钛合金表面TiO2-FHA-HA梯度生物陶瓷涂层的制备

采用溶胶-凝胶工艺在经过微弧氧化预处理的钛基体表面制备二氧化钛(TiO2)-含氟羟基磷灰石(FHA)-羟基磷灰石(HA)梯度结构的生物陶瓷涂层.采用X射线衍射检测了涂层的相组成,采用扫描显微镜观察了梯度涂层的形貌,采用划痕法测定了涂基结合力,结果表明:所制备的涂层是均匀和致密的具有梯度结构的TiO2-FHA-HA涂层;与单一的HA涂层相比梯度的引入显著提高了涂基结合力.生物溶解性实验结果显示了溶解速度FHA小于HA,这就表明了可以通过梯度设计来提高涂层的植入寿命.     

Structural,mechanical and biological properties of hydroxyapatite-zirconia-lanthanum oxide composites

Novel hydroxyapatite-zirconia-lanthanum oxide composites for bioceramic applications were synthesized and their structural, mechanical and biological properties were studied. Pure HA was produced via precipitation method and the composites were obtained by several fabrication steps: powder milling, mixing, cold pressing and sintering at 1100 °C for 1 h. The experimental results indicated that the composites consisted of hydroxyapatite as the main phase with a trace amount of tricalcium phosphate. Calcium zirconate (CaZrO₃) was also formed by the reaction between zirconia and calcium oxide (CaO) which is the thermal decomposition product of hydroxyapatite. Addition of zirconia and lanthanum oxide resulted a more loose and porous structure on the surface. The diametral tensile strength of the composites was higher with respect to pure hydroxyapatite. The microhardness of the composites, except the one with the composition of 90 wt% HA and 10 wt% Zr, was relatively lower than that of pure HA but these composites had higher machinability. Cell culture studies with osteoblast-like Saos-2 cell line showed that composites and pure hydroxyapatite were biocompatible. Based on these findings, hydroxyapatite-zirconia-lanthanum oxide composites hold potential to be used in hard tissue replacement and regeneration therapies.     

固相离子交换法制备碳酸羟基磷灰石涂层的研究

通过涂覆-烧结法在氧化铝(Al2O3)基体上制备羟基磷灰石(HA)/氟羟基磷灰石(FHA)双层涂层,然后采用固相离子交换法在湿CO2气氛中对HA表层进行碳酸化处理。XRD、FTIR和SEM测试结果表明:FHA中间层能有效地抑制HA与Al2O3的反应,湿CO2气氛中的湿气有利于分解相的恢复,而碳酸根能进入到表面涂层结构内部,形成A型替代为主的碳酸羟基磷灰石(CHA)。所获得的双层涂层具有多孔粗糙的表面,但与Al2O3基体结合紧密。     

Preparation,characterization and mechanical properties of controlled porous gelatin/hydroxyapatite nanocomposite through layer solvent casting combined with freeze-drying and lamination techniques

In this present study, to mimic the mineral and organic component of natural bone, hydroxyapatite (HA) and gelatin (GEL) nanocomposite was prepared via layer solvent casting combined with freeze-drying and lamination techniques. Glutaraldehyde (GA) was used as cross-linking agent. The synthesized nanocrystalline hydroxyapatite and nanocomposite samples were characterized by the commonly used bulk techniques. The results showed that GEL/HA nanocomposite were porous with 3-dimension interconnected microstructure, pore sizes were 100 μm to 1 mm, porosity were 75% to 93% and HA particles are dispersed evenly among gelatin fibers. It was also found that increasing initial GEL concentration and HA content enhance the elastic modulus (E) and reduce toughness and affect pore size and morphology. Finally, the stress–strain behavior in compression was very similar to natural spongy bone where the compressive modulus obtained was about 180 MPa.     

