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PubMed1998

Direct injection of large volumes of plasma/serum on a new biocompatible extraction column for the determination of atenolol, propranolol and ibuprofen. Mechanisms for the improvement of chromatographic performance.

Very large volumes of serum/plasma can be directly injected to a new extraction column based on particles with a biocompatible outer surface and C18 groups within the pores. The biocompatibility has been obtained by attaching the human plasma protein alpha 1-acid glycoprotein to the outer surface of the particles. The pores are small enough to exclude the plasma protein molecules. Atenolol and propranolol were extracted on the extraction column as ion-pair with octanesulfonic acid as the counterion. The same counterion was used in the analytical mobile phase. A strong improvement of the recovery can be obtained using octanesulfonic acid as counterion in the extraction mobile phase. The recovery of atenolol increased from about 53.5% to about 93.4% using octanesulfonic acid as counterion. The chromatographic performance was also strongly affected by chromatography of the basic drugs as ion-pair with octanesulfonic acid. The improvement was due to trapping in a smaller section of the extraction column and enrichment of the drug on top of the analytical column. The enrichment was due to the transfer of the analyte to the analytical column in a zone with high concentration of counterion. Furthermore, the sample zone is compressed during the migration on the analytical column. The compression effect was caused by the counterion zone, migrating in front of the sample zone, giving the analyte higher retention on the front side than on the back side of the sample zone. Displacement of protein bound drug (ibuprofen) by addition of octanoic acid, was tested in order to study the influence on the recovery and the effect on the chromatographic performance. The recovery was improved and the chromatographic performance was greatly improved. The improvement obtained on the separation efficiency of ibuprofen was due to enrichment on top of the analytical column and compression during the migration through the analytical column. The enrichment was caused by a reduction of pH in the sample--octanoic acid zone transferred from the extraction column. The octanoic acid zone migrated in front of the sample zone giving a lower pH in front of the ibuprofen zone than behind. Thus, higher retention occurred in front of than behind the sample zone, which gave rise to compression. The methods developed for atenolol, propranolol and ibuprofen could be used for the determination of serum/plasma concentrations after single doses of the drugs with very high accuracy and precision. Linear calibration graphs were obtained and the r values were > or = 0.9999.

Adrenergic beta-Antagonists↗

PubMed1996

Biocompatibility of heparin-coated extracorporeal bypass circuits: a randomized, masked clinical trial.

Cardiopulmonary bypass circuits cause morbidity during cardiac operations. Plasma proteins and cellular components are stimulated by contact with the cardiopulmonary bypass circuit and can cause bleeding and postperfusion syndrome. This is especially true in patients undergoing reoperative cardiac procedures, which carries a higher risk of postoperative bleeding and prolonged ventilation compared with primary cardiac surgical procedures. Recently, cardiopulmonary bypass circuit surfaces have been coated with antithrombotic agents to improve their biocompatibility. This study evaluated the effect of a heparin-coated cardiopulmonary bypass system (Duraflo II, Baxter Bentley Healthcare Systems, Irvine, Calif.) on thrombin formation, platelet stimulation, and leukocyte activation in patients undergoing reoperative coronary artery bypass grafting or valve operation. Fifty patients were selected and randomly assigned to a standard noncoated control system (n = 26) or the Duraflo heparin-coated system (n = 24). Similar heparin doses were used in both groups (3 mg/kg). The heparin-coated group used a completely heparin-coated bypass circuit including the cardiotomy reservoir; arterial filters were heparin-coated in both groups. Samples were obtained before cardiopulmonary bypass, 30 minutes into cardiopulmonary bypass, 5 minutes after crossclamp removal, and 5 minutes after protamine administration. Thrombin formation (thrombin-antithrombin III by enzyme-linked immunosorbent assays) and platelet activation (beta-thromboglobulin by enzyme-linked immunosorbent assays; P-selectin expression by flow cytometry) were assayed. Leukocyte activation was determined by quantitative and qualitative analysis of arterial filters by scanning electron microscopy in six patients from each group. In both circuits, thrombin values increased markedly 30 minutes into cardiopulmonary bypass compared with baseline values (p < 0.001) (heparin-coated, 7 +/- 5 to 96 +/- 115 ng/ml; noncoated, 10 +/- 9 to 115 +/- 125 ng/ml). Platelet activation as measured by beta-thromboglobulin (heparin-coated, 104 +/- 100 to 284 +/- 166 IU/ml; noncoated, 81 +/- 74 to 288 +/- 277 IU/ml) and P-selectin expression (heparin-coated, 1.5% +/- 1.5% to 6.4% +/- 6.1%; noncoated, 1.4% +/- 1.1% to 6.2% +/- 4.3%) also significantly increased 30 minutes into cardiopulmonary bypass compared with baseline values (p < 0.001). Platelet activation and thrombin generation did not differ between the two circuits at any time. Granulocyte activation and platelet deposition did not differ between the two circuits when arterial filters were evaluated. Both groups had similar heparin and protamine administration, blood transfusions, postoperative alveolar-arterial oxygen gradient, time to extubation, length of intensive care unit stay, and overall morbidity and mortality. Clinical outcome and blood loss did not differ between the groups. We conclude that heparin-coated cardiopulmonary bypass circuits did not improve biochemical or clinical markers of biocompatibility in a reoperative patient population.

