小肠粘膜下层复合成骨诱导的骨髓基质干细胞体内成骨的实验研究

目的探讨利用组织工程方法,以小肠粘膜下层为支架材料复合成骨诱导后的骨髓基质干细胞构建骨组织的可行性。方法将取自兔骨髓中的骨髓基质干细胞经成骨诱导液诱导后,与经处理的猪小肠粘膜下层在体外共培养。1周后,将共培养的猪小肠粘膜下层埋置于无胸腺裸鼠皮下。分别在不同时间进行扫描电镜、透射电镜、组织学和免疫组织化学观察。结果体外培养时,见细胞与材料粘附良好,且分泌大量的细胞外基质,细胞分化、增殖活跃。大体观察植入体内的细胞-材料复合物,见颜色变白,组织硬度增加,组织学和电镜观察见有大量骨组织形成。免疫组化示细胞为具有分泌特异性骨钙蛋白的成骨细胞。结论骨髓基质干细胞经成骨诱导为成骨细胞后与小肠粘膜下层共培养,植入裸鼠体内后可形成骨组织,小肠粘膜下层是一种良好的骨组织工程支架材料。     

Small Intestinal Submucosa as a Bioscaffold for Tissue Regeneration in Defects of the Colonic Wall

Background  Small intestinal submucosa (SIS) has proved considerable regenerative capacity for repair of bowel wall defects at different locations. This study assesses the effectiveness of SIS in the repair of defects at a gastrointestinal location with strong bacterial contamination. Methods  Fourteen domestic pigs had a 4.5 × 1.5 cm full-thickness defect created on the wall of the descending colon. Repair was done by suturing an SIS patch to the defect. Grafts were harvested after 30, 60, and 90 days. Outcomes were evaluated on the basis of animal survival, clinical course, and macroscopic, histological, and immunohistochemical assessment. Results  All animals survived the scheduled observation period. No patch failure and no postoperative leakage occurred. No luminal narrowing occurred at SIS-patched colon. Morphometric examination revealed contraction of the patched area of 77% after 30 days and more than 90% after 60 and 90 days. By 60 and 90 days, all animals showed mucosal regeneration at the margins of the graft. By 90 days, regeneration of smooth muscle cells was present at the original site of the muscularis mucosae. None of the reconstructed areas showed complete mucosal coverage or regeneration of a structured muscular layer. Conclusion  SIS can be used effectively for patch repair of colonic defects in a porcine model. Distinctive contraction of the reconstructed area and limited architectural regeneration of the bowel wall suggest limitation of morphologic regenerative capacities in large-bowel regeneration.     

Unsuccessful Alloplastic Esophageal Replacement With Porcine Small Intestinal Submucosa

Abstract:  In general, there is no perfect method for esophageal replacement under consideration of the numerous associated risks and complications. The aim of this study was to examine a new material—small intestinal submucosa (SIS)—in alloplastic esophageal replacement. We implanted tubular SIS prosthesis about 4 cm in length in the cervical esophagus of 14 piglets (weight 9–13 kg). For the first 10 days, the animals were fed parenterally, supplemented by free given water, followed by an oral feeding phase. Four weeks after surgery, the animals were sacrificed. Only 1 of the 14 animals survived the study period of 4 weeks. The other piglets had to be sacrificed prematurely because of severe esophageal stenosis. On postmortem exploration, the prosthesis could not be found either macroscopically or histologically. Sutures between the prosthesis and the cervical muscles did not improve the results. Until now, the use of alloplastic materials in esophageal replacement has failed irrespective of the kind of material. As well as in our experiments, severe stenosis had been reported in several animal studies. The reasons for this unacceptable high rate of stenosis after alloplastic esophageal replacement seem to be multifactorial. Possible solutions could be transanastomotic splints, less inert materials, the decrease of anastomotic tension by stay sutures, the use of adult stem cells, and tissue engineering.     

