance
KANG Meng, WANG Pengfei, WANG Meng, WU Qiang, KE Xiaoling, ZHOU Jianhua
 doi: 10.14133/j.cnki.1008-9357.20210131001
[Abstract](102) [FullText HTML](76) [PDF 1152KB](10)
The performance of supercapacitors degenerates at low tempertures, even fails to work sometimes. Solar photothermal conversion could provide a new direction for the performance improvement of supercapacitors. Manganese dioxide (MnO2) has high specific capacity, however, it needs to be compounded with other active materials due to its low electric conductivity. Therefore, this work aims to improve the performance of MnO2-based supercapacitor using the photothermal effect of polypyrrole (PPy), where PPy exhibits both excellent light absorption ability and pseudocapacitance property. MnO2 and PPy were successively deposited on slow filter paper by wet chemistry method and low-temperature interfacial polymerization method, and PPy/MnO2 paper-based composites with different PPy contents were prepared. The structure and properties of the composites were characterized by infrared spectroscopy, scanning electron microscopy, cyclic voltammetry, galvanostatic charge/discharge and AC impedance spectroscopy. The results show that the porous structure of filter paper is well preserved after PPy deposition, and MnO2 particles can be covered to form a large active area. The specific capacitance of MnO2/PPy-400 single electrode can reach 1487.1 mF/cm2, which is 67% higher than that of pure PPy electrode. Under the simulated sunlight with intensity of 1 kW/m2, the surface temperature of the assembled symmetrical supercapacitor rose from 21.2 °C to 46.7 °C after 10 min. The specific capacitance of the symmetrical supercapacitor assembled by paper electrode with PPy of 400 μL is 52.9 mF/cm2 with illumination, which is 5 times of that in dark, suggesting excellent photothermal effect enhanced the capacitor properties.
Poly(2-aminoazulene)-Based all-Solid-State Supercapacitors
JIN Xin, CHEN Zhian, SUN Sai, ZHUANG Xiaodong, CHEN Yu
 doi: 10.14133/j.cnki.1008-9357.20210112002
[Abstract](255) [FullText HTML](189) [PDF 1263KB](14)
Conductive polymers with good intrinsic conductivity and high charge density are considered as potential electrode materials for supercapacitors. However, it has been reported that the chains of polypyrrole and polyaniline could expand and contract during charging and discharging process to leading structural de-conformation. Poly(2-aminoazulene) was lately reported to present large area film morphology and remarkable electrical conductivity at room temperature, nevertheless, relevant studies based on azulene as supercapacitor electrode materials has rarely been reported. Here, we report an all-solid-state supercapacitor based on a conductive polymer, poly(2-aminoazulene), as the electrode material. According to conventional electrochemical measurement, poly(2-aminoazulene) film-based device exhibits promising capacitive performance in the operating voltage window of −0.2 ~ 0.8 V: maximum volumetric capacitance of 83 F/cm3 and maximum areal capacitance of 0.34 mF/cm2, maximum energy density of 11.6 mW·h/cm3 and maximum power density of 3304 W/cm3. In addition, the supercapacitor retains 95.1% of the initial capacitance after 1000 cycles, indicating good cycling stability which enables its reliability during practical applications. These results not only prove that poly(2-aminoazulene) could be next generation candidates of all-solid-state supercapacitor electrode materials but also provide a new strategy for exploration of intrinsic conductive polymers for energy storage.
Preparation of PDA-TiO2 Hybrid Nanoparticles and Their Application in Sun Protection
LI Saiyao, WANG Yang, LI Ting, DONG Weifu
 doi: 10.14133/j.cnki.1008-9357.20210104001
[Abstract](210) [FullText HTML](209) [PDF 1136KB](15)
Organic filters in conventional sunscreens generally have a poor photo stability and can easily penetrate through stratum corneum and dermis into the blood vessel, thus causing potential health-threatening issues. Polydopamine (PDA) nanoparticles can be formed by self-polymerization of dopamine. Inspired by its excellent anti-ultraviolet, free radical scavenging and adhesion properties, the titanium dioxide (TiO2) precursor is prepared by the sol-gel method and blended with dopamine hydrochloride to prepare PDA-TiO2 hybrid nanoparticles. Infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible light absorption spectroscopy (UV-Vis), thermal weight loss curve (TGA) and skin penetration experiments were used to characterize the basic structures and properties of nanoparticles. Under the synergistic effect of PDA and TiO2, the particles have highly effecient UV protection. By simply adjusting the reaction material ratio, it was found that the more dopamine content, the better UV absorption effect was obtainee, and It showed better UV absorption performance than small particle size PDA. Therefore, PDA-TiO2 (1/10) had the best UV absorption effect. The PDA-TiO2 (1/10) was introduced as the sole active ingredient to formulating sunscreen, whose sun protection factor (SPF) values could reach 33.7, which can meet daily sun protection needs. Most importantly, PDA has good bioadhesion and can effectively prevent the penetration of PDA-TiO2 hybrid nanoparticles. The thickness of the stratum corneum of the human body was about 15-20 μm. Upon comparing the PDA-TiO2 with commercially available benzophenone small molecule sunscreens, it was found that the skin permeability of PDA-TiO2 was significantly reduced, and the penetration depth was 9~17 μm, mainly distributed in the upper and middle parts of the stratum corneum of the skin, it is not easy to enter the human body and will not pose a potential threat to skin health. The commercially available benzophenone sunscreen small molecules had a skin penetration of 18~35 μm, indicating that they penetrate the stratum corneum to reach the living epidermis and enter the human body. Therefore, the prepared nanoparticles have excellent UV resistance and biocompatibility, ensuring their excellent performance and safe use in sunscreens.
