负载噬菌体内溶素Lys84水凝胶的制备及性能表征

Preparation and properties of hydrogels loaded with phage endolysin Lys84

摘要:

探究聚(N-异丙基丙烯酰胺)[poly(N-isopropylacrylamide)]基互穿网络(interpenetrating polymer network)温敏水凝胶(记作：IPNT)作为噬菌体内溶素Lys84递送载体的可行性，及载药水凝胶作为抗菌材料的应用潜力。以海藻酸钠和N-异丙基丙烯酰胺为原材料，通过自由基聚合的方法制备互穿网络温敏水凝胶，采用干态浸泡法负载金黄色葡萄球菌(Staphylococcus aureus)噬菌体内溶素Lys84获得载药水凝胶(IPNT-Lys84)。通过红外光谱仪、扫描电子显微镜(scanning electron microscopy, SEM)、差示扫描量热仪(differential scanning calorimetry, DSC)对水凝胶载药前后的物理性能进行表征，并研究水凝胶溶胀、退溶胀以及内溶素Lys84释放情况、在不同温度及不同浓度药液浸泡的抗菌性能。结果表明，IPNT-Lys84水凝胶孔洞均匀，低临界溶解温度(lower critical solution temperature, LCST)为32 ℃；水凝胶平衡溶胀度为30 g/g，退溶胀时失水率为88%；在37 ℃时内溶素释放率在6 h内达到70%以上；IPNT-Lys84水凝胶杀菌率达99.9%以上。研究表明，采用IPNT递送内溶素Lys84具有可行性，IPNT-Lys84水凝胶有望成为针对多重耐药金黄色葡萄球菌的有效抗菌材料。

Abstract:

This study investigated the application of poly(N-isopropylacrylamide)-based interpenetrating network temperature-sensitive hydrogels (notation: IPNT) as the delivery vehicle for phage endolysin Lys84 and the potential of drug-loaded hydrogels as antimicrobial materials. Interpenetrating network temperature-sensitive hydrogels were prepared by free radical polymerization of sodium alginate and N-isopropylacrylamide. Drug-loaded hydrogels (IPNT-Lys84) were obtained by dry soaking method with the endolysin Lys84 of Staphylococcus aureus phage. The physical properties of the hydrogels with and without drug loading were characterized by infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry. The swelling and deswelling of the hydrogels as well as the release of endolysin Lys84 were investigated. Moreover, the antibacterial properties of IPNT-Lys84 hydrogels at different temperatures and concentrations of the drug solution were studied. The results showed that IPNT-Lys84 hydrogel had uniform pores and a low critical solubility temperature (LCST) of 32 ℃. The equilibrium swelling of the hydrogel was 30 g/g, and the water loss rate was 88% upon deswelling. The release rate of endolysin reached more than 70% within 6 h at 37 ℃. The bactericidal rate of IPNT-Lys84 hydrogel was over 99.9%. The research results showed the feasibility of using IPNT to deliver the endolysin Lys84, and IPNT-Lys84 hydrogel might be an effective antimicrobial material against multi-drug resistant Staphylococcus aureus.