过表达非分泌型TNF-α的巨噬细胞药物递送系统用于结直肠癌靶向治疗的研究

Macrophage Drug Delivery System Overexpressing Non-secretory TNF-α for Targeted Therapy of Colorectal Cancer

关键词:  基因工程  巨噬细胞  肿瘤坏死因子-α  近红外光

Key words:  genetic engineering  macrophage  TNF-α  NIR

摘要:

目的 构建具有可控性光响应能力并可被“按需”热爆破的智能型巨噬细胞药物递送系统，实现肿瘤组织局部释放肿瘤坏死因子-α(tumor necrosis factor-α，TNF-α)效应蛋白用于结直肠癌的靶向治疗。方法 运用基因工程技术构建高表达非分泌型TNF-α效应蛋白的巨噬细胞(M^ET)，通过材料学方法制备搭载光敏剂吲哚菁绿(indocyanine green，ICG)的丝胶纳米粒(ICG@SNP)作为细胞内TNF-α效应蛋白释放的开关，同时利用巨噬细胞强吞噬特性使其负载上述有荧光特性和光热转换效应的ICG-丝胶纳米粒(ICG@SNP@M^ET)；体外实验评价巨噬细胞中过表达TNF-α蛋白的生物活性和存在形式，M^ET细胞摄取及滞留ICG@SNP纳米粒的效率以及ICG@SNP@M^ET响应近红外光(NIR)触发TNF-α效应蛋白释放的能力；体内实验评价该功能化巨噬细胞的肿瘤归巢能力及抗肿瘤效果。结果 M^ET细胞中的TNF-α蛋白具有生物活性且以非分泌形式稳定存在于巨噬细胞中； ICG-丝胶纳米粒能增强巨噬细胞对ICG的摄取和滞留；而ICG@SNP@M^ET在响应NIR照射后能够热“爆破”释放具有生物学活性的TNF-α效应蛋白。本研究也在皮下结肠癌CT26荷瘤小鼠模型中初步验证了ICG@SNP@M^ET能够迁移并渗入到肿瘤部位，联合NIR照射后表现出优异的抗肿瘤活性。结论 ICG@SNP@M^ET药物递送系统能够靶向结直肠癌，在NIR照射后释放TNF-α效应蛋白发挥抗肿瘤治疗作用。

Abstract:

OBJECTIVE To construct an intelligent cell carrier system that has controllable near-infrared light response capability and can be thermally blasted "on demand" to achieve localized release of tumor necrosis factor α(TNF-α) protein in tumor tissues for targeted therapy of colorectal cancer. METHODS This project modified macrophages to overexpress non-secretory TNF-α effector protein(M^ET) through genetic engineering technology and prepared sericin nanoparticles (ICG@SNP) equipped with the photosensitizer indocyanine green(ICG) as a switch for the release of intracellular drug protein through materials science methods. Utilizing the strong phagocytic properties of macrophages, M^ET was loaded with the ICG@SNP with fluorescence characteristics and photothermal conversion effect. To evaluate the biological activity and existence form of TNF-α protein overexpressed in macrophages, the uptake and retention efficiency of ICG@SNP nanoparticles by M^ET cells, and the ability of ICG@SNP@M^ET to release TNF-α protein triggered by near-infrared light(NIR) in vitro. To evaluate the tumor-homing ability and anti-tumor effect of the functionalized macrophages in vivo. RESULTS The TNF-α protein in M^ET cells had biological activity and was stably present in macrophages in a non-secreted form, the uptake and retention efficiency of ICG by macrophages had been enhanced through sericin nanoparticles, and ICG@SNP@M^ET could be thermally "blasted" to release biologically active TNF-α effector protein triggered by NIR. This study also preliminarily verified that ICG@SNP@M^ET could migrate and penetrate into the tumor site in the CT26 tumor-bearing mouse model of subcutaneous colon cancer, and exhibited excellent anti-tumor activity combined with NIR irradiation. CONCLUSION The ICG@SNP@M^ET drug delivery system can be targeted to the colorectal cancer and release TNF-α effector protein triggered by NIR to play an anti-tumor therapeutic effect.