Synthesis and Properties of Self-Assembling Diselenide-Containing Polycarbonate Micelles
MA Xiaoning, ZHOU Chen, LANG Meidong
 doi: 10.14133/j.cnki.1008-9357.20201126001
[Abstract](119) [FullText HTML](101) [PDF 1223KB](12)
Diselenide bond is a kind of stimulus-responsible chemical bond with sensitive redox response, which can be in respone to oxidants or reducers, leading to breakage of their chemical bonds. It will be of great potential and research significance to develop new stimulus responsive materials by combining the responsive redox characteristics of selenium with degradable polymers, which has aroused great concern among academic circles. It is still a challenge to introduce diselenide bond into polymeric carriers. Herein, a series of diselenide. containing carbonate copolymers were designed and synthesized by ring opening polymerization (ROP) through adjusting the feeding ratio during polymerizing. The structure and molecular weight of the obtained copolymers were characterized by different methods such as nuclear magnetic resonance spectroscopy (NMR) and gel permeation chromatography (GPC). Results showed that they had suitable molecular weight, narrow molecular weight distribution and adjustable selenium mass content. Then the diselenide polycarbonates were self-assembled into micelles by dialysis method, film dispersion method and ultrasonic emulsification method, respectively. Morphology of micelles was confirmed by transmission electron microscopy (TEM). Advantages and disadvantages of these different micelle preparation methods were investigated by comparing the particle size and particle-size distribution measured by dynamic light scattering (DLS), as well as drug loading ability measured by ultraviolet spectrophotometer (UV-Vis). Dialysis method and film dispersion method were suitable in preparing the diselenide-containing polycarbonate into micelles. The average particle size of these prepared micelles was less than 200 nm. In vitro drug release experiments showed that this kind of diselenide containing polycarbonate could release drugs under the stimulation of glutathione (GSH) effectively, and the cumulative release percentages and release rates were related to the selenium content of copolymers. These results laid a solid foundation for the development and application of diselenide-containing polymers as drug carrier materials.
pH and Magnetic Responsive Janus Cage
JI Xuyang, ZHANG Yang, LIANG Fuxin
 doi: 10.14133/j.cnki.1008-9357.20200731001
[Abstract](384) [FullText HTML](319) [PDF 1437KB](46)
Composite core/shell Fe3O4@mSiO2 nanoparticles are synthesized by coating mesoporous silica onto a submicrometer-sized Fe3O4 spheres. A Janus silica cage was synthesized by selectively grafting a hydrophilic polymer amine ended PEG-NH2 containing folic acid (FA) and pH responsive polymer of poly(2-diethylaminoethyl methacrylate) (PDEAEMA) onto the exterior and interior sides of the mesoporous SiO2 shell. The chemical composition and microstructure of Janus cages were studied by SEM, TEM, XRD, FT-IR, UV-Vis and TGA. The results showed that the prepared Janus cage had a clear chemical partition and the paramagnetic core inside the cavity was responsible for magnetic collection. Oil-soluble substances can be collected in pH responsive Janus cages at pH higher than 7.2, and controlled release can be achieved at pH lower than 7.2. Furthermore, doxorubicin (DOX) was selected as a model drug, and the performance as a responsive drug carrier for loading and controlling release of oil-soluble drugs were investigated. The results showed that Janus cages loaded with drugs could achieve responsive drug release in a simulated tumor pH environment. It has good application potential in the field of targeted drug delivery and responsive release.
Thieno[3,2-b]thiophene-Bridged Polypyrrole Film-Based Micro-Supercapacitors
HOU Pengxin, JIANG Kaiyue, ZHAI Guangqun, ZHUANG Xiaodong
 doi: 10.14133/j.cnki.1008-9357.20210110001
[Abstract](309) [FullText HTML](244) [PDF 1610KB](20)
Polypyrrole, which is one of the famous conventional conductive polymers, has been well studied in past decades. Due to the rational controlling methods of morphology and structure, polypyrrole-based materials have shown great potential in the field of energy conversion and storage. For example, polypyrrole could contribute excellent pseudocapacitance as electrode material for supercapacitors. However, synthesis of two-dimensional polypyrrole or ultra-thin films remains challenge because of the easy aggregation and poor solubility features. In this work, the electron-rich thieno[3,2-b]thiophene unit is used to bridge pyrrole monomers to produce four-armed bipyrrole monomer. At liquid-liquid interface, conventional oxidative polymerization reaction can take place and uniform polypyrrole film with large area can be easily produced. Through directly laser scribing, interdigitated micro-supercapacitors based on Au layer supported polypyrrole film can be produced. After evaluation through cyclic voltammetry curves, impedance curves, etc., the microsupercapacitors show areal specific capacitance of 1.10 F/cm2, volumetric specific capacitance of 68.4 F/cm3, ESR value of 4.2 Ω. The maximum energy and power densities of as-prepared micro-supercapacitors reach 9.50 mWh·cm−3 and1433 W/cm3, respectively.
Gelation Systems and Mechanisms of Chondroitin Sulfate-Based Injectable Hydrogels
WANG Qin, QIU Yuzhi, QIAO Weihua, DONG Nianguo, YANG Yajiang
 doi: 10.14133/j.cnki.1008-9357.20200811001
[Abstract](827) [FullText HTML](510) [PDF 1366KB](69)
Chondroitin sulfate (ChS), a kind of natural polysaccharide, is the sulfated glycosaminoglycan which is widely distributed in the extracellular matrix and on the surface of animal cells. ChS possesses various biological activities, such as promoting cartilage growth, regulating growth factors and accelerating wound healing. As a novel biomaterial, in recent years, ChS-based injectable hydrogels have attracted much attention due to their biocompatibility, biodegradability combined with their unique bioactivity, particularly, their applications in the fields of tissue engineering, drug delivery, cell therapy and so on. The gelation systems gelation mechanisms and modification methods of ChS-based injectable hydrogels are reviewed in this paper. Herein, the formation methods of the three dimensional network structure in ChS-based injectable hydrogels are mainly introduced, involving physical thermo-induced gelation, chemical crosslinking through Schiff’s base formation, click chemical reaction, formation of amide bonds and photo-crosslinking and enzyme-catalyzed crosslinking, etc. These developed precursor polymer systems, the corresponding crosslinking methods and mechanisms have been illustrated in detail. In addition, the methods about regulating gelation time, mechanical properties and tissue adhesion are also discussed in this paper. The reported strategies can be summarized as the combination of two or more crosslinking methods, adjusting the constitute of the gelation systems and forming composite hydrogels, etc. Finally, future development of ChS-based injectable hydrogels as biomaterials is prospected. We propose that more feasible injectable hydrogel systems with suitable properties will be developed in the future. Furthermore, the relationships among the chemical structure of ChS, the gelation behavior and biological functions should be studied further. In addition, because of the excellent bioactivity of ChS, ChS-based injectable hydrogels applied in other biomedical fields should be explored.
