Repair of articular cartilage defects in minipigs by microfracture surgery and BMSCs transplantation

Objective：To investigate the feasibility of minimal invasive repair of cartilage defect by arthroscope-aided microfracture surgery and autologous transplantation of mesenchymal stem cells. Methods： Bone marrow of minipigs was taken out and the bone marrow derived mesenchymal stem cells （BMSCs） were isolated and cultured to passage 3. Then 6 minipigs were randomly divided into 2 groups with 6 knees in each group. After the articular cartilage defect was induced in each knee, the left defect received microfracture surgery and was injected with 2.5 ml BMSCs cells at a concentration of 3×107 cells/ml into the articular cavity; while right knee got single microfracture or served as blank control group. The animals were killed at 8 or 16 weeks, and the repair tissue was histologically and immunohistochemically examined for the presence of type Ⅱ collagen and glycosaminoglycans （GAGs） at 8 and 16 weeks. Results： Eight weeks after the surgery, the overlying articular surface of the cartilage defect showed normal color and integrated to adjacent cartilage. And 16 weeks after surgery, hyaline cartilage was observed at the repairing tissues and immunostaining indicated the diffuse presence of this type Ⅱ collagen and GAGs throughout the repair cartilage in the treated defects. Single microfracture group had the repairing of fibrocartilage, while during the treatment, the defects of blank group were covered with fewer fiber tissues, and no blood capillary growth or any immunological rejection was observed. Conclusion： Microfracture technique and BMSCs transplantation to repair cartilage defect is characterized with minimal invasion and easy operation, and it will greatly promote the regeneration repair of articular cartilage defect.     

STUDY OF CULTURING CARDIOVASCULAR TISSUE IN VITRO

Objective To evaluate the feasibility of utilizing vascular cells combined with folded and framed culture model to develop completely autologous human tissue without using any scaffold material under the principles of Tissue Engineering. Methods Human vascular cells cultured from ascending aorta (group A ) and saphenous vein (group B) were seeded into 15cm-dishes (each n = 12 ) and cultured to form cell sheets over a period of four weeks with Dulbecco‘s modified Eagle‘s medium supplemented with lmmol/L L-ascorbic acid 2-phosphate. Thereafter, cell sheets (6 samples of each group) were four-layer folded and cultured in a newly developed frame device for additional four weeks. Controls remained under standard culture conditions. Tissue development was evaluated by light and electron microscopy, biochemical assays. Results The formation of multi-layered cell sheets and production of extracellular matrix were observed in each group after the initial four weeks. Analysis of the folded and framed neo-tissue revealed a solid structure with increased matrix formation and tissue organization compared to the control groups after additional four weeks. DNA assay indicated significantly lower cell proliferation infolded and framed cell sheets than in that of unframed counterparts. Yet hydroxyproline assay demonstrated significant increase of collagen content in the framed aortic and venous derived tissues, which contained 82% and 42% that of human pericardium. Conclusion It is feasible to obtain completely autologous human cardiovascular tissue with the alternative new approach. Numerous issues including improvement of mechanical strength of neo-tissue remain to be investingated.     

A surface-modified biodegradable urethral scaffold seeded with urethral epithelial cells

Background  Efficient cell adhesion and proliferation is a central issue in cell-based tissue engineering, which offers great promise for repair of urethral defects or strictures. This study evaluated the adhesion and growth of rabbit uroepithelium on a surface-modified three-dimensional poly-L-lactic acid (PLLA) scaffold.

Methods  Urethral mucosa were harvested from male New Zealand rabbits and the urothelium were dissociated and then cultured. Immunocytochemistry on cultured uroepithelium for pancytokeratin and uroplakin II and TE-7 confirmed pure populations. After in vitro proliferation, cells were seeded onto a surface-modified urethral scaffold with non-knitted filaments. The morphology and viability of the cells were examined by immunohistochemical and fluorescence staining. Inverted and scanning microscopes were used to document cell growth and adhesion.

Results  Three to five days after primary culture, the uroepithelial cells gradually became confluent, assuming a cobblestone pattern. The filaments of the urethral scaffold had excellent biocompatibility and allowed growth of the uroepithelium, without affecting viability. The uroepithelial cells adhered to and grew well on the scaffold. After 3–7 days, the cells grew vigorously and meshes of the scaffold were full of uroepitheliums.

Conclusions  The surface-modified urethral scaffold with non-knitted filaments allows the growth of uroepithelium and can serve as a carrier for the tissue engineering of urethra.

