Objective To study the feasibility of using mice marrow stromal stem cells(MSCs) as seed cells for tissue engineering cartilage to embed the seed cells in acellular cartilage matrix of human auricle. Methods Acellular cartilage matrix was made from human auricle cartilage. The MSCs were isolated from the nucleated cells fraction of mice marrow by centrifuge.The MSCs were embedded in acellular cartilage matrix. After 10 day’s combined culture, the specimens were observed with optical and electrical microscope.Results The MSCs could well proliferate in the acellular cartilage matrix. The cells were not well-distributed in acellular cartilage matrix. There were more cells in the peripheral part of the matrix than in the central part of the matrix. Most of the cells were in cartilaginous lacunae. There were 1 or 2 cells in every cartilaginous lacunae.Conclusion The MSCs can be used as seed cells of tissue engineering and can well proliferate in the acellular cartilage matrix and become tissue engineering cartilage.
ObjectiveTo explore the effects of several immunosuppressants on the proliferation of pheochromocytoma 12 (PC12) and L929 cells. 〖WTHZ〗Methods Different concentrations of methylprednisolone(10-3,10-4, 10-6and 10-8 mol/L), cyclosporin A(CsA,10-5 ,10-6 , 10 -7and 10-8 mol/L) and FK506 (10-6 ,10-7 , 10-8and 10-9mol/L)were administrated to the PC12 and L929 cells, while control group was given no drugs. At 24, 48 and 72 hours after administration, the cell proliferationwasmeasured with MTT methods respectively. The results were compared and analyzed statistically. Results High concentration methylprednisolone (10-3 mol/L) and low concentration CsA (10-8-10-7mol/L) could promote the proliferation of PC12 cells within 48 hours after administration, after that, the proliferation effects were no longer significant. There were no promotion effects for different concentrations of FK506. Under high concentrations, both CsA (10-6 -1×10-5 mol/L) and methylprednisolone (10-3 mol/L) could significantly inhibit the proliferationof L929 cells after 24 hours of administration. And high concentration (10-6mol/L) FK506 could promote the proliferation of L929 cells transitorily (only for 48 hours after administration). Conclusion 10-3 mol/L methylprednisolone and 10-8 -10-7mol/L CsA can promote the proliferation of PC12 cells for a short period of time. Both 10-3 mol/L methylprednisolone and 10-6-10-5mol/L CsA can significantly inhibit proliferation of L929.
Objective To know the possibility of nerveregeneration after artery sleeve anastomosis and end-to-side suture Methods Seventy-five SD rats were divided into 5 groups. First, the distal end ofsevered peroneal nerve was sutured end-to -side with artery sleeve anastomosis withnormal nerve tibial trunk in groups A, B, C and D. Second, the tibial epineurium at the suture site was not removed in group A; the epineurium at the suturesite was removed(windowing) in group B; the distal end of pre-injured peroneal nerve was sutured after 14 days and windowing was done in group C; and the neural growth factor was injected into artery sleeve and windowing was done in group D. While the distal end of severed peroneal nerve was sutured end to side directly with normal nerve tibial trunk and windowing was done in group E. The histological observation was made and the number of nerve fibers was recorded after 4, 8 and 12 weeks of operation.Results After 4 weeks, there existed the regeneration of axons and myeline sheaths in groups C, D, E, and no nerve fiber regeneration was seen in group A. After 8 weeks, the regenerating nerve fibers were significantly more in groups C, D and E than in group B and ingroup E than groups C and D(Plt;0.05). After 12 weeks, the regenerating nervefibers were significantly more in groups C，D and E than in group B(Plt;0.05).Conclusion End-to-side coaptation with artery sleeve anastomosis is a new valuable method in repair of peripheral nerve injuries.
Objective To explore the effective autologous bone marrow stem cell dosage for treatment of severe lower limb ischemia. Methods From December 2003 to December 2004, 22 cases of bilateral lower limb ischemia were treated with autologous bone morrow cell transplantation. All the patients were randomly divided into two groups according to ischemia degree. In group A(severe ischemia side), the amount of transplanted autologous bone marrow cells was more than 1×108, and ingroup B(mild ischemia side), the amount was less than 1×105. A series of subjective indexes, such as improvement of pain, cold sensation and numbness, and objective indexes, such as increase of ankle/brachial index (ABI) and transcutaneous oxygen pressure (TcPO2), angiography, amputation rate, and improvement of foot wound healing were used to evaluate the effect of autologous bone marrow stem cells implantation. Results The rates of pain relief were 90.0% in group A and 16.7% in group B (Plt;0.01); the rates of cold sensation relief were 90.5% in group A and 5.3% in group B（Plt;0.01）;the improvement of numbness was 62.5% in group A and 9.1% in group B（Plt;0.01）. Increase of ABI was 31.8% and 0 in groups A and B respectively（Plt;0.01） at 4 weeks after implantation. Increase of TcPO2was 94.4% and 11.1% in groups A and B respectively（Plt;0.01） at 4 weeks after implantation. Twelve cases of angiography showed rich new collateral vessels in 100% of the limbs in group A while no remarkable new collateral vessel in group B. The amputation rates were 4.5% in group A and 27.3% in group B（Plt;0.05） at 4 weeks after implantation. The rate of improvement of foot wound healing was 75% in group A and there was no changein wound healing in group B after 4 weeks of implantation. Conclusion The effectiveness of autologous bone marrow stem cell implantation depends on the number of implanted stem cells. Effectiveness is expected in most patients if the implanted stem cell is more than 1×108, whereas there would be little effect if the cell number is less than 1×105.
