Weng Y, Cao Y, Silva C A, Vacanti M P, Vacanti C A
Center for Tissue Engineering, Department of Anesthesiology, University of Massachsetts Medical School, Worchester, USA.
J Oral Maxillofac Surg. 2001 Feb;59(2):185-90. doi: 10.1053/joms.2001.20491.
This study evaluated the feasibility of creating a tissue-engineered adult human mandible condyle composite of bone and cartilage.
A polymer template composed of polyglycolic acid (PGA) and polylactic acid (PIA), and formed in the shape of the human mandible condyle, was seeded with osteoblasts isolated from a bovine periosteum suspended in calcium alginate. Chondrocytes isolated from the same calf suspended in 30% pluronic were then "painted" onto the articular surface of the scaffold, and it was then implanted into subcutaneous pockets on the dorsum of athymic mice. Animals were divided into 3 groups: group I (n = 6) received a PGA/PLA scaffold saturated with hydrogels not containing cells; group II (n = 6) received scaffolds seeded with both cell types suspended in saline rather than hydrogels; and group III (n = 6) received scaffolds seeded with both cell types suspended in hydrogel composites. Constructs were harvested after 12 weeks and evaluated grossly and microscopically by using histologic stains.
In group I, the constructs formed a small mass without evidence of new bone or cartilage. In group II, the constructs were small and irregular. Microscopically they contained scattered islands of bone and cartilage. All specimens in group III retained their original condylar shape and were quite firm. Microscopic evaluation indicated trabecular bone interfacing with hyaline cartilage on the articulating surface.
These findings show that the composites of bone and cartilage can be engineered to serve as condylar substitutes. The interdigitation of bone and cartilage at their interface is similar to the normal interface of these composite tissues seen in articulating joints.
本研究评估构建组织工程化成人人类下颌骨髁突骨与软骨复合材料的可行性。
将由聚乙醇酸（PGA）和聚乳酸（PIA）组成、呈人类下颌骨髁突形状的聚合物模板接种从牛骨膜分离并悬浮于海藻酸钙中的成骨细胞。然后将从同一只小牛分离并悬浮于30%普朗尼克中的软骨细胞“涂抹”到支架的关节表面，接着将其植入无胸腺小鼠背部的皮下囊袋中。动物分为3组：第I组（n = 6）接受用不含细胞的水凝胶饱和的PGA/PLA支架；第II组（n = 6）接受接种两种悬浮于生理盐水而非水凝胶中的细胞类型的支架；第III组（n = 6）接受接种两种悬浮于水凝胶复合材料中的细胞类型的支架。12周后取出构建体，通过组织学染色进行大体和显微镜评估。
在第I组中，构建体形成一个小肿块，无新骨或软骨形成的证据。在第II组中，构建体小且不规则。显微镜下可见它们含有散在的骨和软骨岛。第III组的所有标本均保持其原始髁突形状且相当坚实。显微镜评估显示小梁骨与关节表面的透明软骨相连。
这些发现表明，骨与软骨复合材料可经工程化处理用作髁突替代物。骨与软骨在其界面处的相互交错类似于在关节中所见的这些复合组织的正常界面。
