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The influence of lithium fluoride on in vitro biocompatibility and bioactivity of calcium aluminate-pMMA composite cement.

The objective of this study is to assess the influence of lithium fluoride on in vitro biocompatibility and bioactivity of calcium aluminate (CA)-polymethylmethacrylate (PMMA) composite cement exhibiting quick setting time ( < 15 min), low exothermic temperature (< 47 degrees C), and high compressive strength (> 100 MPa). The biocompatibility was measured by examining cytotoxicity tests such as the agar diffusion test with L929 cell line and the hemolysis test with fresh rabbit blood. To estimate the bioactivity of CA-PMMA composite cement, we determined hydroxyapatite (HAp) formation on the surface of composite cement in the simulated body (SBF) solution by using thin-film XRD, XPS, SEM, EPMA and ICP-AES. The results of biocompatibility tests indicated that all experimental compositions of this study had no cytotoxicity and no hemolysis so that there was no cytotoxicity with regard to non-reacted monomers (MMA and TEGDMA) and lithium fluoride. The results of bioactivity tests revealed that CA-PMMA composite cement without lithium fluoride did not form HAp on its surface after 60 days of soaking in the SBF. On the other hand, LiAl2(OH)7 . 2H2O and HAp were formed on the surface of CA-PMMA composite cement including 1.0% by weight of lithium fluoride after 7 and 15 days of soaking in the SBF, respectively. The 5 microm of LiAl2(OH)7 . 2H2O and HAp mixed layers were formed on the surface of specimen after 60 days of soaking in the SBF.

Acrylic Resins↗

Biocompatibility of an electrochemical sensor for continuous glucose monitoring in subcutaneous tissue.

BACKGROUND: The continuous monitoring of glucose allows for tighter control of the glucose concentration and thus may prevent hyper- and hypoglycemia as well as long-term complications of diabetes. While most current systems depend on the transport of fluid to a glucose sensor outside the body, we investigate the possibility of implanting a reagent-based sensor directly into the skin. In this manuscript, the biocompatibility of an electrochemical sensor for continuous glucose monitoring was assessed in vitro and in vivo. METHODS: Cytotoxicity was investigated in vitro using agar diffusion testing. In vivo biocompatibility was assessed by means of histomorphological examination of the surrounding tissue 10 days after sensor implantation in rats. RESULTS: The grade of cytotoxicity of the individual sensor components in vitro was between none and mild based on agar diffusion testing. The complete sensor also showed no cytotoxic effects when coated with the co-polymer MPC (2-methacryloyloxyethyl phosphorylcholine, Lipidure CM 5206, NOF Corp., Tokyo, Japan) and when assessed under working conditions, i.e., when a bias voltage was applied to the sensor. Additionally, the hydrogen peroxide-which is inherently generated by the enzymatic glucose detection process using glucose oxidase (GOD)-is likely to have been sufficiently decomposed under these working conditions. Finally, no toxic leachable substances were found during the cytotoxicity testing of sensors and its extracts in vitro. In the in vivo experiments, the strongest foreign body reaction (FBR) was found near the GOD-electrode using a sensor without MPC coating and without a porous membrane. Covering the sensor with MPC, a porous membrane, or both led to a gradual decrease of the FBR down to the level of the negative control. CONCLUSIONS: The electrochemical, reagent-based sensor with MPC coating and/or a porous membrane is suitable for continuous monitoring of glucose from a biocompatibility standpoint.

Animals↗

Biocompatibility of an enzyme-based, electrochemical glucose sensor for short-term implantation in the subcutis.

BACKGROUND: Continuous glucose measurements provide improved glycemic control and may prevent hypoglycemia and long-term complications of diabetes. One of the most promising techniques is the short-term implantation of electrochemical glucose sensors in subcutis. However, the inflammatory reaction to these sensors may lead to bioinstability of sensor measurements. The purpose of the present investigation was to examine factors contributing to the observed subcutaneous inflammatory reaction to an enzyme-based electrochemical glucose sensor for continuous glucose measurements. The sensor biocompatibility was assessed in vitro and in vivo. METHODS: A toxicological assessment was performed on sensor materials and leachables, and the endotoxin content of sensors was determined by a Limulus amoebocyte lysate (LAL) test. Moreover, as a consequence of permanent penetration of the skin by the sensor the role of bacterial migration to the tissue was investigated. In vivo biocompatibility was investigated through histological examination of implanted sensor membranes for 3 days in pigs. Additionally, the effect of needle size and type (normal vs. inserter needle) on tissue trauma at sensor insertion was evaluated, and the healing of subcutis was assessed histologically from 3 to 14 days after removal of sensors. RESULTS: The toxicological assessment and the LAL test showed no concerns in a 3-day implantation scenario, and bacterial migration to the subcutis could not be detected. The histological examination showed that a reduction in needle size reduced the extent of inflammation to very low levels, and that the different sensor membranes showed similar extent and type of inflammation. Additionally, the extent of subcutaneous tissue reaction after removal of sensors declined gradually over time and returned to near-normal levels after 2 weeks. CONCLUSION: The electrochemical enzyme-based glucose sensor for continuous glucose measurements in subcutis is acceptable from a biocompatibility point of view. Reducing the inserter needle in size reduces the trauma induced at sensor implantation to neglible levels. Furthermore, the tissue reaction to the sensor returns to near-normal 2 weeks after the sensor has been removed following a 3-day implantation period.

