Papers by Keyword: Biocompatibility

Abstract: Long surgical incisions required application of more flexible cyanoacrylate adhesive to relieve skin tension. A new formulation of octyl-2-cyanoacrylate (OCA) was modified by 0%, 3%, 6% and 9% (w/v) polytrimethylene carbonate (PTMC). The OCA/PTMC adhesives showed higher viscosity and bond strength than OCA monomer. The OCA/6% PTMC adhesive plus subcutaneous suture was used as group A (Treatment group), and the OCA/6% PTMC tissue adhesive alone was used as group B (Control group). 30 days later, there was no apparent scar formation in group A. A linear scar formation still could be seen in group B. The results supported the use of OCA/6% PTMC adhesive alone or adhesive plus subcutaneous suture in long surgical incisions, and the latter maintained better scar formation.

Abstract: This work presents a bio-degradable glass probes and its biocompatibility assessment for neural applications. The probes can be implanted into different sites of the human brain for recording and stimulating purposes. Current existing neural probe address the probe stiffness requirement for the penetration of brain tissue. However, this requirement normally resulted in the rigidity of the probe which is non-compatible with the brain tissue movement for long term implantation. The brain neuron cells will be damaged by too rigid probe substrate. In order to address this issue, bio-degradable glass probes having sufficient stiffness for a smooth brain insertion as well as ability to degrade after implantation; leaving behind the flexible circuitry substrate was being explored. The biodegradability of the proposed probe was evaluated.

Abstract: Several techniques of implant surface structuring have been used in the past to modify the surface of titanium and its alloys. We first investigated the adhesion property of human osteoblasts (MG-63) on femtosecond laser treated Ti-6Al-4V for application in dental implant. Two different kinds of surface structures were generated with varied laser fluence. (1) Laser-induced periodic surface structures (LIPSS) with a period on the sub-micron level. (2) Microscale peaks and troughs surface structures (MPTSS) with superimposed submicron and nanoscale features. According to the cell quantity and adhesion property of MG-63 on polished and structured samples, femtosecond laser treated Ti-6Al-4V with LIPSS may more suitable for applied in dental implant.

Abstract: Unsoluble composite films have been prepared by blending konjac glucomannan (KGM)/sodium hyaluronate (SH) aqueous solution with chitosan (CS) solution in acetate solution, filtering, deaerating, tape casting, drying at 55°C for 8h and crosslinking with the aid of sodium hydroxide solution for 2h. The effect of KGM content on the structure and properties of SH/CS/KGM composite films were investigated. It was indicated that the KGM can significantly improve the tensile strength (σ_b) and breaking elongation (ε_b) of the SH/CS composite films, and the tensile strength (σ_b) and breaking elongation (ε_b) increased with the increase of KGM content in composite films. It was revealed by IR and X-ray analysis that the crystallinity of composite films decreased with the increase of KGM content and the composite films was mainly amorphous. It was indicated via scanning electron microscopy (SEM) and bone marrow mesenchymal stem cell experiments that the films could support the growth of cells and were non-toxicity and good biocompatibility.

Abstract: PEEK based composites have been increasingly employed as biomaterials due to its excellent biological characteristics. In this paper, the biocompatibility, bioactivity, bio-tribology and biomechanics of PEEK composites were investigated. The results showed that PEEK possesses excellent cellular and blood compatibility. The bioactivity of PEEK could be improved by various techniques such as plasma treatment, surface grafting, surface deposition and addition of bioactive glass ceramic in the PEEK matrix. The results of bio-tribology showed that the biotribological properties of PEEK based composites could be comparable with that of traditional artificial joint materials such as UHMWPE. It is even superior to UHMWPE under certain conditions. The biomechanical properties of PEEK composites showed that they can improve the initial stability, reduce the stress shielding and improve bonding strength between bone and implant after replacement, while they are compared with traditional implants such as stainless steel, titanium alloy and Co-Cr-Mo alloy.

