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本文采用pH值测量、特性粘度、失重、DSC和电子探针的研究方法,研究了PLGA组织工程支架在模拟体液中的降解性能和生物矿化性能。研究发现随着在SBF中浸泡时间的增长,PLGA支架材料的分子量不断下降;浸泡在SBF中的PLGA组织工程支架材料的重量由沉积进程和降解进程共同决定;DSC测试显示,浸泡在SBF中的PLGA组织工程支架材料的羟基乙酸单元(GA)相对于乳酸单元(LA)更易降解;电子探针测试显示,浸泡在SBF中的PLGA组织工程支架材料表面有磷酸盐沉积物产生。 相似文献
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目前,治疗创伤、先天畸形、肿瘤组织切除等原因造成的大段骨缺损仍是骨科手术面临的主要挑战。利用骨组织工程支架代替自体骨移植在缺损部位进行骨重建为解决该问题带来新的方案。鉴于理想骨组织工程支架应具备良好生物相容性、适宜生物降解性、与骨组织相匹配的力学性能以及抗菌性等特征,多孔Zn基支架可能成为理想骨组织工程支架的最佳候选者。然而,近些年的研究发现目前开发的多孔Zn基支架存在力学性能差、体外浸泡及植入体内初期降解速率相对较快导致过量Zn2+释放、高浓度Zn2+能够抑菌杀菌但也会使Zn基支架细胞毒性增强进而导致支架植入体内后出现骨整合延迟等问题。鉴于此,近些年关于多孔Zn基支架的研究主要聚焦于改善支架力学性能、调控支架降解速率,同时赋予支架抑菌杀菌性能和良好生物相容性等方面。研究者们主要采取了对多孔Zn支架进行合金化处理、控制孔隙率、控制孔隙形貌和尺寸等手段来提高多孔Zn基支架的力学性能,同时实现对多孔Zn基支架降解速率的调控。此外,也有研究者利用电偶腐蚀原理调控多孔支架的降解速率。由于多孔Zn基支架降解过程中释放的Zn2+严重影响支架的抑菌杀菌性能和生物相容性,且抑菌杀菌性能和良好生物相容性... 相似文献
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利用静电纺丝和模拟体液仿生矿化技术制备了聚乳酸-羟基乙酸共聚物/柞蚕丝素/羟基磷灰石((PLGA/TSF/HA)骨组织工程复合支架。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射测试(XRD)和热重分析(TG)对复合纳米纤维的形貌结构进行了表征。此外,在复合纳米纤维支架材料上接种人骨髓间充质干细胞(hMSCs),通过四甲基偶氮噻唑蓝比色(Four methyl azo thiazole blue colorimetric,MTT)法,观察细胞在材料表面的生长情况评价纳米纤维的生物相容性。结果显示,PLGA/TSF纳米纤维毡具有精细的三维结构,纤维直径分布均匀,表面光滑。矿化后HA颗粒均匀地分布在PLGA/TSF纳米纤维表面,矿物含量约占63%。与PLGA/TSF纳米纤维支架相比,PLGA/TSF/HA纳米纤维支架的亲水性、生物相容性都得到显著提高。 相似文献
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采用XRD、DSC、体外降解实验和细胞相容性实验等方法对羟基磷灰石/聚醚酯聚氨酯(HA/PU)多孔支架的结构和性能进行了研究。结果表明,HA粒子添加到聚醚酯聚氨酯基体中,在一定程度上降低了聚氨酯软段的结晶,提高了聚氨酯基体的力学性能。体外降解实验表明HA/PU复合支架的降解不会引起浸泡液pH值较大的波动,且降解初期的力学性能衰减缓慢。MG63细胞与HA/PU复合支架共培养的实验表明,细胞生长良好,牢固地黏附在支架表面,并在支架表面充分伸展,复合支架具有良好的细胞相容性。这些结果表明HA/PU支架有望用于骨组织工程修复。 相似文献
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《Materials Letters》2005,59(29-30):4000-4005
The purpose of this study was to fabricate composites consisting of three interpenetrating networks: tricalcium phosphate (TCP), hydroxyapatite (HA), and poly(dl-lactide-co-glycolide) (PLGA). The porous TCP network was first produced by coating a polyurethane (PU) foam with hydrolysable alpha-TCP slurry. The HA network was derived from a calcium phosphate cement (CPC) filled in the porous TCP network. The remaining open pore network in the HA/TCP composite was further infiltrated with a PLGA network. The three sets of spatially continuous networks would have different biodegradation rates and thus bone tissue would grow towards the fastest biodegrading network while the remaining networks still maintaining their geometrical shape and carrying the physiological load for the tissue ingrowth. 相似文献
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A. Champa Jayasuriya Nabil A. Ebraheim 《Journal of materials science. Materials in medicine》2009,20(8):1637-1644
The aim of this study was to evaluate the composite matrices prepared using Poly(lactic-co-glycolic acid)- PLGA (85:15) by
incorporating human bone matrix (BM) powder or demineralized bone matrix (DBM) powder with the weight ratio of polymer: BM
or DBM (75:25) to apply for bone repair. Murine Bone Marrow Stromal Cell (BMSC) attachment was studied with different time
points at 30 min, 1 h, 2 h, 4 h, and 6 h for BM/PLGA, DBM/PLGA and PLGA control matrices. All types of matrices were linearly
increased the BMSC attachment with the increase of time. Significantly higher number of BMSCs was attached to the both BM/PLGA
and DBM/PLGA matrices after 2 h compared to the controls. If BM or DBM is incorporated into biodegradable PLGA matrices and
cultured with BMSCs, those composite matrices could be potentially used for bone tissue engineering applications. In addition,
particle migration and handling difficulties in DBM powder in clinical applications eliminate using a PLGA matrix. Furthermore,
we have observed that DBM/PLGA matrices were structurally stronger compared to the BM/PLGA or control PLGA matrices when they
exposed to physiological environment for 72 days. 相似文献
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An overview about the development of porous bioresorbable composite materials for applications as scaffolds in tissue engineering is presented. A thermally induced phase separation method was developed to fabricate porous foam-like structures of poly(lactide-co-glycolide) (PLGA) containing bioactive glass particle additions (up to 50 wt.%) and exhibiting well-defined, oriented and interconnected porosity. The in vitro bioactivity and the degradability of the composite foams were investigated in contact with phosphate buffer saline (PBS). Weight loss, water absorption and molecular weight measurements were used to monitor the polymer degradation after incubation periods of up to 7 weeks in PBS. It was found that the presence of bioactive glass retards the polymer degradation rate for the time period investigated. The present results show a way of controlling the in vitro degradation behaviour of PLGA porous composite scaffolds by tailoring the concentration of bioactive glass. 相似文献