Preparation of Albumin/Hyaluronic Acid Composite Nanoparticles for Cisplatin Delivery
WANG Taibing, LI Ying, JIA Zhuohan, GUO Min, XU Weijun, QIAN Junmin, SUO Aili
 doi: 10.14133/j.cnki.1008-9357.20210318001
[Abstract](68) [FullText HTML](53) [PDF 1336KB](6)
Cisplatin is one of typical anti-tumor chemotherapeutic drugs, but its clinical application is restrained by serious toxic side effects and multidrug resistance. However, emerging nanotechnologies have great potential in overcoming the above problems. By means of albumin templating method, an albumin/hyaluronic acid composite nanocarrier was prepared from albumin, hydrazided hyaluronic acid and aldehyde hyaluronic acid. Cisplatin could be loaded into the nanocarrier via Pt-hydrazide coordination chemistry. Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, transmission electron microscopy and inductively coupled plasma mass spectrometry were employed to characterize the chemical structure of nanocarrier and the physiochemical properties of nanodrug. The results showed that the nanodrug exhibited a subsphaeroidal morphology with an average size of about 150 nm and the loading content of cisplatin was as high as 10.8%. Moreover, the nanodrug displayed a reduction/acid dual responsive drug release behavior. In vitro cell experiments showed that the cytotoxicity of the nanocarrier was negligible and the nanodrug had good targeting ability towards hepatocellular carcinoma HepG2 cells. Importantly, the effect of the nanodrug in killing HepG2 cells was comparable to free cisplatin. It was found that inducing cell apoptosis was still major mechanism of killing HepG2 cells by the nanodrug. The albumin/hyaluronic acid composite nanoparticles are a promising carrier with excellent comprehensive performances for the targeting delivery of cisplatin, and might improve the therapeutic efficacy of cisplatin and reduce its toxic side effects in vivo.
Preparation and Electrocatalytic Applications of Surface-Coordinated Metal-Organic Framework Thin Films
JIN Zhibin, ZHANG Jian, GU Zhigang
 doi: 10.14133/j.cnki.1008-9357.20200718001
[Abstract](505) [FullText HTML](375) [PDF 2731KB](81)
With the increasing demand for energy resources, the development of efficient electrocatalysts has attracted much attention on energy storage and conversion. As a kind of inorganic-organic hybrid materials, recently crystalline metal-organic frameworks (MOF) have been used as electrocatalysts in electrocatalytic reactions due to their abundant metal nodes and organic linkers, high porosity and large surface area. Particularly, MOF thin films are crucial to achieve effective reactions due to their fast charge transfer and sufficient catalytic sites. Particularly, MOF thin films are coordinated on substrate surfaces by liquid phase epitaxial (LPE) layer by layer (LBL) growth method (called surface-coordinated MOF thin films, SURMOF), which recently have been studied in various fields due to their controlled thickness, preferred growth orientation and homogeneous surface. The backgrounds of electrocatalysis, MOF and SURMOF are briefly introduced at the beginning of this review. Then, the preparation and electrocatalytic applications of SURMOF and their derived thin films (SURMOF-D) are summarized respectively. Owing to the SURMOF based thin films possess tunable structures, controllable thickness and growth orientation, strong coordination interaction between MOF and substrate surface, and compact film, they can provide abundant catalytic sites and fast charge transfer for efficient electrocatalytic activities in oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), carbon dioxide reduction reaction (CRR), supercapacitor, tandem electrocatalysis and so on. At the end of the review, SURMOF and SURMOF-D for the electrocatalytic applications are also discussed on the current research challenges and problems to be solved.
Advances in the Application of Functional Polymer in Phase Change Heat storage Materials
XIAO Changren, ZHU Shengtian, ZHANG Guoqing, YANG Xiaoqing
 doi: 10.14133/j.cnki.1008-9357.20210113001
[Abstract](132) [FullText HTML](92) [PDF 2235KB](14)
Phase change thermal storage material (PCM) can store/release tremendous thermal energy through phase-transition while keeping the temperature within a constant range, and therefore, they have been widely employed in many fields, e.g. building energy conservation, waste heat recovery, refrigerated transport and solar thermal energy conversion/storage, battery thermal management and so on. However, conventional solid-liquid PCMs confront severe problems of leakage and shape collapse after the saturation of heat storage. The most promising ways to solve these stability problems of PCM while guaranteeing adequate thermal storage density, are to elaborately design/synthesize high adsorptive functional polymer materials as the skeleton to encapsulate PCM, or constrain phase change molecular into polymer backbone to obtain phase-changeable functional polymer. In this paper, based on the theme of functional polymer materials, the application research progress of functional polymer in PCM is reviewed from three aspects: the elaborately designed/synthesized functional polymer skeleton of solid-liquid PCMs, solid-solid phase change functional polymers and their applications. This paper is expected to provide references for the design and preparation of functional polymer materials related to PCMs.