     

Cartilage Regeneration by Delayed Engraftment of an Injectable Fibrin Clue/Hyaluronate Hybrid Scaffold Mixed with Mesenchymal Stem Cells

Objective To evaluate the effect of an injectable hybrid fibrin/hyaluronate scaffold in cartilage defect by delayed engraftment. Methods A cartilage defect model was established by drilling deep into the femoropatellar grooves of rabbits with a diameter of about 4.5 millimeter. The defects were not treated until 42 days after drilling. An injectable scaffold was developed by combining fibrin glue and hyaluronate to mimic the structure of cartilage matrix. Autologous mesenchymal stem cells （MSCs） were induced to chondrocytes in vitro, and mixed with the injectable scaffold and then implanted into the cartilage defects. 30 rabbits （both sides of knees, n=60） were used in this study and they were randomly divided into three groups： group A （n=20） were treated by implanting the injectable scaffolds mixed with MSCs; group B （n=20） were treated by drilling the bottom of defect to reach medullary cavity; group C （n=20） were blank control. The regenerated cartilages were evaluated by both macroscopic observation and histological scores at 12 and 24 weeks after treatment. Results In group A, most cartilage defects were well repaired; the histological scores were significantly higher compared with group B and C （p〈0.01）. The reconstitution of the cartilage surfaces was also better in group A （p〈0.001）. There were no significant difference between 12 and 24 weeks in group A （p=0.917）. Conclusion this study revealed that by using autologous mesenchymal stem cells and an injectable fibrin clue/hyaluronate hybrid scaffold, defects of articular cartilage can be well repaired in a delayed manner, which has considerable relevance to the clinical practice.     

Repair of Rabbit Femoral Defects with a Novel BMP2-derived Oligopeptide P24

In this study, the bioactivity of a novel BMP2-derived oligopeptide P24 was investigated by using the model of rabbit femoral defect after loaded in the biodegradable poly （lactic acid / glycolic acid / asparagic acid-co-polyethylene glycol） （PLGA-[ASP-PEG]）. A 1.5-cm unilateral segmental bone defect was created in the left femoral diaphysis in each of the 30 new zealand white rabbits. The defects of 18 legs filled with BMP2-derived peptide P24 combined with PLGA-[ASP-PEG] scaffold serves as the experimental group, and the defects in the rest 12 rabbits filled with （PLGA-[ASP-PEG]） without P24 as control group. The bone-repairing capability in the target region of the two group was grossly, radiologically, histopathologically and biomechanically evaluated 4, 8 and 12 weeks after the operation. Our results showed that in each group, primary healing of incision was achieved in the two groups. Radiographically, in experimental group, defects were filled with induced callus within 8 weeks, and a cortical bone-like structure was observed in some animals at the 12th week. According to the standardized stage of bone defect repair, 9 （64.28%） achieved grade-4 healing. In contrast, little bone formation was seen in the defects even 12 weeks after the operation, and 5 （62.50%） had grade 0 healing in this group. Histologically, tissue engineering material was mostly absorbed and cartilage was found around implants in the experimental group at the 4th week; 8 weeks after operation, the engineering material was completely absorbed, and formation of woven bone was observed and typical trabecular bone structure could be seen. In control group, 8 weeks after operation, the defect was filled with fibrous tissues, and no bone-like structure was observed. Statistical analysis showed very significant difference in biomechanical indicators between the two groups （P〈0.05）. It is concluded that new oligopeptide P24 can induce excellent bone regeneration and promote bone repair.     

Effects of granulocyte-macrophage colony stimulating factor on the repair of vessel intima damaged by balloon

