Studies on bioactive glass and glass-ceramic are important research high-lights in the field of biomedical materials. Due to their bioactivity, these materials can form a tight chemical bond with the living bone, when implanted. As a preeminent kind of these materials, A-W(Apatite/Wollastonite) bioactive glass ceramic has not only the excellent bioactivity and biocompatibility, but also the eminent mechanical properties, so it has been largely applied and developed in clinical practice. The development, preparation, properties, applications and the mechanism of its bond with bone are introduced in this paper. We will also put forward the prospect of the research and development of A-W bioactive glass ceramic.
Apatites ; chemistry ; Bone Substitutes ; chemistry ; Calcium Compounds ; chemistry ; Ceramics ; chemistry ; Mechanics ; Research ; Silicates ; chemistry ; Surface Properties

A composite material consisting of carbonate apatite (CAp) and type I atelocollagen (AtCol) (88/12 in wt/wt%) was designed for use as an artificial bone substitute. CAp was synthesized at 58 degrees C by a solution-precipitation method and then heated at either 980 degrees C or 1,200 degrees C. In this study, type I AtCol was purified from bovine tail skins. A CAp-AtCol mixture was prepared by centirfugation and condensed into composite rods or disks. The scanning electron-microscopic (SEM) characterization indicated that the CAp synthesized at 58 degrees C displayed a crystallinity similar to that of natural bone and had a high porosity (mean pore size: about 3-10 microns in diameter). SEM also revealed that the CAp heated at 980 degrees C was more porous than that sintered at 1,200 degrees C, and the 1,200 degrees C-heated particles were more uniformly encapsulated by the AtCol fibers than the 980 degrees C-heated ones. A Fourier transformed-infrared spectroscopic analysis showed that the bands characteristic of carbonate ions were clearly observed in the 58 degrees C-synthesized CAp. To enhance the intramolecular cross-linking between the collagen molecules, CAp-AtCol composites were irradiated by ultraviolet (UV) ray (wave length 254 nm) for 4 hours or vacuum-dried at 150 degrees C for 2 hours. Compared to the non cross-linked composites, the UV-irradiated or dehydrothermally cross-linked composites showed significantly (p < 0.05) low collagen degradation and swelling ratio. Preliminary mechanical data demonstrated that the compressive strengths of the CAp-AtCol composites were higher than the values reported for bone.
Animal ; Apatites*/chemistry ; Bone Substitutes*/chemistry ; Bone Transplantation ; Cattle ; Collagen*/chemistry

Bone tissue engineering is a novel, developing and challenging science which provides a new way to repair bone lost from injury and disease. Porous calcium polyphosphate bioceramic is one kind of absorptable bioceramic. Owing to its fine biocompatibility and degradability, more and more pieces of research wark have been carried out in bone tissue engineering, and because of its special characteristics, calcium polyphosphate bioceramic is regarded as a promising material for solving the problem of how to match the degradation velocity of scaffold with the velocity of cell growth. The recent research of using calcium polyphosphate bioceramic as the scaffold in bone tissue engineering is summarized, including the property, synthesis and advances.
Bone Substitutes ; chemistry ; Bone and Bones ; Calcium Phosphates ; chemistry ; Humans ; Porosity ; Tissue Engineering ; Tissue Scaffolds ; chemistry

Chitin short fiber reinforced polycaprolactone composite was prepared by melting blending method. The cytotoxicity and biocompatibility of pure polycaprolactone and of chitin short fiber reinforced polycaprolactone composite were investigated in order to provide useful scientific basis for clinical application. The biocompatibility of pure polycaprolactone and that of chitin short fiber reinforced polycaprolactone composite were evaluated by a series of tests, including cytotoxicity test in vitro, acute systemic toxicity test, hemolysis test, pyrogen test and sensitivity test. The results showed that the cytotoxicity scores of the two materials were grade 0 and the growth and proliferation of the cultured cells were not significantly inhibited by the two materials. There were no potential allergic materials in the composites and the maceration extract showed no hemolytic reaction, no acute systemic toxicity and no pyrogen reaction. We conclude that the composites have fine biocompatibility and are safe for clinical use in the reconstruction treatment for chest wall defect.
Biocompatible Materials ; chemistry ; Bone Substitutes ; chemistry ; Chitin ; chemistry ; Materials Testing ; Polyesters ; chemistry

A simple plasma spraying method was employed in coating hydroxyapaptite (HA) on to carbon/carbon composites (C/C composites). The morphology of the coating was examined under scanning electron microscope (SEM). The phase constitutions of the HA coating were determined by X-ray diffractometer (XRD). The shear strength of the HA coating-C/C composite substrates was detected. A hydroxyapatite coating with rough surface was observed. A considerable amount of amorphous phase appeared as a result from the coating process, which could be transformed into the morphous phase crystalline HA after subsequent heat treatment. The shear strength between the HA coating and C/C composite substrates was 7.15 MPa.
Bone Substitutes ; chemistry ; Carbon ; chemistry ; Carbon Compounds, Inorganic ; chemistry ; Coated Materials, Biocompatible ; chemistry ; Durapatite ; pharmacology ; Humans