The Porcine Small Intestinal Submucosa (SIS) Patch in Foot and Ankle Reconstruction

We undertook a retrospective cohort study of 54 patients who underwent foot and ankle soft tissue reconstructive surgery augmented with a porcine small intestinal submucosal (SIS) patch. The mean patient age was 44 (range 17 to 68) years, there were 21 (38.89%) males in the cohort, and the mean follow-up duration was 1080 (range 365 to 1943) days. Clinical outcomes were considered excellent in 46 (85.19%) patients, good/fair in 3 (5.56%) patients, and poor in 5 (9.26%) patients; and no adverse events attributable to the xenograft were observed. Direct SIS patch failure, resulting in stretching of the repair, re-tear, or tendon stenosis, occurred in 3 (5.56%) patients, and delayed incision healing occurred in 6 (11.11%) patients. Based on our observations, we concluded that the porcine SIS xenograft, when used to augment cellular and vascular in-growth, is a viable adjunct to musculoskeletal reconstructions of the foot and ankle.     

组织工程引导骨再生膜修复节段性骨缺损

目的　将组织工程技术和引导性骨再生技术相结合修复长骨节段性缺损。方法　兔 2 7只 ,动物模型均为桡骨 1 2cm节段性骨 骨膜缺损 ,分成 3组 ,A组 :利用体外构建的细胞 材料复合物膜修复 ;B组 :利用单纯的膜材料进行修复 ;C组 :断端不作任何处置作空白对照。分别观察 3、 6、 12周后进行X线观察和组织学观察。结果　A组的骨愈合优于B组 ,在 12周时已经完成骨缺损的修复 ,B组在术后 12周仍处于塑形改建之中 ;C组 12周形成典型的骨不连。结论　将组织工程的技术与引导性骨再生技术相结合 ,可以比单纯的引导性骨再生更好地修复长骨节段性缺损。     

小肠粘膜下层组织工程支架材料的生物相容性研究

目的 观察小肠粘膜下层(SIS)的生物相容性和作为组织工程支架材料的可行性.方法 参照国际标准ISO10993-1制定的医疗器械生物学评价的相关方法和标准,通过细胞毒性试验、热原试验、溶血试验、致敏试验、肌肉刺激试验等体内外生物学实验相结合的方法评价SIS的生物相容性及免疫原性.结果 实验证明小肠粘膜下层细胞相容性良好,不溶血,无致热、致敏反应,肌肉刺激试验的组织学检查见SIS周围无明显炎症及排斥反应,材料部分降解并见大量结缔组织生长.结论 SIS具有良好的生物相容性和免疫原性,可作为组织工程的支架材料.     

Small Intestinal Submucosa as a Vascular Graft: A Review

Continuing investigations of vascular graft materials suggest that unacceptable graft complications continue and that the ideal graft material has not yet been found. We have developed and tested a biologic vascular graft material, small intestine submucosa (SIS), in normal dogs. This material, when used as an autograft, allograft, or xenograft has demonstrated biocompatibility and high patency rates in aorta, carotid and femoral arteries, and superior vena cava locations. The grafts are completely endothelialized at 28 days post-implantation. At 90 days, the grafts are histologically similar to normal arteries and veins and contain a smooth muscle media and a dense fibrous connective tissue adventita. Follow-up periods of up to 5 years found no evidence of infection, intimal hyperplasia, or aneurysmal dilation. One infection-challenge study suggested that SIS may be infection resistant, possibly because of early capillary penetration of the SIS (2 to 4 days after implantation) and delivery of body defenses to the local site. We conclude that SIS is a suitable blood interface material and is worthy of continued investigation. It may serve as a structural framework for the application of tissue engineering technologies in the development of the elusive ideal vascular graft material.     

组织工程化骨修复四肢骨缺损的初步临床研究

目的探索以人自体骨髓基质干细胞(Human bone marrow stromal cells,hBMSCs)为种子细胞构建的组织工程骨用于修复四肢骨缺损的可行性。方法选择9例四肢骨缺损病例(良性骨肿瘤5例、骨缺损4例)。经病人髂前上嵴,穿刺抽取10mL骨髓,用密度梯度离心法分离得到hBMSCs,用成骨诱导培养液定向培养、扩增,应用第3代的hBMSCs与珊瑚复合,继续在体外培养1周后,手术植入骨缺损区。分别在术后2个月、6个月、12个月和24个月进行临床观察和X线检查。1例病人在二次手术时,在原骨缺损区取出少量新生组织活检,进行组织学观察(HE染色)。结果患者术后X线检查显示,组织工程骨在原位形成新骨,能较好地修复骨缺损。活检标本HE染色显示,局部形成正常松质骨组织。结论以自体hBMSCs为种子细胞,利用组织工程技术制成的自体组织工程骨可以修复四肢骨缺损,并且能够修复较大的骨缺损,但组织工程骨的临床成骨效果与植骨床血供密切相关,目前所使用的组织工程骨植骨方法具有一定的适应证。     

