Experience with freeze-dried PGLA/HA/rhBMP-2 as a bone graft substitute.

We investigated bone induction by recombinant human bone morphogenetic protein-2 in rodents. The purpose of this study was to evaluate the osteoinductive potential of a resorbable bone substitute fabricated from freeze-dried poly(glycolic acid-co-lactic acid) (PGLA) mixed with hydroxyapatite particles incorporated with bone morphogenetic protein-2 in skull defects of rats (FD-PGLA/HA/rhBMP-2). The FD-PGLA/HA/rhBMP-2 composite or as a control, the FD-PGLA/HA by itself were implanted in skull defects (psi 8 mm) of rats. The samples were harvested at 2 or 4 weeks postoperatively and were studied radiographically and histologically. Four weeks after implantation, the FD-PGLA/HA/rhBMP-2 discs were completely replaced by newly-formed bone possessing bone marrow. In contrast, the defects implanted with FD-PGLA/HA were filled only with fibrous connective tissue. The results suggest that the FD-PGLA/HA/rhBMP-2 composite could be an optimum bone substitute with osteoinductive potential and could function as an alternative bone graft material for autogenous bone in humans.     

Bio-Oss-FG结合口腔组织补片修复犬下颌骨缺损的实验研究

目的:分析口腔组织补片(ADM)是否可以改善Bio-Oss经纤维蛋白胶(FG)塑形后诱导成骨性能下降的问题。方法:9条杂种犬,每只拔除双侧下颌第2、4前臼齿和第2臼齿,造成6个1cm×1cm大小的骨缺损区,将Bio-Oss+FG+ADM、Bio-Oss+FG、Bio-Oss共3组材料随机植入骨缺损区,每组2处缺损。分别在术后4、8、12周各处死3条实验犬,观察软硬组织的愈合情况,大体标本观察补片生长情况,组织切片观察新生骨组织形态、组织补片的愈合情况,计算机图像分析得出新生骨百分率,利用SAS软件进行方差分析。结果:软组织均一期愈合;组织补片在12周时仍未吸收,紧密结合在骨组织表面,显微镜下显示补片与新生骨组织紧密结合。实验组新生骨百分比在4、8、12周均高于对照组。结论:组织补片吸收时间超过12周,可以促进经纤维蛋白胶塑形后的Bio-Oss成骨性能,同时可以促进覆盖软组织在植入物表面的早期附着,对防止伤口裂开有一定预防作用。     

A histological evaluation of the involvement of Bio-Oss in osteoblastic differentiation and matrix synthesis

This study was designed to investigate the responses of bone cells to a deproteinized bovine bone material, Bio-Oss (Geistlich-Pharma, Wolhunsen, Switzerland), which was grafted in artificial bone defects of rat femurs. Standardized bone defects in the cortical bone of the right femurs were grafted with Bio-Oss particles. Narrow penetrations were prepared on the bottom of the cavity, enabling osteogenic cells to migrate from the bone marrow. A defect in the left femur without Bio-Oss was used as a control. The treated femurs were histochemically examined at 1, 3, 5, 7, and 14 days after the operation. At day 1, no osteogenic migration into the cavities occurred in either the control or experimental groups. At day 3, alkaline phosphatase (ALPase) immunohistochemistry showed a migration of the positive cells at the bottom of the cavities of the experimental groups, but not in the control ones. At day 5, new bone formation was recognized at the bottom of the cavity of both groups. In the experimental group, ALPase-positive cells were localized on Bio-Oss and/or on the thin bone matrix that covered this material. The superficial layer of Bio-Oss underlying the newly formed bone exhibited osteocalcin immunoreactivity. Transmission electron microscopy revealed osteoblasts depositing bone matrices--including collagen fibers--on the surface of Bio-Oss. At days 7 and 14, woven bone occupied the previous cavities of both control and experimental groups, accompanied by osteoclasts. Thus, Bio-Oss appears to serve as a scaffold for osteogenic cells as well as to promote osteoblastic differentiation and matrix synthesis.     