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

Porous calcium polyphosphate (CPP) has shown promise of tissue engineered implant application because of the biocompatibility and biodegradation. CPP with different polymerization degree were prepared by controlling the calcining time, and its polymerization degree could be calculated by developed method in this paper. Different crystal types CPP were prepared by quenching from the melt and crystallization of amorphous CPP. From the in vitro degradation, carried out in Tris-HCl buffer, the degradation velocity of CPP was controllable. The weight loss of CPP with different polymerization degrees and crystal types were different. With the increasing of polymerization degree, the weight loss during the degradation was decreasing, contrarily the strength of CPP was increasing. The amorphous CPP could degrade completely in 17 days while gamma-CPP do completely in 25 days. The degradation velocity beta-CPP and alpha-CPP was slower than gamma-CPP and the weight loss was about 12% and 5% respectively. The results of this study indicate that CPP have potential applications for bone tissue engineering as inorganic polymeric biomaterials.
Absorbable Implants ; Biocompatible Materials ; chemistry ; Bone Substitutes ; chemistry ; Calcium Phosphates ; chemistry ; Humans ; Tissue Engineering

Calcium polyphosphate (CPP) may be a promising bone substitute with controllably-degraded ability. In this investigation, the effects of sintering temperatures on its phase transformation and structure parameters, such as crystalline size distribution and micro-strain were investigated by X-ray diffraction (XRD). The phase composition was calculated with reference intensity ratio (RIR). The crystalline size distribution and micro-strain were calculated with Warren-Averbach Fourier transfer (W-A/FT) method. The results demonstrated that at the temperature of 585 degrees C-900 degrees C, the phase transformation of amorphous CPP into crystalline gamma-CPP and then into beta-CPP occurred,and the course of such transformation was accompanied with the significant change of the mean crystalline size (D) and the mean micro-strain (epsilon).
Biocompatible Materials ; Biodegradation, Environmental ; Bone Substitutes ; chemistry ; Calcium ; chemistry ; Humans ; Polyphosphates ; chemistry ; Stress, Mechanical

This study was aimed to create strontium-calcium sulfate compounds for making a new bioactive material with osteoconductive and osteoinduceable activity for bone repairing. Its mechanics and degradation features were assessed in vitro. Powders of alpha-calcium sulfate hemihydrate (alpha-CSH) and SrCl2 were mixed completely to make Sr-calcium sulfate compounds materials with 6 different concentrations (0%, 0.1%, 0.3%, 0.5%, 1% and 2%) of Sr. Scanning electron microscope was used to observe the configuration of the new materials. The compressive strength of each material was tested. The materials were soaked into simulated body fluid (SBF) to test the features of degradation, which included pH, weight loss, declination of compressive strength and the changes of strontium ion concentration. The crystal appearances were influenced by incorporating of strontium. The compressive strength of non-strontium incorporating calcium sulfate was 36.65 +/- 2.22 MPa. When the concentration of strontium was increasing, the compressive strength measurements of the materials tended to decline. The compressive strength declined to 20.56 +/- 2.64 MPa when the strontium concentration reached to 2%. The pH value of the SBF declined when the time of degradation increased, but both of them were very stable. All of the materials got weight loss after being soaked in SBF for several weeks. The weight loss was slight within 4 weeks and it became dramatic after 4 weeks. When the concentration of strontium was increasing, the weight loss became more rapid and significant (P<0.05). During 0-4 weeks' degradation in SBF, the materials' compressive strength decreased much slower when the strontium concentration was below 0.5%; however, when the decrement of strength became faster, the strontium concentration became higher. The concentration of strontium ion in SBF began to increase faster after 4 weeks' soaking in SBF. As the concentration of strontium was increasing, the strontium ion concentration in SBF became higher (P = 0.000). The new compound materials made by the mixing of alpha-calcium sulfate hemihydrate and SrCl2 can provide efficient compressive strength. The features of degradation of the materials are very stable. The new materials can release lots of bone inducible substance-strontium ions to repair bone defection after 4 weeks of degradation.
Bone Substitutes ; chemical synthesis ; chemistry ; Calcium Sulfate ; chemistry ; Compressive Strength ; Humans ; Osteogenesis ; Strontium ; chemistry

Magnesium based implants have the characteristics of bio-degradability, osteoconductive, and, regulatory strength. After the tissue has healed sufficiently, the burden of a second surgical procedure can be avoided. However, the degradation speed is so fast as to limit its clinical application. Hence, it is crucial for the biomedical magnesium alloys to be able to change their biodegradation behavior and speed. This paper reviews the degradability, biological activity and biocompatibility of magnesium and its alloys as orthopedic biomaterial in vitro and vivo to explore the possible way to modify the characteristics of its degradability, for the purpose of controllable degradation speed.
Absorbable Implants ; Alloys ; chemistry ; Animals ; Biocompatible Materials ; chemical synthesis ; Bone Plates ; Bone Screws ; Bone Substitutes ; chemistry ; Humans ; Magnesium ; chemistry