Small Intestinal Submucosa as a Small-Diameter Arterial Graft in the Dog

Autogenous saphenous vein, human umbilical vein, modified bovine collagen, Dacron, and PTFE have been used as small-diameter arterial grafts with moderate success. We tested autogenous small intestine submucosa as a small-diameter arterial graft in both a carotid and femoral artery (mean ID 4.3 mm) of 18 dogs (total of 36 grafts). All dogs received aspirin and warfarin sodium for the first 8 weeks after surgery. Graft patency was evaluated by Doppler ultrasound techniques and angiography. Two grafts ruptured and 5 grafts occluded by 21 days after surgery. One graft became occluded at 14 weeks. Fifteen dogs were sacrificed at periodic intervals until 48 weeks after surgery. Patent grafts had no evidence of infection, propagating thrombus, or intimal hyperplasia. Graft aneurysmal dilation occurred in 4 grafts (11%). The grafts were composed of a dense organized collagenous connective tissue with no evidence of endothelial cell growth on the smooth luminal surface. Three dogs are alive at 76 to 82 weeks after surgery. Overall, graft patency was 75%. Graft patency after cessation of anticoagulation therapy was 92.3% (12 of 13 grafts). We conclude that autogenous small intestinal submucosa can be used as a small-diameter arterial graft in the dog and is worthy of further investigation.     

胎猪BMSC体外构建软骨的实验研究

目的比较胎猪骨髓间充质干细胞（Bone Marrow Mesenchymal Stem Cells,BMSCs）和成年猪BMSCs构建软骨能力的差异,寻找合适的同种异体组织工程软骨种子细胞来源。方法通过剖腹产手术获得胎龄为70 d的胎猪,胎猪骨髓液贴壁培养获得胎猪BMSCs;抽取成年猪骨髓液,经贴壁培养法获得成年猪BMSCs。两种细胞体外扩增培养后,观察第3代细胞形态,并进行成骨、成脂和成软骨诱导。分别取两种细胞以1×108 cells/mL的细胞终浓度,接种于聚乳酸包埋的聚羟基乙酸支架,体外诱导培养8周后取材。通过大体观察、糖胺聚糖（GAG）含量测定、总胶原含量测定、组织学,以及免疫组化等方法,对两种细胞构建的组织工程软骨的相关生物学特性进行比较。结果胎猪BMSCs比成年猪BMSCs具有更好的增殖和成骨、成脂和成软骨能力。胎猪BMSCs构建的软骨有良好的软骨外观,而且GAG含量和总胶原含量均高于成年猪BMSCs构建的软骨（P<0.01）。组织学和免疫组化显示,胎猪BMSCs构建的软骨组织结构致密,基质及Ⅱ型胶原显色程度均明显强于成年猪BMSCs构建的软骨。结论胎猪BMSCs是组织工程软骨较好的种子细胞来源。     

胶原膜与复合自体骨髓的自体骨引导骨再生的实验研究

目的　观察胶原膜引导骨再生的效果 ,探讨胶原膜的理化特性、自体骨髓、膜下空间的维持在引导性骨再生中的作用。方法　建立兔双侧桡骨缺损模型 ,实验组移植胶原膜与复合自体骨髓的自体骨 ,对照组仅移植复合自体骨髓的自体骨 ,并行大体标本、组织学、生物力学检查。结果　实验组新骨生长及成熟骨替代过程较对照组快 ,且有增生的小血管及神经纤维。结论胶原膜是一种理想的骨移植材料 ,它能有效地发挥阻隔及引导的作用     

Regenerative Urinary Bladder Augmentation Using Small Intestinal Submucosa: Urodynamic and Histopathologic Assessment in Long-term Canine Bladder augmentations

Purpose

To evaluate small intestinal submucosa (SIS) as a possible bladder augmentation material.