纤维蛋白粘合剂与羟基磷灰石复合人工骨的实验研究

以具有良好生物相容性和生物降解性的纤堆蛋白(FS)粘合剂作为颗粒型羟基磷灰石人工骨(HA)的粘接成形剂，将HA—PS复合材料植入狗下颌实验性骨缺损中，采用组织学、定量组织学、扫描电镜和X线等方法评价其骨缺损修复能力。研究结果发现，HA—FS复合人工骨具有良好的组织相容性、骨引导性，能与新骨形成紧密结合，阻止HA颗粒散动及改善其操作性能，PS在植入后2周完全吸收。本研究表明，HA—PS复合人工骨作为骨修复材料，具有良好组织相容性和较理想的操作性能。     

The bone regenerative effect of platelet-rich plasma in combination with an osteoconductive material in rat cranial defects

The effect of platelet-rich plasma (PRP) on bone regeneration, in combination with an osteoconductive material, was evaluated in a rat model. Cranial defects, 6.2 mm in diameter, were filled with HA/beta-TCP particles, HA/beta-TCP particles combined with PRP and HA/beta-TCP particles combined with PRP gel, where some were left empty as a control. After 4 weeks of implantation histological, histomorphometrical and micro-computed tomography analyses revealed no difference in new bone formation among the groups. Further, no additional effect of PRP gel in comparison with PRP liquid was detected, except for the increased handling capacity of the graft. These findings suggest that PRP had no positive effect on bone formation in addition to an osteoconductive material after an implantation period of 4 weeks. Also, no negative effect was seen, and neither PRP nor HA/beta-TCP hampered bone ingrowth into the defects.     

Differential effects of bone graft substitutes on regeneration of bone marrow

Background: This study used a rat tibial marrow ablation model to test the hypothesis that bone remodeling within the medullary canal varies with bone graft materials of different chemical compositions and structural properties, impacting marrow cavity restoration. Bone graft materials were selected based on their relative resorption or degradation in vivo and their osteogenic properties. Methods: Following ablation of the right tibial marrow in male Sabra‐strain rats, materials were implanted in the proximal marrow cavity: poly‐d,l ‐lactide‐co‐glycolide 75 : 25 (PLGA); coralline‐hydroxyapatite (HA), calcium‐sulfate (CaSO4), collagen–HA–tricalcium phosphate granules, anorganic bovine bone mineral, demineralized bone matrix (DBM), 45S5 Bioglass (BG), PLGA with BG 50 : 50, PLGA : BG 80 : 20, and PLGA and PLGA:BG 50 : 50 plus bone marrow (BM). Control tibias were ablated but received no implants. At 2 (endosteal bone healing), 4 (marrow cavity remodeling) and 8 weeks (marrow restoration), six to eight animals per group were euthanized and tibias processed for histomorphometry of proximal and distal medullary canals. Results: Control tibias showed primary bone in proximal and distal medullary canals at 2 weeks, with trabeculae surrounded by cellular marrow. At 4 and 8 weeks, control trabeculae were thinned and marrow had more fat cells. In the treated tibias, trabecular bone volume (TBV) varied with time and was material specific. Most implants supported comparable TBV at 2 weeks. Sites with CaSO4 or DBM exhibited decreased TBV with time whereas trabecular bone was retained in proximal tibias containing other materials, closely juxtaposed to the implants. TBV did not always correlate directly with implant volume, but changes in BM volume were correlated inversely with TBV. Addition of BM increased marrow restoration in sites containing PLGA; however, BM reduced restoration of marrow when added to PLGA : BG. Although the presence of implants in the proximal tibia resulted in retention of trabecular bone, there was a time‐dependent reduction in TBV in distal canals; the rate and extent of the distal TBV reduction were implant dependent. Conclusions: Thus, although many materials can support bone formation in the marrow cavity, bone quality, quantity, and physical relationship to the implant, and its rate of resorption differ in a material‐dependent manner, resulting in differences in the restoration of marrow. Clinical relevance: Bone graft materials should be selected not only for their ability to support new bone formation but also for their impact on the remodeling phase of bone healing.     

