Objective To investigate the feasibility and characteristic of tissue engineered testicular prosthesis with highdensity 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 6mmand 4mm 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 cell-scaffold construct was implanted into subcutaneous pockets on the back of nude mice. In the control group, the Medpor-PGA 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 Ⅱ expression was bly 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.
OBJECTIVE: To investigate the feasibility to seed vascular endothelial cell(VEC) and vascular smooth muscle cell (VSMC) into tissue engineered blood vessel scaffold material. METHODS: 1. A blood vessel scaffold with a combined polymer was designed, which mainly is composed of rabbit VSMC and collagen with reinforcement by a non-spinning fabric mesh made of polyglycolic acid (PGA). 2. VEC were isolated from rabbit thoracic aorta by enzyme digestion methods and subcultured and purified. Then the cells were seeded into scaffold material. The morphological characteristics of tissue engineered blood vessel was analyzed by scanning electron microscopy. RESULTS: VEC could adhere well to the inner surface of the tissue engineered tubular scaffold material with a tenacity and elasticity. VSMC could sustain bioactivity of cell. CONCLUSION: Non-spinning PGA porous biodegradable materials coated with collagen is benefit for cells to adhere and grow. It will lay a foundation of a laminated structure of tissue engineered blood vessel.
OBJECTIVE: To explore the distribution and effect of endogenic bone morphogenetic protein (BMP) in repairing rabbit skull with tissue engineered bone. METHODS: The autologous osteoblast-like cells were instantly implanted onto polyglycolic acid (PGA) matrix coated with collagen. The rabbit skull defect models were established by resection of bilateral 1.5 cm x 1.0 cm full-thickness parietal bone in 18 New Zealand rabbits, which were randomly divided into two groups. In one group, the composite of osteoblast- like cells and PGA matrix were grafted into the defect on one side of the skull as experimental group I, leaving the same defect area on the other side as control group without any graft implanted. In the other group, simply PGA was done in the same way as experimental group II. The tissue samples were harvested at 3, 8 and 14 days postoperatively and examined by histological and immunohistochemistry methods. The concentrations of BMP in different regions of the samples were measured using computer image analysis system. RESULTS: After 3 days of operation, the BMP positive cells were found in the matrix of experimental group I. At 8 days postoperatively, the formation of new bone on experimental group I was prior to that of experimental group II and control group. On the 14th day, bone trabecula was formed on the experimental group I, but there was only fibrous tissue on control group. The concentration of BMP on the experimental group I and II were higher than that of corresponding region on control side. CONCLUSION: The osteoblast-like cells instantly implanted onto PGA matrix can synthesize and secrete BMP. It may be one of the reasons of tissue engineered bone inducing new bone regeneration that localizing endogenic BMP in bone defect area, increasing the concentration of endogenic BMP and improving its distribution by tissue engineering technique.
OBJECTIVE: To explore the feasibility of reconstructing tissue engineered vessel in vitro. METHODS: Bovine endothelial cells were isolated from calf thoracic aorta by enzyme digestion methods and subcultured and purified. The endothelial cells of the 3rd to 7th passages were seeded into the inner surface of tubular scaffold material by polyglycolic acid(PGA) coated with cross-linked collagen, and cultured in vitro for 10 days using dynamic rotation culture technique. Scanning electron microscopy was used to analyse the morphological characteristics, and prostacyclin released by endothelial cells was measured by radioimmunoassay of 6-keto-prostaglandin F1 alpha. RESULTS: The VIII factor staining of cultured endothelial cells was positive. The endothelial cells adhered well on the inner surface of tubular scaffold material with confluent monolayer covering(91.2 +/- 1.5)%. The endothelialized model released prostacyclin at a rate of (4.6 +/- 0.5) micrograms/cm2.min. There was significant difference to control group (P lt; 0.05). CONCLUSION: The PGA coating with collagen is an ideal scaffold for endothelial cells, the coverage rate is increased through dynamic rotation culture technique. It will lay a good foundation for architecture of a laminated structure of tissue engineered vessel.