pH敏感水凝胶微球的制备及二甲酸钾缓释和抗菌性能分析

二甲酸钾(KDF)为抗生素的新型替代品,但在牲畜饲养中还未大量普及。采用水热法自制P型分子筛(Zeolite P),负载KDF分散在羧甲基纤维素(CMC)溶液中,与FeCl₃交联,利用凝聚法制备壳聚糖-羧甲基纤维素-P型分子筛-二甲酸钾pH敏感水凝胶抗菌微球。通过FT-IR,TGA和SEM分析可知,壳聚糖(CS)和CMC通过离子键形成结构稳定的聚电解质复合物,Zeolite P镶嵌缠绕在CMC基质中。溶胀差异性表明水凝胶微球具有高pH敏感性,可以适用不同pH条件下的持续给药。缓释动力学研究表明:抗菌微球对KDF具有一定的缓释作用,且遵循一级动力学释放模型和Higuchi模型。体外抗菌实验发现,抗菌液浓度为24 mg/mL和48 mg/mL时对大肠杆菌和金黄色葡萄球菌有显著的抗菌性,可以有效地抑制细菌的生长。

Preparation of p H-sensitivity hydrogel microspheres and potassium diformate sustained-release and antibacterial performance analysis

Potassium diformate(KDF)is a novel substitute for antibiotics,which is not widely used in livestock production.The P-type molecular sieve(Zeolite P)was prepared by hydrothermal method with loading KDF and dispersed in the carboxymethyl cellulose(CMC)solution.The dispersed CMC mixed solution was added dropwise to the FeCl₃ solution for cross-linking.Chitosan-carboxymethyl cellulose-Zeolite P-potassium diformate pH-sensitive hydrogel antibacterial microspheres were prepared by coacervation method.FT-IR,TGA and SEM results show that CS and CMC form the structurally stable polyelectrolyte complex through ionic bonds,and Zeolite P is included in the CMC matrix.The difference in swelling study indicates that the hydrogel microspheres have high pH-sensitivity and can be applied for sustained-release under different pH value.The slow-release kinetics study shows that antimicrobial microspheres have a certain sustained-release effect on KDF.The first-order kinetic model and the Higuchi model fits well with release data.In vitro antibacterial experiments,the antibacterial microspheres display significant antibacterial property against Escherichia coli and Staphylococcus aureus in the concentration of the antibacterial solution at 24 mg/mL and 48 mg/mL.Antibacterial microspheres can effectively inhibit the growth of bacteria,and the antimicrobial microsphere model provides a theoretical basis for the use of KDF.