OBJECTIVETo evaluate the biological safety of compound galvano-ceramic bridge by measuring the consistency of released nickel ion of the galvano-form slices cohered with Ni-Cr alloy slice specimens which were immersed in artificial saliva.

METHODSSpecimens were divided into five groups with four tests and one control. Test specimens were made into the structure like rectangle sandwich that one side of Ni-Cr alloy was cohered to the center surface of galvano golden base of 0.2 mm and another side was fused porcelain with the thickness of 0.3 mm (group A), 0.5 mm (group B), 1.0 mm (group C), and 0.3 mm (group D). And the Ni-Cr alloys were totally embedded in galvano golden base and firing porcelain. Naked Ni-Cr alloy was taken as control. Group D was immersed into acid artificial saliva (AS) with high fluoride, while others were in acid AS at 37 degrees C for 120 h. Then the consistency of released nickel ion in the solution was measured with inductively coupled plasma-atomic emission spectrometry (ICP-AES).

RESULTSNickel ions detected in the artificial saliva for the groups A, B, C, and D in acid AS with or without high fluoride were all under 0.005 mg/L Significant differences were found between each test group and the control [(0.65 +/- 0.45) mg/L].

CONCLUSIONSGalvano-ceramic bridge, Ni-Cr alloy bridge with fused porcelain and golden base, shows biological safety responsible for the consistency of released nickel ion.

Biocompatible Materials ; chemistry ; Dental Materials ; Materials Testing ; Metal Ceramic Alloys ; chemistry ; Nickel ; analysis

This study was designed to investigate the surface properties especially surface porosity of polyhydroxybutyrate (PHB) using scanning electron microscopy. PHB granules were sprinkled on the double-sided sticky tape attached on a SEM aluminium stub and sputtered with gold(10nm thickness) in a Polaron SC515 Coater, following which the samples were placed into the SEM specimen chamber for viewing and recording. Scanning electron micrographs with different magnification of PHB surface revealed multiple pores with different sizes.
Biocompatible Materials/*analysis ; Hydroxybutyrates/*analysis ; *Materials Testing ; *Microscopy, Electron, Scanning ; Porosity ; Surface Properties

Quantification of residual DNA in animal-derived biological scaffold materials is one of technical specifications for evaluating decellularization process and immunotoxicity risk. Up to now, there have been no standard methods available for quantification of residues DNA in animal-derived biological scaffold materials. In this study, a three-step method, including proteinase K digestion, DNA purification and determination of DNA using fluorescence assay, was designed for residual DNA quantification. A parallel recovery experiment of standard DNA using the same protocol to test article determination was used for adjusting final results of residuul DNA amount. DNA purification based on magnetic beads enabled the experiments to get high accuracy and repeatability. The validation experiment showed that the three-step method had high sensitivity up to 6.25ng of DNA per sample with good linearity (recovery curve R2 > 0.99) in the concentration range of 3. 125-100ng, and 25-400ng per sample. This method is useful for determining micro or trace amount DNA remained in the biomaterials.
Animals ; Biocompatible Materials ; chemistry ; DNA ; analysis ; isolation & purification ; Materials Testing ; methods ; Tissue Scaffolds ; chemistry

Biocompatible Materials ; analysis ; Chromatography ; methods ; Chromatography, Gas ; methods ; Chromatography, Liquid ; methods ; Paraquat ; analysis ; Pesticide Residues ; analysis

The aim of this study was to elaborate a dense, strong and thin calcium-phosphate coating on commercial porous pure titanium implant surface in the light of a fast biomimetic procedure. After being polished, sandblasted, cleaned and treated with the mixture of HF and HNO3, the titanium plates were divided into two groups, namely group A and group B. The specimens of group A were free from any treatment. The specimens of group B were treated with the mixture of 48% H2SO4 and 18% HCl. All specimens soaked in SBF-A solution for 1d. Then the specimens were immersed in the SBF-B solution for 2 d. A thin calcium-phosphate coating was deposited on all the specimens of the two groups, the surface consisted of well-formed crystals, which were proved to be the mixture of hydroxycarbonated apatite (HCA) and octacalcium phosphate (OCP); the coating's Ca/P rate was 1.51. A thin carbonated calcium-phosphate coating was deposited on porous pure titanium by the use of the fast biomimetic procedure.
Biomimetic Materials ; analysis ; chemistry ; Calcium Phosphates ; analysis ; chemistry ; Coated Materials, Biocompatible ; chemistry ; Crystallization ; Prostheses and Implants ; Surface Properties ; Titanium ; chemistry

Biocompatibility has always been the focal point in the study of biomaterials applied to medical apparatus. But at present, the standard system hasn't formed completely to evaluate the biomaterials. In recent years scientists tend to use general standard of evaluation. In this article, based on the recalcification time, the adhesion of platelets as well as the total quantity of plasma protein and some other evidences, combining with the Analytic hierarchy process (AHP), the method of general evaluation on the biocompatibility of anticoagulant biomaterials was discussed.
Anticoagulants ; analysis ; Biocompatible Materials ; standards ; Blood Proteins ; analysis ; Humans ; Materials Testing ; methods ; standards ; Platelet Adhesiveness ; drug effects

OBJECTIVETo prepare a rabbit meniscus acellular matrix scaffold and explore the histomorphological and biomechanical properties of the scaffold.