Adsorption and Desorption Behavior of Fibrinogen on Poly (2-methyl-2-oxazoline)/Poly(acrylic acid) Mixed Brushes
HU Fei, ZHU Liangyu, WANG Yuchen, HE Kang, ATIF Muhammad, WANG Yanmei
 doi: 10.14133/j.cnki.1008-9357.20210119002
[Abstract](248) [FullText HTML](208) [PDF 1282KB](33)
The mixed polymer brushes which combine the poly(2-methyl-2-oxazoline)(PMOXA) with anti-protein adsorption properties and the poly(acrylic acid)(PAA) with stimulus-responsive properties were prepared on the material surfaces (including glass, silicon, and gold) by using poly(dopamine)(PDA) as an anchor. The surface chemical composition and thickness of the mixed polymer brushes were characterized by X-ray photoelectron spectroscopy (XPS) and variable angle spectroscopic ellipsometry (VASE). The hydrophilicity of the polymer brush surface were studied by water contact angle (WCA). Choose pH=9 and I = 0.01 mol/L I is as the fibrinogen adsorption conditions, and pH=9 and I = 0.15 mol/L as the fibrinogen desorption conditions. The adsorption and desorption behavior of fibrinogen on mixed polymer brushes was studied qualitatively and quantitatively by fluorescence microscope and surface plasmon resonance (SPR). The results show that when the environmental pH and I change from pH=9 and I = 0.01 mol/L to pH=9 and I = 0.15 mol/L, the surface of the mixed polymer brushes will change from a relatively hydrophobic state to hydrophilic state. Increasing the degree of polymerization of PMOXA will reduce the amount of protein adsorption of the mixed polymer brushes, and will also significantly improve the protein desorption rate of the mixed polymer brushes. The mixed polymer brush prepared by sequential grafting PMOXA with a degree of polymerization of 60 and PAA with a degree of polymerization of 90 in a mass ratio of 3∶2 achieved the desorption rate of 83.5% for fibrinogen.
Glycopeptide-Based Polymers and Their Biomedical Applications
ZHANG Jingkai, LIU Xiaoxuan, LI Li-Li
$v.latestStateEn  doi: 10.14133/j.cnki.1008-9357.20210309001
[Abstract](59) [FullText HTML](50) [PDF 2171KB](7)
Glycopeptide-based polymers are a kind of biodegradable polymers composed of polypeptides and carbohydrate. Owing to their chemical similarity to natural glycopeptides and glycoproteins, they can mimic the structure and function of natural products, attracting a lot of attention. There are two main types of glycosides: N-glycosides and O-glycosides. Glycosides are coupled with amino acids in advance to form glycosylated amino acid building blocks, and then participate in the synthesis of glycopeptides together with amino acids in solid phase synthesis. Native chemical ligation is also often used to synthesize longer glycopeptide that cannot be obtained by solid phase synthesis. Glycopeptides are designed to reflect multivalence, so the most common types include branched glycopeptides, self-assembled glycopeptides and polymer glycopeptides. Branched glycopeptides mainly include glycopeptide dendrimers. Self-assembled glycopeptides mainly consist of modifying various glycosyl groups on self-assembled polypeptides. Based on these self-assembled glycopeptides, glycopeptide materials can self-assemble into various nanostructures, such as micelles, vesicles, fibers and nanorods. As a kind of structural mimic of natural glycoproteins, synthetic glycopeptides can play a variety of biomedical roles. Synthetic glycopeptides are capable of binding to lectin or adhesive of bacteria or targeting intracellular bacteria of macrophages. Due to the overexpression of carbohydrate-binding proteins on tumor cells surfaces, glycopeptides have been widely investigated as anti-tumor vaccine. In addition, glycopeptide-based hydrogels can be used as a biomimetic scaffold for mammalian cell growth due to their high-water content and similar structure, shape and composition to the extracellular matrix (ECM) in tissues. Glycopeptides can also simulate natural glycosaminoglycans to play a role in tissue and cartilage repair. In this article, we summarize the synthesis method, material design and biomedicine application of glycopeptides, focusing on the material design of glycopeptides in branched glycopeptides, self-assembled glycopeptides and polymer glycopeptides, and the application of glycopeptides in antibacterial, anti-tumor vaccine, bionic scaffold, tissue and cartilage repair.
Coarse-Grained Molecular Simulation of Zwitterionic Polypeptides on Improving the Bioactivity of Glucagon-Like Peptide-1(GLP-1)
TENG Jiaman, LIU Yuting, ZHU Guoliang, SHEN Zhuanglin, CHEN Yantao
 doi: 10.14133/j.cnki.1008-9357.20210118002
[Abstract](304) [FullText HTML](145) [PDF 1917KB](28)
Zwitterionic polypeptides (ZIPPs) have demonstrated great protection to protein drugs owing for their anti-fouling or “stealth” properties. ZIPPs endow the target protein with better pharmacokinetics than non-zwitterionic counterparts, while the microscopic mechanism is still unclear due to the complicated conformation space. As an alternative, in the present work, we designed three pentapeptides, which share the ZIPP-repeat units VPX1X2G. Here, X1 and X2 are cationic and anionic amino acids, respectively. Glucagon-like peptide-1 (GLP-1), an important drug for type-II diabetes, was selected as a research subject, which is mixed with different types of pentapeptides. The interaction mode and conformation space were explored using molecular simulation with coarse-grained PACE (Protein in Atomistic details coupled with Coarse-grained Environment) forcefield. Our molecular simulations revealed that the initially constructed α-helix was quickly destroyed by thermal fluctuation for isolated GLP-1. Finally, only 30% of helix exited in the conformation of GLP-1 and the N- and C-terminus tended to contact each other to form short β-sheet. When mixing with pentapeptides, the percent of helical structure increased to about 60% for GLP-1, and the formations of one or two helical segment depended on the interaction mode between pentapeptide and GLP-1. Among them, the zwitterionic pentapeptide VPKEG with the strongest hydrophilicity preferred to be uniformly dispersed in solution, and thus producing a loose protective layer around GLP-1. Because of the arginine residue, the zwitterionic pentapeptide VPREG exerted the strongest electrostatic interaction to GLP-1, which is conducive to the highest helicity of GLP-1 but hardest to the diffusion process. In the control system, pentapeptide VPGAG with the strongest hydrophobicity formed the densest aggregate, but cannot fully enwrapped GLP-1 and provide sufficient protection yet. In short, the same content of lysine and glutamate endows zwitterionic pentapeptide VPKEG with proper hydrophobicity and electrostatic effects, which can not only maintain GLP-1 conformation but also avoid being recognized by immune protein, showing the "stealth" property. In contrast, the arginine residing in VPREG tended to form electrostatic interactions with other residues instead of water molecules, making it not so hydrophilic as VPKEG.
