Effectiveness Study of Chitosan from Pearl Oyster Shells (Pinctada maxima sp.) as Antibacterial in Bone Scaffold Application

Abstract

Chitosan functional material is a promising material in manufacturing bone scaffolds, as it has antibacterial properties, low toxicity, biodegradability, biocompatibility with human tissues, and facilitates regenerative processes in wound healing. Graft placement is prone to bacterial invasion, and alternatives are made scaffolds with antibacterial activity. This study aims to identify changes in functional groups in each isolation process and identify the effect of chitosan concentration (5%, 10%, 20%, 40%, and 80%) on the activity of Straphylococcus aureus and Escherichia coli bacteria. Chitosan isolation methods are demineralization, deproteination, decolorization, and deacetylation by microwave irradiation. Analysis of chitosan functional groups using FTIR, while antibacterial activity test using diffusion method. Isolation of chitosan from pearl oyster shells (Pinctada maxima sp.) obtained a degree of deacetylation of chitosan of 95.37%. Pearl oyster shell powder identified typical peaks of calcium carbonate (CaCO₃). The demineralized powder sample had calcium carbonate (CO₃²⁻) peaks that disappeared. Furthermore, the deproteinated powder sample produced peaks with amide groups (C=O dan N-H) of reduced protein. Decolorized powder samples did not show drastic changes in the bands of the deproteinated powder spectra, but the spectra could show cleaner and clearer peaks without any interference from pigments. The last, deacetylated powder sample showed a decrease in peak intensity in the 1650 cm⁻¹ (C=O amide). The analysis of the ability of chitosan to inhibit the growth of E. Coli and S. Aureus bacteria was effective at a minimum chitosan concentration of 20%. In comparison, antibacterial activity in S. aureus is better than in E. coli. Therefore, chitosan from this shell can be used as an antibacterial, but it is necessary to optimize chitosan manufacturing techniques to obtain better antibacterial efficacy.