Autologous osteochondral transplantation for the treatment of chondral defects of the knee

Full-thickness chondral defects of weight-bearing articular surfaces of the knee are a difficult condition to treat. Our aim is to evaluate the mid- and long-term functional outcome of the treatment of osteochondral defects of the knee with autologous osteochondral transplantation with the OATS technique. Thirty-six patients (37 procedures) were included in this study. Twenty-three patients were male and thirteen were female with a mean age of 31.9 years (range: 18-48 years). The cause of the defect was OCD in 10 cases, AVN in 2, lateral patellar maltracking in 7, while in the remaining 17 patients the defect was post-traumatic. The lesion was located on the femoral condyles in 26 cases and the patellofemoral joint in the remaining 11. The average area covered was 2.73 cm(2) (range: 0.8-12 cm(2)) and patients were followed for an average of 36.9 months (range: 18-73 months). The average score in their Tegner Activity Scale was 3.76 (range: 1-8), while their score in Activities of Daily Living Scale of the Knee Outcome Survey ranged from 18 to 98 with an average of 72.3. Thirty-two out of 37 patients (86.5%) reported improvement of their pre-operative symptoms. All but 5 patients returned to their previous occupation while 18 went back to sports. No correlation was found between patient age at operation, the size or site of the chondral lesion and the functional outcome. We believe that autologous osteochondral grafting with the OATS technique is a safe and successful treatment option for focal osteochondral defects of the knee. It offers a very satisfactory functional outcome and does not compromise the patient's future options.     

An anti-inflammatory cell-free collagen/resveratrol scaffold for repairing osteochondral defects in rabbits

Inflammatory factor overexpression is the major cause of cartilage and osteochondral damage. Resveratrol (Res) is known for its anti-inflammatory, antioxidant and immunmodulatory properties. However, these effects are hampered by its water insolubility and rapid metabolism in vivo. To optimize its therapeutic efficacy in this study, Res was grafted to polyacrylic acid (PAA, 1000 Da) to obtain a macromolecular drug, PAA-Res, which was then incorporated into atelocollagen (Coll) hydrogels to fabricate anti-inflammatory cell-free (Coll/Res) scaffolds with improved mechanical strengths. The Coll/Res scaffolds demonstrated the ability to capture diphenylpicrylhydrazyl free radicals. Both pure Coll and Coll/Res scaffolds could maintain their original shape for 6 weeks in phosphate buffered saline. The scaffolds were degraded by collagenase over several days, and the degradation rate was slowed down by Res loading. The Coll and Coll/Res scaffolds with excellent cytocompatibility were shown to promote the proliferation and maintain the normal phenotype of the seeded chondrocytes and bone marrow stromal stem cells (BMSCs). In addition, the Coll/Res scaffold exhibited the capacity to protect the chondrocytes and BMSCs against reactive oxygen species. The acellular Coll/Res scaffolds were transplanted into the rabbit osteochondral defects. After implantation for 2, 4 and 6 weeks, the samples were retrieved for quantitative real-time polymerase chain reaction, and the inflammatory related genes interleukin-1β, matrix metalloproteinases-13, COX-2 and bone and cartilage related genes SOX-9, aggrecan, Coll II and Coll I were determined. Compared with the untreated defects, the inflammatory related genes were down-regulated and those bone and cartilage related genes were up-regulated by filling the defect with an anti-inflammatory scaffold. After 12 weeks, the osteochondral defects were completely repaired by the Coll/Res scaffold, and the neo-cartilage integrated well with its surrounding tissue and subchondral bone. Immunohistochemical and glycosaminoglycan staining confirmed the distribution of Coll II and glycosaminoglycans in the regenerated cartilage. The anti-inflammatory acellular Coll/Res scaffolds are convenient to administer in vivo, holding a greater potential for future clinical applications.     

