Production of Biocompatible and Antimicrobial Bacterial Cellulose Polymers Functionalized by RGDC Grafting Groups and Gentamicin

摘要

Bacterial cellulose (BC), a three-dimensional fibril, is a natural polymer that can be used for many applications. BC effectiveness may be improved by enhancing surface characteristics contributing to a better physiologic interaction with human and animal cells and to intrinsically present antimicrobial agents. In the present study, gentamicin-activated BC membranes were obtained by chemically grafting RGDC peptides (R: arginine; G: glycine; D: aspartic acid; C: cysteine) using coupling agent 3-aminopropyltriethox- ysilane (APTES) followed by covalent attachment of gentamicin onto the surface of the BC membrane network. X-ray photoelectron spectroscopy (XPS) analyses showed that the BC-APTES contained 0.7% of silicon in terms of elemental composition, corresponding to a grafting ratio of 1:12. The presence of silicon and nitrogen in the BC—APTES confirmed the surface functionalization of the BC membrane. Fourier-transform infrared (FTIR) analyses show the formation of the secondary amide as supported by the valence bond C=O (v_(C=O)), a characteristic vibrational transition at 1650 cm~(-1) which is particularly intense with the BC-RGDC—gentamicin membrane. Energy-dispersive X-ray (EDX) analyses showed a low level of carbon and nitrogen (C + N) in pure BC but a high level of (C + N) in BC-RGDC- gentamicin confirming the surface modification of the BC membrane by RGDC and gentamicin enrichment. Of great interest, the gentamicin—RGDC-grafted BC membranes are bactericidal against Streptococcus mutatis but nontoxic to human dermal fibroblasts and thus may be useful for multiple applications such as improved wound healing and drug delivery systems.