With the aging of the population, postmenopausal osteoporosis becomes increasingly widespread and severe as fractures caused by osteoporosis may lead to permanent disabilities and even death. Inspired by extracellular vesicles that participate in bone remodeling, we present a biomimicking polymer vesicle for bone-targeted β-estradiol (E₂) delivery. This vesicle is self-assembled from a poly(ε-caprolactone)₂₈-block-poly[(l-glutamic acid)₇-stat-(l-glutamic acid-alendronic acid)₄] (PCL₂₈-b-P[Glu₇-stat-(Glu-ADA)₄]) diblock copolymer. The alendronic acid (ADA) on the coronas endows the polymer vesicles with a high bone affinity and acts synergistically with E₂ to achieve an enhanced therapeutic effect. As confirmed with ovariectomized osteoporosis rat models, bone loss was significantly reversed as the recovery rates of total BMD (bone mineral density) and trabecular BMD were 70.4% and 99.3%, respectively. Overall, this work provides fresh insight into the treatment of osteoporosis.

中文翻译：

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用于有效治疗骨质疏松症的骨靶向聚合物囊泡

随着人口老龄化，绝经后骨质疏松症变得越来越普遍和严重，因为骨质疏松症引起的骨折可能导致永久性残疾甚至死亡。受参与骨重塑的细胞外囊泡的启发，我们提出了一种用于骨靶向 β-雌二醇 (E ₂ ) 递送的仿生聚合物囊泡。此囊泡是自组装由聚（ε -己内酯）₂₈ -嵌段-聚[（升谷氨酸）₇ - STAT - （升谷氨酸-阿仑膦酸）₄ ]（PCL ₂₈ - b -P [谷氨酸₇ -统计-（Glu-ADA）₄]) 二嵌段共聚物。电晕上的阿仑膦酸 (ADA) 赋予聚合物囊泡高骨亲和力，并与 E ₂协同作用以实现增强的治疗效果。正如去卵巢骨质疏松大鼠模型所证实的那样，由于总 BMD（骨矿物质密度）和小梁 BMD 的恢复率分别为 70.4% 和 99.3%，因此骨丢失得到显着逆转。总的来说，这项工作为骨质疏松症的治疗提供了新的见解。