首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 250 毫秒
1.
目的制备适合于骨组织工程的高强度纳米羟基磷灰石/Ⅰ型胶原/壳聚糖复合支架材料。方法用原位合成法代替传统的直接分散法,以胶原和壳聚糖为模板原位合成羟基磷灰石,再用冷冻干燥法使材料成型,制成可用于骨组织工程的多孔支架材料。结果制备的材料孔隙率高,孔的连通性好,材料中羟基磷灰石结晶度更小,表面能大,与有机物基底结合紧密,也能为成骨细胞的粘附提供更多的活性位点。结论用紫外辐照对材料进行处理,能使其抗压性能得到提高。制备的支架材料适用于骨组织工程。  相似文献   

2.
背景:目前骨组织工程常用的支架材料主要有无机材料、有机高分子材料及天然衍生材料等,上述材料各有优缺点,为了充分发挥各类材料的优势,弥补其不足,目前多采用联合材料制备复合支架。 目的:制备新型仿生支架材料骨形态发生蛋白7多肽/壳聚糖/纳米羟基磷灰石/胶原,并观察其对骨髓间充质干细胞增殖、黏附及分化的影响。 方法:制备壳聚糖/纳米羟基磷灰石/胶原复合支架材料,扫描电镜观察支架材料表面微观形貌;采用真空吸附法将骨形态发生蛋白7多肽与支架材料复合,高效液相色谱仪检测骨形态发生蛋白7多肽在体外的释放规律;将骨髓间充质干细胞接种到复合骨形态发生蛋白7多肽的仿生支架材料上,以未复合多肽的支架材料作为对照,检测支架材料表面细胞增殖、黏附率、生长形态及碱性磷酸酶活性。 结果与结论:壳聚糖/纳米羟基磷灰石/胶原支架材料呈多孔状,孔径10~100 µm;骨形态发生蛋白7多肽可以从支架材料中缓慢释出;在复合多肽的仿生支架材料表面,骨髓间充质干细胞的黏附及向成骨细胞方向分化能力均明显强于对照组(P < 0.05),而增殖能力与对照组差异无显著性意义(P > 0.05)。说明新型仿生支架材料骨形态发生蛋白7多肽/壳聚糖/纳米羟基磷灰石/胶原是一种理想的骨组织工程支架材料,具有良好的细胞相容性。  相似文献   

3.
随着骨组织工程的发展,纳米羟基磷灰石(nHA)作为一种新型的骨组织支架材料应运而生,而骨髓间充质干细胞(BMSCs)是骨组织工程中一种理想的种子细胞。目前,BMSCs 与 nHA 复合后的骨修复材料用于临床的技术和条件还不完善。本研究通过对骨髓间充质干细胞和纳米羟基磷灰石的复合以及复合后BMSCs 增殖、分化、坏死、凋亡、矿化以及 nHA 支架材料体内降解的检测技术和指标进行概述,同时对二者复合的影响因素进行综述,为骨髓间充质干细胞与纳米羟基磷灰石复合骨修复材料应用于临床提供依据。  相似文献   

4.
背景:骨组织工程骨构建中如何使生长因子持续高效发挥作用是影响成骨速度和质量的关键,现多以各种材料的微球或支架作为缓释载体,但缓释作用有待提高。目的:实验拟制备壳聚糖微球,然后复合到纳米羟基磷灰石/聚乳酸-羟基乙酸支架上,形成双重缓释作用,并测量对牛血清白蛋白的释放效果。方法:以牛血清白蛋白为模型药物,采用乳化交联法制备壳聚糖微球。将微球与纳米羟基磷灰石、聚乳酸-羟基乙酸按一定比例混合,以冰粒子为致孔剂,采用冷冻干燥法制备壳聚糖微球/纳米羟基磷灰石/聚乳酸-羟基乙酸复合支架。利用扫描电镜、激光粒度分析仪、压泵仪和力学性能测试仪检测复合支架的形态性能,考察药物在缓释支架上的体外释放规律。结果与结论:所制备的壳聚糖微球形态良好,呈规则圆球形,粒径集中分布在20~40μm,微球药物包封率为86.5%,载药量为0.8%,随牛血清白蛋白初始用量的增加,载药量可升高至2.6%,但包封率下降至74.1%。壳聚糖微球能均匀分布在聚乳酸-羟基乙酸支架上,形成壳聚糖微球/纳米羟基磷灰石/聚乳酸-羟基乙酸复合支架,孔径为100~400μm,孔隙率80%,压缩强度为1.1~2.3MPa,10周降解率为26.5%。单纯纳米羟基磷灰石/聚乳酸-羟基乙酸支架其牛血清白蛋白在36h累积释放量达85%以上,壳聚糖微球其牛血清白蛋白10d累积释放量为33.6%,复合支架其牛血清白蛋白40d累积释放量为81.5%。结果证实包埋壳聚糖微球的纳米羟基磷灰石/聚乳酸-羟基乙酸支架其压缩强度和降解速率合适,对蛋白类药物具有良好的缓释作用,有望作为组织工程的支架材料和生长因子的缓释载体。  相似文献   

