载四羧基酞菁锌明胶微球的制备及其光动力抗菌活性

Preparation and Photodynamic Antimicrobial Activity of Tetra(4-carboxyphenoxy)-Phthalocyaninatozinc(II)Loaded Gelatin Microspheres

基于光敏剂的抗菌光动力疗法已成为抗生素治疗的一种替代治疗方法,但光敏剂水溶性差、易聚集的问题严重阻碍了抗菌光动力疗法的广泛应用。文章利用四羧基酞菁锌(TPZnPc)和明胶的羧基与Cu2+相互配位,采用油包水乳化交联法,制备载四羧基酞菁锌明胶微球(TPZnPc-GMs),使用傅里叶变换红外光谱、扫描电镜、紫外可见光谱等对微球进行了表征。结果表明:TPZnPc-GMs成功负载了TPZnPc,负载率为0.6%;微球平均粒径为1.6μm,其中TPZnPc以单体形式存在于微球中。TPZnPc-GMs溶液在红光(630~710 nm)照射下能生成单线态氧,与革兰氏阳性枯草芽孢杆菌(B. subtilis)混合培养,当TPZnPc-GMs质量浓度为1 mg/m L时,光动力抑菌率为65%,较高质量浓度的TPZnPc-GMs(3 mg/mL)光动力抑菌率可达100%。

Antimicrobial photodynamic therapy(APDT)based on photosensitizers has emerged as an alternative treatment to antibiotics.However,the poor water solubility and tendency to aggregate of photosensitizers severely impede the widespread application of APDT.Therefore,in this study,tetra(4-carboxyphenoxy)-phthalocyaninatozinc(II)-loaded gelatin microspheres(TPZnPc-GMs)were prepared by using a water-in-oil emulsion cross-linking method.The carboxyl groups in TPZnPc and gelatin were employed to coordinate with Cu2+ions.The microspheres were characterized by using Fourier transform infrared spectroscopy,scanning electron microscopy and UV-visible spectroscopy.Results demonstrated the successful loading of TPZnPc into TPZnPc-GMs with a loading rate of 0.6%.The average particle size of TPZnPc-GMs was 1.6μm,and TPZnPc remained its monomeric form within these microspheres.The TPZnPc-GMs solution,when exposed to red light(630-710 nm),produced singlet oxygen.When co-cultured with Gram-positive Bacillus subtilis(B.subtilis),the TPZnPc-GMs solution at a concentration of 1 mg/mL exhibited 65%photodynamic bactericidal rate.The photodynamic bactericidal rate of 100%was achieved when its concentration was improved to 3 mg/mL.