Mayo Clinic Alix School of Medicine, Rochester, Minnesota, USA.
Mayo Clinic Graduate School of Biomedical Sciences, Rochester, Minnesota, USA.
J Orthop Res. 2024 Sep;42(9):1974-1983. doi: 10.1002/jor.25839. Epub 2024 Mar 24.
Segmental bone defects, often clinically treated with nondegradable poly(methylmethacrylate) (PMMA) in multistage surgeries, present a significant clinical challenge. Our study investigated the efficacy of 3D printed biodegradable polycaprolactone fumarate (PCLF)/PCL spacers in a one-stage surgical intervention for these defects, focusing on early bone regeneration influenced by spacer porosities. We compared nonporous PCLF/PCL and PMMA spacers, conventionally molded into cylinders, with porous PCLF/PCL spacers, 3D printed to structurally mimic segmental defects in rat femurs for a 4-week implantation study. Histological analysis, including tissue staining and immunohistochemistry with bone-specific antibodies, was conducted for histomorphometry evaluation. The PCLF/PCL spacers demonstrated compressive properties within 6 ± 0.5 MPa (strength) and 140 ± 15 MPa (modulus). Both porous PCLF/PCL and Nonporous PMMA formed collagen-rich membranes (PCLF/PCL: 92% ± 1.3%, PMMA: 86% ± 1.5%) similar to those induced in the Masquelet technique, indicating PCLF/PCL's potential for one-stage healing. Immunohistochemistry confirmed biomarkers for tissue regeneration, underscoring PCLF/PCL's regenerative capabilities. This research highlights PCLF/PCL scaffolds' ability to induce membrane formation in critical-sized segmental bone defects, supporting their use in one-stage surgery. Both solid and porous PCLF/PCL spacers showed adequate compressive properties, with the porous variants exhibiting BMP-2 expression and woven bone formation, akin to clinical standard PMMA. Notably, the early ossification of the membrane into the pores of porous scaffolds suggests potential for bone interlocking and regeneration, potentially eliminating the need for a second surgery required for PMMA spacers. The biocompatibility and biodegradability of PCLF/PCL make them promising alternatives for treating critical bone defects, especially in vulnerable patient groups.
骨段缺损临床上常采用多阶段手术用不可降解聚甲基丙烯酸甲酯（PMMA）治疗，这是一个重大的临床挑战。我们的研究调查了 3D 打印可生物降解聚己内酯富马酸酯（PCLF）/聚己内酯（PCL）间隔物在这些缺陷的一次性手术干预中的效果，重点关注间隔物孔隙率对早期骨再生的影响。我们比较了非多孔 PCLF/PCL 和 PMMA 间隔物，这些间隔物常规模压成圆柱体，与多孔 PCLF/PCL 间隔物进行比较，后者通过 3D 打印结构模拟大鼠股骨的骨段缺损，进行为期 4 周的植入研究。进行了组织学分析，包括组织染色和骨特异性抗体的免疫组织化学，用于组织形态计量评估。PCLF/PCL 间隔物表现出 6 ± 0.5 MPa（强度）和 140 ± 15 MPa（模量）范围内的压缩性能。多孔 PCLF/PCL 和非多孔 PMMA 都形成了富含胶原蛋白的膜（PCLF/PCL：92%±1.3%，PMMA：86%±1.5%），类似于 Masquelet 技术诱导的膜，表明 PCLF/PCL 具有一次性愈合的潜力。免疫组织化学证实了组织再生的生物标志物，强调了 PCLF/PCL 的再生能力。这项研究强调了 PCLF/PCL 支架在临界尺寸骨段缺损中诱导膜形成的能力，支持其在一次性手术中的应用。实心和多孔 PCLF/PCL 间隔物均表现出足够的压缩性能，多孔变体表现出 BMP-2 表达和编织骨形成，类似于临床标准的 PMMA。值得注意的是，多孔支架中的膜早期骨化到孔中，表明存在骨联锁和再生的潜力，可能无需进行 PMMA 间隔物所需的第二次手术。PCLF/PCL 的生物相容性和可生物降解性使其成为治疗临界骨缺损的有前途的替代品，特别是在脆弱的患者群体中。