Bio-Oss骨复合富血小板纤维蛋白修复兔牙周骨缺损

目的探讨组织工程骨Bio-Oss骨复合富血小板纤维蛋白（PRF）修复牙周骨缺损中骨形成蛋白2（BMP-2）、骨保护素（OPG）和核因子κB受体活化因子配体（RANKL）的表达及意义。 方法3月龄雄性新西兰大白兔36只,采用随机数表法分为4组,每组9只,制备单侧牙周骨缺损模型,于骨缺损处分别植入Bio-Oss骨（Bio-Oss组）、PRF（PRF组）和Bio-Oss/PRF复合物（Bio-Oss/PRF组）,以未植入任何材料者作为空白对照。术后4、8和12周处死动物,行大体观察、Masson染色及BMP-2、OPG、RANKL免疫组化观察,并对其表达进行析因设计的方差分析。 结果Masson染色结果显示,Bio-Oss/PRF组术后8周时见部分成熟骨,12周见骨板形成,骨成熟度较高。析因分析显示Bio-Oss组在4、8和12周时BMP-2表达量逐渐增高,差异有统计学意义（F = 51.30,P<0.001）;OPG表达量随时间延长先升高后减低,差异有统计学意义（F = 167.03,P<0.001）;RANKL表达量随时间延长逐渐减低,差异有统计学意义（F = 5.39,P = 0.046）。PRF组在4、8和12周时BMP-2表达量无统计学意义（F = 0.68,P = 0.544）;OPG和RANKL表达量随时间延长逐渐减低,差异有统计学意义（F_OPG = 1070.93,P_OPG<0.001;F_RANKL = 2306.15,P_RANKL<0.001）。Bio-Oss/PRF组在4、8和12周时BMP-2、OPG和RANKL表达量逐渐降低,差异有统计学意义（F_BMP-2 = 13.29,P_BMP-2<0.001;F_OPG = 237.91,P_OPG<0.001;F_RANKL = 132.48,P_RANKL<0.001）。空白对照组在4、8和12周时BMP-2和OPG表达量先升高后减低,差异有统计学意义（F_BMP-2 = 88.33,P_BMP-2<0.001;F_OPG = 30.06,P_OPG<0.001）,RANKL表达量随时间推移逐渐减低,差异有统计学意义（F = 56.52,P<0.001）。 结论Bio-Oss骨复合PRF应用可促进成骨以修复牙周骨缺损。     

rhBMP-2/Co/PLGA复合生物膜对腭裂骨缺损修复的实验研究

目的:观察引导性骨再生(guidedboneregeneration,GBR)技术修复腭裂骨缺损的效果。方法:16只成年犬分为2组:实验组8只,对照组8只。实验组将rhBMP-2/Co/PLGA复合生物膜植入骨缺损区,对照组植入Co/PLGA复合生物膜。分别于术后第4、8、12、24周,对其上颌骨进行三维CT扫描观察,同时进行新骨组织学检查。结果:从影像学、组织学检查的结果看,实验组的新骨形成优于对照组。结论:植入rhBMP-2/Co/PLGA复合生物膜可用于修复腭裂骨缺损。     

Evaluation of a novel biphasic calcium phosphate in standardized bone defects: a histologic and histomorphometric study in the mandibles of minipigs

OBJECTIVE: A novel biphasic calcium phosphate (CaP) granulate consisting of hydroxyapatite (HA) and beta-tricalciumphosphate (TCP) was compared with pure HA and pure TCP and with autograft as positive control. MATERIALS AND METHODS: Four standardized bone defects were prepared in both mandibular angles of 16 minipigs and grafted with autogenous bone chips, HA, HA/TCP (60% : 40%), or TCP. Histologic and histomorphometric analysis of bone formation and graft degradation followed healing periods of 2, 4, 8, and 24 weeks. RESULTS: 2 weeks: more bone formation in defects filled with autograft than with the three CaP materials (P<0.05). 4 weeks: bone formation differed significantly (P<0.05) between all four materials (autograft>TCP>HA/TCP>HA). 8 weeks: more bone formation in defects with autograft and TCP than with HA/TCP (P<0.05), and HA/TCP had more bone formation than HA (P<0.05). 24 weeks: no difference in bone formation between the groups. Autograft and TCP resorbed quickly and almost completely over 8 weeks, whereas HA/TCP and HA showed limited degradation over 24 weeks. CONCLUSION: All defects healed with mature lamellar bone and intimate contact between bone and the remaining graft material. The rate of bone formation corresponded to the content of TCP in the CaP materials.     

Combined implantation of particulate dentine, plaster of Paris, and a bone xenograft (Bio-Oss) for bone regeneration in rats.