Research Progress of Low Dielectric Polymers for High-Frequency Printed Circuit Boards
LIAO Lingyuan, PENG Zhongquan, ZHANG Mingqiu, RUAN Wenhong
 doi: 10.14133/j.cnki.1008-9357.20210203002
[Abstract](165) [FullText HTML](139) [PDF 2307KB](24)
With the development of high-frequency communication technology, the demand for polymer materials used in high-frequency printed-circuit board (PCB) is increasing, such as low dielectric loss for reduced signal loss as it passes along a transmission line on a dielectric material, low moisture absorption and low dielectric constants for higher signal propagation speeds, high glass transition temperature for plated through hole reliability and high heat resistance for short term resistance of products to solder processing. However, performance of traditional printed circuit board based on phenolic resin and epoxy resin cannot meet the requirements of the high-frequency communication technology. Consequently, developing the new materials with low dielectric constant, low dielectric loss, heat resistance, low moisture absorption and excellent dimensional stability is significant to high-frequency signal transmission. Polybenzoxazine, cyanate ester, polytetrafluoroethylene, polyimide and polyphenylene oxide had attracted much attention for relatively lower intrinsic dielectric constant and dielectric loss, enormous research have been done. In order to further reduce dielectric constant and dielectric loss, and improve comprehensive performance of polymers, recently, enormous research have been done. For instants, to reduce dielectric constant and dielectric loss, the extensive works have been directed to design molecular structure, which includes the incorporation of low polarizability groups, space-occupying groups and fluorinated monomers, and some works focused on adding nano porous materials, such as polyhedral oligomeric silsesquioxane, mesoporous silica and hollow silicon tube, or introducing pore structure in polymers. To improve thermal stability or mechanical property, some researches concentrated on blending two or more polymers together, and special performance materials are obtained by playing the advantage of each component polymers. In this review, the up-to-date research progresses in the field of low dielectric polymers for high frequency PCB and the relationship of chemical structures and properties of these polymers are discussed.
Preparation and Antifouling Properties of Silicon-Modified Waterborne Polyurethane Coatings
LI Min, HAN Long, GUO Xuhong, WANG Jie
 doi: 10.14133/j.cnki.1008-9357.20201231001
[Abstract](103) [FullText HTML](59) [PDF 2391KB](6)
Silicone can be used to improve the antifouling properties of polyurethane (PU) coatings. A series of uniform and stable nano-scale waterborne PU were prepared by using toluene diisocyanate (TDI), polycaprolactone diol (PCL2000) and hydroxy-terminated polydimethylsiloxane (PDMS) as the main raw materials. Fourier transform infrared spectrometer (FT-IR), dynamic light scattering (DLS), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), polarizing microscope (PM) were used to test the structures and properties of the material.Subsequently, the coatings with different PDMS mass fractions /w(PDMS) were painted on the panels and immersed in the river, so the practical antifouling levels of the materials were test. Results showed that the thermal stability of the film increased with the increase of PDMS contents. While the surface free energy (γ), gradually decreased to 13.87 mJ/m2. PDMS reduced the glass transition temperature (Tg) of the material, and enhanced the water resistance of the coatings. Besides, the addition of silicon oil effectively reduced the elastic modulus (E) of the coatings. Correlation (between the theory that the adhesion of pollutants on antifouling coating is positively relevant to the square root of the product of the elastic modulus of the coating and the surface energy and the actual antifouling level (coatings actually immersed in water) was explored. Results showed that the PDMS-modified PU had excellent antifouling performance, and the actual antifouling effect of the coating was consistent with the calculation results of the theoretical reference value \begin{document}$ \sqrt{\gamma \cdot E} $\end{document} .
Research Progress of Functional Polymer for Spinal Cord Regeneration
SUN Xiumin, PANG Mao, FENG Feng, LIU Bin, RONG limin, HE Liumin
 doi: 10.14133/j.cnki.1008-9357.20210118001
[Abstract](202) [FullText HTML](113) [PDF 2332KB](11)
Spinal cord injury (SCI) is a severe and irreversible injury in the central nervous system, which often leads to permanent motor and sensory dysfunction. The outcome of nerve regeneration after SCI is mostly limited by the resulting adverse microenvironment from the spontaneous inflammatory cells infiltration and host cell death. The activation and accumulation of macrophages/microglia at the lesion sites often leads to a secondary damage, including neuron death, astrocyte gliosis and collagen fibrosis, which eventually impairs biological functions of neural stem cells, such as migration and differentiation, either endogenously or exogenously. Although recent studies have shown that axons can regenerate in a suitable matrix environment after spinal cord injury, there is no feasible measure for the functional recovery. In recent years, biomaterial scaffold-based strategies have become an attractive alternative for neural regeneration. Biocompatible polymer have multiple functons: promoting cell growth and differentiation; minimizing cavitation, inhibiting cicatrization and astrocytes/collagen accumulation; presenting nonspecific infiltration of inflammatory cells; serving as carriers of cells and bioactive factors. Therefore, polymer scaffolds have been investigated as potential therapies for SCI. This review will highlight the composition, forms and microenvironment construction in polymer scaffolds for SCI treatment. Additionally, the peculiar properties of the polymer materials used in the therapeutic process of SCI also have new guiding significance to tissue engineering approaches.