Abstract: Previous studies have shown that using biodegradable magnesium alloys such as Mg-Zn and Mg-Zn-Al possess the appropriate mechanical properties and biocompatibility to serve in a multitude of biological applications ranging from endovascular to orthopaedic and fixation devices. The objective of this study was to evaluate the biocompatibility of novel as-cast magnesium alloys Mg-1Zn-1Cu wt.% and Mg-1Zn-1Se wt.% as potential implantable biomedical materials, and compare their biologically effective properties to a binary Mg-Zn alloy. The cytotoxicity of these experimental alloys was evaluated using a tetrazolium based-MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay and a lactate dehydrogenase membrane integrity assay (LDH). The MTS assay was performed on extract solutions obtained from a 30-day period of alloy immersion and agitation in simulated body fluid to evaluate the major degradation products eluted from the alloy materials. Human foreskin fibroblast cell growth on the experimental magnesium alloys was evaluated for a 72 hour period, and cell death was quantified by measuring lactate dehydrogenase concentrations. Both Mg-Zn-Se and Mg-Zn-Cu alloys exhibit low cytotoxicity levels which are suitable for biomaterial applications. The Mg-Zn-Cu alloy was found to completely degrade within 72 hours, resulting in lower human foreskin fibroblast cell viability. The Mg-Zn-Se alloy was shown to be less cytotoxic than both the Mg-Zn-Cu and Mg-Zn alloys.

Abstract: To obtain optimal medical ceramic film with bioactivity, Microarc oxidized TiO2-based films containing Ca and P on titanium alloy were formed in electrolytes containing hydroxyapatite and β-tricalcium phosphate salts. After that the biocompatibility tests including invitro soaking test and invivo implant experiment were carried out, and component and phases of films were analysed by energy dispersive spectrometer and X-ray diffraction, respectively.The obtained result shows the porosity biomedical ceramic films with different proportional of Hydroxyapatite/β-tricalcium are fabricated through changing the electrolyte composions,respectively.The bioactivity of biphasic calcium phosphate is enhanced comparing to the pure HA ones.So the biphasic calcium phosphate film material can be satified with medical application.

Abstract: Nanometer titanium dioxide powders were prepared by hydrolysis of titanium-tetrabut- oxide with ethanol. Using the process that titanium alloys were embedded by the nanometer TiO₂ powders and sintered in the high temperature furnace, the nano-TiO2 / titanium alloy biomaterials was fabricated out. The particle size of TiO₂ particles on the surface of Ti alloy was mainly 50-70 nm. The experimental results indicated that the films of nanocrystalline titanium oxide powders on the surface of Ti alloy were with an excellent biocompatibility. By cultivation in the simulated body fluid for 7 days, the Ca phosphates were deposited on the specimen surface, and n (Ca) / n (P) atom ratio is about 1.61:1, which is similar to that of HA and human bone. The nano-TiO₂ / titanium alloy possessed favorable cell compatibility testified by the cell cultivation experiment.

Abstract: Magnesium alloys have a good application prospect in the fields of bone implants and cardiovascular stents due to their excellent properties, such as close density and elastic modulus to those of nature bone, high specific strength and rigidity, biodegradation and biocompatibility. In this paper, the feasibility of the use of the forged Mg-Li-X alloys (Mg-Li-Al-Zn-Ca-Sr) as biodegradable metals was investigated by immersion tests in the Hanks solution and skin-tissue implantation tests. The methods of SEM-EDS and XRD were used to research the corrosion morphology and corrosion products of the forged Mg-Li-X alloys after the in-vitro and in-vivo tests. At last, the in-vitro cytotoxicity was investigated by the MTT tests on L929 cells. Results showed that corrosion mechanism of the forged Mg-Li alloys was pitting and the surfaces were covered by Mg (OH)₂,CaCO₃ and Ca (H₂PO₄)₂ . During the 5 weeks implantation period, the rats survived from the operation, which indicates that the elements and the compounds formed are non-toxic to the rats. The forged Mg-Li alloy showed Grade 0~1 cytotoxicity, which manifests the forged Mg-Li alloy has good biocompatibility and eligible toxicity for implant applications.

Abstract: In this study, an in situ formed bulk metallic glass matrix composite (BMGMC) (Zr_58.5Ti_14.3Ni_4.9Cu_6.1Nb_5.2Be_11.0) was synthesized. Bulk metallic glass (BMG) (Zr5_2.5Cu_17.9Ni_14.6Al_10.0Ti_5.0) was also included in this work and a Ti-6Al-4V alloy was used as a reference material. Due to the glassy matrix that postpones the growth of corrosion pits, the BMGMC displays high positive corrosion potentials and low corrosion current densities. The BMGMC exhibited a higher improved corrosion resistance than the Ti alloys. Furthermore, the biocompatibility of this BMGMC was assessed by studying the cellular behavior of bone-forming mouse M3T3-E1 pre-osteoblast cells. The matrix did not significantly affect cell adhesion, proliferation and ALP activity. The general biosafety of Zr-based BMGMC for M3T3-E1 cells was revealed as normal cell responses. Zr-based BMGMC shows great potential for applications in the hard tissue implants.