不同比例PLGA/β-TCP电纺纤维支架的制备与性能研究

目的：通过静电纺丝法制备不同比例PLGA/β-TCP纳米纤维支架,筛选出最合适比例,以便为进一步的体内植入提供依据。方法：利用静电纺丝法制备比例为10：0、9：1、8：2、7：3、6：4、5：5的PLGA/β-TCP纳米纤维支架,扫描电镜观察纤维支架的多孔结构,液体置换法测量支架的孔隙率;分别于1%胰酶PBS溶液中进行体外降解,测定材料的降解性;接触角仪测量材料的接触角,评价其亲水性能。结果：电镜观察显示制备的不同比例的PLGA/β-TCP纤维中（除6：4、5：5组）,直径均一,呈相互联通的三维多孔结构,各组支架材料的孔隙率均〉80%,其中6：4、5：5组的孔隙率〉85%,电镜下观察纤维成分有限,大部分为颗粒状,不具有多孔支架的三维结构;体外降解实验中7：3、6：4、5：5组均在第7周时完全降解。结论：通过静电纺丝法制备不同比例的PLGA/TCP支架材料,9：1、8：2、7：3组均符合骨组织工程要求,体外降解实验中,7：3组的降解率较另两组材料为优,具有用作体内骨修复材料的潜力。     

3D打印技术制备颌骨组织工程支架的研究进展

骨组织工程具有创伤小,不受供体来源限制,个性化修复的优势,有望实现颌骨缺损后外形结构的恢复和相关功能的重建。目前,传统方法制备的骨组织工程支架尚无法实现个性化外形的构建和生物力学强度的精确调控。随着3D打印技术和计算机技术的迅速发展,应用3D打印技术制备颌骨组织工程支架的研究取得了较大进展,本文对其相关研究进行综述。     

3D打印HAP-GEL支架复合BMSCs和HUVECs修复兔颅骨缺损的效果评价

目的:定性分析3D打印羟基磷灰石-胶原(hydroxyapatite-gelatin,HAP-GEL)支架材料复合骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)和脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC...     

PLGA微囊支架材料的制备及对成骨细胞粘附和增殖的影响

[摘要]目的：制备一种新型结构的聚乳酸-羟基乙酸共聚物[poly（1actic—co—glycolicacid,PLGA]微囊支架,对其进行表征,并检测其对成骨细胞增殖与粘附的影响。方法：采用复乳法制备PLGA微囊,以激光粒度仪分析其粒径分布,筛选出合适的粒径大小,通过二氯甲烷蒸汽熏蒸使微囊结合,再经过烧结最终形成三维支架,通过扫描电子显微镜观察微囊及微囊支架形态。将MC3T3-E1成骨细胞接种到该支架上,通过扫描电镜观察细胞在支架上的粘附形态,通过CCK-8法检测细胞增殖的情况,并与无支架对照组进行比较。结果：制备的PLGA微囊支架具有一定孔径和孔隙率,具有三维连通的多孔结构,且孔隙结构均匀。细胞可在支架表面粘附生长。微囊支架上的细胞增殖活性高于对照组。结论：本方法制备的PLGA微囊支架具有一定的孔隙率和内部连通性,有利于细胞的粘附和增殖,在骨修复中有应用前景。     

3D打印制备不同重量比例的n-HA/PLA/PVA复合膜性能比较

目的:通过3D打印的方法制备的不同重量比例的纳米羟基磷灰石/聚乳酸/聚乙烯醇(n-HA/PLA/PVA)复合膜,并对其相关性能检测。方法:采用3D打印技术制备不同重量比例的n-HA/PLA/PVA复合膜,分别为PLA/PVA复合膜、15%n-HA/PLA/PVA复合膜、50%n-HA/PLA/PVA复合膜、75%n-HA/PLA/PVA复合膜。扫描电镜下观察各组膜形态,对其力学性能、细胞毒性及动物实验相应指标进行检测。结果:扫描电镜下观察,n-HA/PLA/PVA复合膜呈现三维网状结构,各材料间相互结合,孔隙分布不均,大小不一。随着n-HA质量浓度的提高,电镜下见各材料间孔隙逐渐减小,形成结构均匀的复合膜。力学性能及吸水率检测中,随着nHA含量的增加,n-HA/PLA/PVA复合膜的拉伸强度及吸水率呈下降趋势;细胞毒性检测,不同比例复合膜的细胞增殖率无明显差别,无细胞毒性。动物实验测量牙周菌斑指数及龈沟出血指数未发现不同比例n-HA/PLA/PVA复合膜有统计学差异。结论:3D打印不同比例的n-HA/PLA/PVA复合膜具有良好的物理性能和细胞生物相容性,n-HA比例更高的复合膜可能具有更好的物理性能及良好的生物相容性。     