Preparation and Proformance of Propargyl Phenyl Ether-Containing Phosphoramide Modified Cyanate Esters
XIA Jun, YUAN Qiaolong, LI Chuan, WANG Xiaolei, HUANG Farong
 doi: 10.14133/j.cnki.1008-9357.20201216001
[Abstract](217) [FullText HTML](141) [PDF 1324KB](22)
N,N’-di(4-propargyloxyphenyl) phosphoramide (DPPPA) was successfully synthesized by nucleophilic substitution of 4-propargyloxy aniline and phenylphosphonyl dichloride. The structure of DPPPA was characterized by nuclear magnetic resonance (NMR) and Fourier transformation infrared (FT-IR) analyses. DPPPA was used to mix with bisphenol A of dicyanate ester (BADCy) and bisphenol E of dicyanate ester (BEDCy) in solution. The DPPPA modified cyanate esters (BADCy/DPPPA and BEDCy/DPPPA) were obtained after the solvent was evaporated under vacuum. The thermal properties, limited oxygen index (LOI) and mechanical properties of the modified cyanate esters were studied. The results show that the residual yield at 800 ℃ in air of the cured BADCy/DPPPA and cured BEDCy/DPPPA increase from 0 to 33% and 26% in comparison with the cured neat cyanate esters, and the LOI of the cured modified cyanate esters reach 39.4% and 35.4%, but the glass transition temperatures of the cured modified cyanate esters decrease by 19 ℃ and 24 ℃, respectively. The flexural and tensile strength of the cured BADCy/DPPPA are 123 MPa and 45 MPa, which are higher than that of the cured BEDCy/DPPPA. The impact strength of the cured BADCy/DPPPA and BEDCy/DPPPA are 11 kJ/m2 and 14 kJ/m2, respectively. The water absorption of the cured neat cyanate esters decreases with blended with DPPPA.
Preparation and Properties of Fluorinated Benzoxazine Modified Si-Containing Arylacetylene Resin
ZHANG Hongxiang, WANG Fan, ZHU Yaping, QI Huimin
 doi: 10.14133/j.cnki.1008-9357.20201116001
[Abstract](366) [FullText HTML](215) [PDF 1783KB](56)
Fluorinated benzoxazines with allyl (BOZF-1), phenyl acetylene (BOZF-2) and propargyl (BOZF-3) were synthesized and used to modify silicon-containing arylacetylene (PSA). The effects of the structure and the contents of BOZF on the properties of modified resin (BOZF/PSA) were investigated. The curing behavior of BOZF/PSA resins were studied by differential scanning calorimetry (DSC). The micro-morphology of the blend resin casting was analyzed by Scanning Electron Microscope (SEM). The thermal stability and thermal mechanical properties of the cured BOZF/PSA resin were analyzed by Thermogravimetric Analysis (TGA) and Dynamic Mechanical Analysis (DMA). The dielectric property was also studied. Results showed that the addition of BOZF resins could improve the toughness of PSA resin, and the bending properties of cured products improved with the increase of benzoxazine mass fraction. Among them, the bending strength of modified resin (w(BOZF-1)=30%) could reach to 28.1 MPa, which was increased by 44.1% compared with PSA resin. The heat resistance of modified PSA resin decreased slightly with the addition of BOZF resin, the 5% mass loss temperature of the cured resin BOZF-1/PSA BOZF-2/PS and BOZF-3/R (w(BOZF) = 10%) was 544, 604 ℃ and 584 ℃ in nitrogen, and their residual rate at 1 000 ℃ was 84.4%, 89.0% and 88.1%, respectively. With the addition of BOZF, dielectric constant of modified resin were slightly increased, but still maintained a good dielectric performance. The cross-section morphology observed by SEM showed that the cast cross-section changed from smooth and flat to with many cracks and ductile fracture zones, which proved that the modified resin changed from typical brittle fracture to ductile fracture.
Universal Morphology Engineering for Organic Bulk Heterojunction: Hot Fluorous Solvent Soaking
LIANG Jianghu, CHEN Junchao
 doi: 10.14133/j.cnki.1008-9357.20210107002
[Abstract](217) [FullText HTML](172) [PDF 752KB](35)
The power conversion efficiency of polymer solar cells based on bulk heterojunction is gradually increasing. However, to achieve an ideal donor/acceptor morphology with bicontinuous and interpenetrating network structure is still challenging. Recently, Hongliang Zhong’s group at Shanghai Jiaotong University and the coworkers developed a new post-treatment strategy, namely hot fluorous solvent soaking (HFSS), to optimize the morphology of the active layer. The treatment of HFSS can anneal the active layer quickly and uniformly. When the selected fluorous solvent is miscible with the residue of processing solvent above upper critical solution temperature, the mixed solvent will further promote the reorganization of the donor/acceptor materials in the film, thereby forming a highly ordered fibrous structure. Consequently, the device shows higher carrier mobility and slightly red-shift absorption spectrum, providing an improved photovoltaic performance. This strategy performed with short processing time at relatively temperature is suitable for various combinations of donor/acceptor materials, including polymer/small-molecule systems, all-polymer and all-small-molecule systems.
