带蒂颈阔肌肌皮瓣与镍钛合金网结合再造颈段气管实验研究

目的探讨用带蒂颈阔肌肌皮瓣与镍钛合金网结合再造颈段气管。方法选健康狗20只,袖状切除8—10个气管环长度的颈段气管,用带蒂颈阔肌肌皮瓣卷成肌皮管,表皮衬里,腔内置硅胶管临时扩张,将肌皮管移于气管缺损处,与气管切端吻合,再用相应长度镍钛合金网状支架套于肌皮管外,并固定。术后4—6月经气管镜拔出硅胶管。结果2只动物术后切口感染而终止实验。余动物均健康存活,呼吸、发音、及运动正常。CT检查示新气管管腔宽敞,无狭窄现象。术后6—18月分期处死动物,见植入物与气管连为一体,镍钛支架与肌皮管及周围组织粘连紧密,不易分离。管壁皮肤的鳞状上皮逐渐变薄,并最终化生为单层矮柱状上皮组织。镍钛合金光洁如初。结论带蒂颈阔肌肌皮瓣与镍钛合金网结合组成的“新气管”可适用于颈部气管的重建。     

记忆合金材料弹力金属支架在犬肺组织瓣重建气管缺损中的应用

背景：生物相容性好的内衬支架是肺组织瓣成功修补气管缺损的关键,记忆合金支架成为目前研究热点。 目的：探讨应用自体肺组织瓣内衬金属弹力支架替代气管缺损的可行性。 方法：由中国医科大学附属盛京医院动物实验室提供杂种成年犬14只,雄性8只,雌性6只,体质量12~26 kg,气管整段切除3 cm或5 cm,采用自体肺组织瓣内衬金属弹力支架替代气管缺损方法行胸段气管重建。 结果与结论：4只犬死亡,死于并发症及其他原因,10只成活,吻合口愈合良好,食管钡透通畅。结果表明自体肺组织瓣内衬金属弹力支架替代气管缺损是一种可行的气管重建方法。     

纳米β-磷酸三钙/Ⅰ、Ⅱ型胶原层状支架复合骨髓间充质干细胞修复膝关节骨软骨缺损

背景:关节软骨损伤修复面临的难题主要表现在再生软骨的结构及生理功能距正常软骨相差较远,无法满足正常生理需要,目前修复方法很多,但效果均不理想。目的:探讨纳米β-磷酸三钙/Ⅰ、Ⅱ型胶原层状支架-骨髓间充质干细胞复合物修复犬膝关节骨软骨缺损的可行性。方法:12月龄杂种犬10只,随机分为实验组、缺损对照组,无菌条件下自髂后嵴处抽取骨髓分离培养骨髓间充质干细胞,传至第3代消化、收集,调整细胞浓度为2×109L-1,与纳米β-磷酸三钙/Ⅰ、Ⅱ型胶原共培养24h,即制成纳米β-磷酸三钙/Ⅰ、Ⅱ型胶原层状支架-骨髓间充质干细胞复合物。两组犬均制备右膝关节骨软骨缺损,实验组于缺损处植入支架-细胞复合物,缺损对照组不做任何处理。结果与结论:第12周,实验组缺损内充填以白色半透明组织,表面光滑,触之较软,稍高出周围软骨面,软骨细胞分布较均一,排列无方向性;第24周,实验组缺损内充填白色半透明新生软骨组织,色泽与正常软骨相似,质韧,表面平整,与正常软骨界限消失,表面细胞平行于关节面,深层细胞排列紊乱,细胞呈团状,基质异染广泛,与周围正常软骨连接良好。缺损对照组缺损未修复,底部为白色纤维组织。提示骨髓间充质干细胞是修复关节软骨缺损较理想的种子细胞,在新生软骨形成的同时,纳米β-磷酸三钙/Ⅰ、Ⅱ型胶原层状支架逐渐降解吸收,是组织工程修复关节软骨缺损适宜的支架材料。     

