Comparative study of chitosan/fibroin–hydroxyapatite and collagen membranes for guided bone regeneration in rat calvarial defects: micro-computed tomography analysis

This study aimed to utilize micro-computed tomography （micro-CT） analysis to compare new bone formation in rat calvarial defects using chitosan/fibroin-hydroxyapatite （CFB-HAP） or collagen （Bio-Gide） membranes. Fifty-four （54） rats were studied. A circular bony defect （8 mm diameter） was formed in the centre of the calvaria using a trephine bur. The CFB-HAP membrane was prepared by thermally induced phase separation. In the experimental group （n= 18）, the CFB-HAP membrane was used to cover the bony defect, and in the control group （n= 18）, a resorbable collagen membrane （Bio-Gide） was used. In the negative control group （n= 18）, no membrane was used. In each group, six animals were euthanized at 2, 4 and 8 weeks after surgery. The specimens were then analysed using micro-CT. There were significant differences in bone volume （BV） and bone mineral density （BMD） （P〈O.05） between the negative control group and the membrane groups. However, there were no significant differences between the CFB-HAP group and the collagen group. We concluded that the CFB-HAP membrane has significant potential as a guided bone regeneration （GBR） membrane.

Repair of Rat Segmental Defects with Mineralized Collagen Grafts Combined with or without Mesenchymal Stem Cells and BMP-2

The aim of the present study was to investigate and compare the bone formation capacity with three different grafts. Four millimeter segmental defects were created in adult rat tibias and were either left empty （control defects） or implanted with （1） nano-hydroxyapatite/collagen/PIA （nHAC/PIA） composite, （2） nHAC/ PIA composite added with bone marrow mesenchymal tem cells （ BMSCs ）, （ 3 ） nHAC/ PIA composite added with bone morphogenetic protein 2 （ BMP- 2）. Radiographs of the defects were taken weekly post-surgery. After 1 or 2 months, the rats were eathaaized. Histologic analyses were performed on the harvested tissue. nHAC/ PIA composite could enhance the repair of rat tibia segmental defects. Addition of BMSCs or BMP- 2 to nHAC/ PIA led to an increase in osteogenesis, nHAC/ PIA composite could be an Meal alternative bone-grafi material and it could also be used as an Meal carrier of BMSCs or BMP- 2.

Electrospun Nanofibers of Hydroxyapatite / Collagen / Chitosan Promote Osteogenic Differentiation of BMSCs

Bone tissue engineering, aiming at developing bone substitutes for repair and regeneration of bone defects instead of using autologous bone grafts,has attracted wide attention in the field of tissue engineering and regenerative medicine.Developing biomimetic biomaterial scaffolds able to regulate osteogenic differentiation of stem cells could be a promising strategy to improve the therapeutic efficacy.In this study, electrospun composite nanofibers of hydroxyapatite / collagen / chitosan( HAp / Col / CTS)resembling the fibrous nanostructure and constituents of the hierarchically organized natural bone,were prepared to investigate their capacity for promoting bone mesenchymal stem cells( BMSCs)to differentiate into the osteogenic lineage in the absence and presence of the osteogenic supplementation, respectively.Cell morphology,proliferation and quantified specific osteogenic protein expression on the electrospun HAp / Col / CTS scaffolds were evaluated in comparison with different controls including electrospun nanofibrous CTS,HAp / CTS and tissue culture plate.Our results showed that the nanofibrous HAp / Col / CTS scaffolds supported better spreading and proliferation of the BMSCs than other substrates( P < 0.01).Expressions of osteogenesis protein markers,alkaline phosphatase( ALP) and Col,were significantly upregulated on the HAp / Col / CTS than those on the CTS( P < 0.01) and HAp /CTS( P < 0.05) scaffolds in the absence of the osteogenic supplementation.Moreover,presence of osteogenic supplementation also proved to enhance osteogenic differentiation of BMSCs on HAp /Col / CTS scaffolds, indicative of a synergistic effect.This study highlights the potential of BMSCs / HAp / Col / CTS cell-scaffold system for functional bone repair and regeneration applications.

