HEMICELLULASE – MEDIATED HYDROLYSIS OF CHITOSAN: AN EFFICIENT METHOD TO SYNTHESIZE WATER SOLUBLE CHITOSAN

Chitosan is a natural biopolymer that has been extensively used traditionally for the treatment of various ailments and as an efficient vehicle or carrier for fabrication, encapsulation and target-specific delivery of a wide range of pharmacological moieties for improved therapeutic efficacy. Despite of numerous characteristic features, the pharmaceutical significance of chitosan is limited due to its poor water solubility. The present study was aimed to investigate the impact of enzyme (hemicellulase)-mediated hydrolysis on the physicochemical characteristics including solubility, physicochemical nature, crystallinity, contact angle/wettability and surface morphology of the WSC. The sustainability of enzymatic method was evaluated by testing aqueous solubility and carrying out fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), thermogravimetric analysis (TGA), contact angle measurement and scanning electron microscopic (SEM) analysis. Results of solubility studies revealed that hemicellulase-mediated hydrolysis significantly enhanced the aqueous solubility and wettability of the chitosan and exhibited smaller contact angle (θ) in comparison to the unmodified LMWCS. FTIR analysis showed that WSC synthesised via enzymatic hydrolysis exhibited ultra-low molecular weight and increased deacetylation degree in comparison to the unmodified LMWCS. Moreover, there was no change in chemical nature of all the functional groups. XRD analysis indicated that the increased in crystallinity of the WSC after enzymatic degradation, however, solubility of WSC was not affected. These findings indicated that hemicellulase-mediated hydrolysis of LMWCS is an efficient alternative method to synthesise WSC without altering its physicochemical nature and pharmaceutical integrity.