Objective To investigate the clinical feasibility of different types of the saphenous neuro-veno-fascial cutaneous flaps. Methods From June 1996 to October 2002, 18 cases of skin defects in the knee and the lower part of the limb were treated with proximally(4 cases) or distally(11 cases) based pedicles of saphenous neuro-venofascial cutaneous flap or crossleg flap (3 cases)according to the site of defects . The sizes of the flaps ranged from 4 cm×5 cm to 9 cm×20 cm. Results The flaps survived completely in 17 cases, distal 1/5 of the flap necrosed partially in 1 case because of vein drainage disturbance. The colour and texture of flaps were excellent, the appearance and function were satisfactory after a follow up of 6-24 months.Conclusion The saphenous neuro-veno-fascial cutaneous flap is an idea flap in repairing skin defects of the knee, the leg, the ankle and the foot because it is easy to be designed and dissected and it has reliable blood supply and preserved main artery. The relationship between the septal perforating branches of the tibial posteriorartery and survival size of flap need to be investigated further.
Objective To investigate the distribution of the perforating branches artery of distally-based flap of sural nerve nutrient vessels and its clinical application. Methods The origins and distribution of perforating branchesartery of distally-based flap were observed on specimens of 30 adult cadavericlow limbs by perfusing red gelatin to dissect the artery.Among the 36 cases, there were 21 males, 15 females. Their ages ranged from 6 to 66, 35.2 in average. The defect area was 3.5 cm×2.5 cm to 17.0 cm×11.0 cm. The flap taken ranged from 4 cm×3 cm to 18 cm×12 cm. Results The perforating branches artery of distally-based flap had 2 to 5 branches and originated from the heel lateral artery, the terminal perforating branches of peroneal artery(diameters were 0.6±0.2 mm and 0.8±0.2 mm, 1.0±1.3 cm and 2.8±1.0 cm to the level of cusp lateral malleolus cusp).The intermuscular septum perforating branches of peroneal artery had 0 to 3 branches. Their rate of presence was 96.7%,66.7% and 20.0% respectively(the diameters were 0.9±0.3, 1.0±0.2 and 0.8±0.4 mm, andtheir distances to the level of cusp of lateral malleolus were 5.3±2.1, 6.8±2.8 and 7.0±4.0 cm). Those perforating branches included fascia branches, cutaneous branches, nerve and vein nutrient branches. Those nutrient vessels formed longitudinal vessel chain of sural nerve shaft, vessel chain of vein side and vessel network of deep superficial fascia. The distally-based superficial sural artery island flap was used in 18 cases, all flaps survived. Conclusion Distally-based sural nerve, small saphenous vein, and nutrient vessels of fascia skin have the same origin. Rotation point of flap is 3.0 cm to the cusp of lateral malleolus, when the distally-based flap is pedicled with the terminal branch of peroneal artery.Rotation point of flap is close to the cusp of lateral malleolus, when the distally-based flap is pedicled with the heel lateral artery.
Objective To compare the efficiency of epidermis cell culture between big graft method and small strip method. Methods The big graft method was to cut the skin tissue reticularly from dermis layer while the epidermis were not cut off. After it was digested fully in trypsin, theepidermis was separated from skin and was used to culture epidermal cells. The small strip method was routine. The time to cut the skin and to separate the epidermis was recorded, and the number and quality of cells were compared between two methods. Results It took 8-10 minutes to cut an area of 5 cm2 skin into small strips and 1-2 minutes into big grafts. It took 10-15 minutes to separate the epidermis from the same area skin by small strip method and 2 minutes by big graft method. The cells showed better vigor and its number was more by big grafts than by small strips.The chance of fibroblast contamination was reduced obviously. Conclusion The big graft method is simpler than the small strip method and can culture more epidermis cells with less chance of fibroblast contamination.
