Bano Ijaz, Ghauri Muhammad Afzal, Yasin Tariq, Huang Qingrong, Palaparthi Annie D'Souza
Industrial Biotechnology Division, National Institute for Biotechnology, Genetic Engineering, P.O. Box 577, Faisalabad, Pakistan; Department of Metallurgy and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore, Islamabad 45650, Pakistan.
Industrial Biotechnology Division, National Institute for Biotechnology, Genetic Engineering, P.O. Box 577, Faisalabad, Pakistan.
Int J Biol Macromol. 2014 Apr;65:81-8. doi: 10.1016/j.ijbiomac.2014.01.015. Epub 2014 Jan 10.
Naturally available chitosan (CHI), of high molecular weight, results in reduced efficiency of these polymers for antibacterial activity. In this regard, irradiation is a widely used method for achieving reduction in molecular weight of polymers, which may improve some of its characteristics. Chitosan was extracted from crab shells and degraded by gamma radiations. Effect of radiation dose on chitosan was analyzed by Fourier transform infrared (FTIR) spectroscopy. Furthermore, the irradiated chitosan was blended with poly(vinyl alcohol) (PVA) and crosslinked with tetraethylorthosilicate (TEOS) into membranes. The membranes were found to be smooth, transparent and macroporous in structure, exhibiting high tensile strength (TS: 27-47 MPa) and elongation at break (EB: 292.6-407.3%). The effect of molecular weight of chitosan and chitosan blends on antibacterial activity was determined. Irradiated low molecular weight chitosan and membranes showed strong antibacterial activity against Escherichia coli and Bacillus subtilis.
天然存在的高分子量壳聚糖（CHI）会导致这些聚合物的抗菌活性效率降低。在这方面，辐照是一种广泛用于降低聚合物分子量的方法，这可能会改善其某些特性。壳聚糖从蟹壳中提取并通过伽马射线降解。通过傅里叶变换红外（FTIR）光谱分析辐射剂量对壳聚糖的影响。此外，将辐照后的壳聚糖与聚乙烯醇（PVA）共混，并与正硅酸四乙酯（TEOS）交联制成膜。发现这些膜结构光滑、透明且具有大孔，表现出高拉伸强度（TS：27 - 47 MPa）和断裂伸长率（EB：292.6 - 407.3%）。测定了壳聚糖及其共混物的分子量对抗菌活性的影响。辐照后的低分子量壳聚糖及其制成的膜对大肠杆菌和枯草芽孢杆菌表现出很强的抗菌活性。