Preparation and Moisture Absorption Behavior of PAM/CS/GO Hydrogels
WU Yinqiu, FU Tao, GAO Hongxin, CAO Zheng, Cheng Junfeng, LIU Chunlin, TAO Guoliang, WU Dun
 doi: 10.14133/j.cnki.1008-9357.20201221001
[Abstract](230) [FullText HTML](151) [PDF 1184KB](23)
Using acrylamide (AM) as monomer, chitosan (CS) and graphene oxide (GO) as functional components, N, N'-methylene bisacrylamide (MBA) as crosslinking agent, a series of PAM/CS/GO composite hydrogels with three-dimensional network structure were prepared by free radical polymerization. The chemical composition, structure, morphology, and mechanical properties of the composite hydrogels were analyzed using Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffractometer (XRD), scanning electron microscope (SEM), and universal testing machine. The experimental results show that GO is uniformly dispersed in the PAM/CS hydrogel matrix. Compared with PAM/CS hydrogels, PAM/CS/GO hydrogels have a tighter porous structure with an average pore diameter of about 55.7 μm. In addition, the mechanical properties of PAM/CS/GO hydrogels have been significantly improved, the largest elongation at break is 2 039%, and the maximum breaking stress reaches 237 kPa. This is due to the fact that GO acts as a physical crosslinking agent in the PAM/CS hydrogel to form good interface bonds. The hydrogel with cross-linked network structure and plenty of hydrophilic groups can be used as the sensing coating of the quartz crystal microbalance (QCM), and the QCM humidity sensor based on the functional hydrogel film is prepared. The moisture absorption behavior of composite hydrogel films was studied using QCM technology under different humidity conditions. As the air relative humidity (RH) increases from 33% to 85%, the frequency response of the composite hydrogel film modified QCM sensor increases from 12.2 Hz to 22.3 Hz. This research work provides valuable reference for the application of the hydrogel coating in the field of QCM humidity sensors.
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Development and Applications of Polymeric Biomimetic Tissue Adhesives
WU Keke, ZHAO Yitao, WU Min, LI Yue, HU Zhiqi, LU Zhihui, GUO Jinshan
2021, 34(2): 93-113.   doi: 10.14133/j.cnki.1008-9357.20201215001
[Abstract](488) [FullText HTML](307) [PDF 2253KB](75)
As a potential substitute of surgical suture for wound closure use, biomedical/tissue adhesives can be widely used in the repair/regeneration of wounds on soft/hard tissue such as skin, viscera, cardiovascular, bone and teeth, possessing a broad market prospect. However, it is still a challenge for the science community to produce strong adhesion to tissues at wet state. To address this problem, scientists developed a series of biomimetic tissue adhesives by imitating the adhesion strategies of various animals and plants in nature. In this review, the development of various polymeric biomimetic medical/tissue adhesives and their applications in surgical wound adhesion, daily wound care, chronic wound regeneration, bone fracture fixation and other soft/hard tissue repair/regeneration, as well as local drug delivery and in situ therapy are summarized in detail. The future development trend of tissue adhesives is also prospected, including their application potential in the field of medical cosmetology.
Progress in Functionalized Polyethersulfone Membranes
ZHANG Xiang, ZHAO Weifeng, ZHAO Changsheng
2021, 34(2): 114-125.   doi: 10.14133/j.cnki.1008-9357.20210108001
[Abstract](396) [FullText HTML](201) [PDF 1165KB](66)
As a type of polymeric membrane with excellent comprehensive performance, polyether sulfone (PES) membrane is widely applied in many fields, including blood purification and water treatment fields. However, there are still some drawbacks exist during the current application of PES membranes: the main disadvantage is related to its relatively hydrophobic character. Membrane fouling is directly related to the hydrophobicity, which is caused by adsorption of nonpolar solutes, hydrophobic particles or bacteria. Meanwhile, when contacting with blood, proteins will rapidly adsorb onto the surface of the PES membrane and the adsorbed protein layer may lead to further undesirable results, such as platelet adhesion, aggregation and coagulation. As the consequence, the antifouling property and blood compatibility of PES membranes need to be improved. In addition, PES membrane is stable in water. Being an inert membrane, PES membrane acts only as a barrier in the separation process. Thus, the performances of PES membrane would be weakened upon unavoidable membrane fouling, and they cannot be applied in cases where self-regulated permeability and selectivity are required. As a result, smart PES membrane which can self-regulate their permeability and selectivity via the flexible adjustment of pore sizes and surface properties also needs to be developed. With the aim of achieving these purposes, endowing the PES membranes with special functions by various modification methods has aroused more and more attention. In this review, the widely used modification methods for functionalized PES membranes were briefly introduced. Meanwhile, the recent studies of design and fabrication of PES membranes with various functions were summarized, including: (1) the anticoagulation, antifouling and antibacterial membranes for blood purification and biomedical engineering; (2) the stimuli-responsive membranes with switchable permeability and selectivity; (3) the modified membranes with improved adsorption performance for wastewater treatment. Finally, we give the future perspective of the research and development directions of the functionalized PES membranes.
Advances of Biomedical Polymeric Materials in Dentistry and Its Industrialization
XU Xinyuan, SUN Hui, LI Jianshu
2021, 34(2): 126-143.   doi: 10.14133/j.cnki.1008-9357.20201211001
[Abstract](374) [FullText HTML](214) [PDF 1311KB](50)
Dental materials including restorative materials and auxiliary materials are used for repairing injured or missing human maxillofacial soft and hard tissues. At present, the types of dental materials include metals, ceramics, inorganics, polymers and composites, among which polymeric materials have a variety of excellent controllable physical/chemical properties due to their tailorable molecular structure. Here is a summary of the applications of polymer materials in dentistry such as prevention medicine, restoration medicine and regenerative medicine. Furthermore, this paper reviews the existing problems and cutting-edge research directions, and prospects for the future development and commercialization of medical polymer materials in the dental field. The polymer materials for oral prevention mainly include plaque indicator which can show the bacteria to help children to develop good oral health habits and anti-caries materials which can resist bacterial erosion and demineralization by forming a fluoride-releasing protective film on the tooth surface. The polymer materials used in oral cavity repair are mainly composite resin materials including polymerized resin and fillers, which can be used to fill small defects and as repair dentures. It is difficult to improve the service life of the materials. The main solution is to enhance the antibacterial properties, mechanical strength and environmental stability. The polymer materials for tissue regeneration are implants and maxillofacial tissue repair materials. Although implant is produced using titanium and its alloy, the surface modification by polymer has advantages on reducing peri-implantitis and new high-performance polymer, like polyetheretherketone(PEEK), can better match the elastic modulus with the natural bone than metal materials. Direct bone replacement materials are using inorganic apatite as main substances, but polymer materials as tissue engineering scaffold for bone regeneration are still in development. Other polymer materials include not only mature auxiliary products for dental technicians, but also advanced regenerative materials like enamel-like substances, remineralize dentin and bio-root, which are expected to realize clinical transformation and product application in the future.