Background The dysfunction of vascular endothelial cells plays a key role in starting and facilitating restenosis. The acceleration of intima repair and the recovery of endothelial function would reduce the restenosis rate. This study was undertaken to assess the effect of granulocyte-macrophage colony stimulating factor (GM-CSF) on the repair of damaged iliac arteries.Methods Twenty-four male New Zealand white rabbits undergoing primary iliac artery deendothelialization were randomly divided into two groups (GM-CSF group and control group). The GM-CSF group received a subcutaneous injection of GM-CSF ［10 μg·kg（-1）·d（-1）］, and the control group was given a subcutaneous injection of equivalent saline. The iliac arteries of all animals were damaged by balloon after 7 days. The levels of nitric oxide (NO) were detected before, 1 week, 2 weeks and 4 weeks after angioplasty. The repair and hyperplasia of the intima were observed microscopically and the indices of stenosis were evaluated by computerized planimetry after 4 weeks of angioplasty.Results The NO levels of the GM-CSF group were higher than those of the control group 2 weeks and 4 weeks after angioplasty ［(91.92±11.57) μmol/L vs. (81.67±12.18) μmol/L; (97.67±10.13) μmol/L vs. (83.16±12.64) μmol/L］. Four weeks after balloon damage, histological examination showed that neointima formation, vascular smooth muscle cells and fibrous tissue of the GM-CSF group were less than those of the control group. The endothelium of the GM-CSF group was more integrated, and stenosis of lumen was slighter than that of the control group. Morphometry showed the lumen area of the GM-CSF group was larger than that of the control group ［(1.27±0.31) mm2 vs. (0.92±0.24) mm2］, the neointimal area and percent of intima hyperplasia were significantly smaller than those of the control group ［(0.85±0.34) mm2 vs. (1.18±0.38) mm2; (40±7)% vs. (55±6)%］.Conclusion GM-CSF could facilitate the repair of the intima, reduce neointima formation, better the function of the endothelium, and decrease the rate of restenosis.     

Combined Transplantation of Neural Stem Cells and Olfactory Ensheathing Cells Improves the Motor Function of Rats with Intracerebral Hemorrhage

Objective To investigate the effects of combined transplantation of neural stem cells （NSC） and olfactory ensheathing cells （OEC） on the motor function of rats with intracerebral hemorrhage. Methods In three days after a rat model of caudate nucleus hemorrhage was established, NSCs and OEC, NSC, OEC （from embryos of Wistar rats） or normal saline were injected into bematomas of rats in combined transplantation group, NSC group, OEC group, and control group, respectively. Damage of neural function was scored before and in 3, 7, 14, 30 days after operation. Tissue after transplantation was observed by immunocytochemistry staining. Results The scores for the NSC, OEC and co-transplantation groups were significantly lower in 14 and 30 days after operation than in 3 days after operation （P〈0.05）. The scores for the NSC and OEC groups were significantly lower than those for the control group only in 30 days after operation （P〈0.05）, while the difference for the NSC-OEC group was significant in 14 days after operation （P〈0.05）. Immunocytochemistry staining revealed that the transplanted OEC and NSC could survive, migrate and differentiate into neurons, astrocytes, and oligodendrocytes. The number of neural precursor cells was greater in the NSC and combined transplantation groups than in the control group. The number of neurons differentiated from NSC was significantly greater in the co-transplantation group than in the NSC group. Conclusion Co-transplantation of NSC and OEC can promote the repair of injured tissue and improve the motor fimction of rats with intracerebral hemorrhage.     

Immediate or delayed repair of pelvic fracture urethral disruption defects in young boys: twenty years of comparative experience

Background The treatment of the patient with pelvic fracture urethral disruption defects （PFUDD） remains controversial especially in pediatric urology. Debate continues in regarding the advisability of immediate repair versus delayed repair. The aim of this study was to analyze our experience in the outcomes of immediate and delayed repair of pelvic fracture urethral distraction defects in young boys. Methods We retrospectively reviewed the records of 210 boys with posterior urethral disruption after pelvic injury between 1992 and 2012. Exclude partial urethral injury, a total of 177 cases acquired follow-up. All patients were evaluated by plain radiography, ultrasonography, or a computed tomography scan to assess the conditions of the upper urinary tract and to exclude other severe injuries. Data on 35 patients who underwent immediate repair were compared to those on 142 treated with delayed urethroplasty. After the diagnosis of a complete urethral injury, the immediate repair group underwent urethroplasty via the perineal approach if the patient＇s condition was stable, and serious complications were treated. The delayed repair group patients with the delayed urethroplasty average 6 months after injury. All patients were evaluated postoperatively for urethral strictures, incontinence and impotence. The patients were assessed by uroflowmetry and renal ultrasonography with evaluation of the postmictional residue every 3 months during the first year of follow-up. We assessed incontinence and erectile function by questioning the parents or the children themselves. Statistical analysis with the chi-square test was performed using SPSS software. Results One hundred and seventy-seven patients were followed up with an average 58 months （range 6 to 192 months）. Strictures developed in 3 （9%） patients in immediate repair group; two recluired direct visual internal urethrotomy （DVIU）, the other patient required dilatation. Strictures developed in 11.9% of the delayed repair group, 17 patients need visual     

Urethral stricture of battle wound repair with biodegradable stents

Objective To develop an experimental model of warinjured urethral stricture and evaluate its reconstruction using a biodegradable stents in the rabbits.Methods Twenty-eight New Zealand male rabbits were randomly divided into study group （20） and control group （8）.In study group,bulbar urethra of the rabbits was bombed with a special instrument to develop the model of war-injured urethral stricture.     

