多孔 n2 HA/ PA26复合材料的制备及性能

采用注塑方法制备了多孔纳米磷灰石/聚酰胺26 (n2 HA/ PA26) 复合材料 , 采用 SEM、XRD、IR、 力学性能测试考察了多孔材料的性能。结果发现 : 多孔纳米磷灰石/聚酰胺26复合材料的孔隙分布均匀 , 贯通性良好 , 孔的尺寸约为 100～700μm , 平均孔径约 300～500μm , 大孔壁上有丰富的微孔 ; 所得多孔复合材料的孔隙率可控 , 总孔隙率最高可达 881 6 %; 多孔材料的总孔隙率降低 , 则开孔率随之降低 ; 多孔纳米磷灰石/聚酰胺26 复合材料的抗压强度为 1. 1～15. 6 MPa , 压缩模量为 0. 4～1. 4 GPa ; 在总孔隙率相近的条件下 , 多孔材料的抗压强度随 n2 HA质量分数增加而升高; 发泡剂和发泡过程对组成纳米磷灰石/聚酰胺26复合材料的两组元材料的性质和结构无影响。这种多孔材料可望作为人体非承重部位的植入骨修复体和组织工程支架使用。     

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。     

孔结构渐变聚己内酯/羟基磷灰石仿生骨材料

为获得具有类似人骨的渐变孔结构、力学性能良好的羟基磷灰石(hydroxyapatite,HA)/聚己内酯(polycaprolactone,PCL)仿生骨材料,采用水热法制备了HA粉末,通过溶剂共混法将其与PCL复合,并采用浇铸/NaCl微粒浸出法制备了多孔状HA/PCL复合材料.通过控制造孔剂NaCl的粒径和用量得到了不同孔径、不同孔隙率的HA/PCL复合材料及具有渐变孔结构的HA/PCL复合材料.利用光学显微镜观察了其孔结构,结果为孔径在100～300μm,最大孔隙率达到80%.同时研究了它们在人体体温附近(37±5)℃的力学性能,结果表明渐变孔结构的HA/PCL复合材料的力学性能较单一孔结构的HA/PCL复合材料有了很大的提高.通过梯度造孔不仅可获得与人骨极为类似的多孔仿生材料,同时还可大幅提高多孔材料的力学性能.     

PES/HA多孔生物材料的制备及其生物相容性

制备PES/HA复合材料,红外光谱分析显示该复合材料主要是物理结合;以氯化铵为制孔剂,制备复合材料与制孔剂质量比为1∶0.25,1∶0.5,1∶0.75,1∶1的多孔复合材料。测定PES/HA孔结构复合材料吸水率。当复合材料与制孔剂质量比为1∶0.25时吸水率为40%。制孔剂含量比例越高,复合材料吸水率越高,当复合材料与制孔剂质量比为1∶1时PES/HA复合材料吸水率为88%。通过光学显微镜和电镜比较发现4组复合材料孔径多数分布在200~300μm之间,最小孔径约为40μm,最大孔径约为470μm;体外培养MG-63细胞,通过噻唑蓝(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltet razolium bromide,MTT)研究PES/HA复合材料对细胞毒性的影响,PES/HA复合材料毒性级别为I,该材料对MG-63细胞无毒性,这种细胞在PES/HA多孔材料表面和孔结构中粘附良好,细胞伸出多个伪足贴附在材料表面及孔壁上。     

多孔ZnO/羟基磷灰石生物复合材料的制备与性能

利用放电等离子烧结技术制备多孔ZnO/羟基磷灰石(HA)生物复合材料,研究不同纳米ZnO含量对ZnO/HA复合材料微观结构、孔隙特征、力学性能、矿化和降解性能的影响。结果表明:烧结后ZnO/HA复合材料主要由HA相和ZnO相组成;随着ZnO含量提高,多孔ZnO/HA复合材料孔隙率缓慢增大,抗压强度略有减小,弹性模量变化不大;多孔ZnO/HA复合材料的孔隙率40%,孔径在50～500μm之间,抗压强度148MPa,弹性模量为6.5GPa左右,能够满足骨修复材料的要求;模拟人工体液中矿化和降解实验表明,多孔ZnO/HA复合材料浸泡7天后表面开始形成大量类骨磷灰石层,且随着ZnO含量增加,磷灰石形成能力明显增强而降解速率加快。     