自体软骨细胞移植和微骨折术修复膝关节软骨缺损的Meta分析

背景：现有一些文献报道证实,自体软骨细胞移植治疗膝关节软骨缺损在某些方面较微骨折术好,但关于两种术式优劣比较,尚缺乏循证医学方面证据。 目的：整合现有临床研究的数据进行系统和科学的分析,明确自体软骨细胞移植是否在提高临床功能方面优越于微骨折术。 方法：文章检索了电子数据库MEDLINE,EMBASE,CINAHL和 Cochrane Register数据库,万方数据库、中国知识资源总库和维普数据库,检索时间从1979年到2015年1月。收集自体软骨细胞移植和微骨折术治疗膝关节软骨缺损疗效的相关文献,按纳入与排除标准筛选文献并对其进行质量评价,运用 RevMan 5.2软件进行Meta分析。 结果与结论：共纳入8篇文献。在比较最终随访的IKDC评分(WMD=-9.93;95%CI：-13.16至-5.43;P < 0.000 01)和5年随访的各项评分(SMD=-0.30;95%CI：-0.55至-0.05;P=0.02)方面,自体软骨细胞移植比微骨折术能更好的改善患者的临床功能。在最终随访的Tegner评分(WMD=0.44;95%CI：0.04至0.84;P=0.03),最终随访的Lysholm评分(WMD=-10.21;95%CI：-33.68至13.26;P=0.39)和2年随访的各项评分(SMD=-0.25;95%CI：-0.92至0.43;P= 0.47)的对比中,未发现微骨折术的优越性。结果证实,自体软骨细胞移植能带来更稳定更长久的临床功能,并且在一定程度上比微骨折术更能达到缓解疼痛、提高功能的目的。但是在一般情况下,自体软骨细胞移植是否都优越于微骨折术需要更多的临床研究来支持。     

A prospective, randomised study comparing two techniques of autologous chondrocyte implantation for osteochondral defects in the knee: Periosteum covered versus type I/III collagen covered

INTRODUCTION: The results for autologous chondrocyte implantation (ACI) in the treatment of full thickness chondral defects in the knee are encouraging. At present two techniques have been described to retain the chondrocyte suspension within the defect. The first involves using a periosteal cover (ACI-P) and the second involves using a type I/III collagen membrane (ACI-C). To the authors knowledge there are no comparative studies of these two techniques in the current literature. We have therefore undertaken such a study to establish if there is a difference between the 2 techniques based on a clinical and arthroscopic assessment. METHODS: A total of 68 patients with a mean age of 30.52 years with symptomatic articular cartilage defects were randomised to have either ACI-P (33 patients) or ACI-C (35 patients). The mean defect size was 4.54 cm2. All patients were followed up at 24 months. RESULTS: A clinical and functional assessment showed that 74% of patients had a good or excellent result following the ACI-C compared with 67% after the ACI-P at 2 years. Arthroscopy at 1 year also demonstrated similar results for both techniques. However, 36.4% of the ACI-P grafts required shaving for hypertrophy compared with none for the ACI-C grafts at 1 year. DISCUSSION: This study has shown no statistical difference between the clinical outcome of ACI-C versus ACI-P at 2 years. A significant number of patients who had the ACI-P required shaving of a hypertrophied graft. We conclude that there is no advantage in using periosteum as a cover for retaining chondrocytes within an osteochondral defect; as a result we advocate the use of an alternative cover such as a manufactured type I/III collagen membrane.     