不饱和聚磷酸酯/β-磷酸三钙复合材料修复骨缺损的实验研究

目的 观察以不饱和聚磷酸酯（UPPE）／β-磷酸三钙（β—TCP）制备的复合材料对骨缺损的修复效果。方法利用溶液浇铸法技术制备UPPE／β-TCP复合材料。将36只新西兰大白兔随机等分为两组,手术造成右股骨髁部腔洞状直径8mm骨缺损,实验组植入直径8mm复合材料,对照组作空白对照。通过影像学、组织学、图像分析技术观察骨缺损的修复效果及材料的降解情况。结果影像学结果表明,实验组术后8周新生骨痂将缺损修复,术后16周骨痂塑形良好;对照组术后16周内均无骨痂形成,缺损未修复。组织学显示,实验组术后8周复合材料降解成较大的数块,有新骨形成;术后16周正常骨与材料之间形成贯通的髓腔;对照组为少量纤维组织连接。术后8周和16周材料降解率分别是30．3％和52．2％。结论以不饱和聚磷酸酯／β-磷酸三钙制备的骨修复材料对骨缺损具有良好的修复作用。     

硅橡胶管对兔气管软骨缺损修复之影响的实验研究

硅橡胶管对兔气管软骨缺损修复之影响的实验研究李正贤（１６３医院耳鼻咽喉科，长沙４１０００３）迟汝澄，陈文弦（第四军医大学唐都医院耳鼻咽喉科，西安）关键词：兔；气管；软骨缺损；硅胶管本实验将３０只兔颈段气管第３至５气管软骨环腹侧中部切除４ｍｍ宽的软骨，...     

兔气管软骨缺损致气管狭窄的实验研究

将28只兔颈段气管第3～5环腹例中部切除4mm宽的软骨,对照组气道内放置硅橡胶支撑管。实验发现:兔气管软骨缺损由于气道软骨被切断导致气管特定的生物力学性质失衡;肌成纤维细胞引起缺损部位的收缩;气道腹部平滑肌收缩最终导致气道狭窄。     

新型复合型人工气管移植实验研究

以聚四氟乙烯人造血管为主体,两端压制钛金属支撑环集成构建一种新型复合型人工气管。制作犬颈段气管缺如模型,用复合人工气管重建呼吸道。通过犬体内移植动物实验观察复合型人工气管初步效果和影响长期生存的因素。直接移植复合人工气管作为对照组(n=8),复合人工气管移植后加生长因子等改善组织环境作为实验组(n=8)。术后定期气管镜检查以及处死后组织检查评价复合型人工气管移植效果。16只实验动物复合型人工气管均顺利完成移植,无手术死亡。一月后各组吻合口处有肉芽增生。对照组4只犬因移植后呼吸困难死亡,实验组有2只死亡。死亡犬经解剖标本显示吻合口感染、裂开,气道狭窄,人工气管移位脱落。其余犬按计划14月后处死。实验组平均生存时间长于实验组(558.6dvs 401.8d,P0.05);实验组吻合口感染、裂开、重度狭窄以及意外死亡的发生率均低于对照组(P0.05)。犬处死后解剖显示复合人工气管已被纤维组织包裹,人工气管腔内未见内膜生长。以聚四氟乙烯为主体连接支撑钛环的新型复合型人工气管替代自体气管重建气道,恢复气道通畅性,能保持移植物不变形。人工气管的复合设计减轻了吻合口狭窄,而感染和裂开仍是复合型人工气管移植的主要并发症,影响动物长期生存。应用生长因子改善局部环境可促进组织愈合。     

聚己内酯和β-磷酸三钙复合支架经血小板衍生生长因子BB修饰后的促血管生成作用

背景：组织工程技术的发展为骨缺损的修复重建提供了新的思路,但是血管化问题使组织工程骨应用于临床受到了制约。血小板衍生生长因子在促进骨细胞形成的同时也可促进骨组织中血管的形成。目的：观察聚己内酯/β-磷酸三钙/血小板衍生生长因子BB支架对骨髓间充质干细胞成骨分化及人脐静脉内皮细胞增殖、黏附的影响,以及修复骨缺损的效果。方法：(1)利用3D快速成形机制备聚己内酯/β-磷酸三钙支架(记为PCL/β-TCP支架),将支架浸渍于血小板衍生生长因子BB溶液中制备聚己内酯/β-磷酸三钙/血小板衍生生长因子BB支架(记为PCL/β-TCP/PDGF BB支架)。(2)体外实验：将骨髓间充质干细胞、人脐静脉内皮细胞分别接种于两种支架上,检测骨髓间充质干细胞的成骨分化情况,检测人脐静脉内皮细胞的增殖、黏附与成血管基因表达。(3)体内实验：取21只成年大鼠,建立双侧胫骨缺损模型,实验组植入PCL/β-TCP/PDGF BB支架,对照组植入PCL/β-TCP支架,空白组不植入支架,每组7只。术后12周,进行Micro-CT扫描、骨组织形态学观察及成骨与成血管基因检测。结果与结论：(1)体外实验：与PCL/β-...     