METHODSRabbit meniscuses were collected and acellularized using a modified eight-step detergent process with hydrogen peroxide, distilled water, Triton X-100, and sodium deoxycholate. Its color and texture were observed. Histomorphological assessment was performed using routine hematoxylin-eosin stain, toluidine blue stain, Saffron stain, Hoechst-33258 stain, and immunohistochemical staining of collagen I. The ultrastructure of the specimens was observed with inverted phase contrast microscopy. Transient recovery rate of deformation, maximal recovery rate of deformation, and maximal compressive strength were tested to determine the biomechanical properties of the scaffold.

RESULTSThe processed meniscus was milk-white in color with loose structure. It histologically appeared cell-free, stained positively for collagen I, and had abundant micropores according to phase-contrast microscopy. The transient recovery rate of deformation was (76.65∓4.61)%, the maximal recovery rate of deformation was 100%, and the maximal compressive strength was (4.51∓0.69) N when the specimens were compressed 40%.

CONCLUSIONSThe rabbit meniscus acellular matrix scaffold, with numerous micropores, is easy to be recovered from deformation and suitable for the adhesiveness and growth of breeding cells. This scaffold can be used as an ideal implant for future tissue engineering of the meniscus.

Animals ; Biocompatible Materials ; analysis ; Biomechanical Phenomena ; Materials Testing ; Menisci, Tibial ; chemistry ; cytology ; ultrastructure ; Rabbits ; Tissue Engineering ; Tissue Scaffolds

Hemocompatibility is an important component of biocompatibility; it reflects the degree of interaction between material and blood. Hemocompatibility is multifaceted, so that the material's impact on the blood and the underlying mechanism are very complicated. This article presents a review of researches probing the impact of material on blood via contact activation and plasma protein adsorption; via the platelet activated and the formation of thrombin; via the complement system activated and the activation of leukocytes as well as other mechanisms of hemolysis. The current methods for evaluation and the future trend of development are also introduced.
Biocompatible Materials ; standards ; Blood ; Humans ; Materials Testing ; methods ; Platelet Activation ; Platelet Adhesiveness ; Stress, Mechanical ; Surface Properties ; Thrombin ; analysis

According to the related standards, an in vitro corrosion fatigue testing of coronary stents was designed. The stents were fixed in the latex tubes, which were full of 0.9% saline solution, and radial stress was produced for simulating natural vessel. The accelerated fatigue test was performed with 4 x 10(8) cycles at a frequency of 60 Hz, which was equal to 10 years in vivo implantation. Twelve coronary stents made from stainless steel were adopted in the experiment. The bulk structure and surface morphology before and after testing were analysed by scanning electron microscopy. The structure damage and surface change caused by corrosion fatigue were identified and the probable reasons were proposed.
Biocompatible Materials ; chemistry ; Computer Simulation ; Corrosion ; Equipment Failure Analysis ; Humans ; Materials Testing ; Models, Cardiovascular ; Stainless Steel ; chemistry ; Stents ; Time Factors

OBJECTIVE: In addition to bone bridging inside a cage or graft (intragraft bone bridging, InGBB), extragraft bone bridging (ExGBB) is commonly observed after anterior cervical discectomy and fusion (ACDF) with a stand-alone cage. However, solid bony fusion without the formation of ExGBB might be a desirable condition. We hypothesized that an insufficient contact area for InGBB might be a causative factor for ExGBB. The objective was to determine the minimal area of InGBB by finite element analysis. METHODS: A validated 3-dimensional, nonlinear ligamentous cervical segment (C3–7) finite element model was used. This study simulated a single-level ACDF at C5–6 with a cylindroid interbody graft. The variables were the properties of the incorporated interbody graft (cancellous bone [Young’s modulus of 100 or 300 MPa] to cortical bone [10000 MPa]) and the contact area between the vertebra and interbody graft (Graft-area, from 10 to 200 mm²). Interspinous motion between the flexion and extension models of less than 2 mm was considered solid fusion. RESULTS: The minimal Graft-areas for solid fusion were 190 mm², 140 mm², and 100 mm² with graft properties of 100, 300, and 10000 MPa, respectively. The minimal Graft-areas were generally unobtainable with only the formation of InGBB after the use of a commercial stand-alone cage. CONCLUSION: ExGBB may be formed to compensate for insufficient InGBB. Although various factors may be involved, solid fusion with less formation of ExGBB may be achieved with refinements in biomaterials, such as the use of osteoinductive cage materials; changes in cage design, such as increasing the area of polyetheretherketone or the inside cage area for bone grafts; or surgical techniques, such as the use of plate/screw systems.
Biocompatible Materials ; Diskectomy* ; Finite Element Analysis* ; Ligaments ; Spinal Fusion ; Spine ; Transplants