The purpose of this study is to assess the combination of particulate dentine and plaster as bone substitute material in calvarial bone defects in rats, and to compare it with a bone xenograft (Bio-Oss). MATERIAL AND METHODS: Forty rats were assigned randomly to five groups and each group was further divided into two subgroups, 8 and 16 weeks after implantation. The defect was filled with different graft materials in each group: Group 1, defects were filled with particulate dentine and plaster using a 2:1 ratio; Group 2, defects were filled with particulate dentine; plaster, and Bio-Oss using a 2:1:1 ratio; Group 3, defects were filled with plaster and Bio-Oss using a 1:1 ratio; Group 4, defects were filled with Bio-Oss only; and Group 5, untreated control defects. Histological sections and histomorphometric analysis of defects were obtained at 8 and 16 weeks postoperatively. RESULTS: New bone formation was highest in Group 4, followed by Group 3, than Group 2, Group 1, and finally the control group. CONCLUSION: The combination of particulate dentine and plaster is an alternative bone substitute, although it is less effective than Bio-Oss.     

Effect of porous xenographic bone graft with collagen barrier membrane on periodontal regeneration

The purpose of this study was to investigate the effect of porous xenographic bone graft (Bio-Oss) with a collagen barrier membrane (Bio-Gide) on formation of new cementum and new bone in experimental intrabony defects of dogs. The intrabony defects were treated by either guided tissue regeneration with the collagen membrane (control group) or the collagen membrane with the porous bone mineral graft (experimental group). After 8 weeks, the animals were sacrificed and the tissues were histologically examined. New cementum with inserting collagen fibers was observed on the exposed surfaces in both groups. The amount of nevv bone was significantly greater in the group using the bone graft with the membrane than in the control group. The use of the collagen barrier membrane in combination with the porous bone graft material may enhance new bone and cementum formation.     

煅石膏、骨形成蛋白及羟基磷灰石三元复合人工骨修复骨缺损的实验研究

以煅石膏(PLP）作为颗粒型羟基磷灰石(HA)人工骨粘接成形剂和骨形成蛋白(BMP)的载体，制成三元复合人工骨．分别用HA—bBMP、HA—PLP和单纯HA植入狗下颌骨实验性骨缺损中，采用组织学、定量组织学、免疫组织化学、X线摄片和扫描电镜观察的方法评价该复合人工骨的生物学性能。术后1，2，4，8和16周观察发现，HA—bBMP—PLP复合人工骨具有明显的骨诱导活性．PLP可充当BMP缓慢释放系统载体．增强BMP骨诱导活性，和作为颗粒型HA的粘接成形剂．使复合人工骨具有一定的可塑性和成形性，可达到准确的植入，植入后早期可有效防止HA颗粒移动。本研究证实．HA—bBMP—PLP三元复合人工骨不但可限制植入后HA颗粒的早期移动，更重要的是可以迅速增加新骨形成量．从形态和功能上大大提高了复合人工骨修复骨缺损的质量。     

Osteogenic potential of cultured human periosteum-derived cells – A pilot study of human cell transplantation into a rat calvarial defect model

BACKGROUND: Periosteum shows osteogenic potential and has received considerable attention as a grafting material for the repair of bone and joint defects. The osteogenic potential of cultured periosteal cells has also been reported. The findings of bone formation induced by cultured human periosteum-derived cells using a rat model are presented. MATERIAL AND METHODS: Human mandibular periosteum was placed into a culture medium with 10% foetal bovine serum for 14 days. After reaching confluence, periosteal cells were re-suspended with 0.25% trypsin/EDTA and then re-cultured three dimensionally on a collagen sponge. The periosteal cell/collagen complex was grafted into rat calvarial defects and an immunosuppressant (FK506, 1.0 mg/kg/day) was administered intramuscularly. At 2, 3, and 5 weeks postoperatively, grafted tissue was extirpated and compared histologically and radiographically with tissue from a collagen-only grafted group. RESULTS: In the experimental group, periosteal cells had proliferated and differentiated into osteogenic cells by 2 weeks post grafting. At 3 weeks, new bone formation was evident. By 5 weeks, bone growth was observed and new calcification was detected in the defect. CONCLUSION: Cultured human periosteum-derived cells showed osteogenic potential in a xenogeneic graft model using rat calvarial defects.     