Repair of osteochondral defects in rabbits with ectopically produced cartilage

Cartilage has poor regenerative capacity. Donor site morbidity and interference with joint homeostasis should be considered when applying the autologous chondrocyte transplantation technique. The use of ectopically produced cartilage, derived from periosteum, might be a novel method to heal cartilage defects. Ectopic cartilage was produced by dissecting a piece of periosteum from the tibia of rabbits. After 14 days the reactive tissue at the dissection site was harvested and a graft was cored out and press-fit implanted in an osteochondral defect in the medial condyle of the femur with or without addition of hyaluronan. After 3 weeks and 3 months the repair reaction was evaluated by histology. Thionine- and collagen type II-stained sections were evaluated for graft viability, ingrowth of the graft, and joint surface repair. Empty defects remained empty 3 weeks after implantation, ectopic cartilage filled the defect to the level of the surrounding cartilage. Histologically, the grafts were viable, consisting mainly of cartilage, and showed a variable pattern of ingrowth. Three months after implantation empty defects with or without hyaluronan were filled primarily with fibrocartilaginous tissue. Defects treated with ectopic cartilage contained mixtures of fibrocartilaginous and hyaline cartilage. Sometimes a tidemark was observed in the new articular cartilage and the orientation of the cells resembled that of healthy articular cartilage. Subchondral bone repair was excellent. The modified O'Driscoll scores for empty defects without and with hyaluronan were 12.7 +/- 6.4 and 15.3 +/- 3.2; for treated defects scores were better (15.4 +/- 3.9 and 18.2 +/- 2.9). In this conceptual study the use of ectopic cartilage derived from periosteum appears to be a promising novel method for joint surface repair in rabbits.     

Autologous chondrocyte implantation for treatment of focal chondral defects of the knee--a clinical, arthroscopic, MRI and histologic evaluation at 2 years

To determine the efficacy of autologous chondrocyte implantation (ACI) in treating focal chondral defects of the knee, we reviewed the 2-year treatment outcome of ACI in 53 patients (72 lesions) through clinical evaluation, MRI, second-look arthroscopy and biopsies obtained. Improvement in mean subjective score from preoperative (37.6) to 12 months (56.4) and 24 (60.1) months post-ACI were observed. Knee function levels also improved [86% International Cartilage Repair Society (ICRS) III/IV to 66.6% I/II] from preoperative period to 24 months postimplantation. Objective IKDC score of A or B were observed in 88% preoperatively. This decreased to 67.9% at 3 months before improving to 92.5% at 12 months and 94.4% at 24 months post implantation. Transient deterioration in all these clinical scores was observed at 3 months before progressive improvement became evident. MRI studies demonstrated 75.3% with at least 50% defect fill, 46.3% with near normal signal, 68.1% with mild/no effusion and also 66.7% with mild/no underlying bone marrow oedema at 3 months. These values improved to 94.2%, 86.9%, 91.3% and 88.4%, respectively, at 12 months. At 24 months, further improvements to 97%, 97%, 95.6% and 92.6%, respectively, were observed. Second-look arthroscopy carried out in 22 knees (32 lesions) demonstrated all grafts to be normal/nearly normal based on the International Cartilage Repair Society (ICRS) visual repair assessment while core biopsies from 20 lesions demonstrated 13 grafts to have hyaline/hyaline-like tissue. Improvement in clinical and MRI findings obtained from second-look arthroscopy and core biopsies evaluated indicate that, at 24 months post-ACI, the resurfaced focal chondral defects of the knee remained intact and continued to function well.     

Treatment with bioscaffold enhances the the fibril morphology and the collagen composition of healing medial collateral ligament in rabbits

Porcine small intestinal submucosa (SIS) was shown to be an effective bioscaffold in enhancing the mechanical properties of healing medial collateral ligaments (MCL). The purpose of this study was to investigate whether there are corresponding improvements in morphology and tissue compositions. Fourteen rabbits were equally divided into two groups. In the SIS-treated group, a 6 mm gap was surgically created in the right MCL and a layer of SIS was sutured covering the gap. For the nontreated group, the gap-injured MCLs remained untreated. All the left MCLs were sham operated and used as controls. At 12 weeks, the status of collagen types I and V was evaluated with immunofluorescent staining. The collagen type V/I ratios were obtained using SDS-PAGE. Collagen fibril diameters were calculated from the transmission electron micrographs. The results revealed that in the SIS-treated group, the collagen fibers were more regularly aligned as were the cell nuclei. The collagen fibril diameters were 22.2% larger and the ratio of collagen type V/I was 28.4% lower than those for the nontreated group (p < 0.05). These improvements in the morphological characteristics and biochemical constituents of healing MCLs following SIS treatment are the likely reasons for improved mechanical properties.     