芯壳型PEI／PLGA同轴电纺纤维的制备及其相关理化性能研究

目的：利用同轴静电纺丝技术制备纳米级聚乳酸-羟基乙酸共聚物（PLGA）与聚乙烯亚胺（PEI）芯壳型复合纤维,评价其相关理化性能。方法：运用同轴静电纺丝法制备壳层为PLGA,芯层为PEI的电纺纤维膜。扫描电子显微镜观察纤维膜表面形貌、激光共聚焦显微镜检测纤维同轴结构、接触角测量仪测定接触角、万能试验机测量纤维力学性能。结果：所制备的同轴芯壳型PEI/PLGA电纺纤维表面光滑、分布均匀、直径范围175～1076 nm,激光共聚焦显微镜下可见清晰的芯壳结构,接触角为72．45±2．02°,拉伸强度（3．65±0．35）Mpa、弹性模量9．0±1．70。结论：作为一种新型支架材料,采用同轴静电纺丝法可以制备PEI/PLGA芯壳结构的电纺纤维在组织工程领域有进一步的应用前景。     

3D打印白硅钙石支架材料在大鼠Onlay骨移植中的应用

目的 评价3D打印白硅钙石（bredigite,BRT）骨支架材料在大鼠Onlay骨移植中的效果。方法 通过3D打印技术制备骨BRT支架材料作为实验组,β-磷酸三钙（β-tricalcium phosphate,β-TCP）骨支架材料作为对照组,通过扫描电镜（scanning electron microscopy,SEM）、X射线衍射（X-ray diffraction,XRD）、力学测试和体外降解测试实验对其进行表征观察。建立SD大鼠颅骨Onlay骨移植的动物模型,根据移植物的不同,分为自体骨移植组（Auto组）、β-TCP组及BRT组。术后12周获取标本行大体观察、micro-CT扫描检测分析、组织学HE染色。结果 SEM观察显示,BRT有规则的多孔结构,XRD衍射峰较为锐利。与β-TCP组（11.29±1.30）MPa相比,BRT支架材料（46.80±3.44）MPa具有更好的力学强度（P<0.001）;在体外第35天时,BRT降解率为27.18%±1.41%,并且在降解过程中释放钙、镁、硅离子。micro-CT及组织学染色实验结果提示,Auto组有一定程度的骨吸收,β-...     

3D打印复合PVA骨组织工程支架研究现状

3D打印复合多孔性骨组织工程支架已成为研究热点。复合聚乙烯醇(polyvinyl alcohol,PVA)具备良好生物相容性及可降解性能,但因不能抵抗较大机械抗力,不能单独制备支架,复合其他机械性能佳及生物相容性良好的材料,可表现出良好的生物相容性、可降解性及机械性能等优点,因此3D打印复合PVA支架材料可以优化PVA支架的性能,本文从3D打印骨组织工程支架技术、PVA、复合PVA支架在体内外骨形成效果等方面作一综述。     

Bioactive amorphous magnesium phosphate-polyetheretherketone composite filaments for 3D printing

ObjectiveThe aim of this study was to develop bioactive and osseointegrable polyetheretherketone (PEEK)-based composite filaments melt-blended with novel amorphous magnesium phosphate (AMP) particles for 3D printing of dental and orthopedic implants.Materials and methodsA series of materials and biological analyses of AMP-PEEK were performed. Thermal stability, thermogravimetric and differential scanning calorimetry curves of as-synthesized AMP were measured. Complex viscosity, elastic modulus and viscous modulus were determined using a rotational rheometer. In vitro bioactivity was analyzed using SBF immersion method. SEM, EDS and XRD were used to study the apatite-forming ability of the AMP-PEEK filaments. Mouse pre-osteoblasts (MC3T3-E1) were cultured and analyzed for cell viability, proliferation and gene expression. For in vivo analyses, bare PEEK was used as the control and 15AMP-PEEK was chosen based on its in vitro cell-related results. After 4 or 12 weeks, animals were euthanized, and the femurs were collected for micro-computed tomography (μ-CT) and histology.ResultsThe collected findings confirmed the homogeneous dispersion of AMP particles within the PEEK matrix with no phase degradation. Rheological studies demonstrated that AMP-PEEK composites are good candidates for 3D printing by exhibiting high zero-shear and low infinite-shear viscosities. In vitro results revealed enhanced bioactivity and superior pre-osteoblast cell function in the case of AMP-PEEK composites as compared to bare PEEK. In vivo analyses further corroborated the enhanced osseointegration capacity for AMP-PEEK implants.SignificanceCollectively, the present investigation demonstrated that AMP-PEEK composite filaments can serve as feedstock for 3D printing of orthopedic and dental implants due to enhanced bioactivity and osseointegration capacity.     