Experimental replacement of thoracic esophageal segment with a biomaterial artificial esophagus in dogs

Objective：To implant 80 mm-long artificial esophagi constructed of biomaterial in dogs, observe the perioperative survival rates and the incidence of postoperative complications, and study the mechanisms of postoperative healing. Methods： Specimens of the implanted esophagus, the ＂neo-esophagi＂, were taken for histopathologic study 1, 3, 6, 12, 24 months after operation. Results： The incidence of anastomotic leakage after the artificial esophagus implantation was 3.33%. The perioperative survival rate was 96.67%. The incidence of postoperative stenosis in the ＂neo-esophagi＂ was 81.48%; the stenoses were treated by expanding with esophagoscopy and implanting a stent. Epithelization of the mucosa in the ＂neo-esophagi＂ was completed in 3 to 6 months after surgery Structures such as submucosal muscle layers, mucous glands, nerve fibers, capillaries, etc. were regenerated after 12 months, and then reconstruction of the fibrous connective tissue layer was completed. Conclusion： Implanting a biomaterial artificial esophagus accomplishes safe reconstruction of defects in the esophagus. Advanced cellular structure of ＂neo-esophagus＂ can be regenerated after 1 year. Postoperative stenosis, which is related to hyperplasia and retraction of scar tissue, is still the most common complications which limiting the clinical application of the artificial esophagus.     

去细胞尿道修复大鼠尿道缺损

目的 探讨化学去细胞尿道修复尿道缺损的效果.方法 取SD大鼠尿道20根,每段长1cm,采用化学去细胞法处理大鼠尿道的细胞成分,保留细胞外基质,制备去细胞尿道.将10只Wistar大鼠尿道制成1cm整段缺损模型,用SD大鼠去细胞同种异体尿道移植修复大鼠尿道的整段缺损.术后3周进行大鼠尿动力学检测及VG染色.另取10只Wistar大鼠异体移植及10只Wistar大鼠自体移植作对照.结果 与对照组相比,处理组术后尿道压力、膀胱最大容积和残余尿量差异无统计学意义(P＞0.05).VG染色结果显示,去细胞处理组吻合口断端被染成红色,肌纤维排列整齐分布均一,再生肌纤维长入远端尿道.异体移植对照组肌纤维形态均一,肌纤维排列整齐分布均一未见肌纤维长入远端尿道.结论 化学去细胞同种异体尿道,可修复大鼠尿道损伤.     

丝素蛋白膜修复兔尿道缺损的实验研究

目的 探索丝素蛋白膜修复尿道缺损的效果.方法 24只雄性新西兰白兔随机分成3组,实验组、对照组Ⅰ及对照组Ⅱ.实验组12只兔切除尿道中段1.5 cm建立尿道缺损模型,应用丝素蛋白膜修复,术后2、4、8、16周每次3只行逆行尿道造影、组织学及免疫组织化学检测;对照组16只兔行尿道海绵体游离后即缝合切口,对照组Ⅱ6只兔切除尿道中段1.5cm建立尿道缺损模型后缝合切口依靠尿道自体再生修复缺损,术后8周、16周对照组Ⅰ及对照组Ⅱ每次3只行逆行尿道造影、组织学及免疫组织化学检测.结果 实验组12只兔应用丝素蛋白膜修复尿道缺损未见尿道狭窄,尿道粘膜细胞及平滑肌细胞修复缺损区,未见纤维化形成,16周时丝素蛋白膜完全降解,粘膜细胞及平滑肌细胞排列有序,免疫组织化学染色证实修复区腔面覆盖细胞为尿道移行细胞.结论 丝素蛋白膜能够诱导尿道粘膜上皮细胞及尿道平滑肌的生长,具有促进尿道缺损修复的能力.     