Anticoagulants↗

PubMed1998

An in vitro biocompatibility evaluation of double-J stents.

OBJECTIVES: For several years, studies performed to estimate in vitro biocompatibility of urinary catheters have been carried out using permanent cell lines. However, for a rational design of the testing procedure, the cell culture model should depend on the material application. We assess the biocompatibility of 13 double-J stents using an in vitro model of normal human urothelial cells (HUC). This article aims to mimic in vitro, on HUC monolayers, the close contact existing in vivo between the urothelium and double-J stents and to evaluate the subsequent effect on these cells. METHODS: Fragments of each stent were deposited into the wells containing confluent HUC, with close contact maintained between the material and the cells. The same procedure with either no material or fragments of latex catheter was undertaken to provide the negative and positive controls, respectively. The contact was maintained for 1, 3, and 8 days. At the end of the incubation period, fragments of stent were removed and cell activity tests were performed (neutral red assay, MTT assay, and cell proliferation). RESULTS: One of the silicone stents is significantly deleterious on HUC as determined by three tests after 8 days of contact. For two copolymers, a tendency to increase cell proliferation was noted. Concerning polyurethanes, we observed significant decreases in HUC viability and cell metabolic activity for five stents after 8 days of contact. All seven polyurethane stents significantly inhibited cell proliferation. CONCLUSIONS: The HUC culture model may be of relevance for the screening of materials intended for use as double-J stents.

Biocompatible Materials↗

PubMed1997

The investigation of biocompatibility and apical microleakage of tricalcium phosphate based root canal sealers.

The biocompatibility and apical microleakage of tricalcium phosphate based Sankin Apatite (SA) Type I, II, and III root canal sealers were investigated. Teflon tubes containing freshly mixed test materials were implanted in the subcutaneous tissue of mice. The observation periods were 24 h, 7, and 30 days, after which the areas of tissue reaction to the implanted materials were histopathologically analyzed. A dye-recovery, spectrophotometric method was used to evaluate apical microleakage. Results showed that the severity of tissue reaction among the tested materials decreased with time and at the end of the observation period both SA Type II and Type III were found more biocompatible than either Type I or Grossman's cement (GC). On the other hand, a fibrous tissue capsule was seen around the implants. There was no significant difference in spectrophotometrically measured leakage among teeth obturated with the test materials.

Analysis of Variance↗

PubMed1997

Evaluation of the biocompatibility of a nonceramic hydroxyapatite.

In this study, the biocompatibility of calcium phosphate cement (CPC) was systematically investigated, which included systemic injection acute toxicity assay, cell culture cytotoxicity assay, gene mutation assay (Ames test), chromosome aberration assay (micronucleus test), DNA damage assay (unscheduled DNA synthesis test) and implant histological evaluation. The results showed that the CPC had no toxicity and all tests for mutagenicity and potential carcinogenicity of CPC extracts are negative. CPC was implanted into the femurs of rabbits under no-load condition and the histology of specimens revealed that the implant tightly joined with the surrounding bone, only a very slight histological inflammatory reaction occurred. Thus, CPC is a highly biocompatible material and seems to be safe for application in humans.

Animals↗

PubMed1997

Comparison of the intraosseous biocompatibility of Dyract and Super EBA.

The purpose of this study was to compare the intraosseous biocompatibility of Dyract, a new hydrophilic glass-ionomer cement, to that of Super EBA. Twenty-four New Zealand rabbits were anesthetized, one leg was shaved, the femur exposed, and two holes were drilled through the cortical plate. The materials were loaded into silicone carriers and inserted into the femur. Half of the rabbits were killed 4 weeks after implantation and the other half at 12 weeks and the femurs were prepared using standard histological procedures. The tissue reactions were graded from none to severe. At 4 weeks both materials showed slight to moderate reactions, characterized by the presence of fibrous tissue interposition and inflammatory cells. At 12 weeks, bone healing had occurred, despite the persistence of some fibrous tissue interposition, and the reactions were classified as slight. At both observation periods, statistical analysis failed to show any difference between the two materials indicating that Dyract and Super EBA had similar intraosseous biocompatibility.

