The dissolution of nickel from nitinol alloy under different extraction conditions was investigated when biological tests of nitinol medical devices were carried out. It discussed the equivalence of these extraction conditions and found the best extraction conditions. In the experiment, two brands of nitinol were chosen and extracted under different extraction conditions according to GB/T 16886-12. Plasma emission spectrometer was used to analyse the concentration of nickel in extract liquid. The results show that there is no equivalence among these extraction conditions for nitinol materials. And it is suggested that (37 +/- 1) degree C, (72 +/- 2) h could be used as normal extraction condition and (70 +/- 2) degrees C, (24 +/- 2) h as accelerated extraction condition.
Alloys ; chemistry ; Biocompatible Materials ; Materials Testing ; Nickel ; chemistry ; Temperature ; Titanium

Recently, drug delivery materials have become the hotspot of medical study. Suitable delivery material plays an important role in constructing an excellent drug delivery system. Silk fibroin is a naturally occurring protein polymer with excellent biocompatibility, remarkable mechanical properties, biodegradability and outstanding processability. Due to its unique properties, silk fibroin has become a favorable carrier material for the incorporation and delivery of a range of therapeutic agents. Based on the structure and characteristics of silk fibroin, this article provides an overview of the recent research progress of silk fibroin used as drug delivery materials.
Biocompatible Materials ; Drug Delivery Systems ; Fibroins ; chemistry

As an important auxiliary material, adhesive materials have many important applications in various fields including but not limited to industrial packaging, marine engineering, and biomedicine. Naturally occurring adhesives such as mussel foot proteins are usually biocompatible and biodegradable, but their limited sources and poor mechanical properties in physiological conditions have limited their widespread uses in biomedical field. Inspired by the underwater adhesion phenomenon of natural organisms, a series of biomimetic adhesive materials have been developed through chemical or bioengineering approaches. Notably, some of those synthetic adhesives have exhibited great promise for medical applications in terms of their biocompatibility, biodegradability, strong tissue adhesion and many other attractive functional properties. As natural adhesive materials possess distinctive "living" attributes such as environmental responsiveness, self-regeneration and autonomous repairs, the development of various biologically inspired and biomimetic adhesive materials using natural adhesives as blueprints will thus be of keen and continuous interest in the future. The emerging field of synthetic biology will likely provide new opportunities to design living glues that recapitulate the dynamic features of those naturally occurring adhesives.
Adhesives ; Animals ; Biocompatible Materials ; Biomimetic Materials ; chemistry ; Biomimetics ; Bivalvia

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.

BACKGROUNDIn order to bind or fix bioactive materials directly to the surface of a Ti implant, the prior binding process of functional groups (FGs, -COOH and -OH) to the implant surface is necessary. Conventional binding processes are so high-cost and complex, so it is essential to find a simple and effective procedure for Ti-FG binding.

METHODSVarious electrolyte compositions and electrochemical processing were adopted in this study to develop a relatively simple and effective Ti-FG binding process. The ability of Ti-FG binding and calcium (Ca)/phosphorous (P) absorption and corrosion resistance were evaluated according to various titanium surface treatment in electrolyte involving -COOH and -OH ion by using X ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FE-SEM) and potentiodynamic scan method respectively.

RESULTSIn cases of -COOH, the anodic oxidation process (AN) showed an effective binding ability between -COOH and Ti surface. On the other hand, in cases of -OH, there were no significant differences in the result between the conditions used. In regard to the absorption of Ca and P on Ti surface, there was a minimal amount of Ca absorbed but no P was absorbed. The anodic oxidation series showed homogenous corrosion, whereas the electrolyte immersion (EL) series showed unstable corrosion. Although EL-OH showed a novel corrosion potential, the EL-COOH series showed good corrosion resistance over the anodic potential range.