Properties of gas detonation ceramic coatings and their effect on the osseointegration of titanium implants for bone defect replacement

An optimal performance of bone implants with bioceramic coatings is closely related to the surface modification technology. For the first time, we have evaluated a gas detonation deposition (GDD) approach to obtain biocompatible ceramic coatings based on bioglass (BG) and calcium phosphates on Ti-based alloys as prospective materials towards their application for the development of bone implants. For the production of the coatings, hydroxyapatite (HA), HA metal-substituted (containing Ag⁺, Cu²⁺, or Zn²⁺) and tricalcium phosphate (TCP) were synthesized and characterized. Pure powders and their combination with BG were used to obtain coatings on a Ti–6Al–4V alloy using the developed automatized GDD setup. The microstructure, phase and chemical composition of the produced coatings were studied using XRD, SEM-EDS and Raman spectroscopy. The produced coated materials were evaluated in vivo in Wistar rats to analyze a reparative osteogenesis over a period of 12 weeks. The results regarding the optimization of the GDD method indicate its high productivity, as confirmed by high deposition rates. The highest deposition rate was observed for the coatings obtained from the HA metal-substituted powders. The results revealed a partial transformation of a HA phase to an α-TCP phase during the deposition, with a prevalence of the HA-phase in the coatings. According to the histological evaluation, the reparative osteogenesis occurs through the perimeter of the titanium implants, whereas the regeneration level increases from the 4th to the 12th week. The highest osteointegration level was detected for the implants coated with a biocomposite consisting of BG, HA and TCP. The results of the current study demonstrate an effectiveness of the GDD method to produce biocompatible coatings on Ti-based alloys. This provides excellent prerequisites towards the application and standardization of the GDD technology to manufacture bone implants for bone fixation and defect replacement, as well as the development of dental implants.     

Functionalized-radiolabeled hydroxyapatite/tenorite nanoparticles as theranostic agents for osteosarcoma

Hydroxyapatite (HA) nanoparticles (NPs) doped with different radioisotopes for use as theranostic systems play an important role in scientific research nowadays due to their ability to simultaneously act in the treatment and diagnosis of various types of cancers. In this work, we describe the synthesis and characterization of a hydroxyapatite/tenorite nanocomposite functionalized with folic acid, representing a nanotheranostic material with potential for application as an agent in positron emission tomography imaging systems and to act specifically in the treatment and diagnosis of osteosarcoma. ⁶⁴Cu and ³²P were produced by nuclear activation in the TRIGA reactor at CDTN. The obtained samples were characterized by XRD with Rietveld refinement, XAFS, SEM, BET, TGA, FTIR, CHN, ICP-AES, XPS and gamma spectroscopy. We investigated how CuO grows in HA NPs, the stability of the interactions between CuO and HA constituents and the interactions between folic acid and the surface of the HA NPs. The results indicate the formation of a second phase (tenorite) besides hydroxyapatite, and that the interactions between the two phases are stable, resulting in a nanocomposite. Furthermore, the activation of ⁶⁴Cu and ³²P inside the HA matrix, through the exposition to a neutron flux, produces a theranostic material of interest for biological tests.     

Human Gingival Fibroblasts Cell Viability of Poly(Lactic Acid) Powder Reinforced PMMA/Hydroxyapatite Biocomposites

The dental composites based on poly(methyl methacrylate)/hydroxyapatite (PMMA/HA) were prepared through heat-processing polymer powder-liquid method, in the presence of poly(lactic acid) powder (PLA; 5–20 phr). The PLA powder enhanced the flexural modulus and strength of PMMA/HA composites. The Alamar Blue assay results indicated the PMMA/HA/PLA composites were able to sustain human gingival fibroblasts (HGF) cells growth. The images of live/dead cells confocal showed the populations of living cells on the composites surface were confluent and the survival of HGF cells on the PMMA composites surface are assured. These features suggested that the PLA powder reinforced PMMA/HA composites demonstrated excellent biocompatibility.     