超临界CO2中制备聚乳酸/羟基磷灰石复合支架材料

利用盐析/超临界CO2复合方法制备了一系列的PDLLA/HA三维多孔支架材料.利用这种方法可以避免使用有机溶剂、较高温度和降低常规气体发泡法所需的较长时间.制备的三维多孔支架的孔隙率最高达91%,孔与孔之间相互连通,孔分布均匀,孔径大小为100～300μm,抗压强度明显增加.详细研究了CO2压力、温度、浸润时间以及致孔剂含量等条件的变化对复合材料形貌和孔隙率的影响.     

有机硅交联剂对硅树脂/聚苯乙烯多孔复合材料性能的影响

以苯乙烯(St)为单体,含甲基丙烯酰氧基丙基的有机硅树脂(MTQ)为交联剂,采用高内相比乳液模板(HIPE)法制备了蜂窝状、低密度及高孔隙率的MTQ/聚苯乙烯(PS)多孔复合材料,研究了MTQ对聚合物多孔复合材料微观结构、压缩性能及热稳定性的影响。结果表明:MTQ/PS多孔复合材料的泡孔呈立体球形且泡孔壁上有丰富的互连孔,相互贯通性良好,泡孔直径为2~9μm,互连孔的孔径大小介于0.35~1.85μm;所得多孔材料孔隙率可控,总孔隙率最高可达92%;该多孔复合材料的压缩强度为0.28~0.74 MPa,压缩模量为4.86~13.54 MPa。当MTQ与St的质量比为30∶100时,可获得泡孔直径较小、互连孔道较窄、压缩性能和热稳定性较好的MTQ/PS多孔复合材料。     

软骨修复用 HA/PU多孔支架材料的制备与表征

研制了用于软骨的组织工程的HA／PU多孔支架材料，采用气体发泡法制备了三维贯通的多孔HA／PU支架材料，通过XRD、IR对其结构组成进行了分析，用DSC测量了玻璃化转变温度，用SEM观察了微观形貌和孔径尺寸，并计算了孔隙大小和孔隙率的分布．通过燃烧试验分析了HA／PU复合材料中HA的百分含量，并对力学性能进行了评估．结果表明，多孔HA／PU复合支架材料，其大小孔道相互贯通，孔径范围在100-800μm，大孔中含有微孔，孔隙率可达到78％-80％，HA含量达到30wt％，力学强度达到271kPa．多孔HA／PU复合材料具有一定的弹性，是一类性能很好的可望用于软骨修复的支架材料．     

纳米羟基磷灰石/聚合物多孔复合支架材料

为提高骨组织工程支架材料的力学性能,改善其生物活性,综合天然与合成高分子的优点,采用溶液共混相分离法制备出聚己内酯(PCL)-壳聚糖(CS)多孔支架材料, 并进一步采用离心注浆法填充具有生物活性的纳米羟基磷灰石(HA)-聚乙烯醇(PVA)复合浆料, 制备了n-HA-PVA/PCL-CS复合多孔支架材料, 改善了PCL-CS支架材料力学性能。采用扫描电子显微镜、红外光谱、元素分析、孔隙率和抗压强度试验对材料进行了表征。结果表明, PCL-CS支架材料的内部具有蜂窝状的相互贯通的孔隙结构,孔隙率可以达到60%～80%。CS含量越大,孔隙率越大,而抗压强度越小。填充后的n-HA-PVA/PCL-CS复合多孔支架材料,孔隙率有所下降,但仍大于60%,而其弹性模量可提高至25.71 MPa。     