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Tissue engineering has been developed as a prospective approach for the repair of articular cartilage defects. Engineered osteochondral implants can facilitate the fixation and integration with host tissue, and therefore promote the regeneration of osteochondral defects. A biphasic scaffold with a stratified two-layer structure for osteochondral tissue engineering was developed from biodegradable synthetic and naturally derived polymers. The upper layer of the scaffold for cartilage engineering was collagen sponge; the lower layer for bone engineering was a composite sponge of poly(DL-lactic-co-glycolic acid) (PLGA) and naturally derived collagen. The PLGA–collagen composite sponge layer had a composite structure with collagen microsponge formed in the pores of a skeleton PLGA sponge. The collagen sponge in the two respective layers was connected. Observation of the collagen/PLGA–collagen biphasic scaffold by scanning electron microscopy (SEM) demonstrated the connected stratified structure. The biphasic scaffold was used for culture of canine bone-marrow-derived mesenchymal stem cells. The cell/scaffold construct was implanted in an osteochondral defect in the knee of a one-year old beagle. Osteochondral tissue was regenerated four months after implantation. Cartilage- and bone-like tissues were formed in the respective layers. The collagen/PLGA–collagen biphasic scaffold will be useful for osteochondral tissue engineering. 相似文献
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以掺锶β-磷酸三钙/硫酸钙为原料,利用搅拌喷雾干燥法制备出掺锶β-磷酸三钙/硫酸钙复合小球,再将硅胶与制备的复合小球复合,通过在模具中堆垛聚集的方法,制备出硅胶/掺锶β-磷酸三钙/硫酸钙复合生物支架。采用XRD,SEM,FT-IR等方法分析制得复合多孔支架的成分、形貌以及结构特征,并研究复合生物支架的降解性、孔隙率、力学性能和细胞毒性等。结果表明:该复合多孔生物支架具有一定的不规则孔洞结构,小球与小球之间的孔隙约为0.2~1mm,而每个小球上也有大量的微孔,孔径在50~200μm之间,且平均孔隙率达到62%,基本能满足骨组织工程支架对孔隙率的要求;该复合多孔支架无细胞毒性,其降解周期约为80天,抗压强度约为0.1MPa,因此该支架在非承重骨组织修复方面具有良好的应用前景。 相似文献
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Minamiguchi S Takechi M Yuasa T Momota Y Tatehara S Takano H Miyamoto Y Satomura K Nagayama M 《Journal of materials science. Materials in medicine》2008,19(3):1165-1172
Recently, it has become important to develop effective material to be used as scaffolds for bone tissue engineering. Therefore,
we fabricated new three-dimensional (3D) scaffolds consisting of biodegradable poly(d,l-lactide-co-glycolic acid)(PLGA)(75/25) with anti-washout type AC (aw-AC) particles. The aim of this study was to evaluate
this new scaffold concerning its basic properties and biocompatibility. The obtained scaffolds were observed with scanning
electron microscopy (SEM), and measured for porosity, shrinkage and biaxial compressive strengths. It was shown that PLGA
with aw-AC composite scaffolds (aw-AC/PL) showed a greater strength and stability than PLGA scaffolds (PL). Also, the mass
reduction of aw-AC/PL during incubation decreased compared to that of PL. The number of MC3T3-E1 cell in PL and aw-AC/PL was
counted at 5 h, 1 week, and 2 weeks after cell seeding. As a result, aw-AC/PL exhibited a superior performance in terms of
attachment and proliferation compared to PL. Histologically, aw-AC/PL showed an excellent response toward soft tissues. Therefore,
it was shown that aw-AC/PL was more biocompatible than PL. In conclusion, it was strongly suggested that aw-AC/PL was more
useful for cell transplantation than PL in bone tissue engineering. 相似文献
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The design of nanophase titania/poly-lactic-co-glycolic acid (PLGA) composites offers an exciting approach to combine the advantages of a degradable polymer with nano-size ceramic grains to optimize physical and biological properties for bone regeneration. Importantly, nanophase titania mimics the size scale of constituent components of bone since it is a nanostructured composite composed of nanometre dimensioned hydroxyapatite well dispersed in a mostly collagen matrix. For these reasons, the objective of the present in vitro study was to investigate osteoblast (bone-forming cell) adhesion and long-term functions on nanophase titania/PLGA composites. Since nanophase titania tended to significantly agglomerate when added to polymers, different sonication output powers were applied in this study to improve titania dispersion. Results demonstrated that the dispersion of titania