凝胶包埋骨髓基质干细胞复合脱钙骨基质修复关节软骨缺损简

目的探索Ⅱ型胶原凝胶包埋的自体骨髓基质干细胞（BMSCs）接于同种异体脱钙骨基质（DBM）材料修复兔关节软骨缺损的效果。方法15只健康成年新西兰大白兔,雌雄不限,体质量约3．0kg,兔龄6。9个月;以Urist方法制作同种异体DBM材料。以Ⅱ型胶原蛋白配制水凝胶．以水凝胶包埋兔BMSCs并接种于同种异体DBM材料,构建组织工程复合物。在新西兰大白兔股骨髁关节面制造软骨缺损。分组进行修复。将健康成年新西兰大白兔27只（雌雄不限,体质量约2．5kg．兔龄3～4个月）共54侧膝关节随机分为Ⅱ型胶原／DBM／BMSCs修复组（实验组）、Ⅱ型胶原／DBM修复组（实验对照组）及空白对照组。于术后4周、8周及12周各处死9只动物,取材对修复组织进行大体及组织学观察,根据Wakitani法对修复组织进行评分．数据输入SPSS11．5软件进行统计学分析,比较各组的评分差异是否具有统计学意义。结果实验组Ⅱ型胶原／DBM／BMSCs植入后形成透明软骨样修复．表面光滑平坦,与周围软骨及软骨下骨结合良好;实验对照组Ⅱ型胶原／DBM植入后有部分软骨样修复：而空白对照组仅有少量纤维性修复。根据组织学评分标准,实验组组织学评分为（20．25±1．64）分,高于实验对照组[（7．46±1．29）分]及空白对照组[（6．00±2．09）分]。结论Ⅱ型胶原自体BMSCs复合同种异体DBM支架材料修复全层关节软骨缺损的效果良好,是一种修复软骨缺损的行之有效的方法。     

骨髓间充质干细胞与同种异体骨复合修复犬下颌骨缺损：成骨能力检测

 背景：同种异体骨与自体骨有相似解剖外形和生物学特性,是较佳的生物支架材料。自体骨髓来源的间充质干细胞具有多分化潜能,能向成骨、成软骨细胞分化,加速骨组织及软骨组织的形成。目的：探讨同种异体骨支架复合自体骨髓间充质干细胞促进犬下颌骨半侧缺损的新骨成骨能力。方法：拔出24只比格犬左侧下颌牙,伤口愈合后2个月,人为造成犬下颌骨缺损,对照组用单纯冻干同种异体骨修复,实验组用同种异体冻干骨加自体骨髓间充质干细胞修复。术后4,12,24周对下颌骨体部进行骨密度扫描以及Micro-CT检查。结果与结论：实验组移植后12周开始,下颌骨的骨密度显著高于对照组(P < 0.05),随着时间推移,实验组和对照组骨密度均增高,但实验组增高明显高于对照组。随时间推移,实验组骨结构参数成阶梯式递增或递减,对照组虽也有递增或递减,但不明显。术后24周实验组感兴趣区骨小梁分离度大于对照组(P < 0.05),骨体积分数、骨小梁数量、骨小梁厚度小于对照组(P < 0.05)。结果表明骨髓间充质干细胞能加速同种异体骨的骨改建速度。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

Evaluation of the osteoconductivity of α-tricalcium phosphate, β-tricalcium phosphate, and hydroxyapatite combined with or without simvastatin in rat calvarial defect