钛酸酯偶联剂对磷灰石/壳聚糖多孔生物材料性能的影响

以螯合型焦磷酸钛酸酯偶联剂(NDZ-311)为改性剂对壳聚糖(CS)进行改性,采用真空冷冻干燥法制备了HA-TCP/CS多孔生物材料,研究了NDZ-311的用量与多孔生物材料抗压强度和孔隙率的关系,并采用SEM、XRD、IR等对材料进行了分析测试.结果表明,NDZ-311中-O-链状醚键官能团能发生各种类型的酯基转化反应,与CS填料产生交联,材料的抗压强度得到提高,CS填料添加量可达50%以上,且不会发生相分离.随着NDZ-311含量的增加,多孔生物材料的抗压强度先逐渐降低然后升高,孔隙率先逐渐升高然后降低.当m(HA-TCP):m(CS)=7:3时,NDZ-311质量分数为1%时抗压强度为2.3MPa,孔隙率升至最高84.8%,此时多孔生物材料的抗压强度和孔隙率匹配较好,孔隙呈层错板条搭接,且分布均匀,HA-TCP颗粒均匀分散在CS模板上,材料的相结构变化不大,只是材料中各相对应的特征衍射峰的强度略有增强.     

壳聚糖/磷灰石-硅灰石复合多孔支架材料的制备与性能

以磷灰石-硅灰石(AW)生物活性多孔玻璃陶瓷支架材料为基体，采用物理包被法制备了壳聚糖(CS)/AW复合多孔支架材料，通过红外图谱分析、扫描电镜、光学显微镜、强度检测等分析测试方法，研究了复合材料的组成、微观结构、力学和矿化性能。结果发现：复合材料与AW多孔支架材料基体相比，仍具有三维贯通且分布均匀的孔隙结构，孔径尺寸约 100～500μm，孔隙率为80%左右，且力学性能明显增强，平均抗压强度可达3.11 MPa，比多孔AW支架材料基体的平均抗压强度提高了8.3倍。体外模拟体液浸泡实验表明，复合材料具有较高的矿化功能，预示材料具有较好的生物活性。这种复合材料可望作为人体非承重部位的植入骨修复体和组织工程支架使用。     

Mechanical strength of ceramic scaffolds reinforced with biopolymers is comparable to that of human bone

Eight groups of calcium-phosphate scaffolds for bone implantation were prepared of which seven were reinforced with biopolymers, poly lactic acid (PLA) or hyaluronic acid in different concentrations in order to increase the mechanical strength, without significantly impairing the microarchitecture. Controls were un-reinforced calcium-phosphate scaffolds. Microarchitectural properties were quantified using micro-CT scanning. Mechanical properties were evaluated by destructive compression testing. Results showed that adding 10 or 15% PLA to the scaffold significantly increased the mechanical strength. The increase in mechanical strength was seen as a result of increased scaffold thickness and changes to plate-like structure. However, the porosity was significantly lowered as a consequence of adding 15% PLA, whereas adding 10% PLA had no significant effect on porosity. Hyaluronic acid had no significant effect on mechanical strength. The novel composite scaffold is comparable to that of human bone which may be suitable for transplantation in specific weight-bearing situations, such as long bone repair.     

A polylactide/fibrin gel composite scaffold for cartilage tissue engineering: fabrication and an in vitro evaluation

A composite scaffold for cartilage tissue engineering was fabricated by filling a porous poly (l-lactide) (PLLA) scaffold with fibrin gel. The porous PLLA scaffold prepared by a method of thermally induced phase separation has an average pore diameter of 200 μm and a porosity of 93%. Incorporation of fibrin gel into the scaffold was achieved by dropping a fibrinogen and thrombin mixture solution onto the scaffold. For a couple of minutes the fibrin gel was in situ formed within the scaffold. The filling efficiency was decreased along with the increase of the fibrinogen concentration. After fibrin gel filling, the compressive modulus and the yield stress increased from 5.94 MPa and 0.37 MPa (control PLLA scaffold in a hydrated state) to 7.21 MPa and 0.53 MPa, respectively. While the fibrin gel lost its weight in phosphate buffered saline up to ~50% within 3 days, 85% and 70% of the fibrin gel weight in the composite scaffold was remained within 3 and 35 days, respectively. A consistent significant higher level of rabbit auricular chondrocyte viability, cell number and glycosaminoglycan was measured in the composite scaffold than that in the control PLLA scaffold. Rabbit auricular chondrocytes with round morphology were also observed in the composite scaffold by confocal microscopy and scanning electron microscopy. Altogether with the features of better strength and cytocompatibility, this type of composite scaffold may have better performance as a matrix for cartilage tissue engineering.     

