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101.
Narges Johari Mohammadhossein Fathi Zeinab Fereshteh Saeid Kargozar Ali Samadikuchaksaraei 《先进技术聚合物》2020,31(5):1019-1026
Biodegradable cell‐incorporated scaffolds can guide the regeneration process of bone defects such as physiological resorption, tooth loss, and trauma which medically, socially, and economically hurt patients. Here, 0, 5, 10, and 15 wt% fluoridated hydroxyapatite (FHA) nanoparticles containing 25 wt% F? and 75 wt% OH? were incorporated into poly(ε‐caprolactone) (PCL) matrix to produce PCL/FHA nanocomposite scaffolds using electrospinning method. Then, scanning electron microscopy (SEM), X‐ray diffraction (XRD) pattern, and Fourier transform infrared spectroscopy (FTIR) were used to evaluate the morphology, phase structure, and functional groups of prepared electrospun scaffolds, respectively. Furthermore, the tensile strength and elastic modulus of electrospun scaffolds were investigated using the tensile test. Moreover, the biodegradation behavior of electrospun PCL/FHA scaffolds was studied by the evaluation of weight loss of mats and the alternation of pH in phosphate buffer saline (PBS) up to 30 days of incubation. Then, the biocompatibility of prepared mats was investigated by culturing MG‐63 osteoblast cell line and performing MTT assay. In addition, the adhesion of osteoblast cells on prepared electrospun scaffolds was studied using their SEM images. Results revealed that the fiber diameter of prepared electrospun PCL/FHA scaffolds alters between 700 and 900 nm. The mechanical assay illustrated the mat with 10 wt% FHA nanoparticles revealed the highest tensile strength and elastic modulus. The weight loss alternation of mats determined around 1% to 8% after 30 days of incubation. The biocompatibility and cell adhesion of mats improved by increasing the amounts of FHA nanoparticles. 相似文献
102.
Ather Farooq Khan Muhammad Awais Abdul Samad Khan Sobia Tabassum Aqif Anwar Chaudhry Ihtesham Ur Rehman 《应用光谱学评论》2013,48(4):329-355
Abstract Raman spectroscopy of natural bones and hydroxyapatites is described. In addition, how Raman spectroscopy has proved crucial in providing baseline data for the modification of synthetic apatite powders that are routinely used now as bone replacement materials is explained. It is important to understand the chemical structural properties of natural bone. Bone consists of two primary components: an inorganic or mineral phase, which is mainly a carbonated form of a nanoscale crystalline calcium phosphate, closely resembling hydroxyapatite, and an organic phase, which is composed largely of type I collagen fibers. Other constituents of bone tissue include water and organic molecules such as glycosaminoglycans, glycoproteins, lipids, and peptides. Ions such as sodium, magnesium, fluoride, and citrate are also present, as well as hydrogenophosphate. Hence, the mineral phase in bone may be characterized essentially as nonstoichiometric substituted apatite. Such a distinction is important in the development of synthetic calcium phosphates for application as skeletal implants. An understanding of bone function and its interfacial relationship to an implant clearly depends on the associated structure and composition. Therefore, it is essential to fully understand the chemical composition of bone, and Raman spectroscopy is an excellent technique for such an analysis. 相似文献
103.
Hang Wu Di Pang Chi Ma Qing Li Chengdong Xiong 《Journal of Macromolecular Science: Physics》2013,52(6):1242-1255
Hydroxyapatite whiskers (HAW) with a maximum aspect ratio of 20 were employed to improve the toughness of poly(L-lactide-co-glycolide) (PLGA). 3-Aminopropyltriethoxysilane (AMEO) was grafted on the surface of the hydroxyapatite whiskers (g-HAW) to improve its wetting in the PLGA matrix. Composites based on HAW, g-HAW, and PLGA were prepared. The structure and properties of the composites were subsequently investigated by powder X-ray diffraction (XRD), scanning electron microscopy, differential scanning calorimetry, and tensile testing. The g-HAW were distributed homogenously in the PLGA matrix because of improved wetting of g-HAW while the HAW were aggregated. The stronger interfacial bonding also gave rise to improved mechanical properties of the g-HAW/PLGA composites. The HAW/PLGA and g-HAW/PLGA composites failed in a tough manner with intensive plastic deformation. The g-HAW/PLGA composite (5 wt% g-HAW) failed at a maximum elongation of 366%, although the tensile strength dropped slightly. The g-HAW/PLGA composite (1 wt% g-HAW) maintained the initial tensile strength of neat PLGA but failed at an equally high elongation of 347%, whereas PLGA failed at an elongation of 11%. 相似文献
104.
