Tissue engineered bone reconstruction with modified PLGA/Type-I collagen compound scaffold / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To fabricate bone grafts by bone marrow stromal cell combined with modified PLGA/Type-I collagen compound scaffold using tissue engineering method.</p><p><b>METHODS</b>The modified PLGA/Type-I collagen compound scaffold was fabricated. The rabbit primary cultured osteoblasts were identified and seeded onto the modified compound scaffold for one week in vitro. The adhesion and growth of cells were observed with scanning electron microscope. The complex of cells and scaffold was implanted into the subcutaneous region of rabbits and new bone formation was evaluated.</p><p><b>RESULTS</b>The rabbit bone marrow stromal cells were induced and differentiated into osteoblasts. The adhesion and growth of osteoblasts in cluster were observed on the surface of scaffolds. New bone formation was observed at one month postoperatively and active osteoblasts were found on the surface of the newly formed bone in vivo.</p><p><b>CONCLUSION</b>The complex of PLGA and type-I collagen is an appropriate biodegradable scaffold and can be applied in bone tissue engineering.</p>

Effects of physical and chemical properties of polymeric nerve conduit on peripheral neuranagenesis / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate the effects of degradation time and permeability of polymeric conduits on nerve regeneration.</p><p><b>METHODS</b>After establishment of rat models with over 10 mm gap of sciatic nerve in right hind legs,four kinds of poly (ester, carbonate) nerve conduits was used to bridge the gaps and one group without conduit in gaps was used as control. The nerve regeneration and conduit degradation were examined both macroscopically and microscopically. The contraction of the muscle controlled by regenerated nerve was measured electrophysiologically at 4, 12 and 20 weeks after the operation.</p><p><b>RESULT</b>Biodegradation time of nerve conduits in vivo was as fellows: 12 weeks in group A,4 weeks in group B and group C,and 20 weeks in group D,respectively. The histological quality of regenerative sciatic neurofibra in group A was the best among all groups (Mean rank 53.17, 38.83, 26. 60, 49.17 and 20.23,P<0.005), but the inflammatory reaction in group A was only less than that in group D and more than that in the other groups (Mean rank 45.87, 36.27, 34. 83, 51.63 and 21.4,P=0.001). The responsive rates of tibialis anterior muscle for electric stimulation in group A, B, C and D were 93.33%, 60%,20% and 73. 33%, respectively (P<0.005).</p><p><b>CONCLUSION</b>Absorbable conduits with relatively good permeability and appropriate middle degrade time improve nerve regeneration and renovate function.</p>