Fabrication and cell affinity of biomimetic structured PLGA/articular cartilage ECM composite scaffold

An ideal scaffold for cartilage tissue engineering should be biomimetic in not only mechanical property and biochemical composition, but also the morphological structure. In this research, we fabricated a composite scaffold with oriented structure to mimic cartilage physiological morphology, where natural nanofibrous articular cartilage extracellular matrix (ACECM) was used to mimic the biochemical composition, and synthetic PLGA was used to enhance the mechanical strength of ACECM. The composite scaffold has well oriented structure and more than 89% of porosity as well as about 107 μm of average pore diameter. The composite scaffold was compared with ACECM and PLGA scaffolds. Cell proliferation test showed that the number of MSCs in ACECM and composite scaffolds was noticeably bigger than that in PLGA scaffold, which was coincident with results of SEM observation and cell viability staining. The water absorption of ACECM and composite scaffolds were 22.1 and 10.2 times respectively, which was much higher than that of PLGA scaffolds (3.8 times). The compressive modulus of composite scaffold in hydrous status was 1.03 MPa, which was near 10 times higher than that of hydrous ACECM scaffold. The aforementioned results suggested that the composite scaffold has the potential for application in cartilage tissue engineering.     

含Zn生物玻璃、玻璃陶瓷与聚酯复合骨组织工程支架的制备及性能

采用溶胶凝胶法在58S生物玻璃的基础上用氧化锌取代3  mol％的氧化钙制备了含锌的生物玻璃粉体 (58S3Z),对合成的粉体采用有机泡沫浸渍法在700℃及1200℃制备出58S3Z-700℃、58S3Z-1200℃玻璃及玻璃陶瓷多孔支架。在所得支架表面涂覆PLGA及PBS薄膜制备出58S3Z-1200℃-PLGA及58S3Z-1200℃-PBS复合支架。对其形貌、 孔隙率、 力学性能、 体外降解性及细胞相容性进行了系统研究。复合后多孔支架仍然保持三维连通的多孔结构,孔隙率与复合前(86.9%±0.8% (58S3Z-700℃),80.1%±0.6% (58S3Z-1200℃)）相比稍有下降,分别为75.9%±0.6% (58S3Z-1200℃-PLGA)和77.9%±0.9% (58S3Z-1200℃-PBS)。但复合多孔支架显示出较高的抗压强度,分别达到1509.4 kPa±162.8 kPa (PLGA) 和901.6 kPa±94.5 kPa (PBS),与玻璃和玻璃陶瓷支架 (258.4 kPa±23.6 kPa) 相比具有较大的提高。体外降解实验表明58S3Z-1200℃-PLGA、58S3Z-1200℃-PBS复合多孔支架可降解, 经过28天的浸泡其失重率分别达到13.3％和2.1％。体外研究结果表明：58S3Z玻璃陶瓷支架复合PBS或PLGA后支持成骨细胞黏附、铺展和生长。这种新型的复合支架具有三维的网状多孔结构,良好的力学性能、降解性和细胞相容性,有望成为一种较理想的骨组织工程支架。     

