Schaeffer Christine, Pfaff Blaise N, Cornell Nicholas J, Salopek Lisa S, Shan Sarah, Viyar Jan, Omesiete Wilson, Griffin Donald R, Cottler Patrick S, DeGeorge Brent R
From the Department of Plastic Surgery.
Department of Biomedical Engineering.
Ann Plast Surg. 2020 Jun;84(6S Suppl 5):S446-S450. doi: 10.1097/SAP.0000000000002271.
The purpose of this study is to assess the feasibility of a novel microporous annealed particle (MAP) scaffolding hydrogel to enable both articular cartilage and subchondral bone biointegration and chondrocyte regeneration in a rat knee osteochondral defect model.
An injectable, microporous scaffold was engineered and modified to match the mechanical properties of articular cartilage. Two experimental groups were utilized-negative saline control and MAP gel treatment group. Saline and MAP gel were injected into osteochondral defects created in the knees of Sprague-Dawley rats. Photo-annealing of the MAP gel was performed. Qualitative histologic and immunohistochemical analysis was performed of the treated defects at 2, 4, and 8 weeks postsurgery.
The injectable MAP gel successfully annealed and was sustained within the osteochondral defect at each timepoint. Treatment with MAP gel resulted in maintained size of the osteochondral defect with evidence of tissue ingrowth and increased glycosaminoglycan production, whereas the control defects presented with evidence of disorganized scar tissue. Additionally, there was no significant inflammatory response to the MAP gel noted on histology.
We have demonstrated the successful delivery of an injectable, flowable MAP gel scaffold into a rat knee osteochondral defect with subsequent annealing and stable integration into the healing wound. The flowable nature of this scaffold allows for minimally invasive application, for example, via an arthroscopic approach for management of wrist arthritis. The MAP gel was noted to fill the osteochondral defect and maintain the defect dimensions and provide a continuous and smooth surface for cartilage regeneration, suggesting its ability to provide a stable scaffold for tissue ingrowth. Future chemical, mechanical, and biological gel modifications may improve objective evidence of cartilage regeneration.
本研究的目的是评估一种新型微孔退火颗粒（MAP）支架水凝胶在大鼠膝关节骨软骨缺损模型中实现关节软骨和软骨下骨生物整合以及软骨细胞再生的可行性。
设计并改良了一种可注射的微孔支架，使其力学性能与关节软骨相匹配。设立了两个实验组——阴性生理盐水对照组和MAP凝胶治疗组。将生理盐水和MAP凝胶注入Sprague-Dawley大鼠膝关节制造的骨软骨缺损处。对MAP凝胶进行光退火处理。在术后2周、4周和8周对治疗后的缺损进行定性组织学和免疫组织化学分析。
可注射的MAP凝胶成功退火，并在每个时间点持续存在于骨软骨缺损处。MAP凝胶治疗使骨软骨缺损大小得以维持，有组织长入的迹象且糖胺聚糖生成增加，而对照缺损处则出现紊乱瘢痕组织的迹象。此外，组织学检查未发现对MAP凝胶有明显炎症反应。
我们已证明可成功将一种可注射、可流动的MAP凝胶支架递送至大鼠膝关节骨软骨缺损处，随后进行退火并稳定整合到愈合伤口中。这种支架的可流动特性允许微创应用，例如通过关节镜方法治疗腕关节炎。MAP凝胶被发现可填充骨软骨缺损并维持缺损尺寸，为软骨再生提供连续光滑的表面，表明其能够为组织长入提供稳定支架。未来对凝胶进行化学、力学和生物学方面的改良可能会改善软骨再生的客观证据。