Animals↗

PubMed1998

Biocompatibility of two apatite cements.

Biocompatibility and osteogenic potential of two calcium phosphate cements (G-5 and G-6) and Super-EBA were investigated by subcutaneous and intraosseous implantation in 90 rats. Reactions were studied microscopically at 15, 30, and 60 days after implantation. Super-EBA was well tolerated by both soft and hard tissues. G-5 was highly biocompatible with resorption and bone replacement at intraosseous implantation sites. G-6 promoted moderate inflammation and a foreign body giant cell response over the 60-day study period. None of the materials elicited osteogenesis or dystrophic calcification at the subcutaneous implantation sites.

Animals↗

PubMed2001

Corrosion and biocompatibility testing of palladium alloy castings.

OBJECTIVE: The biocompatibility of palladium-copper alloys has been questioned in the literature. The intention of the present work was to study: (a) the release of ions in an immersion test from a copper-containing alloy, Option((R)) (79% Pd, 10% Cu, 9% Ga, 2% Au), compared with an alloy without Cu, IS85 (82% Pd, 6% Ga, 3.5% Sn, 3.5% In, 2.5% Ag, 2.5% Au); (b) the effect of oxide films produced by preoxidation on corrosion resistance; and (c) the possibility of biologically synergetic effects of ions released. METHODS: Specimens of both alloys were cast, rubbed and ultrasonically cleaned. Metallographic specimens were prepared after (a) casting and (b) preoxidizing treatment at approximately 1000 degrees C and studied by SEM and EDS. Immersion tests were carried out in a solution of 0.1mol/l of NaCl and 0.1mol/l of lactic acid at 37 degrees C for 7 days. The alloy specimens were tested in the following three steps: (1) as preoxidized; (2) after subsequent removal of a 0.1mm thick layer by grinding; and (3) after an additional removal of approximately 0.1mm by grinding. The test solutions were analyzed by means of ICP to record the amounts of ions that had leached out from the alloy specimens. The biocompatibility was studied by cell culture tests and the HET-CAM method. Test solutions were prepared by dissolving PdCl(2) and CuCl(2) to appropriate concentrations. RESULTS: The metallographic investigations revealed moderate segregations in interdendritic regions and grain boundaries. After preoxidation in air a zone of oxidation from 25 up to 200 microm thickness for Option and from 5 to 10 microm for IS85 was found. Oxidation was observed along a rim for both alloys and for Option also along interdendritic positions. The oxides were seen as small, dark spots <1 microm in a metallic matrix. These results indicate that: (1) the oxidation of the copper-containing palladium alloy is far more severe than that of the alloy with no copper; and (2) the elemental release from these oxides is substantially larger than that from the corrosion of the metallic structure. The results of the cell culture testing showed that Cu was most toxic, followed by Cu(2+)+Pd(2+) (1:2), based on the determination of the concentration that caused 50% cytotoxicity. The HET-CAM testing showed Cu(2+)+Pd(2+) (1:2) to have the highest irritation score. SIGNIFICANCE: The copper-containing Pd alloy developed a 0.1mm thick rim with small oxide particles in a metallic matrix during preoxidation. If this rim is not completely removed, significantly more Cu, Ga and Pd ions have been shown to leach into the test solution than from the alloy structure. No synergetic effect of Cu and Pd ions was observed in cultured cells, while the mixture Pd(2+)+Cu(2+) (1:2) was most irritating to mucous membrane as evaluated by the HET-CAM method.

Animals↗

PubMed2002

In vitro biocompatibility of oxirane/polyol dental composites with promising physical properties.