CONCLUSIONSThe ability of binding between FG and the Ti surface and Ca/P absorption were strongly associated with the surface potential (ζ potential), which was dependent on the pH of the electrolyte. Accordingly, in order to achieve the effective absorption of various FGs on the Ti surface, it is needed to develop the combination process in addition to the electric affinity, relation with the ζ potential.

As a new type of functional material, magnetic thermosensitive polymeric microspheres offer high potential application in various fields, particularly in bioengineering and biomedical fields. In this review, the development of synthesis and application of magnetic thermosensitive polymeric microspheres was summarized, and the research trends were also discussed.
Biocompatible Materials ; chemistry ; Magnetics ; Microspheres ; Particle Size ; Polymers ; chemistry ; Temperature

The technology of synthesis, extraction and modification of biodegradable polyhydroxybutyrate (PHB) is introduced briefly in this article. It is also summarized that the research progress in application of PHB in drug delivery and tissue engineering.
Biocompatible Materials ; chemistry ; Drug Delivery Systems ; Hydroxybutyrates ; chemistry ; Tissue Engineering

The aim of the present study was to detect the transmission rate of ultrasonic low intensity pulsed ultrasound (LIPUS) through polytetrafluoroethylene (PTFE) membrane (Thickness: 0.01 mm) and Bio-Gide collagen membrane, and to provide the basis for the barrier membrane selection on the study of LIPUS combined with guided tissue regeneration (GTR). The ultrasonic (LIPUS, frequency 1.5 MHz, pulse width 200 micros, repetition rate 1.0 kHz) transmission coefficient of the two kinds of barrier membrane were detected respectively through setting ten groups from 10 to 100mW/cm2 every other 10 mW/cm2. We found in the study that the ultrasonic transmission coefficient through 0.01 mm PTFE membrane was 78.1% to 92.%, and the ultrasonic transmission coefficient through Bio-Gide collagen membrane was 43.9% to 55.8%. The ultrasonic transmission coefficient through PTFE membrane was obviously higher than that through Bio-Gide collagen membrane. The transmission coefficient of the same barrier membrane of the ultrasonic ion was statistically different under different powers (P < 0.05). The results showed that the ultrasonic transmittance rates through both the 0.01 mm PTFE membrane and Bio-Gide collagen membrane were relatively high. We should select barrier membranes based on different experimental needs, and exercise ultrasonic transmission coefficient experiments to ensure effective power.
Biocompatible Materials ; Collagen ; chemistry ; Membranes, Artificial ; Permeability ; Polytetrafluoroethylene ; chemistry ; Ultrasonics

This paper reviews the progress in biochemical design and modification for the surfaces of titanium implants in recent years, the emphasis being laid on the introduction of the surface molecular construction, self-assembly technique and its application in biomedical materials.
Biocompatible Materials ; chemistry ; Prostheses and Implants ; Surface Properties ; Titanium ; chemistry

The corrosion rates of TiNi, CoCrNiW and CoCrNiMo were measured in Tyrode's solution with potentiodynamic linear polarization, fore-point weak polarization, Cao Chunan weak polarization, transient linear polarization and atomic absorption spectroscopy. Results indicated that corrosion rates of these three alloys were very low due to their excellent corrosion resistance and the corrosion resistance of CoCrNiMo was the best. Corrosion rates of TiNi, CoCrNiW and CoCrNiMo were 0.691, 0.0595, 0.0490 micron/a and 0.0528, 0.0383, 0.0387 micron/a, respectively. The results measured by the first three methods were about ten times of those by the latter two methods, this was related to the applicability of each method and the alloy surface state. Transient linear polarization technique can determine low corrosion rate conveniently and quickly. Atomic absorption spectroscopy method, determining directly the concentration of ion in solution, and thus provide reference for material biocompatibility. And these two methods are properly used in measuring corrosion rates for biomedical materials.
Biocompatible Materials ; chemistry ; Cobalt ; chemistry ; Corrosion ; Materials Testing ; methods ; Nickel ; chemistry ; Spectrophotometry, Atomic ; Titanium ; chemistry