5.
背景:组织工程中,种子细胞需依赖于细胞外基质的存在才能发挥功能。因此支架材料的选择具有重大意义。 目的:制备一种新型改性壳聚糖-胶原-羟基磷灰石复合支架,优化易于细胞黏附的组织工程支架材料工艺。 方法:壳聚糖与透明质酸进行交联,红外和差示扫描量热图谱检测其结构;改性壳聚糖与胶原按1∶2,1∶1和2∶1制备3种改性壳聚糖-胶原-羟基磷灰石复合支架,将复合支架与成骨细胞MC3T3-E1联合培养,CCK-8法检测增殖,绘制生长曲线。 结果与结论:透明质酸和壳聚糖以酰胺键形成交联的新化合物,孔径在50~250 μm之间,孔隙率随着胶原水平、弹性模量的增加而增加,而密度则减少;增加胶原的含量在细胞联合培养初期有利于细胞对支架的黏附和增殖,但从第10天开始,3种样品中细胞数量相差不大,均出现平台期;苏木精-伊红染色发现成骨细胞在培养初期沿着支架材料内部空隙贴壁生长,随着培养天数的增加,贴壁细胞呈集落样生长,可明显看到细胞间连接。说明透明质酸改性壳聚糖/胶原/纳米羟基磷灰石复合材料可以作为骨支架材料供成骨细胞黏附、增殖,其中胶原与壳聚糖的体积比为1∶1为较优配比。  相似文献   

6.
为了提高玉米蛋白的骨诱导性和骨结合性,以促进其在骨组织工程领域中的应用,将玉米蛋白多孔支架材料浸泡于5倍模拟体液(5×SBF)中,尝试在不同的条件下对玉米蛋白多孔支架材料表面进行仿生矿化。通过场发射扫描电镜(SEM)观察仿生矿化后多孔支架材料各个表面的形貌,能谱(EDS)计算出钙磷比(Ca/P)比。在5倍模拟体液中浸泡后,材料各表面均形成了分布和尺寸相对均匀的微米级(2~10 um)颗粒。其钙磷比接近羟基磷灰石,可以认为获得了比较理想的玉米蛋白-羟基磷灰石多孔支架复合材料。  相似文献   

7.
近年来,以生物活性陶瓷、聚合物等材料为基础复合而成的人工骨骼材料得到了广泛的研究并取得了巨大的进展。纳米羟基磷灰石(nano Hydroxyapatite,n HA)因其具有良好的生物相容性和生物活性,被大量应用于骨组织的移植与修复,但由于现有工艺制备的磷灰石本身力学性能不够完美,进而限制了其应用的广泛性,因此,制备综合性能优越的纳米羟基磷灰石/聚合物复合生物材料是当今骨组织工程中研究的热点。在此,就纳米羟基磷灰石与壳聚糖、胶原、聚乳酸等高分子材料复合而成的新型骨移植替代材料的合成方法、力学性能和生物相容性进行简单的介绍。  相似文献   

