Pullulan Film Loaded with Levofloxacin for Wound Dressings

Film dressings adhere well to the skin, even in the joints of the human body, and can serve as a wound barrier to promote wound healing. To improve water resistance of the film dressings, sodium trimetaphosphate (STMP) was selected to crosslink pullulan. Using glycerol as plasticizer and levofloxacin as antibacterial drug under alkaline condition, the pullulan composite films were prepared. Chemical structure, transparency, water resistance, water absorption, water vapor permeability, mechanical properties, antibacterial properties, and biocompatibility of the pullulan composite films were studied. Results showed that the composite films had high transparency and good water resistance, which not only facilitated the observation of wound healing, but also maintained its integrity during use, avoiding damage caused by the dissolution of exudate and delaying wound healing, when the addition amount (relative to the mass of pullulan, the same below) of STMP was 10%, glycerol was 30%, NaOH was 0.4%, and levofloxacin was 1%. At the same time, the composite films had appropriate water absorption, moisture permeability, and mechanical properties, which could absorb wound exudate, maintain appropriate humidity conditions for the wound healing to facilitate wound healing, and better fit the skin. Moreover, the composite films had 100% antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), and had good biocompatibility. The resultant pullulan composite films had potential application of wound healing.