Poly (propylene fumarate) is an unsaturated linear polyester, which degrades, in the presence of water, into propylene glycol and fumaric acid, and the degradation products can be cleared from the human body by normal metabolic processes. In this paper, different methods of the synthesis of PPF are listed, the crosslinking characteristics of polymerizing composite as well as the mechanical properties of cross-linked composite are discussed, and the potentialities of PPF composite used as particularly degradable polymeric cement for orthopedic application are reviewed.
Biocompatible Materials ; chemical synthesis ; Biodegradation, Environmental ; Cross-Linking Reagents ; chemical synthesis ; Fumarates ; chemical synthesis ; chemistry ; Humans ; Polypropylenes ; chemical synthesis ; chemistry

An electrochemical co-deposition technique has been developed to prepare a hydroxyapatite (HAP)/organic polymer composite coatings on Ti surface as new biomaterial of hard tissue. The composite coating of organic polymer and calcium phosphate is formed by adding a water soluble polymer of the ethylene series to NH4H2PO4-Ca (NO3)2 solution when conducting an appropriate electrochemical co-deposition experiment. The XRD, SEM, XPS, SIMS and nano indent measurements were performed to characterize the morphology, composition, structure and surface stiffness of the composite coating. It was found that the morphology and surface hardness of the coatings showed a remarkable modification when introducing a minor polymer to HAP coating, and the bonding force between the coating and metal substrate was distinctly increased. The incorporation of minor organic polymer into the HAP compound at molecular level will improve the mechanical properties and morphology of the composite coatings, and this may be helpful to raising its bio-activity.
Coated Materials, Biocompatible ; chemical synthesis ; Durapatite ; chemical synthesis ; Electrochemistry ; Materials Testing ; Titanium ; X-Ray Diffraction

This is a report on the research of HA/Ti6Al4V composite implants that were successfully fabricated by radio frequency magnetron sputtering (RF-MS) technique. The mechanism and bioactivity of these implants immersed in simulated body fluid (SBF) were investigated. Changes in surface morphology, interfacial bond state, crystal structure and phase composition of HA coating before and after immersing in SBF were characterized by Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). Results indicate that a new substance on the surface of HA implant coatings produces accompanying with the dissolution of coatings. The substance is bone-like apatite containing CO3(2-) and lacking of Ca2+. Its ratio of n(Ca)/n(P) is about 1.56. This substance has very small grain size and similarly amorphous structure. Its structure and composition are similar to those of natural bone. Thus, it has good biocompatibility and bioactivity.
Biocompatible Materials ; Coated Materials, Biocompatible ; chemical synthesis ; Durapatite ; chemical synthesis ; Magnetics ; Materials Testing ; Prosthesis Implantation ; Radio Waves ; Titanium ; chemistry

OBJECTIVETo synthesize nanometer hydroxyapatite (HAP) by sol-gel method from Ca (NO3)2.4H2O and PO (CH3O)3 with water and ethanol as solvents and to study the factors that can affect the formation of sol-gel, including the type of solvents, amount of solvents, pH value, as well as properties under the condition of low temperature combustion of dried gel.

METHODSThe viscosities of sol were determined on WU viscosimeter. TG-DTA was used to analyze the thermal procedure of dried gel by increasing temperature. Characterization of the dried gel and powder after combustion were evaluated by X-ray diffraction and infrared spectrum. The morphology of the powder was observed by transmission electron microscopy.

RESULTSStable and homogeneous gel could be obtained at appropriate pH value when ethylene glycol was added into solvent. The dried gel had the feature of low temperature combustion. HAP powder with particle size of 50 nm was directly prepared.

CONCLUSIONNanometer HAP powder with uniform particle size can be synthesized by sol-gel method.

Polyamidoamine (PAMAM) dendrimers is synthesized by the American scientist, Tomalia, in 1985 and is now used widely in many fields such as gene carriers, photoelectric sensor, wastewater treatment, drug carriers and catalyst. The present paper mainly reviews the structure and methods of synthesis, celluar cytotoxicity, achievements of gene and drug carriers research, advancement and prospect of PAMAM as a carrier in glioma therapy. Besides, it also involves an outline for the future research of the radiotherapy for glioma.
Biocompatible Materials ; chemical synthesis ; chemistry ; Dendrimers ; chemical synthesis ; chemistry ; Drug Carriers ; Genetic Vectors