氧化锆坯体钙磷液改性氧化锆陶瓷表面钙磷结晶的制备

目的 探讨经过钙、磷改性的氧化锆坯体经致密烧结、水热处理后表面钙磷结晶物的生成.方法 制备氧化锆坯体试样,实验组经钙、磷混合液浸泡不同的时间,未经钙、磷混合液浸泡的氧化锆为对照组,经1450℃致密烧结后,SEM/EDS观察、分析,并经水热处理后,重新观察、分析.结果 与对照组相比,经钙、磷改性后致密烧结的氧化锆陶瓷表面有钙、磷簇存在,经水热处理后该钙、磷簇生成钙磷结晶.结论 钙、磷改性后在氧化锆陶瓷表面制备钙磷结晶物的方法具有可行性.     

Effects of calcium phosphate nanoparticles on Ca-PO4 composite

Nano-particles of dicalcium phosphate anhydrous (DCPA) were synthesized for the first time. The objectives of this study were to incorporate DCPA nano-particles into resin for Ca-PO(4) release to combat dental caries, and to investigate the filler level effects. Nano-DCPA and nano-silica-fused silicon nitride whiskers at a 1:1 ratio were used at filler mass fractions of 0-75%. The flexural strengths in MPa (mean +/- SD; n = 6) of DCPA-whisker composites ranged from (106 +/- 39) at 0% fillers to (114 +/- 23) at 75% fillers, similar to (112 +/- 22) of a non-releasing composite (TPH) (p > 0.1). The composite with 75% fillers in a NaCl solution (133 mmol/L, pH = 7.4, 37 degrees C) yielded a Ca concentration of (0.65 +/- 0.02) mmol/L and PO(4) of (2.29 +/- 0.07) mmol/L. Relationships were established between ion-release and DCPA volume fraction V(DCPA): Ca = 4.46 V(DCPA)(1.6,) and = 66.9 V(DCPA)(2.6). Nano-DCPA-whisker PO(4) composites had high strength and released high levels of Ca-PO(4) requisite for remineralization. These new nano-composites could provide the needed combination of stress-bearing and caries-inhibiting capabilities.     

Biomimetic calcium phosphate composite coating of dental implants

PURPOSE: The aim of the present study was to test the hypothesis that calcium phosphate coating of titanium screw-type implants enhances peri-implant bone formation in the jaw. MATERIALS AND METHODS: Ten adult female foxhounds received experimental titanium screw-type implants in the mandible 3 months after removal of all premolar teeth. Four types of implants were evaluated in each animal: implants with machined titanium surface (the control group), implants coated with collagen I (the collagen-only group), implants with a composite coating of calcium phosphate and mineralized collagen I (the composite group), and implants with calcium phosphate (hydroxyapatite [HA]) coating (the HA-only group). Peri-implant bone regeneration was assessed histomorphometrically after 1 and 3 months in 5 dogs each by measuring bone-implant contact (BIC) and the volume density of the newly formed peri-implant bone (BVD). RESULTS: After 1 month, BIC was significantly enhanced only in the group of implants with composite coating of calcium phosphate and mineralized collagen (P = .038). Volume density of the newly formed peri-implant bone was significantly higher in all coated implants after 1 month. No significant difference from baseline was found in BIC for the collagen-only and HA-only groups, but BVD was significantly higher in implants with composite coating (P = .041). After 3 months, BIC and BVD were significantly higher in all coated implants than in the controls with machined surfaces. CONCLUSION: It was concluded that composite coating of dental screw-type implant surfaces using calcium phosphate and collagen can enhance BIC and peri-implant bone formation.     

磷酸钙钠/β-磷酸三钙陶瓷支架接种骨髓基质细胞成骨性能的研究

目的：观察磷酸钙钠／β-磷酸三钙(NaCaPO2/β-TCP)支架接种骨髓基质细胞后植入裸鼠皮下的成骨性能。方法：通过理化方法,将煅烧牛松质骨转化为NaCaPO2/β-TCP双相钙磷陶瓷。获取兔髂骨松质骨骨髓基质细胞,体外分离、扩增、诱导后,接种于NaCaPO2/β-TCP支架。将支架／细胞复合物植入裸鼠背部皮下,NaCaPO2/β-TCP陶瓷单纯植入作为对照。植入后4、8周取材,通过大体、组织学观察,评价成骨活性。结果：支架／细胞复合物植入后4周,材料表面见相对较成熟的骨组织,内部主要为软骨;植入后8周,大量骨小梁形成。可见骨髓腔、骨髓细胞及脂肪细胞,在支架材料和骨组织的邻接区域见成骨细胞及破骨细胞。可见软骨内成骨方式。结论：NaCaPO2/β-TCP支架接种骨髓基质细胞后显示良好的成骨活性,能够促进未成熟骨矿化,可以作为骨组织工程支架材料。     