Hydroxyapatite nanospheres (nHA) were first synthesized from (NH4)2HPO4 and CaCl2 precursors in the presence of poly(vinyl alcohol) templates. The structure and morphology of as-synthesized products were examined by materials characterization techniques. X-ray diffraction patterns and Fourier transform infrared spectra showed that the nHA (50–70 nm) exhibit the crystalline structure and vibration bands of HA. The Ca/P molar ratio of nHA approached the stoichiometric value of 1.67. The nHA were then melt blended with polyamide-6 (PA6), followed by injection molding. Tensile and flexural measurements showed that the tensile and bending strengths of injection molded PA6–10 wt% nHA composite were close to those of human cortical bone. A simulated body fluid immersion test revealed that apatite crystals can be readily deposited on the PA6–10 wt% nHA composite surface after immersion for 30 days. 相似文献
105.
纳米羟基磷灰石-聚(己内酯-丙交酯)共聚物复合材料 总被引:1,自引:0,他引:1
通过纳米羟基磷灰石(HA)的羟基引发ε-已内酯(ε-CL)开环聚合,再接枝不同量的丙交酯(LA),制备了HA-P(CL-LA)复合材料.采用TEM、FT-IR、~1H-NMR、~(13)C-NMR等对复合物的结构进行了表征.结果表明:HA在复合物中的分散较均匀,并且保持了原来的针状或棒状形貌;共聚物中n(ε-CL)/n(LA)随着单体投料中n(ε-CL)/n(LA)的增加而增加;样品在制备过程中没有发生丙交酯与己内酯之间的酯交换,只发生了丙交酯自身的酯交换,共聚物中丙交酯链段主要以全同序列为主. 相似文献
106.
F. Z. Mezahi H. Oudadesse A. Harabi A. Lucas-Girot Y. Le Gal H. Chaair G. Cathelineau 《Journal of Thermal Analysis and Calorimetry》2009,95(1):21-29
The dissolution kinetic and structural behaviour of natural hydroxyapatite (N-HA) and synthetic hydroxyapatite (S-HA) was
studied vs. sintering temperature and using ‘in vitro’ experiments. Obtained results highlight the chemical stability of N-HA. Any structural
modification was observed until 1200°C. In the fact S-HA undergoes some modifications. XRD diagrams show the tricalcium phosphate
(TCP) phase formation between 800 and 1100°C and tetracalcium phosphate (TetCP) phase formation at 1200°C. The ‘in vitro’
assay shows that the dissolution was occurred more in N-HA than in S-HA. The formed TCP activated the dissolution kinetic
and then the precipitation phenomena when a continuous dissolution of TetCP leaded to slow down the kinetic precipitation. 相似文献
107.
108.
利用溴代十六烷基三甲基铵(CTAB)为模板, 合成制备了棒状羟基磷灰石颗粒, 并以SEM, XRD, IR等手段进行了表征. 用制备的羟基磷灰石与自制的离子液体([BMIM]PF6)充分混合涂覆在玻碳电极表面制备了羟基磷灰石/离子液体修饰电极, 研究了镉离子在该修饰电极上的富集和电化学行为. 结果发现, 羟基磷灰石对镉离子有较好的富集作用, 而离子液体则可以在开路条件下使镉离子还原为金属镉, 氧化扫描时可以得到镉的灵敏氧化溶出峰, 以此为基础建立了一种高选择性地测定痕量镉离子的新方法, 该方法可以较好地避免铅、汞、银等重金属离子的干扰, 对镉离子检出限可达2.0×10-8 mol•L-1, 在4.0×10-8~2.2×10-7 mol•L-1的浓度范围内, 氧化溶出峰电流与Cd(II)的浓度呈良好的线性关系. 该研究有望在环境检测和环境治理方面发挥重要作用. 相似文献
109.
110.
Adsorbed on porous calcium hydroxyapatite, 1,3‐dipolar cycloaddition of diphenylnitrilimine on olefins is readily catalyzed under solvent‐free microwaves irradiation. The pyrazolines are obtained in few minutes with high yields. Specific surface of porous calcium hydroxyapatite and microwaves effects are discussed. 相似文献