Rosuvastatin 1.2 mg In Situ Gel Combined With 1:1 Mixture of Autologous Platelet‐Rich Fibrin and Porous Hydroxyapatite Bone Graft in Surgical Treatment of Mandibular Class II Furcation Defects: A Randomized Clinical Control Trial

Background: A wide range of regenerative materials have been tried and tested in the treatment of furcation defects. Rosuvastatin (RSV) is a new synthetic, second‐generation, sulfur‐containing, hydrophilic statin with potent anti‐inflammatory and osseodifferentiation mechanisms of action. Platelet‐rich fibrin (PRF) is a platelet concentrate having sustained release of various growth factors with regenerative potential to treat periodontal defects. Porous hydroxyapatite (HA) bone grafting material has a clinically satisfactory response when used to fill periodontal intrabony defects. This double‐masked randomized study is designed to evaluate the potency of a combination of 1.2 mg RSV in situ gel with a 1:1 mixture of autologous PRF and HA bone graft in the surgical treatment of mandibular Class II furcation defects compared with autologous PRF and HA bone graft placed after open‐flap debridement (OFD). Methods: One hundred five mandibular furcation defects were treated with OFD + placebo gel (group 1), PRF + HA with OFD (group 2), or 1.2 mg RSV gel + PRF + HA with OFD (group 3). Clinical and radiologic parameters (i.e., probing depth [PD], relative vertical and relative horizontal clinical attachment level [rvCAL and rhCAL], intrabony defect depth, and percentage of defect fill) were recorded at baseline and 9 months postoperatively. Results: Mean PD reduction was greater in group 2 (3.68 ± 1.07 mm) and group 3 (4.62 ± 1.03 mm) than group 1 (2.11 ± 1.25 mm), and mean rvCAL and rhCAL gain were greater in group 2 (3.31 ± 0.52 and 2.97 ± 0.56 mm, respectively) and group 3 (4.17 ± 0.70 and 4.05 ± 0.76 mm) compared with group 1 (1.82 ± 0.78 and 1.62 ± 0.64 mm). A significantly greater percentage of mean bone fill was found in group 2 (54.69% ± 1.93%) and group 3 (61.94% ± 3.54%) compared with group 1 (10.09% ± 4.28%). Conclusions: Treatment of furcation defects with 1.2 mg RSV in situ gel combined with autologous PRF and porous HA bone graft results in significant improvements of clinical and radiographic parameters compared with OFD alone. These results imply that the combination of RSV, PRF, and HA has synergistic effects, explaining their role as a regenerative material in the treatment of furcation defects.     

Microvessel density in sinus augmentation procedures using anorganic bovine bone and autologous bone: 3 months results

PURPOSE: This study was an immunohistochemical evaluation of microvessel density (MVD) in sinus augmentation procedures with autologous bone and anorganic bone (Bio-Oss). MATERIALS AND METHODS: Twenty-four patients (14 men and 10 women - mean age of 48 years with a range from 34 to 53 years) participated in this study. All the patients presented a maxillary partial unilateral edentulism involving the premolar/molar areas, with a residual alveolar ridge height of about 4 to 5 mm. Twelve patients received sinus augmentation procedures with 100% autologous bone; 100% Bio-Oss was used in the other 12 patients. Endosseous implants were inserted after a mean period of 3 months. As control, the portions of preexisting subantral bone were used. The mean value of the MVD in control bone was 23.4 +/- 1.3. The mean value of the MVD in the sinuses augmented with autologous bone was 29.0 +/- 2.4. The mean value of the MVD in the sinuses augmented with Bio-Oss was 23.8 +/- 2.2. RESULTS: The statistical analysis showed that the differences of the MVD between control bone and sinuses augmented with Bio-Oss were not statistically significant (P = 0.52), while the difference of the MVD between sinuses augmented with autologous bone and those augmented with Bio-Oss was statistically significant (P = 0.0008). CONCLUSIONS: Autologous bone may act not only as a passive filling material in bone defects but may also release osteogenic growth factors; and particles of autologous bone seem to contain vital osteoprogenitor cells.     