Endodontic applications of 3D printing

Computer‐aided design (CAD) and computer‐aided manufacturing (CAM) technologies can leverage cone beam computed tomography data for production of objects used in surgical and nonsurgical endodontics and in educational settings. The aim of this article was to review all current applications of 3D printing in endodontics and to speculate upon future directions for research and clinical use within the specialty. A literature search of PubMed, Ovid and Scopus was conducted using the following terms: stereolithography, 3D printing, computer aided rapid prototyping, surgical guide, guided endodontic surgery, guided endodontic access, additive manufacturing, rapid prototyping, autotransplantation rapid prototyping, CAD, CAM. Inclusion criteria were articles in the English language documenting endodontic applications of 3D printing. Fifty‐one articles met inclusion criteria and were utilized. The endodontic literature on 3D printing is generally limited to case reports and pre‐clinical studies. Documented solutions to endodontic challenges include: guided access with pulp canal obliteration, applications in autotransplantation, pre‐surgical planning and educational modelling and accurate location of osteotomy perforation sites. Acquisition of technical expertise and equipment within endodontic practices present formidable obstacles to widespread deployment within the endodontic specialty. As knowledge advances, endodontic postgraduate programmes should consider implementing 3D printing into their curriculums. Future research directions should include clinical outcomes assessments of treatments employing 3D printed objects.     

三维打印技术制备多孔羟基磷灰石植入体的实验研究

目的评价三维打印成型技术(3DP)制备多孔羟基磷灰石(HA)植入体的可行性,并对烧结体进行微观结构观察及抗压强度评价,为多孔植入体的个性化制作提供实验依据。方法设计直径为25 mm、高度为15 mm的十字网格圆柱体CAD模型,按每层需粘结的面积分为2个实验组,A组粘接面积为100%,B组粘接面积为80%。通过三维打印技术各制作试件5个,并对烧结后的试件进行微观结构观察与抗压强度检测。结果烧结前后的两组植入体均无明显变形,表面细节清楚。烧结后A组孔隙率为(58.58±4.35)%,抗压强度为(84.3±12.1)MPa;B组孔隙率为(68.18±0.71)%,抗压强度为(50.9±5.1)MPa。A组孔径范围为50～150μm,B组孔径大小在100～200μm之间。2组的抗压强度和孔隙率差异均具有统计学意义(P<0.01)。2组XRD衍射峰均符合HA的特征峰,证实烧结过程未发生HA的物相结构变化。结论运用三维打印技术制备的多孔羟基磷灰石植入体,其微观组织结构和抗压强度基本满足医用植入材料的要求。     

3D打印多孔磷酸镁生物陶瓷支架的制备及其体外骨诱导能力的研究

目的:应用3D打印技术及致孔剂浸出法制备具有两种不同尺度孔隙的磷酸镁多孔支架,研究其物理化学性能及骨诱导能力.方法:通过间接打印法制备多孔磷酸镁(MgP)支架,利用NaCl(粒径25～50μm)作为致孔剂引入微孔,制备MgP-Na微孔支架;通过扫描电镜、压汞仪、通用材料试验机及X线衍射仪检测支架的物理及化学性能;应用C...     

Reinforcement of experimental composite materials based on amorphous calcium phosphate with inert fillers

ObjectivesThe aim of this study was to examine the influence of the addition of glass fillers with different sizes and degrees of silanization percentages to remineralizing composite materials based on amorphous calcium phosphate (ACP).MethodsFour different materials were tested in this study. Three ACP based materials: 0-ACP (40 wt% ACP, 60 wt% resin), Ba-ACP (40 wt% ACP, 50 wt% resin, 10 wt% barium-glass) and Sr-ACP (40 wt% ACP, 50 wt% resin, 10 wt% strontium-glass) were compared to the control material, resin modified glass ionomer (Fuji II LC capsule, GC, Japan). The fillers and composites were characterized using scanning electron microscopy. Flexural strength and modulus were determined using a three-point bending test. Calcium and phosphate ion release from ACP based composites was measured using inductively coupled plasma atomic emission spectroscopy.ResultsThe addition of barium-glass fillers (35.4 (29.1–42.1) MPa) (median (25–75%)) had improved the flexural strength in comparison to the 0-ACP (24.8 (20.8–36.9) MPa) and glass ionomer control (33.1 (29.7–36.2) MPa). The admixture of strontium-glass (20.3 (19.5–22.2) MPa) did not have any effect on flexural strength, but significantly improved its flexural modulus (6.4 (4.8–6.9) GPa) in comparison to 0-ACP (3.9 (3.4–4.1) GPa) and Ba-ACP (4.6 (4.2–6.9) GPa). Ion release kinetics was not affected by the addition of inert fillers to the ACP composites.SignificanceIncorporation of barium-glass fillers to the composition of ACP composites contributed to the improvement of flexural strength and modulus, with no adverse influence on ion release profiles.