Herrera David, Lodoso-Torrecilla Irene, Ginebra Maria-Pau, Rappe Katrin, Franch Jordi
Bone Regeneration Research Group, Department of Animal Medicine and Surgery, Veterinary Faculty, Autonomous University of Barcelona, Cerdanyola del Vallès, Spain.
Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Engineering, Universitat Politècnica de Catalunya, Barcelona, Spain.
Front Vet Sci. 2023 Jun 2;10:1149413. doi: 10.3389/fvets.2023.1149413. eCollection 2023.
Engineered bone graft substitutes are a promising alternative and supplement to autologous bone grafts as treatments for bone healing impairment. Advances in human medicine extend an invitation to pursue these biomimetic strategies in animal patients, substantiated by the theory that specialized scaffolds, multipotent cells, and biological cues may be combined into a bioactive implant intended for the enhancement of tissue regeneration.
This proof-of-concept study was designed to evaluate and validate the feasibility of beta-tricalcium phosphate foam scaffolds seeded with canine mesenchymal stem cells derived from adipose tissue. Cell-inoculated samples and sham controls were cultured statically for 72 hours in complete growth medium to evaluate seeding capacity, while a subset of loaded scaffolds was further induced with osteogenic culture medium for 21 days. Produced implants were characterized and validated with a combination of immunofluorescence and reflection confocal microscopy, scanning electron microscopy, and polymerase chain reaction to confirm osteogenic differentiation in tridimensional-induced samples.
After 72 hours of culture, all inoculated scaffolds presented widespread yet heterogeneous surface seeding, distinctively congregating stem cells around pore openings. Furthermore, at 21 days of osteogenic culture conditions, robust osteoblastic differentiation of the seeded cells was confirmed by the change of cell morphology and evident deposition of extra-cellular matrix, accompanied by mineralization and scaffold remodeling; furthermore, all induced cell-loaded implants lost specific stemness immunophenotype expression and simultaneously upregulated genomic expression of osteogenic genes Osterix and Ostecalcin.
β-TCP bio-ceramic foam scaffolds proved to be suitable carriers and hosts of canine adipose-derived MSCs, promoting not only surface attachment and proliferation, but also demonstrating strong osteogenic potential. Although this research provides satisfactory validation for the conceptualization and feasibility of a canine bio-active bone implant, further testing such as patient safety, large-scale reproducibility, and quality assessment are needed for regulatory compliance in future commercial clinical applications.
工程化骨移植替代物作为治疗骨愈合障碍的方法，是自体骨移植的一种有前景的替代和补充。医学的进步促使人们在动物患者中探索这些仿生策略，其理论依据是，特殊的支架、多能细胞和生物信号可以组合成一种生物活性植入物，用于促进组织再生。
本概念验证研究旨在评估和验证接种犬脂肪组织来源的间充质干细胞的β-磷酸三钙泡沫支架的可行性。将接种细胞的样本和假手术对照组在完全生长培养基中静态培养72小时，以评估接种能力，而一部分加载支架的样本进一步用成骨培养基诱导21天。通过免疫荧光和反射共聚焦显微镜、扫描电子显微镜和聚合酶链反应相结合的方法对制备的植入物进行表征和验证，以确认三维诱导样本中的成骨分化。
培养72小时后，所有接种的支架均呈现广泛但不均匀的表面接种，干细胞明显聚集在孔口周围。此外，在成骨培养条件下培养21天时，接种细胞的形态变化和细胞外基质的明显沉积证实了接种细胞的强烈成骨分化，同时伴有矿化和支架重塑；此外，所有诱导的负载细胞植入物均失去了特定的干性免疫表型表达，同时上调了成骨基因Osterix和骨钙素的基因组表达。
β-TCP生物陶瓷泡沫支架被证明是犬脂肪来源间充质干细胞的合适载体和宿主，不仅促进表面附着和增殖，而且具有很强的成骨潜力。尽管本研究为犬生物活性骨植入物的概念化和可行性提供了令人满意的验证，但未来商业临床应用中，为符合监管要求，还需要进行进一步测试，如患者安全性、大规模可重复性和质量评估。
