靶向、多重响应的功能化纳米凝胶给药系统的构建及抗肿瘤转移机制

A targeting and muli-stimuli responsive nanogel drug delivery system is designed to both inhibit tumor metastasis by preventing the adhesion of tumor cells to new vascular endothelial cells and restraining the formation of new blood vessels, and killing tumors directly. The nanogels would reach tumor tissues by targeting effect, response to near-infrared light (NIR) to get separated, and get dissolved in the acidic microenvironment of tumors. DOX is selected as a model drug, ZnO is an pH sensitive nanoparticle to response the low pH environment in tumors, low molecular weight heparin (LMHP) is served as a gel material and the oligomeric proline fragment (OP) is used as a linker to cross-link the nanogels to entrap LMHP-DOX-ZnO, which has the photodynamic properties to generate ROS after excited by NIR. The ROS produced by LMHP-DOX-ZnO would induce the break of OP to disrupt the nanogels. The drug delivery system we built could solve the leakage problem of anti-tumor drugs in blood circulation system, and the side effect of bleeding when LMHP is used as an anti-tumor agent. The nanogels are triggered to release drugs by multiple stimuli, which has a better control of drugs compared with single stimulus responsive delivery systems. This program also offers a new thought for researches of antineoplastic and anti-metastasis, and has a significant value for application.

设计并构建具有靶向、多重响应的功能化纳米凝胶给药系统，通过靶向肿瘤组织、近红外响应、肿瘤酸性环境响应、抑制肿瘤细胞与新生血管内皮细胞的粘附、抑制新生血管生成及直接杀死肿瘤细胞等多重作用，达到抗肿瘤转移及抗肿瘤效果。选择阿霉素（DOX）为模型药物，氧化锌纳米粒（ZnO）为酸敏感纳米粒，低分子肝素（LMHP）为凝胶材料，寡聚脯氨酸片段（OP）为交联剂，LMHP-DOX-ZnO为可响应近红外光释放ROS，进而断裂OP键而解散凝胶系统的物质，制备包载LMHP-DOX-ZnO、经OP交联LMHP的靶向、多重响应的功能化纳米凝胶给药系统（LMHP-DOX-ZnO@LMHP-OP）。该给药系统可解决抗肿瘤药物在血液循环系统中泄漏的问题、LMHP单独使用具有导致出血毒副作用的问题、多重响应触发释药解决单一触发释药可控性不强的问题。该给药系统为抗肿瘤及抗肿瘤转移的研究提供了新思路，具有非常重要的科学价值。

本项目设计并构建具有靶向、多重响应的功能化纳米凝胶给药系统，通过靶向肿瘤组织、近红外响应、肿瘤酸性环境响应、抑制肿瘤细胞与新生血管内皮细胞的粘附、抑制新生血管生成及直接杀死肿瘤细胞等多重作用，达到抗肿瘤转移及抗肿瘤效果。选择阿霉素（DOX），氧化锌纳米粒（ZnO），金纳米棒（AuNR），二氢卟吩e6（Ce6），鲁米诺（luminol），低分子肝素（LMHP）等材料，构建多种靶向功能化纳米给药系统，对其抗肿瘤作用及机制进行研究。.构建可靶向组蛋白H1的LMHP-DOX NPs，对其靶向H1介导的摄取，靶向聚集细胞核周，促进DOX细胞核内递送及其胞内行为进行考察。确定其体内外抗肿瘤药效及靶向作用机制。.合成具有适宜pH/温度敏感性的PAA-PEG-PAA，阿霉素PAA-PEG-PAA凝胶具有响应肿瘤酸性微环境及体温发生凝固、缓慢释放药物的特点。制备具有优良的光学性能及pH敏感性能的氧化锌纳米粒（ZnO NPs），作为载体载带活性物质以产生抗肿瘤治疗和诊断作用。.制备金纳米棒(AuNR)/阿霉素(DOX)凝胶给药系统，联合抗原捕获物质L-Mal和PD-L1抑制剂anti-PD-L1，DOX诱导ICD，触发损伤相关分子模式，促进肿瘤细胞产生肿瘤相关抗原；880nm激光照射AuNRs产生温和光热诱导产生肿瘤相关抗原，L-Mal捕获抗原，促进肿瘤引流淋巴结、脾脏和肿瘤部位DCs的成熟，激活肿瘤部位免疫，与anti-PD-L1协同产生更强的抗肿瘤免疫疗效。.制备过氧化氢触发的智能光动治疗纳米递送系统，响应不同浓度梯度的过氧化氢，在肿瘤血管内皮细胞和肿瘤细胞中产生不同浓度的单线态氧，选择性调控肿瘤血管内皮细胞功能和特异性杀伤肿瘤细胞的目的。.构建LMHP包被的ZnO-Ce6 NPs和LMHP-DOX@ZnO NPs（ZnO-LD NPs），确定其近红外及酸性响应的抗肿瘤功能。.本项目为纳米给药系统的构建提供新思路，具有重要科学意义。