OBJECTIVES: Visible light cure oxirane/polyol resins of Cyracure UVR-6105 with pTHF-250 has been previously shown useful for development of dental composites. This oxirane/polyol (4016) in combination with other oxiranes were formulated into composites (4016E, 4016G and 4016GB) containing 72.9-74.9% quartz filler. The main objective of the study was to evaluate some of the physical properties and the biocompatibility of the composites. RESULTS: PhotoDSC analysis of composites demonstrated twice the enthalphy values of Z100 (31J/g). Composites 4016E and 4016G showed compressive strengths similar to Z100 (337+/-35Mpa), P>0.05. Discs of composite 4016E, containing Epon 825 oxirane (E), and composite 4016G containing Araldite GY 281 oxirane (G) were non-cytotoxic (-) while the composite 4016GB, containing G and Ebecryl 1830 (B), was mildly (+) cytotoxic to L929 cells in the agar diffusion assay. Seven-day extracts of 4016GB composite were cytotoxic while extracts of 4016E and 4016G were less cytotoxic to L929 cells in the MTT assay. Extracts were obtained from 7 day incubations of composite (3 cm(2) surface area/ml) in acetone or ethanol/saline (1:20) at 37 degrees C. All composite extracts were non-mutagenic to Ames strains TA100, TA98, TA97a and TA1535. The overall results with composite 4016GB suggest that leachable components were cytotoxic but non-mutagenic. With the exception of oxirane components, G and E, the oxirane Cyracure UVR-6105 and other components were non-mutagenic. From cytotoxicity studies, the photoinitiator, Sarcat CD 1012, was the most cytotoxic (TC(50)=14 microM) component. Components G (TC(50)=17 microM), E (TC(50)=50 microM) and B (TC(50)=151 microM) were significantly (p < 0.05) more cytotoxic than Cyracure UVR-6105 (1488 microM) and the polyol, pTHF-250 (TC(50)=6072 microM). SIGNIFICANCE: Favorable results obtained with composites 4016G and 4016E indicates that suitable oxirane/polyol formulations can be designed and optimized for development of dental composites with acceptable mechanical properties and biocompatibility. However, leachable analysis of extracts obtained from longer incubation periods is needed before final conclusions could be drawn about the leachability of oxirane components.

Animals↗

PubMed1999

Evaluations of metabolic activities as biocompatibility tools: a study of individual ions' effects on fibroblasts.

OBJECTIVES: Nickel-based dental alloys have been in use since 1930. However, there are concerns regarding the release of metal ions from these alloys to surrounding tissues. Cell culture evaluations can be used to address these concerns and to develop a biocompatibility model by providing a more basic understanding of the metabolic response to individual ions released from dental alloys. This study evaluates the metabolic as well as the morphological response of cultured human gingival fibroblasts to salt solutions of ions which may be released from these alloys; beryllium (Be2+), chromium (Cr6+ and Cr3+), nickel (Ni2+), molybdenum (Mo6+). METHODS: These evaluations include viability, lysosomal activity, oxygen consumption, membrane integrity, DNA synthesis, RNA synthesis, protein synthesis, intracellular ATP levels, and glucose-6-phosphate dehydrogenase activity. The results of all cell culture evaluations are reported as the concentration (ppm) required to cause a significant change from the controls, as determined by Duncan's multiple comparison test at 0.05 significance level. RESULTS: While Ni2+ ion solutions altered metabolic functions at 3-30 ppm and Cr3+ and Mo6+ both at 10 and 100 ppm, Cr6+ and Be2+ were the most toxic causing cellular alterations at 0.04-12 ppm. SIGNIFICANCE: These studies indicated that monitoring metabolic activities may be better than the normally used morphology and viability assays for evaluating biocompatibility.

Beryllium↗

PubMed2001

Biocompatibility and biodegradation of intravitreal hyaluronan implants in rabbits.

To study the biocompatibility and the biodegradation rate in vivo of new intravitreal implants made with three different hyaluronic acid esters: Hyaff7, Hyaff11 and Hyaff11p75 (100% ethyl ester, 100 and 75% benzyl esters, respectively), the plugs were implanted through a sclerotomy at 3.5 mm from the limbus of rabbit eyes. In order to evaluate the in vivo biodegradation the shaft diameter of the plugs was measured by ultrasound biomicroscopy. Slit lamp microscopy, ophthalmoscopy and ERG were performed periodically. The effects of the implants on ocular tissues were also evaluated histologically. All the plugs showed a good biocompatibilitv. Plugs of both the total esters, Hyaff7 and Hyaff11, were found to undergo a slow dissolution process for 60 and 150 days, respectively. The partial benzyl ester, Hyaff11p75, was completely reabsorbed after 15 days. Analysis of variance showed a high correlation between biodegradation rate and the time of resorption (F = 90.5; p < 0.001). The biodegradation rate of each implant is related to the chemical structure of the three types of Hyaff (F = 4.51; p = 0.005). The present data suggest that intravitreal implants based on hyaluronic acid esters represent useful biocompatible and biodegradable devices for a potential drug delivery system in the treatment of posterior segment ocular diseases.