Current Concepts in Bone Graft Substitutes

Purpose: Bone grafting is still requested to fill bone defects in traumatology, or after tumor removal, but also in orthopedic surgery for spine, arthroplasty revisions, and osteotomies. Due to the limitations of autografts and allografts, and the progress of biomaterial research, a large number of nonhuman bony scaffolds have been developed including synthetic calcium phosphates and highly processed xenografts. The most important parameters for bone ingrowth are the macroporosity of the scaffold with the suitable biological autologous cells and factors, optimal osteoinductive, osteointegrative and osteoconductive properties can be achieved. Methods and Results: The important factors regulating these properties are discussed in this paper, which also reports preclinical and clinical results obtained with such bone graft substitutes. Conclusions: Among different bone graft substitutes available, the porosity, the accessibility of pores, the internal surface exposed to the biological components of bone repair, are present in highly processed bovine hydroxyapatites. Compared to autografts, allografts and synthetic substitutes, they associate an initial conductivity, and a long term stability suitable for some orthopedic indications.

胶原基骨、天然煅烧骨在大鼠颅骨缺损修复术中的诱导成骨效果对比观察

目的对比观察胶原基骨和天然煅烧骨在大鼠颅骨缺损修复术中的诱导成骨效果。方法18只SD大鼠随机分为3组,每组6只,均建立SD大鼠颅骨双侧临界尺寸骨缺损模型,均行缺损修复术,术中颅骨一侧缺损部位填充胶原基骨(胶原基骨组),另一侧缺损部位填充天然煅烧骨(煅烧骨组)。术后第4、8、12周,取大鼠颅骨双侧缺损部位新生的骨组织,通过Micro-CT方法及病理检查结果评价成骨效果[成骨速度(新生骨骨体积分数、新生骨骨面积分数)、成骨质量(骨小梁数量、厚度、间隙;新生骨组织中纤维结缔组织、新生毛细血管数量)],并比较。结果Micro-CT结果显示,术后第4、8、12周,胶原基骨组的新生骨骨体积分数、骨小梁数量、骨小梁厚度均高于天然煅烧骨组,骨小梁间隙低于煅烧骨组。HE染色结果显示,术后第4、8、12周,与煅烧骨组比较,胶原基骨组的新生骨骨面积分数高。胶原基骨组胶原基骨吸收速度快,新生骨含较多的结缔组织、新生血管,骨质较软;煅烧骨组天然煅烧骨吸收速度慢,新生骨中结缔组织、血管较少,骨质偏硬。结论在大鼠颅骨临界尺寸骨缺损修复术中,胶原基骨诱导成骨的速度较快,成骨量高,吸收快,新生骨组织中结缔组织、新生血管多,新生骨质类似“松质骨”;天然煅烧骨诱导成骨速度较慢,新生骨组织中结缔组织、新生血管少,新生骨质类似“皮质骨”。

Effect of nano-hydroxyapatite/collagen composite and bone morphogenetic protein-2 on lumbar intertransverse fusion in rabbits

Objective: To investigate the effect of nano hydroxyapatite/collagen (nHA/collagen) composite as a graft extender and enhancer when combined with recombinant human bone morphogenetic protein 2 (rhBMP 2) on lumbar intertransverse fusion in rabbits. Methods: Sixty four adult female New Zealand white rabbits, aged 1 year and weighing 3.5 4.5 kg, underwent similar posterolateral intertransverse process arthrodesis and were randomly divided into 4 groups based on different grafts: autogenous cancellous bone alone (ACB group), nHA/collagen alone (HAC group), half autogenous cancellous bone and half nHA/collagen (ACB+HAC group) and nHA/collagen combined with rhBMP 2 (HAC+BMP group). The fusion masses were analyzed by manual palpation, radiography, biomechanical testing and histological examination. Results: Fusion was observed in 4 cases in the 6th week and in 5 cases in the 10th week after surgery in ACB group. No case showed fusion in HAC group. In ACB+HAC group, there was fusion in 3 cases in the 6th week and in 4 cases in the 10th week after surgery. In HAC+BMP group, fusion in 1 case was found in the 4th week, in 5 cases in the 6th week and in 6 cases in the 10th week after surgery. It suggested that ACB, ACB+HAC and HAC+BMP groups showed similar fusion ratio and mechanical strength in the 6th and 10th week after surgery. According to the microstructure analysis of the samples, nHA/collagen had no negative effect when implanted together with ilium autograft. In HAC+BMP group, new bone like tissue was observed in the 2nd week postoperatively, and nearly all of the implanted composites were replaced by mature bone matrix and new bones in 10th week postoperatively. Conclusions: The nHA/collagen, especially combined with rhBMP 2, is a promising bone substitute, for it has quick biodegradation, fine bone bending ability, and high osteoconductivity on posterolateral spinal fusion in rabbits.