In vivo analysis of retroviral gene transfer to chondrocytes within collagen scaffolds for the treatment of osteochondral defects

To examine a retroviral gene transfer to chondrocytes in vitro and in vivo in tissue-engineered cell-collagen constructs articular chondrocytes from rabbits and humans were isolated and transduced with VSV.G pseudotyped murine leukemia virus-derived retroviral vectors. Viral supernatants were generated by transient transfection of 293T cells using the pBullet retroviral vector carrying the nlslacZ gene, a Moloney murine leukemia virus gag/pol plasmid and a VSV.G coding plasmid. Transduction efficiency was analyzed by fluorescence-activated-cell-sorter analysis and transduced autologous chondrocytes from rabbits were seeded on collagen-scaffolds and implanted into osteochondral defects in the patellar groove of the rabbit's femur (n=10). LacZ-expression was analyzed by X-gal staining on total knee explants and histological sections. Retroviral transduction efficiency exceeded 92.3% (SEM+/-3.5%) in rabbit articular chondrocytes, 74.7% (SEM+/-1.8%) in human articular chondrocytes and 52.7% (SEM+/-5.8%) in osteoarthritic human chondrocytes. Reporter gene expression remained high after 15 weeks in 75.7% (SEM+/-8.2%) of transduced rabbit articular chondrocytes. In vivo, intraarticular beta-galactosidase activity could be determined in the majority of implanted chondrocytes in the osteochondral defects after 4 weeks.     

Extended scope of autologous chondrocyte implantation for osteochondral injuries following septic arthritis: A case report

We report the 9-year clinical, radiographic and histological outcome of autologous chondrocyte implantation (ACI) used to treat massive cartilage lesions of the medial femoral condyle and patella in an adolescent patient after osteomyelitis and subsequent septic arthritis of the knee. This is the first reported case of ACI performed in the knee for significant chondral lesions secondary to infective changes. Long-term clinical success was achieved using this method, which was outside the usual indications for ACI.     

Antibiotic-containing collagen for the treatment of bone defects

Recent studies have explored the use of biodegradable implants that incorporate antibiotics for the treatment of bone infections. In this study, a biodegradable composite containing bovine collagen and teicoplanin (Targobone) was used for the treatment of mandibular nonunion defects. Patients with mandibular nonunion defects subsequent to osteosynthesis were treated with Targobone (n = 9) or with autologous bone grafts (n = 12). Clinical and radiological evaluations were performed preoperatively, immediately postoperatively, and 4 and 24 weeks postoperatively. Bone regeneration was defined relative to the original defect area in the panoramic radiograph by using image analysis software. In the Targobone group, the defect area decreased to 78% (SD +/- 21.8%) of the preoperative area within 4 weeks and to 21% (SD +/- 9.7%) of the preoperative area within 24 weeks. In the autologous bone graft group, the defect area decreased to 69% (SD +/- 32.4%) of the preoperative area within 4 weeks and to 4.7% (SD +/- 5.6%) of the preoperative area within 24 weeks. Thus, Targobone is a promising option for the treatment of bone defects.     

自体软骨细胞移植修复膝关节骨软骨缺损:再生与天然软骨无明显差异

背景:随着医疗水平的提高和人们对生活质量的更高要求,临床对软骨修复的质量和要求也越来越高,传统修复方法不能再生具有良好生物性能的软骨.目的:综述近年来自体软骨细胞移植的相关研究进展,分析其发展历程、基础科学、适应证、禁忌证、外科技术、临床疗效和局限性,展望该领域的发展趋势.方法:以软骨细胞移植、骨缺损、临床技术、临床...     

