磷酸钙骨水泥药物缓释载体的研究进展

磷酸钙骨水泥以其优良的生物相容性、生物活性、自固化性和释放性作为骨修复材料在临床中得到了广泛应用.作者在文中论述了磷酸钙骨水泥作为药物缓释载体的动力学原理、影响因素以及理化性能等方面的研究进展,并指出了存在的问题及今后的研究方向.     

磷酸钙骨水泥修复兔颅骨缺损新骨生长计算机图像分析

利用计算机图像处理技术对磷酸钙水泥修复兔颅骨缺损组织切片标本的光镜图像进行采集,对采集到的原始图像进行滤波、分割和数学开矿学等图像处理,计算不同视野新生骨生长的面积百分比,并对不同视野的结果进行生物统计分析,得到兔颅骨修复过程中新生骨定量生长情况,用计算机图像处理方法将成风过程从传统的组织形态学光镜观察的定性分析上升到了定量分析,为磷酸钙骨水泥修复骨缺损成骨机理和临床材料选择提供了定量的依据。     

熟料粒度对骨粉/磷酸钙生物骨水泥结构与性能的影响

采用新方法首次将动物骨中的鱼骨引入到磷酸三钙和磷酸氢钙等原料体系中通过高温烧结制备磷酸钙基生物骨水泥（CPC）,以柠檬酸和柠檬酸钠的缓冲液为固化液、按一定的液固比制备固化试样,通过扫描电子显微分析（SEM）和力学性能测试等方法,研究了熟料粒度对其固化试样结构与抗压强度的影响.结果表明：制备过程中骨水泥粉末的粒度对其固化试样的微观结构及其抗压强度有着较为显著的影响,通过调整骨水泥粉末的粒度可达到优化其固化试样的微观结构和改善其力学性能的目的.     

无水硫酸钙对α-磷酸三钙骨水泥的结构与性能的影响

将无水硫酸钙（CSA）引入磷酸钙骨水泥（CPC）中,结合热分析（TG-DSC）、扫描电子显微分析（SEM）和力学性能测试等方法,通过对比试验研究了CSA对α-磷酸三钙（α-TCP）体系骨水泥结构与性能的影响.结果表明：CSA的加入对α-TCP骨水泥的结构与性能有一定的影响,是一种可提高骨水泥的抗压强度,调控固化时间的有效添加成分.     

针状硅灰石对磷酸盐骨水泥性能的影响

以磷酸氢二钾和磷酸二氢钾为固化液,以磷酸四钙、α-磷酸三钙、磷酸氢钙、焦磷酸钙、羟基磷灰石和碳酸钙为原料合成骨水泥,向其添加针状硅灰石,研究了针状硅灰石对其性能的影响。结果表明,在磷酸钙骨水泥中添加针状硅灰石可以缩短凝结时间,提高抗压强度。当针状硅灰石的添加量为3%,骨水泥性能达到最佳;其初凝时间、终凝时间分别为14和28 min,样品在Ringer’s模拟液溶液中浸泡2周后抗压强度达49.23 MPa,浸泡液的pH值变化幅度小(7.1~7.8),在安全范围之内。     

聚合磷酸钙骨水泥的制备和性能研究

采用丙烯酸和衣康酸的共聚物与自制磷酸钙粉末反应制备骨水泥。用自凝牙托水对类磷酸四钙（TTCP）粉末进行表面改性后所制备的骨水泥,初凝时间为4．5min,终凝时间为8.5min,抗压强度可达４２MPa。采用类TTCPα－磷酸三钙的混合粉料制备的骨水泥,初凝时间为５．５min,终凝时间为１１．０min,抗压强度可达４３MPa。     

可降解β—Ca3（PO4）2陶瓷的物化性能与生物性能

通过对β－ＴＣＰ陶瓷的生物相容研究，证明 生物体内不会产生全身或局部毒性反应，不致溶血、不引起炎性和排斥反应，不致突变，有利于骨组织迅速长入材料孔内并与材料紧密结合，对β－ＴＣＰ陶瓷的组成，常规理化性能及动物试验，证明具有与人体骨相近的组成，可诱发新骨生成，具有良好的生物降解性，适于作为骨修补和替代材料。     

可降解β－Ca_3（PO_4）_2陶瓷的物化性能与生物性能

通过对β－ＴＣＰ陶瓷的生物相容性研究，证明材料在生物体内不会产生全身或局部毒性反应、不致溶血、不引起炎性和排斥反应，不致突变，有利于骨组织迅速长入材料孔内并与材料紧密结合；对β－ＴＣＰ陶瓷的组成、常规理化性能及动物试验，证明材料具有与人体骨相近的组成，可诱发新骨生成．具有良好的生物降解性，适于作为骨修补和替代材料。     

碳纤维增强磷酸钙骨水泥

以碳纤维为增强相,Na2HPO4/柠檬酸为调和液,α-磷酸三钙、磷酸四钙、磷酸二氢钙、羟基磷灰石和碳酸钙为原料制备骨水泥,研究不同掺杂比例的短碳纤维对其性能的影响。在磷酸钙骨水泥中掺杂碳纤维能够提高样品的致密性,缩短固化时间,提高抗压强度。当掺杂质量分数0.5%的碳纤维时,骨水泥的初凝、终凝时间分别为9.3和24.9min,模拟体液中浸泡28d后抗压强度最大为38.24MPa。掺杂的碳纤维对浸泡液pH影响不大,pH在小范围内浮动,均在人体安全范围内。     