Repair of radius defect with bone-morphogenetic-protein loaded hydroxyapatite/collagen-poly(L-lactic acid) composite

Objective: To explore the method to repair bone defect with bone-morphogenetic-protein loaded hydroxyapatite/collagen-poly(L-lactic acid) composite. Methods: 18 adult beagle dogs were randomly divided into 3 groups. In Group A, bone-morphogenetic-protein (BMP) loaded hydroxyapatite/collagen-poly(L-lactic acid) (HAC-PLA) scaffold was implanted in a 2 cm diaphyseal defect in the radius. In Group B, unloaded pure HAC-PLA scaffold was implanted in the defects. No material was implanted in Group C (control group). The dogs were sacrificed 6 months postoperatively. Features of biocompatibility, biodegradability and osteoinduction were evaluated with histological, radiological examinations and bone mineral density (BMD) measurements. Results: In Group A, the radius defect healed after the treatment with BMP loaded HAC-PLA. BMD at the site of the defect was higher than that of the contralateral radius. Fibrous union developed in the animals of the control group. Conclusions: BMP not only promotes osteogenesis but also accelerates degradation of the biomaterials. Optimized design parameters of a three-dimensional porous biomaterial would give full scope to the role of BMP as an osteoinductive growth factor.

含透明质酸钠无机牛骨植骨块和Bio-Oss collagen■用于牙槽嵴保存效果的研究

目的:对比含透明质酸钠无机牛骨植骨块与Bio-Oss collagen■用于牙槽嵴保存的效果。方法:纳入拔除单颗上颌或下颌第一磨牙的患者80例,随机分为2组(n=40),将含透明质酸钠无机牛骨植骨块(试验组)和Bio-Oss collagen■(对照组)分别植入拔于牙窝内,Bio-Gide■可吸收膜覆盖创面,术后即刻及24周拍摄CBCT,评价牙槽嵴宽度和高度的变化;术后第12周、24周复诊,观察软硬组织愈合情况,比较两种植骨材料牙槽嵴保存的效果。结果:大体观察结果试验组和对照组均表现良好结果,未发生感染、排斥等反应。CBCT结果显示试验组和对照组的牙槽嵴高度和宽度得到了较好保存,牙槽嵴高度和宽度的减少量无统计学差异(P>0.05)。结论:含透明质酸钠无机牛骨植骨块植骨材料能有效地保存拔牙后牙槽嵴的骨量。

Polymethyl Methacrylate-Collagen-Magnesium Hydroxyapatite Bone Cement Preparation for Orthopedic Application

In this research,bone cement was prepared by mixing 2 g of magnesium hydroxyapatite(laboratory synthesized),12 g of polymethyl methacrylate,4 g of methyl methacrylate,and collagen(1,3,and 6 g).The samples were molded in a circular shape.They were inspected by visual microscopy,FTIR,XRD,and FESEM.They were engrossed in synthesized simulated body fluid for 1 month and then inspected by visual microscopy,FTIR,XRD,and FESEM.The samples prepared from 6 g of collagen showed the highest hydroxyapatite formation(high osseointegration)than the other samples.