Animals↗

Nanostructured surface modification of ceramic-based microelectrodes to enhance biocompatibility for a direct brain-machine interface.

Many different types of microelectrodes have been developed for use as a direct Brain-Machine Interface (BMI) to chronically recording single neuron action potentials from ensembles of neurons. Unfortunately, the recordings from these microelectrode devices are not consistent and often last for only a few weeks. For most microelectrode types, the loss of these recordings is not due to failure of the electrodes but most likely due to damage to surrounding tissue that results in the formation of nonconductive glial-scar. Since the extracellular matrix consists of nanostructured microtubules, we have postulated that neurons may prefer a more complex surface structure than the smooth surface typical of thin-film microelectrodes. We, therefore, investigated the suitability of a nano-porous silicon surface layer to increase the biocompatibility of our thin film ceramic-insulated multisite electrodes. In-vitro testing demonstrated, for the first time, decreased adhesion of astrocytes and increased extension of neurites from pheochromocytoma cells on porous silicon surfaces compared to smooth silicon sufaces. Moreover, nano-porous surfaces were more biocompatible than macroporous surfaces. Collectively, these results support our hypothesis that nano-porous silicon may be an ideal material to improve biocompatibility of chronically implanted microelectrodes. We next developed a method to apply nano-porous surfaces to ceramic insulated, thin-film, microelectrodes and tested them in vivo. Chronic testing demonstrated that the nano-porous surface modification did not alter the electrical properties of the recording sites and did not interfere with proper functioning of the microelectrodes in vivo.

Action Potentials↗

Biocompatibility parameters of different dialysis membranes assessed during systemic inflammation.

BACKGROUND: We explored whether biocompatible dialyzer membranes modulate the inflammatory response during blood contact in patients with systemic inflammation. METHODS: 15 patients with end-stage renal disease and systemic inflammation (mean serum C-reactive protein 86 +/- 4 mg/l) were randomly treated with Cuprophan (CU), polyamide (PA) and vitamin-E coated (VEC) membrane-based dialyzers. RESULTS: Changes in blood pressure, capillary blood oxygen saturation and differential blood counts during the hemodialysis session were not significantly different between the three dialyzers. Baseline blood levels of activated circulating complement (C3a) were more than 100 times above normal, and unlike expected they decreased during hemodialysis treatments (CU: from 7,389 +/- 783 to 5,423 +/- 761 ng/ml; PA: from 7,379 +/- 980 to 5,690 +/- 714 ng/ml; VEC: from 7.377 +/- 714 to 5,360 +/- 1,005 ng/ml; all n.s.). No significant differences between treatments were found with respect to changes in blood concentrations of TNF-alpha, interleukin-6 and interleukin-1 receptor antagonist as well as ICAM-1 (CU: from 451 +/- 41 to 477 +/- 41 ng/ml; PA: from 437 +/- 42 to 449 +/- 40 ng/ml; VEC: from 461 +/- 43 to 460 +/- 47 ng/ml). Furthermore, generation of reactive oxygen species by mononuclear blood cells was comparable during hemodialysis with the CU, PA and VEC dialyzer. CONCLUSION: The choice of dialyzer membrane material does not affect most aspects of biocompatibility when patients have significant systemic inflammation. This confounding variable should be taken into account in studies exploring the effects of biocompatible dialyzer membranes.

Female↗

Biocompatibility of a 1.1% amino acid-containing peritoneal dialysis fluid compared to a 2.27% glucose-based peritoneal dialysis fluid.