Animals↗

PubMed2001

Biocompatibility and osteogenesis of refractory metal implants, titanium, hafnium, niobium, tantalum and rhenium.

To evaluate the biocompatibility of refractory metals, titanium, hafnium, niobium, tantalum and rhenium were implanted in rats, and histological observation and elemental mapping were performed by X-ray scanning analytical microscope (XSAM) and electron probe microanalyzer (EPMA). The titanium, hafnium, niobium, tantalum and rhenium wires were implanted in the subcutaneous tissue of the abdominal region and in femoral bone marrow of rats for either 2 or 4 weeks. No inflammatory response was observed around the implants, and all the implants were encapsulated with thin fibrous connective tissue. No dissolution of these metals was detected by XSAM in the soft tissue. Histological examination of the hard tissue showed that the amount of new bone formation decreased slightly from the second to the fourth week after implantation, and that the percentage of bone in contact with the implant increased markedly over the same period. No dissolution of these metals was detected by EPMA in the hard tissue. The Ca and P intensities in the mapping images of newly formed bone were higher after 4 weeks than those after 2 weeks, which suggests that the newly formed bone continued to mature from 2 to 4 weeks after implantation. These results indicate that titanium, hafnium, niobium, tantalum and rhenium have good biocompatibility and osteoconductivity.

Animals↗

PubMed2001

Studies on the effect of surface properties on the biocompatibility of polyurethane membranes.

To study the effect of surface properties on the biocompatibility of biomaterials based on the same material, polyurethane membranes with different surface properties were prepared. Myoblast culture and interleukin-1 (IL-1) generation in an air pouch model and in vitro monocyte culture were used to examine biocompatibility of different polyurethane membranes. Polyurethane membranes were found to exhibit significant differences depending on their surface properties prepared by different fabrication processes. When myoblasts were cultured on polyurethane surfaces, the smooth and hydrophobic membrane (F1), prepared by the solvent evaporation process, showed the greatest inhibition of myoblast adhesion compared with other porous and hydrophilic membranes (F2, F3 and F4), prepared by immersing the polymer solution into a precipitation bath. In contrast, IL-1 generation by monocytes/macrophages on the membrane F1 was more severe than those on the porous and hydrophilic membranes. Based on our results, the interaction of biomaterials with various cells is discussed.

Adult↗

PubMed2001

Effect of calcium-ion implantation on the corrosion resistance and biocompatibility of titanium.

This work presents data on the structure and corrosion resistance of titanium after calcium-ion implantation with a dose of 10(17) Ca+/cm2. The ion energy was 25 keV. Transmission electron microscopy was used to investigate the microstructure of the implanted layer. The chemical composition of the surface layer was examined by XPS and SIMS. The corrosion resistance was examined by electrochemical methods in a simulated body fluid (SBF) at a temperature of 37 degrees C. Biocompatibility tests in vitro were performed in a culture of human derived bone cells (HDBC) in direct contact with the materials tested. Both, the viability of the cells determined by an XTT assay and activity of the cells evaluated by alkaline phosphatase activity measurements in contact with implanted and non-implanted titanium samples were detected. The morphology of the cells spread on the surface of the materials examined was also observed. The results confirmed the biocompatibility of both calcium-ion-implanted and non-implanted titanium under the conditions of the experiment. As shown by TEM results, the surface layer formed during calcium-ion implantation was amorphous. The results of electrochemical examinations indicate that calcium-ion implantation increases the corrosion resistance, but only under stationary conditions; during anodic polarization the calcium-ion-implanted samples undergo pitting corrosion. The breakdown potential is high (2.7-3 V).

Alkaline Phosphatase↗

PubMed2002

Biocompatibility of anionic collagen matrix as scaffold for bone healing.

The basic approach to the treatment of bone defects involves the use of scaffolds to favor tissue growth. Although several bioscaffolds have been proposed for this purpose, the search for new and enhanced materials continues in an attempt to address the drawbacks of the present ones. Modifying current materials can be a fast and cheap way to develop new ones. Among them, type I collagen allows its structure to be modified using relatively simple techniques. By means of an alkaline treatment, anionic collagen with enhanced piezoelectric properties can be obtained through hydrolysis of carboxyamides groups of asparagine and glutamine residues from collagen in carboxylic. The process applied to a raw source of collagen, bovine pericardium, provided a sponge-like structure, with heterogeneous pore size, and, moreover, the complete removal of interstitial cells. For the evaluation of the biocompatibility of such matrices, they were implanted in surgically created bone defects in rat tibias. Empty defects served as controls. This experimental model allowed a preliminary evaluation of the osteoconductiveness of the matrices. The histological results presented a low inflammatory response and bone formation within a short period of time, similar to that of controls. The low cost of production associated to the biocompatibility and osteoconductivity performance make the anionic collagen matrices promising alternatives for bone defects treatment.

