Toxicity of Microcrystalline Cellulose Isolated Through Different Acidic Treatments

Abstract

Rising awareness-about the global enviromnent, govenunent regulations, consumer and market demand has pushed for the development and use of renewable materials. Cellulose, a biodegradable, eco-friendly, sustainable and the most abundant biomaterial ' on earth has the potential to be substituted for many of the fossil based materials. In the present study, microcrystalline cellulose was successfully prepared from cotton wool fibers, by using different acidic treatments viz. hydrochloric acid, sulfuric acid and nitric acid. Isolated microcrystalline cellulose were characterized by X-ray diffraction (XRD), fourier transfonn infrared spectroscopy (FTIR) and sCatming electron microscopy (SEM). Moreover, extraction yield, aqueous suspension stability, biocompatibility, cytotoxicity and antimicrobial potency were also evaluated and compared. The results revealed that type of the acid effect morphology, SIze, crystallanity and dispersion stability of microcrystalline cellulose. Sulfuric acid derived microcrystalline cellulose with average dimensions 40.46 ± 28 x 9.74 ± 4.23 ).tm, exhibited high crystallinity index (80.57%) and stable aqueous dispersions. Hydrochloric acid resulted in microcrystalline cellulose with high yield (73%) and average length and diameter 65.24 ± 30.35 and 13.25 ± 4.45 ~lln, respectively. High aspect ratio (6.9) microcrystals with mean dimensions 76 ± 59 x 11.5 ± 4.1 ).tm, were isolated with nitric acid. Despite having different physicochemical and morphological characteristics, isolated microcrystalline cellulose exhibited excellent compatibility against freshly isolated human red blood cells (ICso > 200 ~lg/ml), macrophages (ICso > 200 ).tg/ml) and brine shrimps (LCso > 200 ).tg/ml). Furthermore, no growth inhibition effect was observed in any of the tested bacterial and fungal strains. The study thus concludes that cotton wool fibers is potential, economic source for manufacturing high valued, safe, microcrystalline cellulose that can be used for broad range of applications in biocomposites, phannaceutical and food industries.