Materials and Methods

Nineteen male dogs underwent 35 to 45 percent partial cystectomy with immediate augmentation with SIS grafts. All dogs were evaluated pre- and postoperatively with blood chemistries, urine cultures, intravenous urograms, cystograms and cystometrograms. Postoperatively (1 to 15 months), bladders were examined with routine histology and image analysis.

Results

All dogs survived their intended survival period without morbidity. All results were normal. Histologically, all 3 layers (mucosa, smooth muscle, serosa) of the normal bladder showed evidence of regeneration.

Conclusions

Small intestinal submucosa acts as a scaffold for bladder augmentation through regeneration and could be a potential option for bladder reconstruction.     

骨髓基质细胞修复颅骨缺损的实验研究

目的为验证三维打印研究中动物模型的可靠性，采用骨髓基质干细胞（Bone marrow mesenchymal stem cells，BMSCs）修复裸鼠颅骨缺损。方法共10只裸鼠，其中实验组（n=5只）：颅骨缺损区植入BMSCs／脱钙骨；材料对照组：颅骨缺损区植入单纯脱钙骨，采用实验组自身对照（n=5只）；空白对照组（n=5只）：双侧颅骨区造成缺损后旷置。术后3个月取材进行大体观察、组织学和免疫组化（骨钙蛋白）检查。结果术后3个月，实验侧组织质地较硬，组织学表现为骨结构，骨钙蛋白免疫组化阳性；对照侧质地较软，组织学表现为结缔组织，骨钙蛋白免疫组化阴性；空白对照组仍表现为颅骨缺损。结论采用BMSCs可修复裸鼠颅骨缺损，验证了三维打印研究中动物模型的可靠性。     

Demineralized Bone Matrix Injection in Consolidation Phase Enhances Bone Regeneration in Distraction Osteogenesis via Endochondral Bone Formation

Background

Distraction osteogenesis (DO) is a promising tool for bone and tissue regeneration. However, prolonged healing time remains a major problem. Various materials including cells, cytokines, and growth factors have been used in an attempt to enhance bone formation. We examined the effect of percutaneous injection of demineralized bone matrix (DBM) during the consolidation phase on bone regeneration after distraction.

Methods

The immature rabbit tibial DO model (20 mm length-gain) was used. Twenty-eight animals received DBM 100 mg percutaneously at the end of distraction. Another 22 animals were left without further procedure (control). Plain radiographs were taken every week. Postmortem bone dual-energy X-ray absorptiometry and micro-computed tomography (micro-CT) studies were performed at the third and sixth weeks of the consolidation period and histological analysis was performed.

Results

The regenerate bone mineral density was higher in the DBM group when compared with that in the saline injection control group at the third week postdistraction. Quantitative analysis using micro-CT revealed larger trabecular bone volume, higher trabecular number, and less trabecular separation in the DBM group than in the saline injection control group. Cross-sectional area and cortical thickness at the sixth week postdistraction, assessed using micro-CT, were greater in the regenerates of the DBM group compared with the control group. Histological evaluation revealed higher trabecular bone volume and trabecular number in the regenerate of the DBM group. New bone formation was apparently enhanced, via endochondral ossification, at the site and in the vicinity of the injected DBM. DBM was absorbed slowly, but it remained until the sixth postoperative week after injection.

Conclusions

DBM administration into the distraction gap at the end of the distraction period resulted in a significantly greater regenerate bone area, trabecular number, and cortical thickness in the rabbit tibial DO model. These data suggest that percutaneous DBM administration at the end of the distraction period or in the early consolidation period may stimulate regenerate bone formation and consolidation in a clinical situation with delayed bone healing during DO.     