软骨移植与软骨微骨折方法修复关节软骨损伤

背景：文献介绍微骨折与骨软骨移植治疗关节软骨缺损都有效,均为目前临床治疗手段。 目的：比较微骨折与骨软骨移植在关节软骨缺损治疗中的实施效果。 方法：回顾性分析50例(50个膝关节)关节软骨缺损患者的临床资料。按照外科修复方式分为2组,每组25例。骨软骨移植组患者采用自体骨软骨移植修复膝关节软骨缺损;微骨折组患者运用微骨折方法修复膝关节软骨缺损。两组患者均随访超过24个月,比较两组患者的膝关节美国特种外科医院(Hospital for Special Surgery,HSS)评分及临床疗效,观察两组患者不良反应和并发症。 结果与结论：骨软骨移植组患者的膝关节HSS评分> 85分和60-85分患者数量明显多于微骨折组(P < 0.05),骨软骨移植组总有效率显著高于微骨折组(92%,60.0%,P < 0.05)。两组患者均无并发症发生。结果表明骨软骨移植在关节软骨缺损治疗中较微骨折具有较好的实施效果。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

微骨折技术与骨软骨移植治疗关节软骨缺损

背景：关节镜下微骨折治疗与骨软骨移植是关节软骨缺损主要的治疗方法之一,具有广阔的应用前景。 目的：探讨关节镜下微骨折治疗与自体和同种异体骨软骨移植治疗膝骨关节炎合并关节软骨缺损的效果。 方法：应用关节镜下微骨折治疗清理术结合软骨缺损区微骨折术治疗膝骨关节炎的临床疗效、临床症状及Tegner运动评级判定疗效并随访观察3-24个月。自体骨软骨移植治疗关节软骨缺损的患者进行观察随访,通过评价移植后关节活动度、临床症状的改善、关节影像学检查等评估自体骨软骨移植治疗的效果。并对同种异体骨软骨移植治疗关节软骨缺损进行动物实验研究,通过对移植部位的大体观察、组织学观察以及免疫组织化学染色观察,评估同种异体骨软骨移植治疗的效果。 结果与结论：关节软骨缺损应用关节镜下微骨折治疗后的患者,关节清理术结合软骨缺损区微骨折术总有效率89.7%。关节软骨缺损应用自体骨软骨移植治疗后的患者,关节疼痛、肿胀的症状改善,关节活动度正常,偶有关节静息痛或活动后轻微疼痛,影像学检查见移植骨软骨位置良好,修复愈合良好。关节软骨缺损应用同种异体骨软骨移植治疗后的实验动物,关节活动度正常,移植关节面光整,关节软骨被透明软骨覆盖,细胞有序排列,软骨基质分泌,修复软骨Ⅱ型胶原免疫组织化学染色强阳性。     

Cell-laden and cell-free biopolymer hydrogel for the treatment of osteochondral defects in a sheep model

The objective of the current study was to determine the suitability of cell-laden and cell-free alginate-gelatin biopolymer hydrogel for osteochondral restoration in a sheep model (n = 12). Four femoral defects per animal were filled with hydrogel (cHG) plus autologous chondrocytes (cHG + C) or periosteal cells (cHG + P) or gel only (cHG) or were left untreated (E). In situ solidification enabled instantaneous implant fixation. Sixteen weeks postoperatively, defect sites were processed for light microscopy and immunofluorescence. A modified Mankin and a semi-quantitative immunoreactivity score were used to evaluate histology and immunofluorescence, respectively. Defects after cHG + C were restored with smooth, hyaline-like neo-cartilage and trabecular subchondral bone. cHG + P and cHG treatments revealed slightly inferior regenerate morphology. Undifferentiated tissue was found in E. The histological score showed significant (p < 0.05) differences between all treatment groups. In conclusion, cHG induces satisfactory defect regeneration. Complete filling of the cavity in one step and subsequent rapid in situ solidification was feasible and facilitated graft fixation. Cell implantation might be beneficial, because cells seem to play a key role in histological outcome. Still, their contribution to the repair process remains unresolved because host cell influx takes place. The combination of alginate and gelatin, however, creates an environment capable of serving implanted and host cells for osteo-chondrogenic tissue regeneration.     

