基于巨噬细胞极化靶向治疗类风湿性关节炎的仿生纳米递药系统研究

Delivering gene or glucocorticoids in a targeted way to inflamed tissue in rheumatoid arthritis (RA) might enhance their therapeutic efficacy and reduce systemic side effects. To this end, drug-loaded liposomes, nanoparticles, polymeric micelles and other nanovehicles have been developed. However, these drug delivery systems are defective in long blood circulation, stability and safety. As an endogenous carrier, exosome have many characteristics of an ideal drug system, such as long cycle, good endocytosis ability, biocompatibility and low toxicity and hypoimmunogenicity in vivo. In RA, the synovial tissue is infiltrated by various immune cells and activated macrophages, which degradecartilage and destroy the synovium via a complicated inflammatory cytokine signaling network. Activated macrophages in inflamed joints, termed M1 macrophages, drive the progression of rheumatoid arthritis by secreting large amounts of inflammatory cytokines, making them prime therapeutic targets in strategies to treat inflammatory disorders. Conversely, macrophages involved with anti-inflammatory activity and tissue repair are considered to be M2 type. Therefore, switching predominant M1 type macrophages in arthritic joints to the M2 type may be an effective treatment of rheumatoid arthritis. IL-10 has multi-function anti-inflammatory activity, which can inhibit the secretion of proinflammatory factor to limit and stop inflammation. Therefore, by promoting the IL - 10 level in M1 macrophages and reducing the levels of proinflammatory factor can realize the macrophages polarization from M1 to M2. pORF5-mIL-10 plasmid DNA can express IL-10 in the nuclei, and prednisolone can enhance its expression. Moreover, IL-10 and PD can both inhibit the secretion of proinflammatory factor. By combining application the two drug, which could promote macrophage polarization through a dual approach and enhance therapy effect and has important scientific significance in RA treatment. Folic acid receptors (FRs) are up-regulated on the surface of activated macrophages in the course of RA. FRs include at least four isoforms (α, β, γ and δ), exhibiting distinct tissue distribution. FRα is usually involved in cancer-targeting, while FRβ is expressed on the activated synovial macrophages in the RA condition. This topic propose to utlize exosome loading pORF5-mIL-10 plasmid DNA and PD, preparing FA-Exsosome-DNA/PD active targeting biomimetic drug delivery system. By elucidating the anti- inflammatory mechanism can lay the foundation of research for the inflammatory targeting drug delivery system.

目前用基因药物或糖皮质激素类药物治疗类风湿性关节炎（RA）的纳米递药系统尚有缺陷，外泌体（exosome）具低毒、低免疫原性及长循环优势。在RA关节滑膜中存在加剧疾病进展的M1型和具抗炎活性的M2型巨噬细胞，促进巨噬细胞从M1型向M2型转化有望成为治疗RA的有效途径。IL-10通过抑制促炎症因子分泌限制并终止炎症，因此促进巨噬细胞内IL-10升高和促炎症因子降低可实现细胞极化。pORF5-mIL-10质粒DNA可在细胞内表达IL-10，泼尼松龙（PD）能增强其表达，且IL-10和PD均可抑制促炎症因子分泌。两药联用可以双重途径促进巨噬细胞极化，有望增强疗效，对治疗RA具有重要科学意义。本课题以exosome共载两药，用叶酸（FA）修饰，借助RA巨噬细胞分泌的叶酸受体β可特异性与FA结合，制备FA-Exosome-DNA/PD仿生纳米递药系统，阐明抗炎机制，为炎症靶向创新药物研究奠定基础。

目前用基因药物或糖皮质激素类药物治疗类风湿性关节炎（RA）的纳米递药系统尚有缺陷，外泌体（exosome）具低毒、低免疫原性及长循环优势。在RA关节滑膜中存在加剧疾病进展的M1型和具抗炎活性的M2型巨噬细胞，促进巨噬细胞从M1型向M2型转化有望成为治疗RA的有效途径。IL-10通过抑制促炎症因子分泌限制并终止炎症，因此促进巨噬细胞内IL-10升高和促炎症因子降低可实现细胞极化。pORF5-mIL-10质粒DNA可在细胞内表达IL-10，糖皮质激素类药物（GCs）能增强其表达，且IL-10和GCs均可抑制促炎症因子分泌。两药联用可以双重途径促进巨噬细胞极化，可极大增强疗效，对治疗RA具有重要科学意义。本课题分别构建以exosome载GCs，用叶酸（FA）修饰，借助RA巨噬细胞分泌的叶酸受体β可特异性与FA结合，制备主动靶向仿生纳米递药系统，在此基础上，为了减少化学修饰对外泌体功能的影响，制备了工程化M2型外泌体包载pDNA和GCs共递药仿生纳米递药系统，分别阐明抗炎机制，为炎症靶向创新药物研究奠定基础。