去细胞猪主动脉瓣支架及兔骨髓干细胞构建组织工程心脏瓣膜的初步研究

目的探讨应用去细胞猪主动脉瓣支架(ace llu larized porc ine aortic va lve scaffo ld,APAV S)与兔骨髓干细胞(bone m arrow strom a l ce lls,BM SC s)体外构建组织工程瓣膜的可行性。方法采用去垢剂+核酸酶消化法处理,去除猪主动脉瓣细胞成分,并作去细胞前后的形态学检查和生物力学测定;在去细胞支架上种植兔BM SC s,行形态学检查和免疫组织化学染色观察。结果光学显微镜、扫描及透射电子显微镜下可见猪主动脉瓣膜中的细胞成分可完全被去除,获得完整无细胞的纤维网状支架。瓣叶去细胞前后的断裂强度(642±102g/mm2vs.636±127g/mm2)和断裂伸长率(62.2%±18.1%vs.54.4%±16.0%)差别无统计学意义(P>0.05)。种植的兔BM SC s在APAV S表面形成一层连续的细胞层。免疫组织化学检查α-平滑肌动蛋白抗体(+),CD 31(-)。结论种植兔BM SC s于APAV S上,可在体外构建组织工程心脏瓣膜。     

Age-Related Decline of Bone Mass and Intestinal Calcium Absorption in Normal Males

Although about 25% of all hip fractures occur in men, little is known about the pattern of their age-related bone loss and its main determinants. The aim of this cross-sectional study was to evaluate the age-related changes of intestinal calcium absorption, bone mass, and bone turnover in normal men. In 70 normal males (age 17–91 years), we measured spinal and forearm bone density (FBD) (by DXA), fractional intestinal calcium absorption (by oral test), serum immunoreactive parathyroid hormone (PTH), dietary calcium intake (diet records), biochemical markers of bone turnover (serum alkaline phosphatase (ALP), osteocalcin, urine calcium, creatinine, and hydroxyproline), and 1,25(OH)₂D₃ serum levels. Vertebral bone density (VBD) showed a modest decline before age 50 and a greater decline after age 50, whereas FBD presented a significant decrease with advancing age starting at age 40, suggesting a predominant age-related cortical bone loss. Intestinal calcium absorption (⁴⁷CaFA) and serum 1,25(OH)₂D₃ also presented an age-related decline similar to FBD. Simple correlation analysis revealed that age was significantly related to ⁴⁷CaFA (r = 0.60), calcium intake (r = 0.32), VBD and FBD (r = 0.79 and 0.63, respectively), serum 1,25(OH)₂D₃ (r = 0.69), and serum iPTH (r = 0.72). No significant correlation was found between age and biochemical markers of bone remodeling. Partial correlation and stepwise variable selection analyses, using ⁴⁷CaFA and bone mass as dependent variables, showed that in normal males, serum 1,25(OH)₂D₃ and dietary calcium intake were the main contributors (64%) to ⁴⁷CaFA variability, whereas only age accounted for 63% of VBD and age and dietary calcium accounted for 45% of FBD variability. These results indicate that bone loss in men accelerates after age 50 years and that among other factors, intestinal calcium malabsorption and 1,25(OH)₂D₃ serum levels play a role. Received: 19 November 1996 / Accepted: 26 January 1998     

利用ADSCs在生物反应器中构建小口径血管的初步研究

目的 尝试利用人的脂肪基质干细胞(Adipose-derived stromal cell,ADSCs)在生物反应器中构建组织工程化小血管.方法 采用脂肪抽吸术获取人脂肪组织,将脂肪细胞分离、传代培养;对培养的第三代细胞进行脂肪干细胞表型鉴定;同时称取一定量的聚羟基乙酸(PGA)制成片状材料,消毒晾干备用,将细胞接种在PGA材料上,静态培养半天后置于生物反应器中动态培养4周,然后进行初步检测.结果 从形态学观察,细胞伸展呈成纤维细胞样,生长有方向性,5～6 d后可见克隆开始形成.对第三代ADSCs进行检测,结果显示除CD166、CD105有高的表达外,CD14、CD34表达很低.从反应器取出的样品能形成血管样组织,扫描电镜观察:样品基质分泌旺盛.结论 采用组织工程方法,从动态培养的角度可以在体外利用ADSCs构建血管形状的组织,为进一步研究ADSCs在血管组织工程中的应用提供了一种好的方法.