Objective To observe whether Nogo-66 can inhibit the neurite outgrowth during the neuronal differentiation of the neural stem cells (NSCs) and remove such an inhibitory effect by the small interfering RNA (siRNA) mediated knockdown of the Nogo66 receptor (NgR). Methods NSCs derived from the rat spinal cord were collected, and were cultured by the suspension culture in vitro. NSCs were transfected by siRNA to knock downtheexpression of NgR. Immunofluorescence and Western blot were used to assess the knockdown efficiency. NSCs were divided into four groups and differentiated in the medium containing 10% FBS. In the control group, no intervention was applied to NSCs; in the Nogo-P4 group, NSCs were differentiated in the presence of Nogo-P4 (active segment of Nogo-66); in the siRNA group, NSCs were transfected by siRNA to knock down NgR before they were differentiated; in the siRNA and Nogo-P4 group, NSCs were transfected by siRNA to knock down NgR before they were differentiated in presence of Nogo-P4. The differentiated neurons were labeled by immunofluorescence, and the neurite length was measured by the ImagePro Plus 5.0 software. The differentiation of the neurite length was compared in each group. Results The suspension-cultured cells became the nerve bulb, which could positively expresses Nestin by immunofluorescence. At 1 week of the differentiation in the medium containing 10% FBS, the positively-labeled neuron specific enolase, the glial fibrillary acidic protein, and the myelin basic protein were observed. Both immunofluorescence and Western blot approved that the expression of NgR was knocked down by transfection of siRNA at 24 hours after the transfection. The knockdown efficiency was 90.35%±3.10%. The neurite length was 97.80±6.97 μm, 80.54±6.75 μm,92.14±7.27 μm, and 94.01±8.37 μm in the control group, the Nogo-P4 group, the siRNA group, and the siRNA and Nogo-P4 group, respectively. The Nogo-P4 group had a significant difference when compared with the otherthree groups (Plt;0.01), and the other three groups had no significant difference when compared with each other（Pgt;0.05）. ConclusionNogo-66 can inhibit the neuronal neurite outgrowth during the differentiation ofNSCs. Such an inhibitory effect can be removed by the siRNA mediated knockdown of NgR.
Objective To study degradation of the antigen-extracted meniscus in PBS solution with no enzyme or with different enzymes. Methods Four types of enzymes (collagenase, hyaluronidase, trypsin, papain) were used to enzymolyze the antigen-extracted meniscus and the fresh meniscus for 3, 7, 15 and 30 days (37℃). The antigenextracted meniscus and the fresh meniscus were immersed in PBS solution (37℃) for 30 days. Weight loss measurement, UV spectrophotometry, and scanning electron microscopy (SEM) were used to characterize the degraded materials. Results The two types of the materials were remarkably digested under the enzymes, especially under trypsin. The degradation curves showed that the antigen-extracted meniscus was enzymolyzed less than the fresh meniscus. The degradation products were grouped as amino, peptide, and polyose by the analysis. Both of the materials could hardly behydrolyzed in PBS solution without the enzymes. The four different enzymes had different surface morphologies under the examination of SEM. Conclusion The antigen-extracted meniscus is enzymolyzed more slowly than the fresh meniscus in vitro, and the result can be used as a guideline to the further research.
Objective To investigate the effect of homograft of marrow mesenchymal stem cells (MSCs) seeded onto poly-L-lactic acid (PLLA)/gelatin on repair of articular cartilage defects. Methods The MSCs derived from36 Qingzilan rabbits, aging 4 to 6 months and weighed 2.5-3.5 kg were cultured in vitroand seeded onto PLLA/gelatin. The MSCs/ PLLA/gelatin composite was cultured and transplanted into full thickness defects on intercondylar fossa. Thirty-six healthy Qingzilan rabbits were made models of cartilage defects in the intercondylar fossa. These rabbits were divided into 3 groups according to the repair materials with 12 in each group: group A, MSCs and PLLA/gelatin complex(MSCs/ PLLA/gelatin); group B, only PLLA/gelatin; and group C, nothing. At 4,8 and 12 weeks after operation, the gross, histological and immunohistochemical observations were made, and grading scales were evaluated. Results At 12 weeks after transplantation, defect was repaired and the structures of the cartilage surface and normal cartilage was in integrity. The defects in group A were repaired by the hylinelike tissue and defects in groups B and C were repaired by the fibrous tissues. Immunohistochemical staining showed that cells in the zones of repaired tissues were larger in size, arranged columnedly, riched in collagen Ⅱ matrix and integrated satisfactorily with native adjacent cartilages and subchondral bones in group A at 12 weeks postoperatively. In gross score, group A(2.75±0.89) was significantly better than group B (4.88±1.25) and group C (7.38±1.18) 12 weeks afteroperation, showing significant differences (P＜0.05); in histological score, group A (3.88±1.36) was better than group B (8.38±1.06) and group C (13.13±1.96), and group B was better than group C, showing significant differences (P＜0.05). Conclusion Transplantation of mesenchymal stem cells seeded onto PLLA/gelatin is a promising way for the treatment of cartilage defects.