搭载咪唑−沸石骨架的减毒沙门氏菌的制备及抗肿瘤作用研究

Preparation of Salmonella typhimurium VNP20009 conjugated with imidazole-zeolite framework and its anti-tumor effect

本研究利用仿生矿化将咪唑−沸石骨架(ZIF-8)巧妙地搭载在减毒沙门氏菌VNP20009表面,同时包载化疗药物盐酸多柔比星(doxorubicin,DOX)得到ZD@VNP;采用透射电镜、激光共聚焦显微镜对ZD@VNP的形貌及ZIF-8与VNP20009的结合情况进行表征。采用荧光分光光度法考察DOX的包封率及体外释放率;通过CCK-8和细胞活/死染色FDA/PI评估ZD@VNP抑制黑色素瘤细胞(B16F10)增殖的能力,并建立黑色素瘤小鼠模型考察ZD@VNP抑瘤效果。实验结果表明ZIF-8均匀地结合在VNP20009表面,共聚焦结果也证实了ZD@VNP中ZIF-8与VNP的结合;ZD@VNP对DOX的包封率为85.7%±3.7%,在pH 6.0的缓冲液中DOX的释放显著高于pH 7.4;细胞实验结果表明ZD@VNP能增强DOX对B16F10细胞增殖的抑制作用;药效实验结果表明与VNP+DOX相比,ZD@VNP治疗在C57BL/6小鼠(实验得到广东医科大学动物保护和伦理委员会批准,编号:GDMU-2023-002518)上可显著抑制B16F10肿瘤生长,并延长小鼠生存期。综上,本研究借助仿生矿化通过一步法制备的ZD@VNP可显著增强DOX和VNP抑制肿瘤细胞生长的作用,在药物递送领域具有较大的应用前景。

In this study,inspired by biomimetic mineralization process,we have developed imidazole-zeolite framework(ZIF-8)conjugated VNP20009,and chemotherapy drug doxorubicin hydrochloride(DOX)was encapsulated to obtain ZD@VNP.The morphology and the combination of ZIF-8 and VNP was characterized by transmission electron microscopy and laser confocal microscopy.Fluorescence spectrophotometry was used to examine the encapsulation rate and in vitro release rate of DOX.CCK-8 and FDA/PI cell viability staining experiments were used to evaluate the ability of ZD@VNP to inhibit cell proliferation.Melanoma mouse model was established to investigate the effect of ZD@VNP to inhibit tumor growth.It was shown that ZIF-8 was evenly bounded to the surface of VNP20009,and laser confocal microscopy results also confirm the combination of ZIF-8 with VNP in ZD@VNP.The encapsulation rate of DOX in ZD@VNP was calculated to be 85.7%±3.7%,and the release of DOX under the buffer at pH 6.0 was significantly higher than that of pH 7.4.ZD@VNP treatment resulted in a greater inhibitory effect on B16F10 cell proliferation compared to DOX treatment.Animal experiment results showed that compared with VNP+DOX,ZD@VNP treatment can significantly inhibit the growth of B16F10 tumors in C57BL/6 mice and prolonged survival(all animal experiments were approved by the Institutional Animal Care and Ethics Committee Guangdong Medical University,No.GDMU-2023−2518).In summary,ZD@VNP was prepared through a facile,one-step method,which can significantly enhance the proliferation inhibitory effect of DOX to inhibit tumor growth and prolong survival.Our results demonstrate that ZD@VNP has great application prospects in the field of drug delivery.