The purpose of this study is to evaluate the osteoconductivity of three different bone substitute materials: α-tricalcium phosphate (α-TCP), (β-TCP), and hydroxyapatite (HA), combined with or without simvastatin, which is a cholesterol synthesis inhibitor stimulating BMP-2 expression in osteoblasts. We used 72 Wistar rats and prepared two calvarial bone defects of 5 mm diameter in each rat. Defects were filled with the particles of 500-750 μm diameter combined with or without simvastatin at 0.1 mg dose for each defect. In the control group, defects were left empty. Animals were divided into seven groups: α-TCP, β-TCP, HA, α-TCP with simvastatin, β-TCP with simvastatin, HA with simvastatin, and control. The animals were sacrificed at 6 and 8 weeks. The calvariae were dissected out and analyzed with micro CT. The specimens were evaluated histologically and histomorphometrically. In α-TCP group, the amount of newly formed bone was significantly more than both HA and control groups but not significantly yet more than β-TCP group. Degradation of α-TCP was prominent and β-TCP showed slower rate while HA showed the least degradation. Combining the materials with Simvastatin led to increasing in the amount of newly formed bone. These results confirmed that α-TCP, β-TCP, and HA are osteoconductive materials acting as space maintainer for bone formation and that combining these materials with simvastatin stimulates bone regeneration and it also affects degradability of α-TCP and β-TCP. Conclusively, α-TCP has the advantage of higher rate of degradation allowing the more bone formation and combining α-TCP with simvastatin enhances this property.     

Orthodontic tooth movement in alveolar cleft repaired with a tissue engineering bone: an experimental study in dogs

Tissue engineering approaches have been successfully used in repairing bone defects and have become a viable alternative to autologous bone. The aim of the present study was to investigate if a construct of porous beta-tricalcium phosphate (β-TCP) combined with osteogenically induced bone marrow stromal cells (bMSCs) could repair alveolar cleft, and allow for subsequent orthodontic tooth movement in a canine model. Twelve alveolar osteotomy surgeries in six animals were made bilaterally and randomly implanted by (1) tissue-engineered bone complex of bMSCs/β-TCP (group A, n=4), (2) β-TCP alone (group B, n=4), and (3) autologous bone obtained from iliac bone (group C, n=4). Contralateral alveolar defects were created in one animal and left untreated to serve as blank control to observe spontaneous healing of the defects. Sequential fluorescent labeling and radiographic observation was used to evaluate new bone formation and mineralization in each defect. Orthodontic tooth movement was initiated 8 weeks after surgical operation for 12 weeks, and then the dogs were sacrificed for histological and histomorphometric analysis. Results indicated that the tissue-engineered complex with bMSCs/β-TCP dramatically promoted new bone formation and mineralization and achieved a favorable height of the repaired alveolar when compared with β-TCP alone, which absorbed severely. The overall effect of the tissue-engineered bone was equivalent to autologous bone; the physiological function of the alveolar bone was restored by allowing the adjacent teeth to move into the newly formed bone in the grafted region. This study demonstrated that the tissue engineering bone from the combination of β-TCP and bMSCs is a feasible clinical approach for patients with alveolar cleft and the subsequent orthodontic tooth movement.     

Repair of rabbit radial bone defects using bone morphogenetic protein-2 combined with 3D porous silk fibroin/β-tricalcium phosphate hybrid scaffolds

Our study aimed to investigate the effect of bone morphogenetic protein-2 (BMP-2) bound to silk fibroin and β-tricalcium phosphate (SF/β-TCP) hybrid on the healing of critical-size radial defects in rabbits. A 15-mm critical-size defect was induced at mid-diaphysis in the left radius of 20 New Zealand white rabbits (average age, 3.5 months; weight, 2.5–3.0 kg). The animals were randomized into Group 1 (SF/β-TCP combined with BMP-2), Group 2 (SF/β-TCP alone), and Group 3 (nothing implanted). Radiographs were obtained every 2 weeks and euthanasia was performed after 8 weeks for visual, radiological, micro-computed tomography (micro-CT), and histological studies. Eight weeks after implantation (SF/β-TCP combined with BMP-2), radiographs showed that new bone formed on the surface of the implant and had bridged the defect in Group 1. Micro-CT imaging also confirmed the formation of new bone around the implant, and the newly formed bone was quantified. Histological examination revealed newly formed bone in the implanted area. Meanwhile, there was no formation of new bone in Group 3. Among the groups, most active formation of new bones was found in Group 1, while there was no difference between Group 2 and Group 3. Based on these results, we concluded that BMP-2-SF/β-TCP showed significant improvement in healing of critical-size defects. Therefore, the combination of BMP-2 and SF/β-TCP would be useful in the field of bone tissue engineering.     