in PLGA was enhanced by increasing the intensity of sonication and that greater osteoblast adhesion correlated with improved nanophase titania dispersion in PLGA. Moreover, results correlated better osteoblast long-term functions, such as alkaline phosphatase activity and calcium-containing mineral deposition, on nanophase titania/PLGA composites compared to plain PLGA. In fact, the greatest collagen production by osteoblasts occurred when cultured on nanophase titania sonicated in PLGA at the highest powers. In this manner, the present study demonstrates that PLGA composites with well dispersed nanophase titania can enhance osteoblast functions necessary for improved bone tissue engineering applications. 相似文献
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Hualin Zhang 《Materials Letters》2009,63(27):2313-2316
Biomimetic mineralization is an effective method to improve the biocompatibility and bone inductivity of certain materials. In this study, composite scaffolds composed of poly(lactic-co-glycolic acid) (PLGA) and multi-walled carbon nanotubes (MWNTs) were prepared by electrospinning. Subsequently, the scaffolds were immersed in a simulated body fluid (1.5 × SBF) at 37 °C for 7, 14 and 21 days for biomimetic mineralization. Scanning electron microscopy, Raman spectroscopy, and X-ray diffraction were used for characterization. It was found that the electrospun scaffolds had extremely resemblant structural morphology to the natural extracellular matrix. After mineralization, apatite crystals were deposited on the PLGA/MWNTs composite scaffolds. The mineralized PLGA/MWNTs composites may be potentially useful in tissue engineering applications, particularly as scaffolds for bone tissue regeneration. 相似文献
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Jung-Ju Huang Shu-Rui Yang I-Ming Chu Eric M Brey Hui-Yi Hsiao Ming-Huei Cheng 《Science and Technology of Advanced Materials》2013,14(5)
AbstractThe clinical demand for cartilage tissue engineering is potentially large for reconstruction defects resulting from congenital deformities or degenerative disease due to limited donor sites for autologous tissue and donor site morbidities. Cartilage tissue engineering has been successfully applied to the medical field: a scaffold pre-cultured with chondrocytes was used prior to implantation in an animal model. We have developed a surgical approach in which tissues are engineered by implantation with a vascular pedicle as an in vivo bioreactor in bone and adipose tissue engineering. Collagen type II, chitosan, poly(lactic-co-glycolic acid) (PLGA) and polycaprolactone (PCL) were four commonly applied scaffolds in cartilage tissue engineering. To expand the application of the same animal model in cartilage tissue engineering, these four scaffolds were selected and compared for their ability to generate cartilage with chondrocytes in the same model with an in vivo bioreactor. Gene expression and immunohistochemistry staining methods were used to evaluate the chondrogenesis and osteogenesis of specimens. The result showed that the PLGA and PCL scaffolds exhibited better chondrogenesis than chitosan and type II collagen in the in vivo bioreactor. Among these four scaffolds, the PCL scaffold presented the most significant result of chondrogenesis embedded around the vascular pedicle in the long-term culture incubation phase. 相似文献
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Timothy Douglas Elzbieta Pamula Dominik Hauk Jörg Wiltfang Sureshan Sivananthan Eugene Sherry Patrick H. Warnke 《Journal of materials science. Materials in medicine》2009,20(9):1909-1915
Poly-lactic-glycolic acid (PLGA) has been widely used as a scaffold material for bone tissue engineering applications. 3D
sponge-like porous scaffolds have previously been generated through a solvent casting and salt leaching technique. In this
study, polymer–ceramic composite scaffolds were created by immersing PLGA scaffolds in simulated body fluid, leading to the
formation of a hydroxyapatite (HAP) coating. The presence of a HAP layer was confirmed using scanning electron microscopy,
energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy in attenuated total reflection mode. HAP-coated
PLGA scaffolds were tested for their biocompatibility in vitro using human osteoblast cell cultures. Biocompatibility was
assessed by standard tests for cell proliferation (MTT, WST), as well as fluorescence microscopy after standard cell vitality
staining procedures. It was shown that PLGA–HAP composites support osteoblast growth and vitality, paving the way for applications
as bone tissue engineering scaffolds. 相似文献