多孔n-HA/CS/PA66三元复合支架材料的制备及性能

采用常压共混复合法制备了纳米羟基磷灰石/壳聚糖/聚酰胺66(n-HA/CS/PA 66)三元复合材料,并以乙醇为溶剂,聚乙烯吡咯烷酮和氯化钠混合物为致孔剂的粒子沥滤法制备了n-HA/CS/PA 66三元复合多孔支架材料,用燃烧试验、IR、XRD、SEM、孔隙率及力学性能测试等手段对其进行了表征。结果表明,n-HA在复合材料中分布均匀且呈弱结晶状态,复合前后三组分的化学组成未发生显著变化,但三相间两两均发生了相互作用。在制备n-HA/CS/PA 66多孔材料时,加入少量的聚乙烯吡咯烷酮可使该多孔材料孔隙率更高,孔的贯通性更好。     

不同热处理温度下纳米羟基磷灰石/聚酰胺66多孔支架制备及力学性能研究

热处理温度是热致相分离法制备多孔支架材料的关键因素。在不同热处理温度下(60℃、75℃和90℃)制备了纳米羟基磷灰石/聚酰胺66(n-HA/PA66)复合多孔支架材料。对比研究了不同热处理温度下制备的多孔支架孔隙结构、孔隙率及力学性能。结果表明:处理温度对多孔支架的孔隙结构,孔隙率,力学性能有显著的影响,随着温度的升高,多孔支架的孔隙率、平均孔径升高,贯通性改善,但弹性模量和屈服极限降低。多孔支架的热处理温度为75℃时,其孔径、孔隙率和力学性能与天然松质骨相当,是较为理想的骨组织工程支架材料。     

壳聚糖修饰纳米羟基磷灰石/聚酰胺复合多孔支架的制备及性能研究

利用相转移法制备了纳米羟基磷灰石/聚酰胺66(n-HA/PA66)复合多孔支架.用不同浓度(1%、3%、5%)的壳聚糖(CS)溶液对多孔支架进行了表面修饰.用扫描电镜(SEM)和材料力学试验机对多孔支架修饰前后的形貌和力学性能进行了表征.研究了经CS修饰的n-HA/PA66复合多孔支架在磷酸盐缓冲溶液(PBS)中的浸泡行为,并初步研究了其与MG63细胞的细胞相客性.结果显示,多孔支架具有较为理想的孔隙结构和贯通性,经CS修饰后,其力学强度有显著提高.体外浸泡结果显示,随着漫泡时间的增加,支架表面微结构变得粗糙和多孔化.细胞实验表明该支架有利于细胞在表面的粘附、铺展、生长和增殖.     

乙烯-醋酸乙烯酯/羟基磷灰石/聚酰胺软骨及骨一体化修复材料的制备与表征

采用共混法和相分离法制备了纳米羟基磷灰石(nHA)和聚酰胺(PA66)复合支架材料。nHA在PA66基质中分布均匀。复合支架材料孔径50～500μm,孔隙率为80.9%。将乙烯-醋酸乙烯脂(EVA)通过热注塑方法在支架材料表面涂覆形成双层结构的软骨及骨一体化修复材料,EVA层用于软骨修复,下层nHA-PA66支架进行缺损骨修复和固定。EVA和nHA-PA66的力学性能测试显示,EVA的拉伸和压缩模量分别为(0.87±0.02)MPa和(9.44±0.46)MPa,多孔支架的压缩强度和模量分别为(0.9±0.02)MPa和(15.2±0.69)MPa。摩擦测试结果表明,EVA摩擦系数为0.23。     

纳米羟基磷灰石/聚酰胺多孔支架材料的制备及其结晶行为研究

以NaCl为致孔剂,采用粒子沥滤-相转移法制备了纳米羟基磷灰石/聚酰胺6(n-HA/PA6)多孔支架材料,用扫描电子显微镜(SEM),X射线衍射(XRD),示差扫描量热仪(DSC)等对其进行表征.结果表明,用该方法制备的多孔支架孔径分布在50～300μm,孔隙率约为77%,孔与孔之间的贯通性良好.用粒子沥滤-相转移法制备的支架中PA6的晶胞体积较制备前有所增大,同时其结晶度也有增加.研究表明,NaCl粒子的存在促进了PA6聚合物晶体的生长.在制备成支架后,n-HA/PA6复合材料中PA6仍为混晶型高聚物,其晶型部分发生了转变,由制备前α晶型占多数变成了制备后γ晶型占多数.支架的制备过程使PA6更容易结晶,但结晶总速率在制备支架前后均没有太大改变.     