三种材料封闭磨牙牙槽嵴保存术创的早期评价

目的:评价应用三种材料封闭磨牙牙槽嵴保存术创的早期临床效果。方法:纳入30颗磨牙样本,随机分为三组,即骨胶原(Bone collagen,BC)组、胶原基质(Collagen matrix,CM)组及自体游离龈移植物(Free gingival graft,FGG)组,分别进行牙槽嵴保存术创封闭,每组10颗。结合CBCT、口腔扫描观察软组织厚度、创口面积、牙槽骨高度及体积变化。结果:术后15 d Collagen组创口面积收缩量明显高于其他两组(P<0.05)。术后即刻、15 d、30 d软组织厚度CM组明显高于其他两组(P<0.05)。术后30 d牙槽骨垂直高度变化三组间差异无统计学意义(P>0.05)。术后30 d牙槽骨体积减少量Collagen组明显高于其他两组(P<0.05)。结论:在牙槽嵴保存术创面愈合早期应用胶原基质及自体游离龈移植物封闭创面能阻止游离龈收缩塌陷,有利于维持附着龈稳定及成骨空间。

Biomimetic Collagen/Hydroxyapatite Composite Scaffolds: Fabrication and Characterizations

Biomimetic collagen/hydroxyapatite scaffolds have been prepared by microwave assisted co-titration of phosphorous acid-containing collagen solution and calcium hydroxide-containing solution. The resultant scaffolds have been characterised with respect to their mechanical properties, composition and microstructures. It was observed that the in situ precipitation process could combine collagen fibril formation and hydroxyapatite （HAp） formation in one process step. Collagen fibrils guided hydroxyapatite precipitation to form bone-mimic collagen/hydroxyapatite composite containing both intrafibrillar and interfibrillar hydroxyapatites. The mineral phase was determined as low crystalline calcium-deficient hydroxyapatite with calcium to phosphorus ratio （Ca/P） of 1.4. The obtained 1% （collagen/HAp = 75/25） scaffold has a porosity of 72% and a mean pore size of 69.4 ~tm. The incorporation of hydroxyapatite into collagen matrix improved the mechanical modulus of the scaffold significantly. This could be attributed to hydroxyapatite crystallites in collagen fibrils which restricted the deformation of the collagen fibril network, and the load transfer of the collagen to the higher modulus mineral component of the composite.

MACROPHAGES IN DEGRADATION OF COLLAGEN / HYDROXYLAPATITE(CHA), BETA-TRICALCIUM PHOSPHATE CERAMICS (TCP) ARTIFICIAL BONE GRAFT AN IN VIVO STUDY

The macrophages mediated biodegradation of two biomaterials, collagen / hydroxylapatite (CHA) and beta-tricalcium phosphate ceramics (TCP), was studied in 24 male Kunming mice and 20 male C57BL / 6 mice with histopathologic, histochemical and ultrastructural observation. It was demonstrated that macrophages infiltrated after CHA, TCP were implanted. The macrophages could be differentiated from fibroblasts and the other infiltrated cells for special cellular profile and strong acid phosphatase activity. Morphologically, monocyte macrophages and infused multinuclear giant cell degraded CHA and TCP by phagocytosis and extracellular resorption. The carbonic anhydrase activity of macrophages was demonstrated by histochemical technique. It suggested that macrophages secreted H+ and accomplished the decalcification of calcium phosphate compound of CHA and TCP. We conclude that macrophages are the main mediating cells which degraded CHA and TCP intracellularly and extracellularly.

Bio-Oss骨胶原植骨联合根管治疗牙周-牙髓联合病变的效果及对牙槽骨密度的影响

目的 探讨Bio-Oss骨胶原植骨联合根管治疗牙周-牙髓联合病变(PECL)的效果及对牙槽骨密度的影响。方法 选取2018年6月至2021年5月收治的62例PECL患者,采用随机数字表法将其分为对照组(n=31,根管治疗)与观察组(n=31,Bio-Oss骨胶原植骨联合根管治疗)。比较两组的治疗效果。结果 观察组的治疗总有效率高于对照组(P<0.05)。术后6个月,两组的牙龈退缩(GR)、探诊深度(PD)及临床附着丧失(CAL)均小于术前,且观察组小于对照组(P<0.05)。术后6个月,两组的牙槽骨密度、咀嚼功能评分均高于术前,且观察组高于对照组(P<0.05)。结论 Bio-Oss骨胶原植骨联合根管治疗PECL效果显著,可减小GR、PD及CAL,提高牙槽骨密度,改善患者咀嚼功能,值得临床推广和应用。