Fe_3O_4-壳聚糖-胶原-纳米羟基磷灰石原位复合支架的仿生制备及表征

为了制备具有磁热效应的多相杂化纳米复合材料,以可溶性钙盐和磷酸盐作为纳米羟基磷灰石(nHAP)的前驱体、可溶性铁盐和亚铁盐作为纳米Fe_3O_4的前驱体,并结合壳聚糖(CS)和胶原(Col)两种有机基体的优越特性,通过原位复合和冷冻干燥技术,制备了纳米Fe_3O_4-CS-Col-nHAP复合支架材料。通过FTIR、XRD、SEM、物理性能测试仪(PPMS)等方法对复合支架的组成、结构、形貌和磁性等方面进行表征。结果表明:纳米Fe_3O_4-CS-Col-nHAP复合支架具有多级孔径结构,孔径尺寸约为100~150μm,孔隙率约为95%;低结晶度的nHAP晶体和纳米Fe_3O_4颗粒均匀分布在有机基体上;通过原位复合技术制备的纳米Fe_3O_4具有超顺磁性,随着磁性粒子含量的不断增加,磁饱和强度不断增强,饱和磁化强度为0.025emu/g。通过原位复合和冷冻干燥技术制备的多相杂化的纳米Fe_3O_4-CS-Col-nHAP复合材料具有良好的磁热效应,有望在骨修复组织工程中得到广泛应用。     

Fabrication and development of artificial osteochondral constructs based on cancellous bone/hydrogel hybrid scaffold

Using tissue engineering techniques, an artificial osteochondral construct was successfully fabricated to treat large osteochondral defects. In this study, porcine cancellous bones and chitosan/gelatin hydrogel scaffolds were used as substitutes to mimic bone and cartilage, respectively. The porosity and distribution of pore size in porcine bone was measured and the degradation ratio and swelling ratio for chitosan/gelatin hydrogel scaffolds was also determined in vitro. Surface morphology was analyzed with the scanning electron microscope (SEM). The physicochemical properties and the composition were tested by using an infrared instrument. A double layer composite scaffold was constructed via seeding adipose-derived stem cells (ADSCs) induced to chondrocytes and osteoblasts, followed by inoculation in cancellous bones and hydrogel scaffolds. Cell proliferation was assessed through Dead/Live staining and cellular activity was analyzed with IpWin5 software. Cell growth, adhesion and formation of extracellular matrix in composite scaffolds blank cancellous bones or hydrogel scaffolds were also analyzed. SEM analysis revealed a super porous internal structure of cancellous bone scaffolds and pore size was measured at an average of 410 ± 59 μm while porosity was recorded at 70.6 ± 1.7 %. In the hydrogel scaffold, the average pore size was measured at 117 ± 21 μm and the porosity and swelling rate were recorded at 83.4 ± 0.8 % and 362.0 ± 2.4 %, respectively. Furthermore, the remaining hydrogel weighed 80.76 ± 1.6 % of the original dry weight after hydration in PBS for 6 weeks. In summary, the cancellous bone and hydrogel composite scaffold is a promising biomaterial which shows an essential physical performance and strength with excellent osteochondral tissue interaction in situ. ADSCs are a suitable cell source for osteochondral composite reconstruction. Moreover, the bi-layered scaffold significantly enhanced cell proliferation compared to the cells seeded on either single scaffold. Therefore, a bi-layered composite scaffold is an appropriate candidate for fabrication of osteochondral tissue.     

A novel bioactive three-dimensional β-tricalcium phosphate/chitosan scaffold for periodontal tissue engineering

The development of suitable bioactive three-dimensional scaffold for the promotion of cellular proliferation and differentiation is critical in periodontal tissue engineering. In this study,porous β-tricalcium phosphate/chitosan composite scaffolds were prepared through a freeze-drying method. These scaffolds were evaluated by analysis of microscopic structure, porosity, and cytocompatibility. The gene expression of bone sialoprotein (BSP) and cementum attachment protein (CAP) was detected with RT-PCR after human periodontal ligament cells (HPLCs) were seeded in these scaffolds. Then cell–scaffold complexes were implanted subcutaneously into athymic mice. The protein expression of alkaline phosphatase (ALP) and osteopontin (OPN) was detected in vivo. Results indicated that composite scaffolds displayed a homogeneous three-dimensional microstructure; suitable pore size (120 μm) and high porosity (91.07%). The composite scaffold showed higher proliferation rate than the pure chitosan scaffold, and up-regulated the gene expression of BSP and CAP. In vivo, HPLCs in the composite scaffold not only proliferated but also recruited vascular tissue ingrowth. The protein expression of ALP and OPN was up-regulated in the composite scaffold. Therefore, it was suggested that the composite scaffold could promote the differentiation of HPLCs towards osteoblast and cementoblast phenotypes.