Animals↗

PubMed2002

Effect of biologically active coating on biocompatibility of Nitinol devices designed for the closure of intra-atrial communications.

Anti-thrombogenicity and rapid endothelialisation are prerequisites for the use of closure devices of intra-atrial communications in order to reduce the risk of cerebral embolism. The purpose of this study was therefore to assess the effect of bioactive coatings on biocompatibility of Nitinol coils designed for the closure of intra-atrial communications. Nitinol coils (n = 10, each) and flat Nitinol bands (n = 3, each) were treated by basic coating with poly(amino-p-xylylene-co-p-xylylene) and then coated with either heparin, r-hirudin or fibronectin. Anti-thrombogenicity was studied in vitro in a dynamic model with whole blood by partial thromboplastin time (PTT), platelet binding and thrombin generation, respectively, and cytotoxicity by hemolysis. Endothelialisation was studied on Nitinol bands with human umbilical venous endothelial cells (HUVEC) by 3-(4,5-dimethylthiazole-2yl)-2,5-triphenyl tetrazolium (MTT) assay and immnuofluorescence analysis of Ki67, vinculin, fibronectin and von Willebrand Factor. Uncoated or coated devices did not influence hemolysis and PTT. r-Hirudin (but not heparin) and fibronectin coating showed lower platelet binding than uncoated Nitinol (p < 0.005, respectively). Heparin and r-hirudin coating reduced thrombin formation (p < 0.05 versus Nitinol, respectively). HUVEC adhesion, proliferation, and matrix formation decreased in the order: fibronectin coating > uncoated Nitinol > r-hirudin coating > heparin coating > basic coating. MTT assay corroborated these findings. In conclusion, r-hirudin and fibronectin coating, by causing no acute cytotoxicity, decreasing thrombogenicity and increasing endothelialisation improve in vitro biocompatibility of Nitinol devices designed for the closure of intra-atrial communications.

Alloys↗

PubMed2002

Evaluation of the TiMo12Zr6Fe2 alloy for orthopaedic implants: in vitro biocompatibility study by using primary human fibroblasts and osteoblasts.

To reveal the biocompatibility of TiMo12Zr6Fe2 (TMZF), a new titanium alloy used since 1998 for orthopaedic prosthesis, we compared the behavior of primary human fibroblasts and osteoblasts grown on TMZF discs or on plastic tissue culture dishes, a widely used material specifically treated by the manufacturer to enhance cell growth. Proliferation, differentiation. RNA and collagen type I expression level of human cells were carried out. The analysis were performed over a period of 96 h. Fibroblasts behaved at the same way on the two different supports after 48 h, their number increased after 96 h when cells were grown on the alloy. Osteoblasts adhered and proliferated on the alloy discs as well as on plastic. RNA expression level was not affected. Interestingly, cell number at each time point was higher for fibroblasts than for osteoblasts. The RNA expression level was higher for the osteoblasts. Both cell types cultured on the alloy revealed an increase in the amount of type I collagen and a similar electrophoretic pattern was found for collagen produced by fibroblasts and osteoblasts grown on either supports. These results indicate good biocompatibility of the TMZF alloy, which allowed adhesion and proliferation of both the examined cell types and suggest that TMZF is a promising material for orthopaedic implants.

Alloys↗

PubMed2002

On the properties of two binary NiTi shape memory alloys. Effects of surface finish on the corrosion behaviour and in vitro biocompatibility.

The present paper compares the transformation behaviour and mechanical properties of two orthodontic wires of close chemical compositions. The effects of surface topography and surface finish residues on the potentiodynamic corrosion behaviour and biocompatibility are also reported. The cytotoxicity tests were performed on both alloys in fibroblast cell cultures from human gingiva using the MTT test. It is shown that the surface finish and the amounts of surface finish residues affect dramatically the corrosion resistance. Bad surface finish results in lower corrosion resistance. The in vitro biocompatibility, though not affected to the extent of corrosion resistance, is also reduced as the surface roughness and the amounts of residues increase. This is thought to be due to surface effects on corrosion and metallic ions release.

Alloys↗