骨组织工程用n-HA/PA66多孔贯通支架的制备及表征

为了解决生物降解性骨组织工程支架难以与人体骨力学强度相匹配的缺点,选用具有良好生物相容性和力学性能的纳米羟基磷灰石/聚酰胺66(n-HA/PA66)复合材料作为基材,通过相转移法和粒子沥滤法相结合的工艺制备了一种骨组织工程用多孔贯通支架.用扫描电子显微镜(SEM)、X射线衍射(XRD)、红外光谱(IR)和万能力学试验机等手段对多孔支架的理化性能进行表征.结果显示, n-HA/PA66多孔支架具有较为理想的孔隙结构和贯通性,且其压缩强度与人体松质骨相当,可满足骨组织工程支架的基本要求.因其具有非生物降解特性,故可为骨组织的再生提供持续稳定的力学支撑.     

用于软骨和软骨下骨修复的纳米羟基磷灰石/聚乙烯醇/聚酰胺66功能梯度材料的制备和表征

利用反复冷冻-解冻法和相分离法,制备出用于软骨和软骨下骨修复的纳米羟基磷灰石(nHA)/聚乙烯醇(PVA)/聚酰胺(PA66)功能梯度材料。研究表面层PVA的力学性能和摩擦学性能,及软骨下骨nHA/PA66(m(HA)∶m(PA66)=1∶1)支架的力学性能及生物学性能。结果表明PVA拉伸强度为1.938MPa,平均摩擦系数在生理盐水及代血浆润滑条件下分别为0.076和0.085;nHA/PA66复合多孔支架孔隙率为80.93%,孔径为50～500μm,压缩强度和压缩模量分别为0.88和15.21MPa,且具有良好的生物相容性。     

纳米羟基磷灰石/壳聚糖-羧甲基纤维素复合支架材料的研究

用冷冻干燥法制备了不同比例的纳米羟基磷灰石/壳聚糖-羧甲基纤维素(n-HA/CS-CMC)无机/有机复合多孔支架材料, 并探讨了其复合机理及无机组分n-HA对复合支架的结构形貌、力学性能、体外降解性能的影响. 结果表明, 其复合支架主要是通过无机组分n-HA均匀分散充填在CS-CMC聚电解质有机网络结构中形成的, 且三组分间有较强的化学键合. 无机组分n-HA的加入使孔结构变得不规则, 孔隙率略有减小, 使复合支架的抗压缩强度提高, 并且可使其体外降解速度减慢. 无机组分n-HA含量为40\%复合支架材料的性能最佳, 有望用作骨组织工程支架材料.     

注射成型羟基磷灰石/聚酰胺6多孔支架的微观结构和力学性能

采用注射成型法制备了羟基磷灰石/聚酰胺6(HA/PA6)多孔支架,用SEM、XRD、DSC等手段表征了支架的组成结构和形貌,检测了其力学性能.研究表明,调节羟基磷灰石(HA)含量、偶氮二甲酰胺(AC)用量和预塑量能有效控制支架的力学性能、孔径大小和孔隙率.HA/PA6支架的孔径在100～500μm左右,孔隙率达到甚至超...     