8.
背景:实践证明,有机和无机材料单独应用都不是理想的支架材料。聚乳酸具有良好的生物相容性、生物降解性和生物吸收性,聚乳酸类复合材料将成为21世纪最重要的生物复合材料之一。目的:观察复合支架材料聚乳酸-壳聚糖纤维/羟基磷灰石-硅酸钙对成骨细胞黏附、增殖、分化的影响。方法:取新生24h内Wistar大鼠的颅盖骨,采用改良胶原酶消化法进行成骨细胞原代培养。通过倒置相差显微镜、苏木精-伊红染色、碱性磷酸酶染色、钙结节茜素红染色对获得的细胞进行生物学特性的观察与鉴定。然后将第3代细胞与聚乳酸/壳聚糖纤维、聚乳酸-壳聚糖纤维/硅酸钙、聚乳酸-壳聚糖纤维/羟基磷灰石-硅酸钙三种支架材料体外复合培养。培养3,6,9d后,采用倒置相差显微镜观察材料周边的细胞形态,通过碱性磷酸酶活性测定法和MTT法观察3种支架材料对细胞分化、增殖的影响。结果与结论:三种材料均有利于成骨细胞的黏附、生长、分化、增殖,而聚乳酸-壳聚糖纤维/羟基磷灰石-硅酸钙复合支架材料较聚乳酸/壳聚糖纤维、聚乳酸-壳聚糖纤维/硅酸钙支架材料促进成骨细胞的分化增殖效果更好,证实其生物相容性好,有望成为一种新型的骨组织工程支架材料。  相似文献   

9.
背景:观察成骨细胞在生物材料上的形态、增殖和分化等项目,可评估生物支架材料的生物相容性。 目的:观察复合支架材料纳米羟基磷灰石/胶原对成骨细胞增殖、分化的影响。 方法:取新生24 h内Wistar大鼠的颅盖骨,采用改良胶原酶消化法进行成骨细胞原代培养,取第3代细胞与纳米羟基磷灰石/胶原支架或普通羟基磷灰石材料体外复合培养。培养3,6,9 d后,观察材料周边的细胞形态及支架材料对细胞分化、增殖的影响。 结果与结论:纳米羟基磷灰石/胶原材料较普通的羟基磷灰石材料更有利于成骨细胞的黏附、生长、分化、增殖,证实其生物相容性更好,有望成为一种新型的骨组织工程支架材料。  相似文献   

10.
目的:合成新型的复合生物材料框架作为骨组织工程研究的细胞外基质材料。方法:本研究采用材料学自组装技术的原理,以Ⅰ型胶原蛋白为分子模板,引导钙磷盐在液相中的矿化,制备具有天然骨基质层状结构的羟基磷灰石/胶原复合材料,并以热致分相法制备了羟基磷灰石/胶原-聚乳酸复合三维多孔框架。结果:羟基磷灰石/胶原复合材料具有与天然骨基质相似的成分与结构,加入聚乳酸制备成三维多孔框架,孔隙直径界于50um-300um。结论:羟基磷灰石/胶原-聚乳酸复合三维多孔框架可能作为骨组织工程良好的细胞外基质材料。  相似文献   

11.
Three-dimensional oriented chitosan (CS)/hydroxyapatite (HA) scaffolds were prepared via in situ precipitation method in this research. Scanning electron microscopy (SEM) images indicated that the scaffolds with acicular nano-HA had the spoke-like, multilayer and porous structure. The SEM of osteoblasts which were polygonal or spindle-shaped on the composite scaffolds after seven-day cell culture showed that the cells grew, adhered, and spread well. The results of X-ray powder diffractometer and Fourier transform infrared spectrometer showed that the mineral particles deposited in the scaffold had phase structure similar to natural bone and confirmed that particles were exactly HA. In vitro biocompatibility evaluation indicated the composite scaffolds showed a higher degree of proliferation of MC3T3-E1 cell compared with the pure CS scaffolds and the CS/HA10 scaffold was the highest one. The CS/HA scaffold also had a higher ratio of adhesion and alkaline phosphate activity value of osteoblasts compared with the pure CS scaffold, and the ratio increased with the increase of HA content. The ALP activity value of composite scaffolds was at least six times of the pure CS scaffolds. The results suggested that the composite scaffolds possessed good biocompatibility. The compressive strength of CS/HA15 increased by 33.07% compared with the pure CS scaffold. This novel porous scaffold with three-dimensional oriented structure might have a potential application in bone tissue engineering.  相似文献   