In vivo growth and differentiation potential of tracheal basal cells of rabbits in vitamin A deficiency

The growth and differentiation potential of rabbit tracheal basal cells were investigated in vitamin A deficient mice. Denuded rat tracheal grafts were xenotransplanted into nude mice made vitamin A deficient by feeding them retinol-free pellets from mid-gestation. Rabbit tracheal epithelial cells harvested enzymatically or cells derived from a basal-cell-rich fraction obtained by elutriation (purity 93.3%) had previously been inoculated into the grafts ( n  = 8, each). The grafts were implanted into the vitamin A deficient or control mice aged about 10 weeks. Four weeks later, the grafts were retrieved for histological examination.
The graft epithelium established by either basal cells or un-fractionated cells in vitamin A deficient hosts (groups 1 and 2, respectively) was atrophic, whereas grafts repopulated with both cell types in the controls had pseudostratified columnar epithelium. Group 1 and 2 grafts both showed squamous metaplasia; 10 metaplastic foci in 32 tracheal rings in group 1 ( P  < 0.02 or 0.002, compared with values for group 2 or controls, respectively), and 2 foci in 35 rings in group 2 (no statistical difference compared with controls).
In conclusion, during vitamin A deficiency, rabbit tracheal epithelial cells, including the progeny of highly-purified basal cells, lost their potential for establishing a mucociliary epithelium and rather appeared to undergo squamous metaplasia.     

Replacement of a tracheal defect with autogenous mucosa lined tracheal prosthesis made from polypropylene mesh

Reliable prosthetic or tissue grafts for the trachea have not, as yet, been developed for reconstruction of large, circumferential tracheal defects. Major limitations are anastomotic dehiscence and stenosis, attributed to the poor epithelialization and vascularization of the prosthetic graft. We have developed a new tracheal prosthesis that has a well vascularized and viable mucosa. The prosthesis consists of a Prolene mesh reinforced with polypropylene rings, and coated with gelatin. We lined the luminal surface of the prosthesis with transplanted autogenous oral mucosa, wrapped the prosthesis with greater omentum, and placed it in the peritoneal cavity for 2 weeks. Complete surgical resection and replacement of a segment (5 cm in length, 8 to 10 tracheal rings) of the thoracic trachea was then performed in nine adult mongrel dogs. The transplanted mucosa was well vascularized and maintained its normal histology in prereplacement analysis. Dogs with tracheal replacement regained their full activity and did not show any respiratory problems until sacrifice at 1, 2, and 6 months. After 6 months, the prostheses were completely incorporated by the host trachea in all dogs and confluent epithelialization was confirmed histologically from the upper to the lower anastomotic site of the prosthesis; furthermore, the transplanted mucosal cells had changed to ciliated columnar epithelium.     

Implantation of green tea catechin α-tricalcium phosphate combination enhances bone repair in rat skull defects

The purpose of the present study is to investigate effects of the combination of epigallocatechin-3-gallate (EGCG) and α-tricalcium phosphate (α-TCP) on bone regenerative capacity in a bilateral rat calvarial bone defect model. Materials and methods: Bilateral 5-mm-diameter calvarial defects were created in adult male Wistar rats and filled with preparations of EGCG (0, 0.1, 0.2, 0.4 mg) combined with α-TCP particles. This was done by dissolving EGCG in 100% ethanol (50 μL/14 mg) and dropping under sterile condition. The control group was left unfilled (n = 8). The animals were sacrificed at 2 and 4 weeks. Radiological images were taken, and histological analysis was done. Six animals from control (0 mg EGCG + α-TCP) group and (0.2 mg EGCG+ α-TCP) group were labeled with fluorescent dyes and histomorphometrically analyzed (n = 6) at 2 and 4 weeks. Results: Histomorphometric analysis revealed that the combination of EGCG and α-TCP at doses of 0.1 and 0.2 mg yielded significantly more new bone formation than untreated control group at 2 and 4 weeks (p > 0.05). Mineral apposition rate at 0.2-TCP group was enhanced compared with the one of the positive control α-TCP group at 4 weeks (p > 0.05). Conclusion: The combination of α-TCP particles and 0.2 mg EGCG stimulates maximum bone regeneration in rat calvarial defects, and this combination would be potentially effective as bone graft material.     