脂肪间充质干细胞双向诱导上皮/平滑肌细胞膜片修复兔尿道缺损

目的探究利用脂肪间充质干细胞(adipose-derived mesenchymal stem cells, ADSCs)向上皮/平滑肌细胞诱导培养细胞膜片重建兔缺损尿道的可行性和效果。方法将18只2~3月龄雄性新西兰兔随机分成ADSCs诱导复合膜片仿生尿道组和单纯无细胞SIS对照组,每组各9只。原代提取ADSCs体外扩增向上皮细胞和平滑肌细胞诱导并在UpCell培养皿中培养成上皮细胞膜片和平滑肌细胞膜片,两种细胞膜片叠加包裹8F医用硅胶管制备长2cm复合仿生尿道置皮下脂肪培养3周后取出。建立新西兰兔长段(2cm)尿道缺损模型,分别将ADSCs诱导复合细胞仿生尿道、单纯无细胞SIS仿生材料置于兔尿道缺损部位行全段端端吻合术修复重构尿道,术后14d移去8F医用硅胶管,分别于术后1、6个月进行尿道造影、大体观察和组织学观察,进行尿道重构效果评估。结果1个月后,尿道造影显示无细胞SIS材料组存在不同程度的尿道管腔狭窄,有明显的瘢痕增生和挛缩,而ADSCs诱导复合细胞仿生尿道组可保持通畅,黏膜平整,与正常尿道黏膜界限不清。ADSCs诱导复合细胞仿生尿道7只正常排尿畅通,2只出现尿瘘,无细胞SIS材料组4只正常排尿,3只尿道狭窄,2只出现尿瘘。组织学观察发现,6个月后ADSCs诱导复合膜片仿生尿道修复段已形成稳定的上皮细胞层多层组织结构,细胞层下可见明显的毛细血管样结构形成。结论ADSCs诱导双复合膜片仿生尿道可修复兔长段(2cm)尿道缺损的重构。     

脱细胞异体真皮在泌尿生殖疾病手术治疗中的应用

Humanacellular dermal matrix (HADM) is widely used in the field of burn wound repair and tissue engineering plastic surgery. HADM is manufactored by physical and chemical decellular process to remove the antigenic components that might cause immune rejection in dermis.The extracellular matrix of three-dimensional cell scaffold structure with collagen fibers had been used for wound repair and tissue regeneration, while HADM characterized with low absorption rate after implantation and strong ability to induce angiogenesis in host tissue. Studies reported that after the HADM was implanted into the patient, the host cells, such as fibroblasts and myofibroblasts, as well as lymphocytes, macrophages, granulocytes and mast cells, rapidly infiltrated the graft. The connective tissue and neovascularization were then formed within the HADM three-dimensional cell scaffold, the lymphatic system also appears after vascular reconstruction. Traditional urethral reconstruction using autologous skin flaps has some defects, such as complexity of the technology, risk of necrosis of the skin flaps after transplantation, and failure to achieve functional repair of the urethral epithelium. It has been reported that using HADM to reconstruct the urethra in patients with urethral stricture, hypospadias and bladder-vaginal fistula, showed promising results. Others have reported the experience of using HADM to repair and reconstruct congenital classic bladder exstrophy. HADM has also been used for tissue repair in patients with penile skin defect caused by Fonier’s gangrene and hidradenitis suppurativa, and implanted under Bucks’ fascia to enlarge the penis. The report of HADM implantation for treating premature ejaculation also deserves attention. Researchers found that HADM implantation can form a tissue barrier between the skin and corpus cavernosum, which can effectively reduce penile sensitivity and treat premature ejaculation. The safety and effectiveness of HADM implantation in the treatment of premature ejaculation need to be further standardized by data from multi-center, large-sample clinical studies. In summary, HADM is the extracellular matrix and three-dimensional cell scaffold of human dermis. As a new type of tissue repair material, new blood vessels are formed actively after implantation, which shows good histocompatibility. HADM has shown increasingly broad application prospects in treatment of genitourinary diseases including penis, urethra and bladder diseases. HADM has also been used in the treatment of premature ejaculation in recent clinical studies, and its long-term safety and efficacy need to be further investigated.     

