Biopolymer starch-gelatin embedded with silver nanoparticle–based hydrogel composites for antibacterial application

A multi-component starch-gelatin hybrid hydrogel was synthesized using eco-friendly approach. The starch-based hydrogel (without gelatin) was also synthesized to highlight the importance of gelatin in the hybrid hydrogel. The RSM-CCD (response surface methodology integrated central composite design) was used to optimize the synthesis of both the hydrogels to their maximum swelling capacity. The synthesis of hydrogel was confirmed using various characterization techniques including FTIR, SEM, XRD, thermal methods, compressive strength etc. The gelatin was found to enhance the compressive strength of the hybrid hydrogel. Further, silver nanoparticle-embedded starch and starch-gelatin hydrogels were synthesized. The hydrogel network itself reduced the silver ions to silver nanoparticles without the use of any external reductant and surfactant. The TEM images revealed the spherical AgNPs in the size range of 4–19 nm and quasi-spherical of 4–58 nm embedded in hybrid and starch hydrogels, respectively. Furthermore, the nanocomposite hydrid hydrogel was found to be better as stabilizing agent for stabilization of silver nanoparticles in comparison to nanocomposite starch hydrogel.The silver-embedded hybrid hydrogel exhibited good anti-bacterial activity for gram-negative (E. coli) along with gram-positive bacteria (S. aureus). Embraced with high mechanical strength, the various characteristics of silver-embedded starch-gelatin hydrogel such as good hydrophilicity, biocompatibility, biodegradability, non-cytotoxicity, and hemocompatibility reflect its utility as wound dressing material.