Clinical observation of mineralized collagen bone grafting after curettage of benign bone tumors

Curettage of benign bone tumor is a common cause for bone defect.For such bone defect repair,autogenous bone,allogeneic bone and traditional artificial bone graft substitutes have many disadvantages.In recent years,a biomimetic mineralized collagen(MC)with similar composition and microstructures to the natural bone matrix was developed and used for treating various bone defects.In this work,a retrospective study analyzed clinical outcomes of patients treated with curettage of benign bone tumors and bone grafting with MC,in comparison to another group treated with the same surgical method and autogenous bone.Lane-Sandhu X-ray score of the autogenous bone group was superior to the MC group at 1 month after the operation,but the two groups had no statistical difference at 6 and 12 months.The MC group was better in Musculoskeletal Tumor Society scoring at 1 and 6 months after the operation,and the two groups had no statistical difference at 12 month.Therefore,the MC performed not as good as autogenous bone in early stage of bone healing but achieved comparable outcomes in long-term follow-ups.Moreover,the MC has advantages in function recovery and avoided potential complications induced by harvesting autogenous bone.

多孔纳米羟基磷灰石／胶原复合材料的制备及性能

目的:探讨多孔纳米羟基磷灰石／胶原复合材料(NHAC)简单有效的复合方法和结构及其作为新型骨替代材料应用于组织工程的可行性。方法:以氢氧化钙和磷酸为原料合成多孔纳米羟基磷灰石晶体,从牛肌腱中提取可溶性I型胶原,应用戊二醛交联冻干法使二者复合制备成生物膜,用XRD和扫描电镜,对材料晶相组成、微观形貌、结构、晶粒大小进行分析。结果:通过对合成工艺研究,制得的生物膜呈三维网孔状结构, 孔径10～40μm,大小均匀,由纳米尺度(10 nm×50 nm～20 nm×80 nm)的羟基磷灰石和胶原纤维组成。复合材料在晶相组成和尺寸上类似于天然骨。结论:NHAC复合材料有望成为理想的骨替代材料。

胶原-羟基磷灰石-硫酸软骨素-骨形态发生蛋白骨修复材料的性质评估

目的:评估以胶原、羟基磷灰石、硫酸软骨素等3种天然骨骼基本成分构建成的三维多孔骨修复材料的理化性能和体内生物学性能,观察其作为骨形态发生蛋白(bone morphogenetic protein 2,BMP-2)载体的效果。方法:以胶原、羟基磷灰石、硫酸软骨素及BMP-2为原料,通过化学交联和冷冻干燥的方法构建具有一定三维结构的骨修复材料。通过HE染色、扫描电镜观察材料的结构性能;通过表面能谱、X线衍射观察材料的理化性能;将骨髓基质干细胞(marrow stromal cells,MSCs)种植在材料表面,观察MSCs在材料表面的粘附、增生和分化;将该复合材料种植在大鼠体内,观察材料在体内的降解和异位成骨情况。结果:骨修复材料在植入局部保持完整的支架结构,具有利于细胞粘附和增殖的多孔结构。通过肌肉埋植,在异位诱导形成了骨组织,并且随着骨组织的形成,支架逐渐降解吸收。结论:胶原-羟基磷灰石-硫酸软骨素-骨形态发生蛋白是具有良好的生物相容性和骨诱导特性的骨修复材料。

HA/TCP双相陶瓷与人成骨细胞生物相容性的体外实验研究

体外复合培养条件下 ,通过观察人成骨细胞与 HA/ TCP的复合生长及监测材料对细胞生理功能的影响来评价材料的生物相容性。研究发现 ,复合培养过程中成骨细胞首先贴附于材料的表面 ,进而攀附于材料边缘切刻处及材料表层微孔的边缘 ,以后逐渐长入孔中。最后 ,材料几乎为细胞所覆盖。复合培养的成骨细胞与正常培养的成骨细胞一样 ,具有分泌大量胶原纤维、表现强烈碱性磷酸酶活性和形成矿化胞外基质等成骨表型。细胞能够与材料很好地复合生长、材料对细胞生理功能又无明显的影响表明 HA/