层状纳米羟基磷灰石的结晶性能及形成机理

在前期利用模板剂法制备层状纳米羟基磷灰石（nano-hydroxyapatite,n-HA）的基础上,利用透射电子显微镜、X射线衍射和Fourier变换红外光谱等研究并讨论工艺参数对材料结晶性能影响以及形成机理。结果表明：反应24h后,HA晶体形成且层状结构清晰;在碱性条件下,生成的产物主要是n-HA,酸性条件下则生成CaHPO4;乙醇与水的质量比为2.0时,纳米晶体形状、大小相对均一。工艺参数的变化会影响表面活性剂的堆积参数,沿着表面活性剂模板生长的羟基磷灰石颗粒有不同的微观结构及形貌。     

In vitro evaluation of natural hydroxyapatite from Osteoglossum bicirrhosum fish scales for biomedical application

This study reports the obtainment of bioactive hydroxyapatite (HAp) extracted from scales of arowana fish (FSHA) (Osteoglossum bicirrhosum) by alkaline treatment followed by calcination at 600 and 800°C. The cell viability and bioactivity of hydroxyapatite particles (FSHA) were investigated and compared with those of HAp synthesized (s.HA) by the precipitation method. The HAp particles from fish scales showed non-toxic behavior to dental pulp stem cells similar to HAp synthesized. Additionally, bioactivity assays show that the Hap from natural source forms the bone-like apatite layer faster than s.HA sample, after being incubated in McCoy medium for 3 days. The results illustrate that HAp obtained from Osteoglossum bicirrhosum fish scale bio-waste showed excellent biocompatibility. Besides, this study provides an effective method for converting low-cost bio-waste into a value-added and it can be a potential alternative biomaterial for various biomedical applications.     

纳米针状羟基磷灰石晶体的常压水热合成研究

利用正交试验法探讨常压下制备纳米针状羟基磷灰石(HA)晶体。用FTIR、XRD及TEM分析了HA的结构和形貌。讨论了前驱体的浓度、反应搅拌速度、pH值(当pH≥10时)及分散剂N,N-二甲基甲酰胺(DMF)含量对羟基磷灰石晶体形貌及尺寸的影响。结果表明:在合成条件变化很宽的范围内,可以制得纯度高、分散性好的纳米级针状HA晶体。这种纳米针状HA晶体与自然骨中的HA晶体在组成、结构、结晶度和形貌方面有十分相似之处。另外,正交分析表明分散剂含量及前驱体的浓度对制备纳米级针状HA晶体的长度影响较为显著,而HA晶体的长径比受搅拌速度和pH值影响较大。     

Nanoflower hydroxyapatite's effect on the properties of resin-based dental composite

To investigate the reinforcing effect of nanoflower-like hydroxyapatite (NFHA) in resin-based dental composites, we synthesized a novel NFHA using microwave irradiation (MW), hydrothermal treatment (HT), and sonochemical synthesis (SS). Silanized NFHA was then used as the reinforcing filler in dental resin composites. We characterized the structure and morphology of various HA nanostructures using x-ray diffraction, scanning electron microscope, and TEM. The mechanical performance of dental resin composites reinforced with silanized NFHA was measured using a universal testing machine. Spherical HA, synthesized through chemical precipitation (CP), served as the control group. One-way analysis of variance was employed for the statistical analysis of the acquired data. The results demonstrate that the nanoflower morphology significantly was improved mechanical and physical properties. After conducting trials, the NFHA synthesized using MW and HT showed a substantial enhancement in mechanical and physical properties compared to the other structures. Therefore, it can be concluded that NFHA can serve as a novel reinforcing HA filler, providing regenerative properties to resin composites with sufficient mechanical strength.     