Enhancement of bone ingrowth into collagen/HA composite implants using e-PTFE membranes

The objective of this investigation was to study the effectiveness of expanded polytetrafluoroethylene (e-PTFE) membranes for enhancement of bone ingrowth through subperiosteally implanted collagen/HA composite blocks. Twelve rabbits aged 12-15 months served as the experimental animals in this study. Two compressed Collagen/HA composite blocks in the shape of two attached cylinders of different diameters were inserted into two defects of each rabbit calvarium, the smaller cylinder being intrabony, the larger subperiosteal in location. One of the two implants was covered with non-resorbable e-PTFE membrane. The other implant was left uncovered. Specimens were obtained at 4, 8, and 12 weeks. While the implant specimens on the membrane side showed progressive bone formation between and around HA particles at the subperiosteal extrabony locations, the HA particles on the non-membrane side were surrounded and separated by dense fibrous tissue. At intraosseous sites, HA particles were surrounded by new bone throughout the defect on the membrane side, but new bone formation occurred only along the periphery on the non-membrane side. It appears that guided tissue regeneration may be used to enhance new bone formation around and between subperiosteally implanted HA particles.     

Evaluation of bone response to various anorganic bovine bone xenografts: an experimental calvaria defect study

This in vivo study investigated the in vivo performance of two newly developed synthetic bone substitutes and compared them to commercially available xenografts (Bio-Oss, Geistlich Pharma AG, Switzerland; OsteoGraf, Dentsply, USA). The materials were tested in a rabbit calvaria model, and the bone forming properties were observed at 4 and 8 weeks after implantation by means of histomorphometry and micro computed tomography (micro-CT). Defects without any graft material were used as negative controls. Micro-CT showed that all materials tested presented new bone formation that filled the defects at both time points, whereas the negative control presented less bone formation, with soft tissue infiltration into the defects. Comparable bone fill percentages were observed for histomorphometric and micro-CT results. Even though no statistically significant difference was found quantitatively between all of the bone graft substitute groups, a higher mean decrease in graft material filling the defects, along with higher remodelling activity, was evident for the experimental materials compared to the commercially available xenografts at 8 weeks. The results indicate that the experimental materials possess high degradability, along with osteoconduction comparable to commercially available xenografts.     

Composite bone graft for treatment of osseous defects after surgical removal of impacted third and second molars: case report and review of the literature

The aim of this case report was to evaluate the clinical and radiographic measurements of mandibular first molar bone support after mandibular third and second molar extraction and immediate augmentation of the extraction site with a combined autogenous bone graft with Bio-Oss materials. A pyramidal full-thickness mucoperiosteal flap with 1 distal releasing incision was used for removal of impacted third and second molars. During the procedure, autogenous bone graft was collected with a bone trap and then combined with Bio-Oss materials. The osseous defects distal to first molar and extraction site was filled with the composite bone graft and covered with Bio-Gide membrane. After 1 year, there was a successful defect regression and gain of bone and clinical attachment level. Moreover, there was a reduction of probing pocket depth and gingival inflammation. From the results of this study, it can be concluded that grafting of osseous defects and extraction site with autogenous bone graft combined with Bio-Oss materials will predictably result in a decreased risk of developing a periodontal defect on the distal aspect of mandibular first molar.     

不同比例的聚乳酸-聚乙醇酸共聚物与羟基磷灰石复合支架对人牙髓干细胞增殖及矿化能力影响研究

目的　探讨不同比例的聚乳酸-聚乙醇酸共聚物与羟基磷灰石（PLGA/HA）复合支架的降解速率及其对人牙髓干细胞（human dental pulp stem cells,hDPSCs）增殖及矿化能力的影响。方法    采用溶液浇筑/颗粒沥析技术构建含质量分数分别为10%、20%及30% HA的PLGA/HA复合支架的3个实验组,单纯PLGA支架作为对照组。采用降解实验检测支架的降解速率。将hDPSCs接种于不同比例的PLGA/HA复合支架进行培养,扫描电镜观察细胞形态,应用MTT法检测细胞增殖能力。hDPSCs接种于各组支架培养72 h后,将复合支架植入裸鼠体内,分别于饲养1个月及3个月后处死裸鼠取出支架,应用HE染色观察组织学形态,应用牙本质基质蛋白1（DMP1）免疫组化染色观察细胞的矿化程度。结果    10%HA组和20%HA组具有较适宜的降解速率。各组均具有较高的促hDPSCs增殖能力,促进效果随HA含量的增加而加强。HE染色和免疫组化染色结果显示,HA可促进hDPSCs在体内的成牙本质向分化,分化程度与HA含量成正比,20% HA组及30% HA组矿化程度均较佳。结论   含20%HA的PLGA/HA复合支架具有较佳的降解速率及促细胞增殖和矿化能力,是比较理想的细胞支架材料。