Medical Speciality Polymer Polyether Ether Ketone Implant and Its Surface Interface Engineering
MAO Yurong, SUN Jiamin, ZHOU Xiong, LIAN Xiaoke, YANG Weizhong, DENG Yi
2021, 34(2): 144-160.   doi: 10.14133/j.cnki.1008-9357.20201130002
[Abstract](429) [FullText HTML](232) [PDF 4448KB](43)
Bone defects caused by surgery or trauma pose great essential challenges to modern clinical medicine. The donor limits traditional bone graft therapies. Thus, it is essential to find alternative therapies. Thanks to fatigue resistance and penetrating of X-rays, polyether ether ketone (PEEK) and its composites which have an elastic modulus similar to natural human bone and good biocompatibility and chemical stability, can be used as implantable material for spinal, trauma and orthopedic applications. Excellent wear resistance shows great superiority in artificial joint replacement. The stable chemical resistance and potential antimierobial activity make it play an important role in dental restorations as well. It is a potential material for the treatment of bone defects, but its surface hydrophobicity and biological inertia limit its application in biomedical science. Thus, improving the poor surface performances of PEEK and functioning PEEK become the focus of PEEK study at home and abroad. Inspired by bone tissue composition, structure and function, many strategies have been proposed to change PEEK structure and make PEEK surface functional. In order to make it better used in surgical clinical application, researchers adopted two different strategies of mixed modification and surface modification, so that the obtained PEEK-based material had better biocompatibility, osteointegration, antibacterial, angiogenesis, anti-tumor, immune regulation and multiple regulation properties. In this paper, various modification strategies for improving the biological activity of PEEK and the application status and prospect of PEEK-based materials in the biomedical field are reviewed. The modification strategies are going through single modification to multi-modification. Multi-modification will become the key of clinic applications of PEEK.
Advances in Protein-Based Biomaterials for Biomedical Applications
SHI Qiankun, WANG Yupeng, ZHANG Hao, ZHOU Dongfang
2021, 34(2): 161-171.   doi: 10.14133/j.cnki.1008-9357.20201201001
[Abstract](614) [FullText HTML](319) [PDF 743KB](104)
Although synthetic biomaterials have great potential and diversity, their biomedical applications are still limited by issues such as biocompatibility, biodegradability, and bioresorbability. Because of the inherent advantages of natural materials in terms of biocompatibility, degradability and absorption, they have become viable substitutes for biomedical applications. Among the many natural materials, proteins have attracted great interest as a new type of biological composite, especially functional biomaterials. Proteins display an essential role in numerous natural systems due to their structural and biological properties. Given their unique properties, protein-based biomaterials show the advantages of inherent biological activity, and do not require excessive functional modification and complex synthesis processes, which can better solve the problems of synthetic materials. Protein-based biomaterials in the form of nanoparticles, nanofibers, microfibers, films, coatings, sponges, foams and gels have been widely used in biomedical fields including tissue engineering, bioelectronics, drug delivery, wound healing, nutraceuticals and pharmaceuticals. Different from the other reviews, this paper reviews the animal and plant-derived protein-based biomaterials for clinical and potential preclinical biomedical applications, and the application prospects are also discussed.
Construction Strategy and Research Progress of Anticoagulant Surface of Medical Polymeric Materials
LUAN Ke, BAN Yu, SHI Dean, SHI Hengchong
2021, 34(2): 172-181.   doi: 10.14133/j.cnki.1008-9357.20201226001
[Abstract](357) [FullText HTML](222) [PDF 1256KB](34)
Biomedical polymer materials and medical devices are mainly used for the diagnosis and treatment of diseases, and are used by thousands of patients every day. When this material/device is implanted/intervened in the human body and comes into contact with blood, plasma proteins will adsorb to the surface of the material/device within a few seconds and bind to the glycoprotein receptor on the platelet, resulting in platelet activation, coagulation cascade and complement activation, coagulation and thrombus. Human health and life safety are seriously endangered. To impart anticoagulant properties to the surface of materials/devices, it is necessary to construct anticoagulant surfaces in a targeted manner. The main methods are as follows: biologically inert coatings, biologically active coatings, surface coatings with endothelial (EC) specific growth factors, and composite anti-coagulation coating. Based on the research developments in this field at home and abroad and the research results of our group in recent years in the construction of anticoagulant surface of biomedical polymer material and medical device, this review summarizes the research progress of anticoagulant surface construction and its application in medical devices.
Recent Progress in Antioxidant Hydrogels
CHEN Peng, YANG Fengying, GU Zhipeng, LI Yiwen
2021, 34(2): 182-194.   doi: 10.14133/j.cnki.1008-9357.20201213001
[Abstract](587) [FullText HTML](356) [PDF 2239KB](92)
Reactive oxygen species (ROS) is an important class of intermediate products during the metabolism process, which plays a key role to maintain the normal physiological activities in human body. The overexpression of ROS can lead to a series of inflammatory responses, resulting in a range of acute and chronic human inflammatory diseases. In recent years, the antioxidant materials have become a hot spot applied to scavenge ROS for treating inflammatory diseases. Meanwhile, the hydrogel is regarded as one of the promising materials due to its unique biomimic properties and multiple biofunctions. In this review, we summarize the recent advances in antioxidant hydrogels, including the antioxidant mechanism, the fabrication strategies, and related application in biomedical area. The further perspective in this field is also discussed.