血管内皮细胞生长因子165基因转染对兔骨缺损修复的影响

目的 构建pcDNA3．1-血管内皮细胞生长因子（VEGF）165质粒,观察其对兔骨缺损修复的影响。方法构建成重组真核表达质粒pcDNA3．1-VEGF165;采用30只新西兰大白兔,制备双侧桡骨骨缺损模型,实验组以体积等大的明胶海绵置于创腔,局部直接注射稀释的质粒液200ng;对照组以同量生理盐水代替质粒液,同法处理。于术后1、2、4、6、8和12周行X线照片后获取标本,观察缺损局部组织修复及新生血管并计算微血管密度（MVD）。结果pcDNA3．1-VEGF165质粒构建成功,测序正确。术后X线：1周时两组无明显差别,实验组2周骨痂形成、骨质修复,12周时骨质已正常,对照组表现为修复迟缓;HE染色：实验组2周大量新生血管形成、通血,4周成骨细胞大量增殖、骨小梁形成,12周骨皮质改建完成,骨髓腔再通;对照组经历过程类似,但相对时间延迟,12周时骨髓腔及皮质改建尚未完成。2周时对照组及实验组MVD分别为56．1±6．1、69．1±5．4,均较1周时42．2±6．4、47．0±7．5时增加,组间及组内间差异有统计学意义（t=8．0347,P=0．0000）。结论骨缺损局部直接应用PcDNA3．1-VEGF165质粒液后,可表达并上调VEGF165,具有促进局部微血管形成、加快骨缺损修复的作用。     

软骨形态发生蛋白1诱导SD仔鼠脂肪干细胞修复兔膝关节软骨缺损的研究

目的:应用软骨形态发生蛋白1(CDMP1),以诱导SD仔鼠脂肪干细胞(ADSCs)以修复兔膝关节软骨缺损,探讨异种细胞作为软骨组织工程种子细胞的可行性。方法:自SD仔鼠腹股沟脂肪组织分离、培养ADSCs,复合于自制牛松质骨支架上,经CDMP1诱导,体外继续培养2周,免疫组化鉴定后备用。建立兔双侧髌骨关节缺损模型。左侧缺损处植入ADSCs-支架复合物,为实验侧;右侧缺损处植入空支架,为对照侧。术后8、16、24和48周各处死9只兔子,缺损处行H-E染色和番红O染色。结果:实验侧8周时可见缺损周围表面充填有薄层白色半透明组织,与周围软骨的界线清楚;16周时缺损表面界限连接较8周时模糊,但仍可辨,24周时,修复良好,修复区新生软骨细胞与周围正常软骨细胞形态相近,呈球形,可见软骨陷窝,H-E染色和番红O染色阳性;48周时,能较容易分清缺损处与修复区的界限,修复效果不及24周时。对照侧8、16、24和48周4个时期标本基本相同,软骨缺损处与周围正常组织边界清楚,缺损处凹陷空洞,被肉芽组织填充,新生细胞呈长梭形,H-E染色和番红O染色阴性。结论:利用CDMP1诱导SD仔鼠ADSCs复合自制牛松质骨支架可较好修复兔膝关节软...     

基因重组人生长素对关节软骨缺损修复作用的实验研究

目的探讨基因重组人生长素(recombinant human growth hormone,rhGH)对创伤性关节软骨创伤的修复作用.方法选用大耳白兔25只,随机分成5组,每组5只.在两侧髌股关节股骨侧的关节面中心分别造成直径3.5 mm的全层关节软骨缺损.选择右侧为实验组,自术后起,膝关节内注射0.1 U/kg的r-hGF,每周3次,共4周;左侧为对照组,与实验组同一时间注射等容量生理盐水.于术后4、6、8、12、24周分别取材进行大体、光镜和透射电镜观察.结果实验组修复组织填充快,质量好.4周时缺损区充填完全浅部,再生软骨明显深部纤维组织为主.24周时再生组织与周围正常软骨外观相近,肉眼难以区分;光镜下损伤区基本恢复正常软骨组织结构;电镜下可见到大量,形态成熟为主的软骨细胞.而生理盐水对照组6周时缺损区仍有浅表凹陷,并以纤维组织性修复为主.除术后4周外,其余各期两组的组织学评分均有显著性差异(P<0.01).实验同时显示再生软骨于24周后变薄.3例修复软骨较正常薄,2例修复软骨与正常软骨厚度大致相同均无裂隙形成.结论 rhGF局部关节腔内注射,能促进创伤性关节软骨缺损的修复,为微创性修复关节软骨缺损提供了一条新途径.     