新型可灌注骨水泥椎弓根螺钉联合普通椎弓根螺钉撑开复位治疗胸腰椎椎体爆裂骨折

目的探讨利用椎弓根螺钉短节段撑开复位联合伤椎新型可灌注骨水泥螺钉灌注骨水泥治疗胸腰椎椎体爆裂骨折的疗效。方法选择32例采用椎弓根螺钉短节段撑开复位联合伤椎新型可灌注骨水泥螺钉灌注骨水泥治疗的胸腰椎椎体爆裂骨折患者;平均随访(11.0±1.5)个月;评估手术前后椎体缘压缩比、椎管侵占率、Cobb角、视觉疼痛评分及Oswestry功能障碍评分等指标。结果平均手术时间(120±10)min,术中出血量平均(350±10)ml。与术前相比,术后椎体缘压缩比、椎管侵占率、Cobb角度、视觉疼痛评分及Oswestry功能障碍评分差异均有统计学意义(P<0.05),且随访中各项指标无显著性改变,末次随访时,影像学复查无螺钉松动、内固定物断裂发生。结论椎弓根螺钉短节段撑开复位联合伤椎新型可灌注骨水泥螺钉灌注骨水泥能够有效治疗胸腰椎椎体爆裂骨折。     

Microstructure and mechanical properties of calcium phosphate cement/gelatine composite scaffold with oriented pore structure for bone tissue engineering

The macroporous calcium phosphate(CPC) cement with oriented pore structure was prepared by freeze casting. SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected aligned along the ice growth direction. The porosity of the as-prepared porous CPC was measured to be 87.6% by Archimede’s principle. XRD patterns of specimens showed that poorly crystallized hydroxyapatite was the main phase present in the hydrated porous calcium phosphate cement. To improve the mechanical properties of the CPC scaffold, the 15% gelatine solution was infiltrated into the pores under vacuum and then the samples were freeze dried to form the CPC/gelatine composite scaffolds. After reinforced with gelatine, the compressive strength of CPC/gelatine composite increased to 5.12 MPa, around fifty times greater than that of the unreinforced macroporous CPC scaffold, which was only 0.1 MPa. And the toughness of the scaffold has been greatly improved via the gelatine reinforcement with a much greater fracture strain. SEM examination of the specimens indicated good bonding between the cement and gelatine. Participating the external load by the deformable gelatine, patching the defects of the CPC pores wall, and crack deflection were supposed to be the reinforcement mechanisms. In conclusion, the calcium phosphate cement/gelatine composite with oriented pore structure prepared in this work might be a potential scaffold for bone tissue engineering.     

Preparation and Compressive Strength of Calcium Phosphate Bone Cement Containing N,O-carboxymethyl Chitosan

1Introduction Calciumphosphatebonecement(CPC)hasbeen preparedbyBrownandChowin1985[1].Thematerial consistsofcementpowderandbuffersolution.Thepow dercontainsteracalciumphosphate(TetCP)anddicalci umphosphate(DCPA).Thebuffersolutionismadeupof phosphateandwate…     

以α-磷酸三钙和磷酸四钙为主要原料的磷酸盐骨水泥的制备及其性能比较

分别以α 磷酸三钙和磷酸四钙为基本原料,添加羟基磷灰石、磷酸氢钙、碳酸钙等其他辅助原料,钙磷比均为1.50,制备了2种类型的骨水泥。对固化骨水泥样品进行了Ringer's模拟液浸泡实验。测定浸泡液pH值、样品的抗压强度和样品的断面显微形貌随浸泡时间的变化。结果表明:2种骨水泥的凝结时间基本相同,初凝时间为5min左右,终凝时间为19.5min;但两者浸泡液的pH值变化和抗压强度等性能有较大的差别,以α 磷酸三钙为主要原料的骨水泥的主要性能明显优于以磷酸四钙为主要原料的骨水泥。     

Preparation, Fundamental Characteristics and Biosafety Evalution of Compound rhBMP-2/CPC

1Introduction Calciumphosphatecement(CPC)isanewtypeof bonesubstituteinrecentyearswithagoodboneconduc tion,absorbability,biologicalcompatibilityandetc.The mechanicalfixationcangraduallyturnintobiologicalfixa tioninitsanaphase[1].Atthesametime,calciumphos phatecementhasbeenprovedtobeagoodcarrierofthe bonemorphogeneticprotein(BMP)[2],whichcanover cometheshortagesthatsimplexBMPwillbedilutedby enchymaanddecomposedbyproteaseafteritsimplanta tionintothehumanbody,anditseffectiveconcentration insom…     

Effect of substitutional Sr ion on mechanical properties of calcium phosphate bone cement

A novel calcium phosphate cement was developed by adding different amount of SrO to tetracalcium phosphate during the fabrication process. The experimental results show that compressive strength of cements based on tetracalcium phosphate doped with SrO significantly increases with the increase of SrO content, approximately 60 MPa, whilst the mechanical behavior of CPC slightly decreases if 0.7wt% SrO is added. X-ray diffraction measurement confirms the setting reaction of doped cements is similar to that of pure calcium phosphate cement (CPC). Low crystalline hydroxyapatite (HA) is found to be the main constituent of set cement. A mechanical reinforcement effect is resulted from the substitution of Sr ion to Ca²⁺ in tetracalcium phosphate (TTCP), accelerating HA crystal formation and a more cross-linked cement structure. In vitro bioactivity tests showed that CPC added with 0.5wt% SrO had a more rapid degradation compared with pure CPC.