Development of new tracheal prosthesis: autogenous mucosa-lined prosthesis made from polypropylene mesh

Reliable tracheal or tissue graft has not been developed yet for the reconstruction of large, circumferential tracheal defects. Major limitations were anastomotic dehishence and stenosis, which were attributed to the poor epithelisation of the prosthetic graft. We developed a new tracheal prosthesis that has a viable lined and well-vascularized mucosa. The prosthesis consists of Prolene mesh reinforced with polypropylene rings, and is coated with gelatin. In addition, we lined the luminal surface of the prosthesis with transplanted autogenous oral mucosa and wrapped the prosthesis with greater omentum. Animal experiments were performed using 10 adult mongrel dogs. The transplanted mucosa and wrapped greater omentum tightly adhered to the prosthesis to make a single unit within two weeks. The mucosa survived well, was well vascularised by new vessels from greater omentum and showed normal histology. Complete surgical resection and replacement of a thoracic trachea (3 cm in length, 6 tracheal rings) were carried out in 2 dogs, which survived well with normal activity. We concluded that this highly biocompatible tracheal prosthesis could be very useful for step-wise reconstruction of tracheal defects.     

三种材料缝合气管吻合口愈合中的生物力学特征与气管重塑

背景：研究表明气管及支气管吻合材料的选用对吻合口愈合质量可产生不同影响。 目的：以3种缝合材料建立兔气管重建模型,分析气管吻合口愈合过程中生物力学特征与气管重塑的关系。 方法：将18只新西兰大白兔随机分为3组,分别以丝线、涤纶线和人工合成可吸收缝线建立气管重建模型。 结果与结论：①吻合口处气管抗拉强度：术后2周,3组气管在一定外力下于接近吻合口处断裂,缝线本身并未断裂;术后4,8周,吻合气管在远离吻合口部位破裂,均未从吻合口处断裂。②吻合口处气管顶破强度：术后2,4,8周,3组均在气管膜部破裂。③吻合口Ⅰ型胶原蛋白水平：术后2周涤纶线组低于较其他两组(P < 0.05),术后4,8周3组间差异无显著性意义。表明不论使用何种缝线均不影响气管吻合口的稳定性,但不同缝线在不同时期引起的气管狭窄有一定差别。     

β-磷酸三钙/聚磷酸钙纤维/聚左旋乳酸支架复合骨髓基质细胞修复节段性骨缺损

背景：组织工程β-磷酸三钙/聚磷酸钙纤维/聚左旋乳酸支架材料具有良好的生物相容性。 目的：评估骨髓基质细胞与β-磷酸三钙/聚磷酸钙纤维/聚左旋乳酸复合体修复兔桡骨大段骨缺损成骨的效果。 方法：取新西兰大白兔40只,建立桡骨双侧大段骨缺损模型,其中35只右侧植入自体骨髓基质细胞与β-磷酸三钙/聚磷酸钙纤维/聚左旋乳酸复合物作为实验组,左侧植入β-磷酸三钙/聚磷酸钙纤维/聚左旋乳酸支架材料作为对照组;另5只作为空白对照不作任何处理。植入后4,8,12,16周拍摄X射线片观察骨缺损修复情况。 结果与结论：实验组术后2周可见缺损处有散在的、少量模糊状骨痂生成,术后4周可见明显骨生成影像,成云雾状,均匀分布在骨缺损区,术后8周整个缺损区均可见骨痂生成,成骨现象更加明显,部分髓腔已通,术后12~16周,缺损区已完全被新生骨组织充填,骨髓腔已完全再通,修复区较正常桡骨细,骨缺损修复效果明显优于对照组与空白对照组(P < 0.01)。说明自体骨髓基质细胞与β-磷酸三钙/聚磷酸钙纤维/聚左旋乳酸复合移植可较完全修复大节段骨缺损。