Present study used dip-coating techniques to fabricate ultrathin nano-HA coating on titanium in organic sol-gel of Ca (NO3)2. 4H2O and PO(CH3)3 and inorganic sol-gel of Ca (NO3)2. 4H2O and (NH4)2HPO4. Scanning electron microscope (SEM) and grazing-incidence X-ray diffraction (XRD) were used to observe the morphology and distribution of crystallite size (D) and lattice strain (epsilon) of ultrathin nano-HA coating. After heated at 400 degrees C, the apatite structure of coatings on titanium began to appear. At heating temperature of 400 degrees C-600 degrees C, the effect of heating temperature on D and epsilon of both coatings was obvious. Precursor types significantly affected the particle diameters of nano-HA coatings, which were 25-40 nm for organic sol-gel and about 100 nm for inorganic sol. The thickness of ultrathin nano-HA coatings was 2.5 microm for organic sol-gel and 5 microm for inorganic sol and morphology of interfaces between coating and titanium was intact and homogenous.
Coated Materials, Biocompatible ; chemical synthesis ; chemistry ; Durapatite ; chemical synthesis ; chemistry ; Gels ; Nanostructures

Hydroxyapatite (HAP) formation on the surface of the degradable polyamides implant by a coating technology was studied. A suspension of HAP-glutin-acetic acid was prepared and brushed on the surface of the implant at room temperature. Scanning electron microscopy (SEM), X-ray diffractometry (XRD) and Fourier transform infrared spectroscopy (FT-IR) were employed to study the composition and the microstructure of the coating. The results obtained indicate that the main composition of coating is crystal HAP, its structural formula is Ca10(PO4)6(OH)2. So the coating has bioactivity. The coating has also small pores, which can stimulate bone regrowth and adsorption of other bioactive materials or mediine. This technology is an effective method to improve medical performance of the polyamides implant.
Bone Substitutes ; Coated Materials, Biocompatible ; chemical synthesis ; chemistry ; Durapatite ; chemical synthesis ; chemistry ; Nylons ; Prostheses and Implants

Oligopeptide T2, a kind of PA (Peptide Amphiphile) molecule, which could build up nano-fiber by self-assembly was designed and synthesized in this study. And the double-diffusion gel system was applied on this molecule to investigate its biomineralization features in vitro. The results showed that T2 could obviously reduce the hydroxyapatite (HA) formation period. And HA was found to possess the characteristics of non-crystalline by analysis of X-ray diffraction (XRD) and scanning electronic microscopy (SEM). These findings point to the conclusion that the negatively charged zone in T2 might make this molecule have the function of promoting HA biomineralization in vitro. And the mechanism responsible for the procession of HA biomineralization needs further research.
Biocompatible Materials ; chemical synthesis ; chemistry ; Bone Substitutes ; chemistry ; Calcification, Physiologic ; Durapatite ; chemistry ; Oligopeptides ; chemical synthesis ; chemistry

Hydroxyapatite (HA) has been earmarked as suitable for implantation within the human of its chemical makeup to human bone. In this paper, HA powders were synthesized via the precipitation method where phosphoric acid (H3PO4) was titrated into calcium hydroxide solution [Ca(OH)2]. Two parameters such as temperature and stirring rate were identified as factors that influenced the amount and purity of HA powder. Phase identification of the synthesized powder was done using X-Ray Diffraction (XRD). The results show that HA phase can be synthesized from this titration process of Ca(OH)2 and H3PO4 with yield amount of HA powder around 45 - 61 grams but with less than hundred percent purity. In order to study the effect of heat treatment to HA crystals structure, HA powder was calcined at 850 degrees C for 2 hours. It's found that the degree of crystallinity increases after calcination because of lattice expansion when the materials were heated at higher temperature
Biocompatible Materials/*chemical synthesis ; Calcium Hydroxide ; Durapatite/*chemical synthesis ; Phosphoric Acids ; Precipitation ; X-Ray Diffraction

The hydroxyapatite (HA) powder surface modified with silane coupling agent was used to prepare HA/epoxy composite. It was found that silane has greatly improved the dispersion of HA in epoxy. The composite has good in vitro bioactivity and biocompatibility with 40 wt% HA, and the flexural modulus is close to that of natural bone, but its strength is lower than that of natural bone. So the composite needs further reinforcement in some way or other.
Biocompatible Materials ; chemical synthesis ; chemistry ; Bone Substitutes ; chemical synthesis ; chemistry ; Durapatite ; chemical synthesis ; chemistry ; Epoxy Resins ; chemical synthesis ; chemistry ; Humans ; Materials Testing