纳米晶胶原基骨加自体骨移植治疗早期股骨头坏死的临床疗效分析

目的回顾性分析经股骨头颈交界处开窗、灯泡状病灶清除、打压植骨术结合纳米晶胶原基骨和自体骨移植治疗早期股骨头坏死(osteonecrosis of femoralhead,ONFH)的临床疗效。方法2001年1月-2005年7月,收治26例35髋ONFH患者。男16例,女10例;年龄19～54岁,平均33.5岁。病程12～36个月,平均18个月。ONFH病因:激素性15例22髋,酒精性10例12髋,特发性1例1髋。ARCO分期:ⅡB期6髋,ⅡC期16髋,ⅢA期9髋,ⅢB期3髋,ⅢC期1髋。Harris评分为(62.2±7.5)分。术中采用经股骨头颈交界处开窗、灯泡状病灶清除,按1∶1比例行纳米晶胶原基骨和自体骨移植治疗。结果患者术后切口均Ⅰ期愈合。术中2例髂骨取骨伤及股外侧皮神经,术后3～6个月神经支配区麻木症状自行缓解消失;2例术后3个月出现异位骨化并发症,未行特殊处理。患者均获随访,随访时间2～7年,平均3.5年。术后3个月患者植骨愈合。术后Harris评分为(85.1±16.2)分,与术前比较差异有统计学意义(P<0.001)。其中优15髋,良11髋,可5髋,差4髋。获差的4例患者均于随访期末行全髋关节置换术。影像学检查示5髋由术前ⅡC期进展至ⅢA期;余髋关节影像学表现稳定,ONFH分期无进展。结论经股骨头颈交界处开窗、灯泡状病灶清除、打压植骨术,结合纳米晶胶原基骨和自体骨移植治疗早期ONFH临床效果满意,纳米晶胶原基骨有利于骨坏死的修复和重建,适于Ⅱ期ONFH的患者保存股骨头手术。

胶原-羟磷灰石复合膜引导骨组织再生的动物实验研究

目的探讨自制胶原-羟磷灰石(COL-HA)复合膜修复SD大鼠颅骨缺损的效果。方法在24只SD大鼠的颅顶骨上各制备4个缺损,其中左、右侧缺损区分别覆盖COL-HA复合单层致密膜(第2组)和COL-HA复合双层膜(第3组),额骨缺损区保留作为空白对照(第1组),枕骨缺损区覆盖Bio-Gide膜作为对比(第4组)。术后2、4、8、12周各处死6只大鼠取材,进行肉眼观察、X线检查、组织切片观察和新生骨量测定,对结果进行广义线性模型/析因设计方差分析和LSD-t检验。结果从术后2周开始除第1组外,其余3组均可见少量新生骨质,12周时3组缺损区由不透明硬组织封闭,并可见分解的部分膜碎片。X线显示,术后12周时第3组和第4组缺损区修复骨密度与原骨质接近,第2组稍低。新生骨量分析显示,术后初期第4组新生骨量大于其余3组,术后12周第4组与第3组和第2组的成骨量无统计学差异。结论 COL-HA复合膜能引导大鼠颅骨组织再生,且复合双层膜成骨效果要优于复合单层致密膜,其结构更有利于成骨细胞的附着和生长。

自体骨膜细胞复合胶原涂层煅烧骨修复骨缺损的实验研究

目的 :观察骨膜成骨细胞 (periosteal derivedosteoblast .POB)与胶原涂层煅烧骨 (trueboneceramiccollage ,TBCc)移植的成骨性能 ,探讨治疗骨缺损的新方法。方法 :选牛松质骨制备胶原涂层煅烧骨载体。用兔骨膜成骨细胞与TBCc复合并自体移植到桡骨 15mm骨缺损模型 ,移植后 4、8、12、16周取材 ,行组织学、X线拍片和X射线能谱分析 ,计算机图像分析新生骨面积。结果 :复合细胞的TBCc组骨生成、新骨面积和骨连接情况明显优于单纯TBCc组。结论