SYNTHESIS AND CHARACTERIZATION OF ELECTROSPUN GELATIN/DENDRIMER SCAFFOLD ENCAPSULATED WITH A SILVER AS A POTENTIAL ANTIMICROBIAL WOUND DRESSING

摘要

A novel nanofiber scaffold was fabricated and characterized as a potential antimicrobial wound dressing. Half generation polyamidoamine (PAMAM) dendrimer G3.5 was covalently conjugated to gelatin. Gelatin alone or with gelatin-dendrimer conjugates was electrospun into nanofiber scaffolds. Gelatin is a derivative of natural collagen, and it is biocompatible, non-toxic and inexpensive, making it a desirable component in a wound dressing. Dendrimers are synthetic polymers comprising of a central core, internal branches and reactive surface groups. They provide a structurally controlled architecture for drug release. Silver was incorporated into the scaffold in situ due to its broad spectrum of antimicrobial properties. The scaffolds were further crosslinked by photo curable PEG-diacrylate in solution or vapor to gain structure stability. The fabricated scaffolds with various compositions displayed a wide range of structure characteristics and properties in terms of fiber morphology, swelling and degradation, mechanical properties, antimicrobial activity and silver release kinetics. The scaffolds showed a similar fiber structure and morphology. It was found that the fiber diameter of the scaffolds containing silver was greater than scaffolds without silver. The porosity of the crosslinked scaffolds ranged from 67.56% to 90.42% and also exhibited a high capacity of swelling and adsorption. The results of the antimicrobial assay showed that scaffolds containing silver could effectively inhibit growth of bacteria at the end of 48 h. In vitro silver release studies demonstrated that silver could be released in a controlled manner over an extended period of time.