Magneto-patterned cartilage constructs for improved osteochondral integration

磁图案软骨结构可改善骨软骨整合

• 批准号: 10395420
• 负责人: Hannah Marie Zlotnick
• 金额: $ 3.11万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-08 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10395420
• 关键词: Address; Autologous; Autologous Transplantation; Biochemical; Cadaver; Cartilage; Cell Density; Cell Fate Control; Cell Survival; Cells; Clinical; Computer Models; Defect; Degenerative polyarthritis; Deposition; Encapsulated; Engineering; Ensure; Environment; Fluorochrome; Glycerophosphates; Growth; Harvest; Histologic; Histology; Hyaluronic Acid; Hydrogels; Implant; In Vitro; Infiltration; Joints; Knee Osteoarthritis; Label; Lead; Lesion; Magnetism; Marrow; Measures; Mechanics; Mediating; Mentors; Metabolism; Methods; Microcapsules drug delivery system; Minerals; Miniature Swine; Modeling; Orthopedics; Osteogenesis; Pain; Patients; Pattern; Persons; Population; Positioning Attribute; Predisposition; Procedures; Research; Research Personnel; Scientist; Site; Source; Structure; Surface; Testing; Thick; Time; Tissue Engineering; Tissue Grafts; Tissues; Training; Triiodothyronine; Work; arthropathies; articular cartilage; base; bone; career; cartilage repair; cartilaginous; clinical efficacy; experience; healing; implantation; improved; improved functioning; in vivo; interfacial; knee replacement arthroplasty; magnetic field; mechanical properties; mesenchymal stromal cell; microCT; mineralization; neurotensin mimic 1; novel; osteochondral tissue; osteogenic; pain relief; preservation; prevent; repaired; subchondral bone; success; treatment strategy

Abstract Articular cartilage has a poor healing capacity, and so, any damage to the joint surface often progresses to osteoarthritis (OA), a debilitating joint disease. For patients with symptomatic knee OA, total knee replacement (TKR) is by far the most common clinical solution. However, TKR is an invasive and end stage procedure, and there is a growing market for alternate treatments to restore the structure and function of articular cartilage to ideally prevent OA, or at least delay the time to TKR. While native tissue grafts can be easily press-fit in vivo, their supply is limited and autologous harvest can lead to pain, motivating tissue engineering (TE) strategies. To date, most of the work in the field of cartilage TE has focused on producing functional tissues, but has ignored the integration of these tissues in vivo, limiting the function and durability of cartilage repair. In this proposal, we seek to engineer cartilage tissues that permit endogenous marrow cell entry in vivo, and subsequently control the fate of these cells to enhance mineralized matrix deposition between the construct and underlying bone, ultimately improving construct anchorage. To permit marrow cell infiltration into our cartilage constructs, a novel magneto-patterning method will be implemented in Aim 1 to mimic the cell distribution of native cartilage in the engineered constructs. This high-to-low cell distribution will lead to a cell and matrix-sparse region at the bottom of the constructs, whereby a secondary cell source—the endogenous marrow cells, can infiltrate. We will create cell gradients in hydrogels using the aforementioned magneto- patterning approach, which eliminates the need for cell-bound magnetic tags, and instead transiently increases the magnetic susceptibility of the hydrogel precursor solution to manipulate cell position under a magnetic field. The magneto-patterned constructs will be cultured in vitro, and we will assess the depth-dependent matrix accumulation in these cartilage constructs via histological, biochemical, and mechanical measures. To promote cartilaginous and mineralized matrix interdigitation, we will exploit the force required to press-fit an engineered construct into a cartilage defect to locally deliver bone-promoting agents (BPAs) at the osteochondral interface. For this, in Aim 2, magneto-responsive press-activated microcapsules containing BPAs—Triiodothyronine and β-glycerophosphate—will be patterned in the cell-sparse region of the engineered constructs. Within the cell laden constructs, the microcapsules will retain their contents throughout the pre-culture period, until they are press-activated upon in vivo implantation to ensure local `on demand' delivery of the BPAs. Finally, in Aim 3, the magneto-patterned constructs with opposing populations of mesenchymal stromal cells and press- activated microcapsules, will be implanted into a minipig trochlear cartilage defect model. Fluorochrome labeling, micro computed tomography, histology, and mechanical testing will elucidate the clinical efficacy of this cartilage repair treatment post-sacrifice. Overall, this work has the potential to advance this novel interface tissue engineering strategy, and specifically improve the state-of-the-art in cartilage repair.

摘要 关节软骨的愈合能力很差，因此，关节表面的任何损伤往往会进展到 骨关节炎(OA)，一种令人衰弱的关节疾病。对有症状的膝关节骨性关节炎患者，行全膝关节置换术 (TKR)是目前最常见的临床解决方案。然而，TKR是一种侵入性和终末期的手术， 为了恢复关节软骨的结构和功能，替代治疗方法的市场正在增长 理想的做法是预防OA，或者至少延迟TKR的时间。虽然天然组织移植物在体内可以很容易地按压配合， 它们的供应是有限的，自体收获会导致疼痛，从而激励组织工程(TE)策略。 到目前为止，软骨TE领域的大部分工作都集中在生产功能组织上，但已经 忽视了体内这些组织的整合，限制了软骨修复的功能和耐久性。在这 建议，我们寻求工程软骨组织，允许内源性骨髓细胞在体内进入，并且 随后控制这些细胞的命运，以增强矿化基质在构建物之间的沉积 和下面的骨，最终改善结构锚定。允许骨髓细胞渗入我们的 软骨结构，将在目标1中实施一种新的磁图案化方法来模拟细胞 天然软骨在工程化支架中的分布。这种从高到低的细胞分布将导致细胞 和结构底部的基质稀疏区，由此产生一个次级细胞来源--内源 骨髓细胞，可以渗透。我们将使用前面提到的磁电机在水凝胶中创建细胞梯度- 图案化方法，消除了对细胞结合的磁性标签的需要，取而代之的是瞬时增加 水凝胶前驱体溶液在磁场下操纵细胞位置的磁化率。 磁性图案构建物将在体外培养，我们将评估依赖于深度的基质 通过组织学、生化和机械措施在这些软骨结构中积累。为了促进 软骨和矿化的基质交错，我们将利用所需的力量，以压配合工程 构建成软骨缺损区，在骨软骨界面局部输送骨促进剂(BPAS)。 为此，在目标2中，含有BPAS-三碘甲状腺原氨酸和 β-甘油磷酸-将在工程构建的细胞稀疏区形成图案。在细胞内 负载结构，微囊将在整个预培养期间保留其内容物，直到它们 在体内植入时按下激活，以确保按需局部交付BPA。最后，在目标3中， 具有相反群体的间充质基质细胞的磁图案化结构和压力- 将活化后的微囊植入小型猪滑车软骨缺损区模型。氟铬 标记，微型计算机断层扫描，组织学和机械测试将阐明临床疗效 这种软骨修复治疗是牺牲后的。总体而言，这项工作有可能推进这一新颖的界面 组织工程策略，特别是改善最先进的软骨修复。