热处理气氛对溶胶-凝胶法合成纳米羟基磷灰石涂层的影响

采用溶胶凝胶法(sol-gel)在钛合金(Ti6Al4V)基材表面合成了纳米结构的羟基磷灰石(HA)涂层,利用扫描电镜和X-射线衍射仪分析了涂层的组成和结构,采用划痕仪测定了涂层的结合强度。结果表明:用sol-gel法成功合成了均匀无开裂的HA涂层,HA晶粒尺寸为33-60nm。热处理气氛对涂层的成分和结构有直接影响,氮气保护700℃下合成的涂层是单一的HA成分,和基材结合强度较高;而空气中700℃时Ti6Al4V基材会被氧化生成TiO(2金红石型),因此合成的是HA/TiO2复合涂层,产生氧化层会严重破坏涂层与基材的结合强度。     

Bioactivity and Antibacterial Behaviors of Nanostructured Lithium-Doped Hydroxyapatite for Bone Scaffold Application

The material for bone scaffold replacement should be biocompatible and antibacterial to prevent scaffold-associated infection. We biofunctionalized the hydroxyapatite (HA) properties by doping it with lithium (Li). The HA and 4 Li-doped HA (0.5, 1.0, 2.0, 4.0 wt.%) samples were investigated to find the most suitable Li content for both aspects. The synthesized nanoparticles, by the mechanical alloying method, were cold-pressed uniaxially and then sintered for 2 h at 1250 °C. Characterization using field-emission scanning electron microscopy (FE-SEM) revealed particle sizes in the range of 60 to 120 nm. The XRD analysis proved the formation of HA and Li-doped HA nanoparticles with crystal sizes ranging from 59 to 89 nm. The bioactivity of samples was investigated in simulated body fluid (SBF), and the growth of apatite formed on surfaces was evaluated using SEM and EDS. Cellular behavior was estimated by MG63 osteoblast-like cells. The results of apatite growth and cell analysis showed that 1.0 wt.% Li doping was optimal to maximize the bioactivity of HA. Antibacterial characteristics against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were performed by colony-forming unit (CFU) tests. The results showed that Li in the structure of HA increases its antibacterial properties. HA biofunctionalized by Li doping can be considered a suitable option for the fabrication of bone scaffolds due to its antibacterial and unique bioactivity properties.     

溶胶凝胶法制备钛基羟基磷灰石涂层的研究

混合硝酸钙乙醇溶液和磷酸三甲酯水溶液作为羟基磷灰石(HA)前驱体,利用旋转涂膜技术在钛片表面制备羟基磷灰石涂层.研究了溶胶陈化时间和凝胶热处理温度对涂膜的影响,同时对涂层的生物活性进行了研究.样品利用X射线衍射仪(XRD)和扫描电子显微镜(ESEM)进行表征.结果表明:利用经过24 h陈化的溶胶涂膜的样品在500℃热处...     

Conversion of HA on NT-C/C Composites from Ultrasonic Induction Heating Deposited Monetite to FHA Coating by an Alkaline Followed by NaF Solution Hydrothermal Treatment Methods

An ultrasonic induction heating (UIH) deposited monetite coating on (NH₄)₂S₂O₈ treated (NT) C/C composites was subjected to a hydrothermal treatment to form a hydroxyapatite (HA) coating. This HA coating was then placed in a NaF solution and hydrothermally treated a second time to produce a fluorinated hydroxyapatite (FHA) coating. The structure, morphology and chemical composition of the HA and FHA coatings were characterized by XRD, FTIR, XPS SEM and EDS, and the adhesiveness of the two coatings to the NT-C/C substrates was evaluated by a scratch test. The results showed that after the NaF treatment, the FHA coating was a mixture of FHA and HA with some calcium oxides, and the FHA showed a higher degree of crystallization than the HA coating though the morphologies were similar. In addition, the EDS-determined Ca/P atomic ratio for the FHA coating was about 1.78 which was larger than 1.69 ratio of the HA coating. The bonding strength of the HA coating on C/C could reach a critical load of 60.3 N, while that of the as-prepared F-containing HA coating only had a critical load of 42.4 N. The reason of the lower adhesion for the FHA coating than that for the HA coating is suggested to be correlated with the constituent and structure of the two coatings.     

