骨关节炎（Osteoarthritis, OA）仍是常见且逐渐加剧的关节退化性疾病，影响超过 30 岁人群中的六分之一；目前缺乏根治方案，临床常见选择主要是止痛处置或关节置换手术。科罗拉多大学博尔德分校（University of Colorado Boulder）由生医工程学者 Stephanie Bryant 领导、并由 Evalina Burger 引述者的团队，获得 ARPA-H NITRO 专案 3,350 万美元（33.5 million USD）资助，研究可在数周内逆转关节损伤的注射疗法。该病以软骨逐渐磨耗为核心病理，造成疼痛、发炎、关节变形与活动受限，为美国最常见的关节炎之一，全球受影响人数估计高达 2.4 亿。

该团队提出两条核心技术路径，皆改采动员自体修复机制，而非植入人工组织或义体。其一为单次注射法，利用粒子载体使已核准药物在关节内持续释放，以低剂量方式在数月内作用，促进修复；其二用于更晚期病例，透过微创程序导入生物材料与蛋白质套组，于体内凝胶化形成足架，吸引 progenitor cells（前驱细胞）填补并再生受损软骨或骨组织。两种方法共享目标：将发炎退化的关节重塑为有利自然再生的微环境。

在动物研究中，处理后关节在 4 至 8 周内可恢复至接近健康状态，且在较严重损伤中观察到受损组织完全再生；专案从概念到展示可逆转 OA 仅历时 2 年。来自关节置换患者的临床前人类细胞实验亦显示明显再生效应，支持转译潜力。研究仍未进入人体临床验证，计划先于本年度后期发表学术成果，并成立 Renovare Therapeutics 以推进商用；下一步将扩大动物实验，并评估毒性与安全性，若顺利，人体试验可能在约 18 个月后启动。

Osteoarthritis (OA) remains a common progressive joint disease that affects one in six adults over age 30, and there is still no cure; current care is mostly pain management or joint replacement. A team at the University of Colorado Boulder led by biomedical engineer Stephanie Bryant, with comments from Evalina Burger, received a $33.5 million (3,350 USD) NITRO grant from ARPA-H to develop a treatment intended to reverse joint damage in weeks. OA is driven by cartilage wear that causes pain, inflammation, joint deformation, and reduced mobility; it is the most common arthritis in the U.S. and is estimated to affect about 240 million people globally.

The researchers are pursuing two complementary strategies that rely on the body’s own regenerative capacity rather than artificial implants. The first uses a single injection with a particle-based delivery system releasing an already approved drug in a controlled way, allowing small doses to be administered over months directly into the diseased joint. The second is for more advanced cases: biomaterials and proteins delivered through minimally invasive procedures that solidify in situ as a scaffold, then recruit progenitor cells to fill and regenerate damaged cartilage or bone. Both approaches aim to convert the diseased joint into a microenvironment that supports natural tissue regeneration.

In animal studies, treated joints returned to a healthy state within 4 to 8 weeks, and severe injuries showed complete tissue regeneration in some cases. Bryant said the team moved from the initial moonshot idea to demonstrating OA reversal in two years. Additional experiments with cells from patients undergoing joint replacement also showed clear regenerative effects, suggesting human translational potential. The findings are not yet validated in clinical trials; publication is expected later this year, and a startup, Renovare Therapeutics, has been formed for commercialization. Next steps are broader animal studies focused on toxicity and safety, with human trials potentially starting in about 18 months.