聚氨酯/纳米羟基磷灰石/聚酰胺66股骨髁修复犬骨软骨缺损的实验研究

制备了PU/n-HA/PA66股骨髁,用扫描电镜观察材料表面情况并测定其孔隙率;将PU/n-HA/PA66股骨髁与自体髁植入犬股骨远端,以替代、修复骨软骨缺损,进行大体观察、组织学、免疫组化、CT、血常规和生化检测以及肝、肾、脾组织学检测。结果表明材料孔隙率为80.89%±5.01%,孔径主要分布在300～800μm之间。术后实验动物活动正常,切口愈合良好,两组髁假体均与自体骨结合紧密,PU/n-HA/PA66股骨髁网孔中的骨小梁逐渐增多成熟,材料孔穴中的新生骨Ⅰ型胶原阳性表达。术后动物碱性磷酸酶水平升高[(62.67±24.04)U/L],肝、脾、肾HE染色未见异常。PU/n-HA/PA66股骨髁具有良好的骨修复、软骨替代能力和生物相容性,具有应用前景。     

Preparation and characterization of nano-hydroxyapatite/polymer composite scaffolds

Polycaprolactone/chitosan (PCL/CS) porous composite scaffolds were prepared by solution phase separation method, and the scaffolds were further enhanced by filling with nano-hydroxyapatite/polyvinyl alcohol (n-HA/PVA) composite slurry to prepare n-HA-PVA/PCL-CS composite porous scaffolds through slurry centrifugal filling technique. The morphology, microstructure, component, porosity and mechanical property of the scaffolds were characterized using scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscope, elemental analyzer and material test machine. The results show that PCL/CS scaffolds have mutual transfixion porous structure just like honeycombs. The porosity of the scaffolds can achieve 60-80%. As the content of CS increases, the porosity increases while the compressive strength decreases. After filled with HA/PVA composite slurry, the porosity of n-HA/PCL-CS composite scaffolds decreases, but still greater than 60%, while the compression modulus can increase to 25.7 MPa.     

Bioactive composite gradient coatings of nano-hydroxyapatite/polyamide66 fabricated on polyamide66 substrates

Tightly bonding of bioactive coating is the first crucial need for orthopaedic implants. This study describes a novel and convenient technique to prepare bioactive coating with high adhesion on orthopaedic substitutes made of polymeric matrix. Here, a chemical corrosion method has been adopted to fabricate a coating on the surface of injection-moulded polyamide66 (PA66) substrates by corrosive nano-hydroxyapatite/polyamide66 (n-HA/PA66) composite slurry. Scanning electron microscopy observation shows that a porous chemical corrosion region presents between the coating and dense PA66 substrate. Energy-dispersive X-ray spectroscopy analysis indicates that the chemical corrosion region is mainly composed of PA66 matrix, and the coating layer is an n-HA-rich layer. Both the pore size and n-HA composition increase gradually from the polymeric substrate towards the coating surface. Mechanical testing shows the bonding strength can reach 13.7 ± 0.2 MPa, which is much higher than that fabricated on polymeric matrix by other coating methods. The gradual transition in coating structure and composition benefits for the interface bonding and for the surface bone-bonding bioactivity. Subsequent cell experiments corroborate n-HA-rich coating and a porous structure is benefitting for cell attachment and proliferation. The convenient coating method could be popularized and applied on similar polymer implants to produce a tightly and porous bioactive coating for bone tissue regeneration.     

纳米羟基磷灰石/聚酰胺多孔支架材料的制备及性能研究

使用多种致孔剂采用粒子沥滤法制备了纳米羟基磷灰石／聚酰胺多孔支架材料，用IR、XRD、SEM等手段对多孔复合材料的组成结构及形貌进行了表征，并检测了其物理性能指标。结果表明，复合材料中两相分散均匀，且发生了界面结合；材料的孔隙率与致孔剂的含量成正比，支架中大孔与微孔并存且相互贯通；以NaCl作致孔剂且孔隙率达到80％左右时的支架材料可以同时满足组织工程对孔隙率和力学强度的双重要求。     

Morphology,hydrogen-bonding and crystallinity of nano-hydroxyapatite/polyamide 66 biocomposites

