文献：Enhanced Therapeutic Effect of RGD-Modified Polymeric Micelles Loaded With Low-Dose Methotrexate and Nimesulide on Rheumatoid Arthritis

文献链接：https://pubmed.ncbi.nlm.nih.gov/30809303/

作者：Yunlong Wang, Zhongbing Liu, Ting Li, Lin Chen, Jiayao Lyu, Chunhong Li, Yan Lin, Na Hao, Meiling Zhou, Zhirong Zhong

相关产品：NHS-PEG3400-PLA2000 活性酯-聚乙二醇3400-聚乳酸2000

原文摘要：Angiogenesis plays an essential role in the progression of rheumatoid arthritis (RA). RGD peptide shows high affinity and selectivity for integrin αvβ3, which is one of the most extensively examined target of angiogenesis. Nimesulide could improve the anti-rheumatic profile of methotrexate. But the clinical application was limited due to water-insolubility of both methotrexate and nimesulide and lacking targeting ability. Therefore, this study aimed to design a targeted drug delivery system of micelles mediated by RGD plus the passive targeting of micelles to solve the application problems of methotrexate and nimesulide (M/N), and thus enhance their

combined therapeutic effect on RA. Methods: RGD was conjugated with NHS-PEG-PLA to form RGD-PEG-PLA for the preparation of RGD-modified drug-loaded micelles (R-M/N-PMs). The size and zeta potential of micelles were measured by dynamic light scattering. Morphology was detected by transmission electron microscopy. The inhibition effect of R-M/N-PMs on angiogenesis was assessed by the chick chorioallantoic membrane assay. The real-time fluorescence imaging analysis was conducted to examine the in vivo distribution of the fluorescence-labeled R-M/N-PMs. Rats arthritis model induced by Freund’s adjuvant was used to evaluate the in vivo anti-inflammatory efficacy of R-M/N-PMs. Results: The in vitro study indicated successful development of R-M/N-PMs. R-M/N-PMs could markedly suppress the angiogenesis of chick embryos. The fluorescence-labeled R-M/N-PMs mainly accumulated in arthritic joints. RGD enhanced the targeting ability of micelles and thus promoted retention of micelles in arthritic joints. Moreover, R-M/N-PMs significantly alleviated the joint swelling while reducing bone erosion and serum levels of inflammatory cytokines. It helped to recover the bone microstructure of arthritic rats. Conclusion: Our results confirmed that the targeted delivery of the combination of a low dose of methotrexate and nimesulide mediated by RGD-modified polymeric micelles could enhance the therapeutic effect on rheumatoid arthritis. These findings provide a promising potential for the clinical therapy of rheumatoid arthritis.

NHS-PEG3400-PLA2000是一种高分子化合物，由聚乙二醇（PEG）和聚乳酸（PLA）通过特定化学反应连接而成，并在一端带有N-羟基琥珀酰亚胺（NHS）活性酯基团。该化合物通常呈现为液体或粘稠状固体，可溶于多种有机溶剂及水中，具有良好的生物相容性和反应活性，其末端的NHS活性基团能与氨基（-NH2）反应，用于修饰蛋白质、多肽、糖类、叶酸、抗体等生物分子。MTX是一种化合物和免疫抑制剂，是RA常用的DMARDs之一，MTX可引起全身有害性。NIM属于NSAID类化合物，是一种COX-2抑制剂，用于RA 的缓解。建议MTX和NIM联合应用于RA，可提高效果，尽量减少MTX 的副作用。RGD肽对整合素αvβ3具有高亲和力和选择性，整合素αvβ3是vessel生成中研究的靶点之一。引用的此篇文献将RGD与NHS-PEG-PLA偶联形成RGD-PEG-PLA，用于制备RGD修饰的载药胶束。

图为：RGD-PEG3400-PLA2000的合成

NHS-PEG3400-PLA2000 在MTX和NIM的RGD改性胶束制备中的应用：

为了制备装载MTX和NIM的RGD修饰胶束，首先合成了共聚物RGD-PEG3400-PLA2000，使用NHS-PEG3400-PLA2000作为交联剂。简单地说，将NHS-PEG3400-PLA2000溶解在无水的N、N-二甲基甲酰胺（DMF）中，并与无水三乙胺（TEA）混合。随后，在混合物中加入RGD，室温搅拌，然后用去离子水透析透析，以去除未偶联的RGD。透析后立即将溶液冻干，并进行1H NMR检测，以确认RGD与PEG3400-PLA2000的偶联。将制备的RGD-PEG3400-PLA2000共聚物和MTX/NIM溶解在DMF中。将混合物在减压下干燥，直到形成干燥的薄膜。为了去除残留的DMF，将其保存在真空干燥室中室温保存过夜。然后加入生理盐水，在培养箱中缓慢摇晃。随后，超声处理溶液。最后，将胶束溶液离心，以去除未卸载的化合物。

图为：RGD-PEG3400-PLA2000的1h核MR谱

结论：NHS-PEG3400-PLA2000在MTX和NIM的RGD改性胶束制备中扮演着关键角色。通过将RGD肽缀合到NHS-PEG3400-PLA2000的NHS活性酯基团上，可以制备出具有主动靶向能力的RGD改性胶束。RGD肽对Blood vessels生成内皮细胞上过度表达的整合素αvβ3显示出高亲和力和选择性，因此能够引导胶束主动靶向到tumor部位。