Electrophoretic deposition of hydroxyapatite-chitosan-CNTs nanocomposite coatings

Three component suspensions of hydroxyapatite (HA), chitosan and CNTs were prepared in ethanol base solution (15 vol% water and 0.05 vol% acetic acid). The adsorption of HA nanoparticles on CNTs was investigated by FTIR and SEM analysis. It was found that HA nanoparticles are adsorbed on CNTs via chemical bonding between -NH₂ groups of chitosan (adsorbed on their surface) and -COOH groups of CNTs. Current density as well as kinetics of EPD was studied at 60 V. It was found that current density increases or remains nearly constant during EPD due to the rise in water electrolysis as deposit grows on the substrate. Deposition weight against EPD time showed a linear trend due to the absence of any voltage drop over the deposit during EPD. The incorporation of chitosan and CNTs in the microstructure of coatings was confirmed by TG/DTA and SEM analysis. CNTs exhibited high efficiency in reinforcing the microstructure of coatings and preventing from their cracking. CNTs incorporation in the coatings improved their mechanical properties (adhesion strength, hardness and elastic modulus) and corrosion resistance.     

纳米针状羟基磷灰石涂层的制备及其性能的研究

用电化学沉积法在钛合金上形成涂层,随后在碱性过热蒸气中进行水热处理,最后进行高温真空烧结。用扫描电镜,Ｘ射线衍射和红外光谱对涂层的组织结构和化学成分进行了分析,测量了涂层的粘接拉伸强度,将涂层浸泡于Ｔｙｒｏｄｅ生理盐液中考虑其抗溶解特性。     

A comparative physico-chemical study of bioactive glass and bone-derived hydroxyapatite

This study aimed at comparing the physico-chemical properties of bioactive glass and bone-derived hydroxyapatite (HA). 63S bioglass particles were obtained by sol-gel process and HA samples were derived from bovine bone. The chemical composition and the crystalline structure of both bioceramics were evaluated. Then the zeta potential in physiological saline and at different pH values was determined. It was found that the negativity of zeta potential for 63S bioglass is higher than that of bone-derived HA. The exothermal behavior through the hydration process was evaluated by isothermal microcalorimetry. The results showed that the librated heat during bioactive glass hydration process and its rate are almost ten times higher than HA. It could be related to different hydration mechanisms of bioglass and HA. However, for both bioglass and HA, this value is in the safe range and cannot be harmful for the adjacent tissues in the body.     

Synergism in novel silver-copper/hydroxyapatite composites for increased antibacterial activity and biocompatibility

This study develops a novel silver-copper/hydroxyapatite composite (Ag–Cu/HA) with high biocompatibility and antibacterial activity. Two different materials were synthesized, namely silver-hydroxyapatite (Ag-HA) and copper-hydroxyapatite (Cu-HA) composites, with 0.1%, 0.5%, and 1.0% (mol) of each metal. These materials were mixed in a planetary mill to obtain the Ag–Cu/HA composites. The results of our characterization demonstrated the low cytotoxicity and hemolytic response. The composite showed higher percent-inhibition for bacterial growth compared to those in separated composites of silver or copper with hydroxyapatite. Hence, these new materials promise higher efficacy as antibacterial hydroxyapatites.     

Nano-hydroxyapatite reinforced zeolite ZSM composites: A comprehensive study on the structural and in vitro biological properties

The bioactive composite of hydroxyapatite and zeolite-ZSM5 was successfully synthesized via the cost effective microwave wet precipitation method. The structural and morphological features were studied by X-ray diffraction, FT-IR spectroscopy and TEM/EDX analysis. These tests revealed the presence of zeolite and hydroxyapatite in the zeolite–HA composites. Spherical particles, 76–88±20 nm in size, were visible on the TEM. The simulated body fluid SBF results in vitro verified the ability of the composites to support and accelerate the growth of the HA. Furthermore, the MTT assay showed the viability of normal human osteoblasts (NHOst) on the composite, up to seven days of culture. The cell adhesion and proliferation of the normal human osteoblast (NHOst) cells onto the disc surface was much higher than the control. Overall, the ZSM–HA samples composite nanostructure can be a considered potential candidate for biomedical application.