DOI: https://doi.org/10.55373/mjchem.v25i3.275

Keywords: Cytotoxicity; antibacterial; bio-based surfactants; palm-based oleochemicals

Abstract

Personal protective equipment such as glove is widely used to protect the hands against chemicals or infectious agents. Surfactants in the glove act to reduce the surface tension and stabilise the rubber particle. However, some of the surfactants may exert toxicity to skin cells. Hence, a series of novel palm oil-based surfactants was synthesised to replace the conventional surfactants in the glove. This study aims to determine the cytotoxicity of this series, namely PS1, PS2, PS3 and PS4. The surfactants were synthesised from different palm-based oleochemicals. The typical ester bond (intense C=O stretch at 1740 cm−1) in the backbone of these surfactants were identified from the Fourier transform infrared (FTIR) spectra, indicating the successful synthesis of these surfactants. Gel permeation chromatography (GPC) results indicate that these surfactants are polydispersed, with the number average molecular weight (Mn) ranged around 2000. These surfactants showed critical micelle concentration (CMC) values ranging from 2.215×10-3 to 3.075×10-3 mM/L with surface tension recorded between 24 and 36 mM/m. 2,5-Diphenyl-2H-tetrazolium bromide (MTT) assay was used to investigate the cytotoxicity of these surfactants against HaCat keratinocytes. Agar dilution susceptibility testing technique was employed to determine the antibacterial activity of the surfactants. All surfactants were non-toxic towards HaCat keratinocytes at 1.56 mg/mL. However, they exhibited dose-dependent toxicity, especially at higher concentrations (25 and 50 mg/mL). Results showed that PS1, PS2 and PS3 slightly reduced the growth of Enterococcus faecalis ATCC 29212 and Streptococcus mutans ATCC 25175 but not Gram-negative bacteria. However, none of the tested bacteria was susceptible to PS4. In conclusion, these surfactants tested exhibited moderate toxicity on skin cells and possessed mild antibacterial activities.