Investigation of antibacterial properties and sustained release of Centella Asiatica extract from Fe-MOF-reinforced gelatin-based hydrogels

The goal of this study is to investigate the antibacterial activity and sustained release of Centella Asiatica (CA) extract loaded in gelatin-based hydrogels, reinforced with MIL-53(Fe) (Fe-MOF) for the potential use as wound dressing. To induce antibacterial activity to the designed wound dressing, CA-extract was incorporated within the nanocomposite hydrogels. FT-IR analysis showed the distinctive peaks related to the Fe-MOF and CA-extract, with little shift, for hydrogel samples, which confirm the successful synthesis of nanocomposite hydrogels containing Fe-MOF and CA-extract. GC-mass analysis showed the antibacterial potential for CA-extract because of the presence of phenol, caryophyllene, and propanoic acid. SEM micrograph demonstrates the presence of Fe-MOF enhancing the porous of hydrogels. The antibacterial activity of prepared nanocomposite hydrogels was investigated by disk diffusion method revealing the significant inhibition zone growth for Basillus, Staphylococcus, and Streptococcus, as gram-positive and E. coli, Klebsiella, and P. aeruginosa as gram-negative bacteria and the "Candida albicans as fungi. Also, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by the micro-broth dilution method. The results showed that the nanocomposite hydrogel has a MIC values of 3.125 mg/ml and 6.25 mg/ml against both groups of bacteria. Cytotoxicity results obtained from MTT tests showed that the prepared hydrogels are biocompatible. The immunohistochemistry-stained hydrogel images revealed that the growth of cells on the CA-extract containing hydrogels was significantly increased in comparison to neat hydrogels.