12.
In this study a series of alginate/hydroxyapatite (HAP) composite scaffolds was prepared by phase separation. HAP was incorporated into the alginate gel solution to improve both the mechanical and cell-attachment properties of the scaffolds. These scaffolds had a well-interconnected porous structure with an average pore size of 150 microm and over 82% porosity. The alginate/HAP scaffold prepared at -40 degrees C with a 50% HAP content showed the best mechanical properties. The morphology of scaffolds could be manipulated by tuning the quenching temperature during the preparation. The dissolution of alginate/HAP composite scaffolds could be slowed by the pretreating them by immersion in 1.0 M CaCl(2) solution. The rat osteosarcoma UMR106 cells, an osteoblastic cell line, seeded in the scaffolds, displayed better cell attachment to the 75/25 and 50/50 alginate/HAP composite scaffolds than to the pure alginate scaffold. The natural polymeric sponges that fabricated in this study may be a promising approach for tissue-engineering applications.  相似文献   

13.
In this study, an injectable calcium silicate (CS)/sodium alginate (SA) hybrid hydrogel was prepared using a novel material composition design. CS was incorporated into an alginate solution and internal in situ gelling was induced by the calcium ions directly released from CS with the addition of d-gluconic acid δ-lactone (GDL). The gelling time could be controlled, from about 30 s to 10 min, by varying the amounts of CS and GDL added. The mechanical properties of the hydrogels with different amounts of CS and GDL were systematically analyzed. The compressive strength of 5% CS/SA hydrogels was higher than that of 10% CS/SA for the same amount of GDL. The swelling behaviors of 5% CS/SA hydrogels with different contents of GDL were therefore investigated. The swelling ratios of the hydrogels decreased with increasing GDL, and 5% CS/SA hydrogel with 1% GDL swelled by only less than 5%. Scanning electron microscopy (SEM) observation of the scaffolds showed an optimal interconnected porous structure, with the pore size ranging between 50 and 200 μm. Fourier transform infrared spectroscopy and SEM showed that the CS/SA composite hydrogel induced the formation of hydroxyapatite on the surface of the materials in simulated body fluid. In addition, rat bone mesenchymal stem cells (rtBMSCs) cultured in the presence of hydrogels and their ionic extracts were able to maintain the viability and proliferation. Furthermore, the CS/SA composite hydrogel and its ionic extracts stimulated rtBMSCs to produce alkaline phosphatase, and its ionic extracts could also promote angiogenesis of human umbilical vein endothelial cells. Overall, all these results indicate that the CS/SA composite hydrogel efficiently supported the adhesion, proliferation and differentiation of osteogenic and angiogenic cells. Together with its porous three-dimensional structure and injectable properties, CS/SA composite hydrogel possesses great potential for bone regeneration and tissue engineering applications.  相似文献   

14.
A novel hybrid biomaterial composed of calcium sulfate (CS) and gelatin (GEL) was prepared with the potential of being used as bone filler or scaffold owing to its osteoconduction. Such composite biomaterial, cross-linked or un-cross-linked, could provide a suitable absorbing rate and prevent the CS crystals migrating from the implant for tissue engineering. The structure of the composite was analyzed with infrared (IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the crystal pattern of CS was affected by the addition of GEL. The GEL part affected the development of the CS dihydrate (CSD) crystal by slowing the conversion from CS hemihydrate (CSH) to CSD; thus, the composite actually contained CSD, CSH and GEL. The compressive strength of the CS/CLGEL composite was also investigated. The compressive strength was correlated to the weight proportions of CS in the CS/cross-linked GEL (CS/CLGEL) composite, and the highest compressive strength of 82 MPa was obtained for the composite containing 40 wt% CS. The in vitro absorption test and the SEM results showed that a porous scaffold was formed in situ with the absorption of CS in the CS/CLGEL composite in a certain time. Therefore, the CS/CLGEL composite material can be used as an in situ porous scaffold with a high initial mechanical strength, and the remaining porous GEL scaffold will enable further in-growth of cells. Human osteoblasts were cultured in contact with the CS/CLGEL composite and the primary results suggested that human osteoblasts could attach and spread on the surface of CS/CLGEL films. The preliminary animal model experiment was operated for assessing the potential of the CS/CLGEL composite as a biodegradable bone substitute. The primary results showed that the CS/CLGEL composite filler could promote new bone in-growth, which will stimulate further study.  相似文献   