Nano-composites for load-bearing bone repair consisting of nano-hydroxyapatite (n-HA) and polyamide 66 were prepared by co-precipitation in ethanol. The relationships between structure and property of the composites were studied. Infrared spectrum results showed that n-HA and PA66 were mainly linked by hydrogen-bonding, which mainly existed between OH of n-HA and amide of PA66. The X-ray diffraction results revealed that the introduction of n-HA to polymeric matrix would weaken the crystallinity of α2 crystals in PA66, and most of the PA66 crystals in the composite were α1 crystals. A differential scanning calorimetry pattern showed that the hydrogen-bonding between organic and inorganic phases in the composite enhanced nucleation spots and played the role of nucleating agent, which resulted in the increase of nucleating speed of PA66 in the composite. However, the relative crystalline degree of PA66 in the composite decreased with the increase of the content of n-HA (the degrees of crystallinity were 27.67% for pure PA66, 23.44% for 30 wt% n-HA/PA66 and 22.98% for 40 wt% n-HA/PA66) because of the high viscosity of the system caused by the addition of n-HA and the hydrogen-bonding between n-HA and PA66.     

醇化改性蓖麻油基聚氨酯/n-HA复合支架材料的结构及力学性能

有机/无机材料的两相界面作用和均匀复合是影响复合支架材料性能的主要因素。本研究通过工艺改进, 对聚氨酯软段成分进行改性得到醇化蓖麻油, 经原位聚合发泡制备出多孔复合支架, 较好地实现了纳米羟基磷灰石(n-HA)颗粒的均匀分散。结果表明, 改性聚氨酯基体有效增加了羟基值, 其与极性n-HA两相界面复合良好, 无明显界面分相和颗粒团聚发生。支架孔径分布均匀, 但支架材料的孔隙率、孔径大小和结晶度略有减小。红外光谱和X射线衍射分析表明, n-HA和醇化蓖麻油基聚氨酯基体的分子间存在丰富的氢键和化学键, 促进了无机-有机相的相容性和稳定性。醇化改性和纳米无机粒子添加对材料性能的协同作用有效改善了支架的力学性能, 复合支架的压缩强度和模量均大幅增长。该种n-HA/聚氨酯复合支架有望用于进一步的骨再生和骨组织工程研究。     

Fabrication and characterization of poly-d-l-lactide/nano-hydroxyapatite composite scaffolds with poly (ethylene glycol) coating and dexamethasone releasing

The control of pore size and structure, drug release capacity, and biodegradation of scaffolds is of importance for bone tissue engineering. In this study, a technique combining polymer coagulation, cold compression molding, salt particulate leaching and drug coating method was developed to fabricate poly (ethylene glycol)/dexamethasone coated porous poly-d-l-lactide/nano-hydroxyapatite (PDLLA/nano-HAp) scaffolds. These scaffolds possess homogenous pore networks with high porosity (66-82%) and controllable pore size (200-300 μm). The compressive moduli and strength of the scaffolds after incorporation of nano-HAp were improved by 50% and 20%, respectively. The surface hydrophilicity of the scaffold was significantly improved by poly (ethylene glycol)/dexamethasone coating and nano-HAp addition, leading to a higher initial drug loading amount. The results showed that the drug release behavior of the scaffolds after 35-day immersion in water could be adjusted by varying the porosity level and by incorporation of 20 wt.% of nano-HAp.     

蜡球造孔法制备多孔HA陶瓷支架及其性能优化

组织工程支架的贯通性对其体内生物学表现具有重要影响。采用甲壳素溶胶体系和蜡球造孔剂制备多孔羟基磷灰石(HA)陶瓷支架, 考查在相同模压条件下, 不同浆料/造孔剂比例对多孔HA陶瓷支架的孔隙率、收缩率、贯通性、多孔结构以及抗压强度的影响。结果表明: 该方法可以制备具有高孔隙的多孔HA陶瓷支架, 随着造孔剂比例的增大, 支架的贯通性更好, 当浆料/造孔剂比例为1:1.2时可以得到孔隙率、贯通性、力学性能最优的多孔HA陶瓷支架。