Management of big osteochondral defects of the knee using osteochondral allografts with the MEGA-OATS technique

Treatment of osteochondral defects in weight-bearing areas of the knee, especially when they are sizeable and involve considerable subchondral bone loss, is a challenging problem. We report our experience on the use of osteochondral allografts with the MEGA-OATS technique in the management of large osteochondral defects of the knee in young patients. Five patients (3 male and 2 female) were included in this study; their age ranged from 22 to 41 years and the mean size of the defect covered was 30 x 30 mm. They were followed for a minimum of 2.5 years (mean: 32.8 months, range 30-36). An age- and size-matched fresh frozen, non-irradiated distal femoral allograft was used to obtain the donor plug, which was then inserted in the recipient area in a press-fit fashion. Patients' Lysholm knee score increased from 37.8 pre-operatively to 73.8 post-operatively. Tegner activity score increased in all five patients; it improved from a mean of 2 pre-operatively (range 1-3) to 4 post-operatively (range 2-7). Four out of five patients returned to work and three went back to sporting activities. With this technique one can cover sizeable osteochondral defects, and compensate for significant subchondral bone loss, while accurate reconstruction of the curvature of the femoral condyle is allowed. We believe that it is a viable salvage option in young patients with big osteochondral defects of the knee. It offers very satisfactory functional results and does not compromise patients' future options.     

Evaluation of a hybrid scaffold/cell construct in repair of high-load-bearing osteochondral defects in rabbits

The objective of this study was to evaluate the feasibility and potential of a hybrid scaffold system in large- and high-load-bearing osteochondral defects repair. The implants were made of medical-grade PCL (mPCL) for the bone compartment whereas fibrin glue was used for the cartilage part. Both matrices were seeded with allogenic bone marrow-derived mesenchymal cells (BMSC) and implanted in the defect (4 mm diameter x 5 mm depth) on medial femoral condyle of adult New Zealand White rabbits. Empty scaffolds were used at the control side. Cell survival was tracked via fluorescent labeling. The regeneration process was evaluated by several techniques at 3 and 6 months post-implantation. Mature trabecular bone regularly formed in the mPCL scaffold at both 3 and 6 months post-operation. Micro-Computed Tomography showed progression of mineralization from the host-tissue interface towards the inner region of the grafts. At 3 months time point, the specimens showed good cartilage repair. In contrast, the majority of 6 months specimens revealed poor remodeling and fissured integration with host cartilage while other samples could maintain good cartilage appearance. In vivo viability of the transplanted cells was demonstrated for the duration of 5 weeks. The results demonstrated that mPCL scaffold is a potential matrix for osteochondral bone regeneration and that fibrin glue does not inherit the physical properties to allow for cartilage regeneration in a large and high-load-bearing defect site.     

Differential cell viability of chondrocytes and progenitor cells in tissue-engineered constructs following implantation into osteochondral defects

Animal studies in cartilage tissue engineering usually include the transfer of cultured cells into chondral or osteochondral defects. Immediately at implantation, the cells are exposed to a dramatically changed environment. The aim of this study was to determine the viability of two cell types currently considered for cellular therapies of cartilage defects-chondrocytes and progenitor cells-shortly after exposure to an osteochondral defect in rabbit knees. To that end, autogenic chondrocytes and periosteal cells were labeled with CM-DiI fluorochrome, seeded or cultured in PEGT/PBT scaffolds for periods up to 2 weeks, transferred into osteochondral defects, harvested 5 days postimplantation, and analyzed for cell viability. In order to further elucidate factors effecting cell viability within our model system, we investigated the effect of serum, 2) extracellular matrix surrounding implanted cells, 3) scaffold interconnectivity, and 4) hyaluronan, as a known cell protectant. Controls included scaffolds with devitalized cells and scaffolds analyzed at implantation. We found that the viability of periosteum cells (14%), but not of chondrocytes (65-95%), was significantly decreased after implantation. The addition of hyaluronan increased periostium cell viability to 44% (p < 0.05). Surprisingly, cell viability in less interconnected compression-molded scaffolds was higher compared to that of fully interconnected scaffolds produced by rapid prototyping. All other factors tested did not affect viability significantly. Our data suggest chondrocytes as a suitable cell source for cartilage repair in line with clinical data on several chondrocyte-based therapies. Although we did not test progenitor cells other the periosteum cells, tissue-engineering approaches using such cell types should take cell viability aspects into consideration.     

