构建带内支撑组织工程睾丸假体的实验研究

EXPERIMENTAL STUDY ON TISSUE ENGINEERED TESTICULAR PROSTHESIS WITH INTERNAL SUPPORT

目的探讨以医用多孔高密度聚乙烯(high-density polyethylene,HDPE,商品名为Medpor)为内支撑,外裹聚羟基乙酸(polyglycolic acid,PGA)的支架,接种软骨细胞后,于裸鼠体内构建组织工程睾丸假体的可行性及特点。方法取新生雌性长枫杂交仔猪1只,取四肢大关节表面软骨,制备密度为5×107/ml的软骨细胞悬液。将其接种于长短半径分别为6mm和4mm的Medpor,外裹2mm PGA的支架,体外培养2周。取4周龄BALB/C裸鼠10只,随机分为两组(n=5)。实验组:采用制备的细胞-支架复合物植入裸鼠背部皮下;对照组:采用Medpor-PGA复合支架植入裸鼠皮下。8周后处死裸鼠取材,行大体观察、组织学及免疫组织化学观察。结果大体观察:实验组标本形状与体积未发生变化,色泽及弹性与正常软骨相似,软骨与Medpor接合紧密;对照组无软骨形成,外包裹纤维样组织。实验组:HE染色见软骨内存在大量成熟的软骨陷窝,无血管长入,部分PGA尚未降解完全;甲苯胺蓝染色示细胞外基质具有异染特性;藏红花染色示基质中大量蛋白聚糖沉积;型胶原免疫组织化学染色呈强阳性表达。对照组:Medpor被大量富含血管的纤维组织包裹。结论利用Medpor与PGA复合的支架,接种软骨细胞后,可于体内构建出具有预构睾丸形态且组织学良好的Medpor-软骨复合体。

Objective To investigate the feasibility and characteristic of tissue engineered testicular prosthesis with high-density polyethylene（HDPE,trade name： Medpor） and polyglycolic acid（PGA）. Methods The chondrocytes were isolated from the swine articular. The PGA scaffold was incorporated with medpor which semidiameters were 6 mm and 4 mm respectively. Then, the chondrocytes （5× 10^7/ml） were seeded onto Medpor-PGA scaffold and cultured for 2 weeks. The ten BALB/C mice were divided into two groups randomly（n=5）. In the experimental group, the cellscaffold construct was implanted into subcutaneous pockets on the back of nude mice. In the control group, the MedporPGA scaffold was implanted. The mice of two groups were sacrificed to harvest the newly formed cartilage prosthesis after 8 weeks. Macroscopy, histology and immunohistochemistry observations were made. Results The gross observation showed that on changes were in shape and at size, the color and elasticity were similar to that of normal cartilage and that the cartilage integrated with Medpor in the experimental group; no cartilage formed and fiberlike tissue was found in the control group. HE staining showed that many mature cartilage lacuna formed without blood vessel and some PGA did not degradated completely. Toluidine blue staining showed extracellular matrix had metachromia. Safranin O-fast green staining showed that many proteoglycan deposited and collagen type Ⅰ expression was strongly positive. In the control group, Medpor was encapsulated by fiber tissue with rich blood vessel. Conclusion The newly formed complex of Medpor-PGA and cells was very similar to testicle in gross view and to normal cartilage in histology. This pilot technique of creating testicular prosthesis by incorporating tissue-engineered cartilage with Medpor demonstrated success.