An experimental study of colonic mucosal graft for urethral reconstruction

目的　探索结肠粘膜重建尿道的可行性。方法　 10条雌性狗在全麻下行游离结肠粘膜替代尿道粘膜的手术。在手术及处死前分别进行尿动力学检查。术后 8～ 16周将狗处死 ,其尿道作病理检查。结果　 1条狗发生尿道狭窄 ,余 9条狗的尿动力学检查提示 :手术前与处死前的最大尿道压之间差异无显著意义(P >0 0 5 )。 10条狗的尿道病理组织学检查提示 :移植于尿道的结肠粘膜全部成活 ,术后 8周处死的狗显示结肠粘膜表面皱襞存在 ,被覆单层低拄状的吸收上皮和杯状细胞 ;术后 12周后处死的狗显示结肠粘膜表面皱襞 ,被覆的单层吸收上皮和杯状细胞消失 ,尿道粘膜大部分已被化生为假多层的移行上皮复盖。结论　结肠粘膜能替代尿道粘膜 ,尿道纵行切开对雌性狗的括约功能影响不大。这种技术尤其适用于包皮或膀胱及颊粘膜应用不合适时的尿道重建     

携载BMP4基因的核壳结构纳米粒子修复兔桡骨临界骨缺损的研究

目的 将改性的壳聚糖包裹骨形态发生蛋白4(BMP4)质粒形成核壳结构,以明胶海绵为此纳米粒子载体,探究其对兔桡骨临界骨缺损的修复作用.方法 新西兰大白兔24只,每只兔子的左右前肢按随机法分为负载BMP4质粒核壳结构组(TACS@EG-HBC/pBMP4/G组)、负载BMP4质粒核结构组(TACS/pBMP4/G组)和对照组.在双侧桡骨制备长约18 mm的完全性临界骨缺损,分别植入含有TACS@EG-HBC/pBMP4或TACS/pBMP4的明胶海绵,对照组仅植入单纯的明胶海绵.术后2、4、8、12周取标本做分别处理,检测缺损部位的大体标本、骨密度及骨矿物质含量、X线、HE染色、免疫组化法、生物力学.结果 24只兔子均纳入分析,术后切口未见感染、化脓等症状.大体标本示:TACS@EG-HBC/pBMP4/G组骨缺损完全骨化修复;骨密度及骨矿物质含量显著高于TACS/pBMP4/G组和对照组(P＜0.05);X线示:术后12周骨缺损处已完全修复,骨髓腔已再通;HE染色结果显示:新生骨小梁相互连接成板层骨;免疫组化结果显示:BMP4棕色蛋白染色明显;生物力学测定结果显示:所形成的新生骨与正常骨组织生物力学差异无统计学意义.结论 TACS@EG-HBC/pBMP4/G具有良好的安全性和成骨能力.     

组织工程化软骨对兔膝关节全层软骨缺损的修复效果

目的 观察同种异体软骨细胞复合人胎盘Ⅰ型胶原蛋白海绵对兔膝关节股骨髁间窝全层软骨缺损的修复效果.方法取2周龄新西兰兔软骨细胞体外培养传代,选择生长状态相对较好的第2代细胞作为种子细胞,并与人胎盘Ⅰ型胶原蛋白海绵复合.取雄性8月龄新西兰兔54只,制作股骨髁间窝全层软骨缺损模型,随机分为3组：分别为对照组、种子细胞组及种子细胞＋支架材料组.后两组分别植入相应成分.于术后12周、24周、36周分别取其膝关节,观察修复效果. 结果 术后12周种子细胞组缺损区可见少量白色半透明组织覆盖,组织结构粗糙,可见多数针尖样结构;复合支架材料组表面相对光滑,亦可见半透明白色组织形成.24周,种子细胞组缺损区可见较多白色组织形成,透明度较前降低,呈半软骨半纤维样组织;复合支架材料组修复明显较种子细胞组快,表面光滑,呈半透明状覆盖于缺损区,与周围组织有较好吻合,但仍未完全修复软骨缺损.36周,种子细胞组可见更多白色组织覆盖,透明度较前更低;复合支架材料组则修复完好,高度基本与周围组织平齐,呈半透明样软骨组织.空白对照组随着时间的推移,呈现不同程度的纤维组织样修复. 结论 关节软骨自身修复能力有限,只能实现纤维样修复;软骨细胞可部分修复关节软骨缺损,但随着修复时间的推移,逐渐去分化而出现纤维样改变;而软骨细胞复合Ⅰ型胶原蛋白海绵则可以较好地修复关节软骨缺损,且随着时间的延长,关节软骨可基本实现完全修复.