Autologous bone versus calcium-phosphate ceramics in treatment of experimental bone defects

Autologous bone grafting is currently considered the treatment of choice for correction of large bone defects. However, to avoid morbidity associated with autologous bone harvesting many artificial bone-substitute materials have been developed over the years. A new generation of resorbable materials is emerging, with promising results so far. In order to investigate the possibility to use one of these new materials as an alternative with better results than hydroxyapatite, an experimental study was performed. A new resorbable calcium phosphate particles and paste forms, the latter of which hardens in situ after application. In 28 sheep, a 3-cm segmental tibial defect was made and intramedullary fixed by an interlocking nail. Twelve weeks after defect filling, radiological, biomechanical, and histological examinations were performed. Mean radiographic and biomechanical tests results were compared with the Mann-Whitney test. Significance was set at p<0.05. Radiographically, the resorbable paste group performed better than all other groups. Biomechanical investigations showed a higher torsional stiffness (p=0.049) for the resorbable calcium-phosphate paste group in comparison with autologous bone. On histological examination, no adverse effects were observed in the calcium-phosphate groups. Resorption by osteoclasts was seen in the resorbable implants. In conclusion, the current study shows an advantageous radiological and mechanical outcome for resorbable calcium phosphates. This indicates that these new materials might be a potential alternative for autologous bone grafting in humans.     

两种交联剂制备软骨细胞移植支架的比较

目的：试用两种交联剂对小牛真皮基质来源的支架材料进行交联,比较支架的细胞毒性、结构、生物相容性和细胞贴附的差异,为在体动物试验提供实验依据。方法将脱细胞真皮基质分为两组,分别浸入0.05%戊二醛溶液和0.2%水溶性交联剂进行交联,MTT 法检测细胞毒性和溶血率。将交联后的支架分别植入大鼠皮下,评价生物相容性。以排液法粗测孔隙率,并在电镜下观察支架的结构和孔隙大小。培养间充质干细胞并贴附于两种方法处理的材料表面,电镜下观察贴附情况。结果以戊二醛溶液和水溶性交联剂两种方法处理的支架细胞毒性检测均合格,溶血率分别为4.61%与2.97%,均符合国家标准。经戊二醛交联的支架生物相容性差,炎症反应始终存在,水溶性交联剂处理的真皮基质组织相容性较好,仅有轻微的炎症反应。水溶性交联剂制备的支架材料孔隙率为84.3%±5.0%,戊二醛制备的支架材料孔隙率为79.7%±10.8%,差异不具有统计学意义（P >0.05）。戊二醛交联的支架细胞贴附差,而水溶性交联剂制备的支架细胞贴附良好。结论应用水溶性交联剂处理的支架细胞毒性和溶血率检测均合格,具有良好的生物相容性、孔隙率和细胞贴附性,该法可以作为后期制备软骨细胞移植支架的交联方法。     

重组人生长激素治疗兔桡骨小段缺损

背景：生长激素可直接作用于外周组织如软骨、骨及脂肪组织等,对骨折应有促愈合作用。 目的：观察重组人生长激素对兔桡骨小段骨缺损的治疗作用。 方法：10只成年新西兰大白兔制备双前臂骨缺损模型,所有模型兔随机分成治疗组和对照组。治疗组造模后第1天开始皮下注射重组人生长激素,连续14 d;对照组同样方法注射等量生理盐水。 结果与结论：治疗组骨痂生长及细胞形态分化与钙质沉着均比对照组快;血糖治疗期间略升高,治疗结束后迅速恢复正常。说明重组人生长激素有促进骨痂生长、加快骨折愈合作用,表明该药可用于骨折及小范围骨缺损的治疗,未见明显不良反应。