15.
In this study, biphasic calcium phosphate (BCP) porous scaffolds with controllable phase compositions, controllable macropore percentages, and thus adjustable properties were in situ prepared by sintering a series of composites consisted of calcium phosphate cement (CPC) and porous resin negative mold made from rapid prototyping (RP) technique. The CPC pastes were formed by mixing a powder mixture of tetracalcium phosphate and anhydrous dicalcium phosphate with liquid phase of diluted phosphate acid solution. Results show that the phase composition was easily adjustable by controlling both weight ratio of the powder mixture to the liquid phase (P/L) and concentration of the liquid phase. The macropore structure of the BCP scaffold can be regulated by using different RP negative molds. Through in vitro compressive strength (CS) and immersion tests, it was demonstrated that both macropore percentage and phase composition played important roles in the CS and also the dissolving rates of the scaffolds. As the macropore percentage of the scaffold increased, its CS decreased but the dissolving rate increased; also, as the weight ratio of hydroxyapatite to tricalcium (HA/TCP) in the scaffold increased, the CS first increased and then decreased but the dissolving rate uniformly decreased. The CS values of the BCP scaffolds with a HA/TCP weight ratio of 59:41 were 5.84 +/- 1.16 MPa for a total porosity of approximately 67.67% containing a macropore percentage of 30%, and 3.34 +/- 0.79 MPa for a total porosity of approximately 70.90% containing a macropore percentage of 50%, respectively, comparable to the corresponding levels of human cancellous bone (2-12 MPa).  相似文献   

16.
A novel hybrid biomaterial composed of calcium sulfate (CS) and gelatin (GEL) was prepared with the potential of being used as bone filler or scaffold owing to its osteoconduction. Such composite biomaterial, cross-linked or un-cross-linked, could provide a suitable absorbing rate and prevent the CS crystals migrating from the implant for tissue engineering. The structure of the composite was analyzed with infrared (IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the crystal pattern of CS was affected by the addition of GEL. The GEL part affected the development of the CS dihydrate (CSD) crystal by slowing the conversion from CS hemihydrate (CSH) to CSD; thus, the composite actually contained CSD, CSH and GEL. The compressive strength of the CS/CLGEL composite was also investigated. The compressive strength was correlated to the weight proportions of CS in the CS/cross-linked GEL (CS/CLGEL) composite, and the highest compressive strength of 82 MPa was obtained for the composite containing 40 wt% CS. The in vitro absorption test and the SEM results showed that a porous scaffold was formed in situ with the absorption of CS in the CS/CLGEL composite in a certain time. Therefore, the CS/CLGEL composite material can be used as an in situ porous scaffold with a high initial mechanical strength, and the remaining porous GEL scaffold will enable further in-growth of cells. Human osteoblasts were cultured in contact with the CS/CLGEL composite and the primary results suggested that human osteoblasts could attach and spread on the surface of CS/CLGEL films. The preliminary animal model experiment was operated for assessing the potential of the CS/CLGEL composite as a biodegradable bone substitute. The primary results showed that the CS/CLGEL composite filler could promote new bone in-growth, which will stimulate further study.  相似文献   

17.
The dipping-drying procedure and cross-linking method were used to make drug-loaded chitosan (CS) coating on nano-hydroxyapatite/polyamide66 (nHA/PA66) composite porous scaffold, endowing the scaffold controlled drug release functionality. The prefabricated scaffold was immersed into an aqueous drug/CS solution in a vacuum condition and then crosslinked by vanillin. The structure, porosity, composition, compressive strength, swelling ratio, drug release and cytocompatibility of the pristine and coating scaffolds were investigated. After coating, the scaffold porosity and pore interconnection were slightly decreased. Cytocompatibility performance was observed through an in vitro experiment based on cell attachment and the MTT assay by MG63 cells which revealed positive cell viability and increasing proliferation over the 11-day period in vitro. The drug could effectively release from the coated scaffold in a controlled fashion and the release rate was sustained for a long period and highly dependent on coating swelling, suggesting the possibility of a controlled drug release. Our results demonstrate that the scaffold with drug-loaded crosslinked CS coating can be used as a simple technique to render the surfaces of synthetic scaffolds active, thus enabling them to be a promising high performance biomaterial in bone tissue engineering.  相似文献   

18.
Poly(lactide-co-glycolide)/hydroxyapatite(50/50) (PLGA/HA(50/50)) composite microspheres were fabricated and treated with a mixture of 0.25 M NaOH aqueous solution and ethanol (v/v = 1/1) at 37 °C. The properties of untreated and treated PLGA/HA(50/50) composite microspheres were determined and compared. The results showed that the surface roughness, HA content and hydrophilicity of the treated PLGA/HA(50/50) composite microspheres increased with treatment time. However, the treatment time should be kept within 2 h in order to maintain the shape of the PLGA/HA(50/50) microspheres. At the same time, a degradation study showed that both the untreated and treated microspheres degraded gradually with time, with the treated microspheres degrading faster in the first 4 weeks. The rhBMP-2-loaded PLGA/HA(50/50) composite microspheres were prepared by solution dipping treated PLGA/HA(50/50) composite microspheres. Mouse OCT-1 osteoblast-like cells were cultured on the untreated, treated and rhBMP-2-loaded PLGA/HA(50/50) composite microspheres and the cell affinity of the various microspheres was assessed and compared. It was found that the surface-treated PLGA/HA(50/50) composite microspheres clearly promoted osteoblast attachment, proliferation and alkaline phosphatase activity. It was considered that the hydrophilicity, osteoconductivity and surface roughness were increased by the increase in the HA component, which facilitated cell growth. Moreover, the rhBMP-2 loaded on the treated PLGA/HA(50/50) composite microspheres could be slowly released and further enhanced osteoblast differentiation. The good cell affinity and enhanced osteogenic potential of the rhBMP-2-loaded PLGA/HA composite microspheres indicate that they could be used as an injectable scaffold.  相似文献   

19.
Nano hydroxyapatite (HAP) was employed to intensify chitosan (CS) scaffolds by two methods. The first one is nano HAP crystallized in situ from the CS matrix by a biomimetic method (in situ scaffold). In the second method the sol-gel nano HAP powder was added directly to the CS solution (physical mixing scaffold). The distribution status of nano HAP was examined by scanning electron microscopy. The compressive performance was measured by a universal material testing machine. The in vitro study in stimulated body fluid was performed to evaluate the biological properties of both scaffolds. MTT testing and alkaline phosphatase activity from human bone mesenchymal stem cell culture showed differences in biocompatibility and bioactivity between the scaffolds. The results indicated that the in situ scaffold possessed more excellent mechanical and bioactive behaviors than that of the physical mixing scaffold.  相似文献   

20.
Kim HW  Knowles JC  Kim HE 《Biomaterials》2004,25(7-8):1279-1287
Hydroxyapatite (HA) porous scaffold was coated with HA and polycaprolactone (PCL) composites, and antibiotic drug tetracycline hydrochloride was entrapped within the coating layer. The HA scaffold obtained by a polymeric reticulate method, possessed high porosity ( approximately 87%) and controlled pore size (150-200 microm). Such a well-developed porous structure facilitated usage in a drug delivery system due to its high surface area and blood circulation efficiency. The PCL polymer, as a coating component, was used to improve the brittleness and low strength of the HA scaffold, as well to effectively entrap the drug. To improve the osteoconductivity and bioactivity of the coating layer, HA powder was hybridized with PCL solution to make the HA-PCL composite coating. With alteration in the coating concentration and HA/PCL ratio, the morphology, mechanical properties, and biodegradation behavior were investigated. Increasing the concentration rendered the stems thicker and some pores to be clogged; as well increasing the HA/PCL ratio made the coating surface be rough due to the large amount of HA particles. However, for all concentrations and compositions, uniform coatings were formed, i.e., with the HA particles being dispersed homogeneously in the PCL sheet. With the composite coating, the mechanical properties, such as compressive strength and elastic modulus were improved by several orders of magnitude. These improvements were more significant with thicker coatings, while little difference was observed with the HA/PCL ratio. The in vitro biodegradation of the composite coatings in the phosphate buffered saline solution increased linearly with incubation time and the rate differed with the coating concentration and the HA/PCL ratio; the higher concentration and HA amount caused the increased biodegradation. At short period (<2 h), about 20-30% drug was released especially due to free drug at the coating surface. However, the release rate was sustained for prolonged periods and was highly dependent on the degree of coating dissolution, suggesting the possibility of a controlled drug release in the porous scaffold with HA+PCL coating.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号