The biocompatibility of a 1.1% amino acid-containing peritoneal dialysis fluid (AA-PDF) was compared to that of a 2.27% glucose-based peritoneal dialysis fluid (G-PDF). Peritoneal macrophages (PMO), isolated from the peritoneal dialysis (PD) effluents of 10 chronic ambulatory PD patients, were tested for their phagocytosis capacity and peak chemiluminescence response. A subset of PMO was cultured for 24 h with and without lipopolysaccharide (LPS) to study the release of interleukin-1 beta (IL-1 beta) and 8 (IL-8). As control, the interleukin release by blood monocytes of healthy donors was tested. The opsonic activity of the PD effluent was tested as well. Compared to PMO isolated from G-PDF, PMO from AA-PDF showed a significantly better phagocytosis capacity. There was no difference in the peak chemiluminescence response between PMO from AA-PDF and G-PDF. The release of IL-1 beta by unstimulated PMO isolated from the two fluids did not differ. Compared to control monocytes, however, PMO from both fluids showed a considerable spontaneous release of IL-1 beta. When stimulated with LPS, IL-1 beta production by PMO from G-PDF exceeded that of PMO from AA-PDF (p < 0.002). The release of IL-8 by PMO from G-PDF was significantly higher in comparison with PMO from AA-PDF, both spontaneously and after stimulation with LPS (p < 0.02). The opsonic activity of undiluted and to 75% diluted effluents was significantly higher for G-PDF than for AA-PDF (p < 0.01). Thus, compared to the regularly used G-PDF, the phagocytosis capacity as measure for PMO function seems to be better preserved after in vivo exposure to AA-PDF. In addition, the higher release of IL-1 beta and IL-8 by PMO isolated from G-PDF suggests a stronger intra-abdominal activation of PMO, with G-PDF acting as a chemical inflammatory agent. Whether the lower opsonic activity of the AA-PDF is more important for biocompatibility than the other parameters is not clear. Therefore, it is concluded that, although macrophage function is better preserved, it is not proven that the 1.1% AA-PDF studied has an improved biocompatibility compared to 2.27% G-PDF.

Adult↗

[Rapid analysis of biocompatibility with graded test samples exemplified by Ni-NiTi-Ti].

The biocompatibility of nickel-titanium alloys was investigated by single-culture experiments on functionally graded samples with a stepwise change in composition from nickel to titanium, including NiTi shape memory alloy of a 50:50 mixture. This approach permitted a considerable decrease of experimental resources by simultaneously studying a full variation of composition. The results indicate a good biocompatibility for a nickel content up to about 50%. The cells used in the biocompatibility studies comprised human osteoblast-like osteosarcoma cells (SAOS-2, MG-63), primary human osteoblasts (HOB), and murine fibroblasts (3T3).

Animals↗

Influence of an erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser on the reestablishment of the biocompatibility of contaminated titanium implant surfaces.

BACKGROUND: The aim of the present study was to evaluate the influence of an erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG laser [ERCL]) on 1) the surface structure and biocompatibility of titanium implants and 2) the removal of plaque biofilms and reestablishment of the biocompatibility of contaminated titanium surfaces. METHODS: Intraoral splints were used to collect an in vivo supragingival biofilm on sand-blasted and acid-etched titanium disks for 24 hours. ERCL was used at an energy output of 0.5, 1.0, 1.5, 2.0, and 2.5 W for the irradiation of 1) non-contaminated (20 and 25 Hz) and 2) plaque-contaminated (25 Hz) titanium disks. Unworn and untreated non-irradiated, sterile titanium disks served as untreated controls (UC). Specimens were incubated with SaOs-2 osteoblasts for 6 days. Treatment time, residual plaque biofilm (RPB) areas (%), mitochondrial cell activity (MA) (counts per second), and cell morphology/surface changes (scanning electron microscopy [SEM]) were assessed. RESULTS: 1) ERCL using either 0.5, 1.0, 1.5, 2.0, or 2.5 W at both 20 and 25 Hz resulted in comparable mean MA values as measured in the UC group. A monolayer of flattened SaOs-2 cells showing complete cytoplasmatic extensions and lamellopodia was observed in both ERCL and UC groups. 2) Mean RPB areas decreased significantly with increasing energy settings (53.8 +/- 2.2 at 0.5 W to 9.8 +/- 6.2 at 2.5 W). However, mean MA values were significantly higher in the UC group. CONCLUSION: Within the limits of the present study, it was concluded that even though ERCL exhibited a high efficiency to remove plaque biofilms in an energy-dependent manner, it failed to reestablish the biocompatibility of contaminated titanium surfaces.

Adult↗

Pre-clinical biocompatibility testing of peritoneal dialysis solutions.

Pre-clinical biocompatibility testing of peritoneal dialysis (PD) solutions has become an integral part of new solution development. The construction of a pre-clinical screening program for solution biocompatibility should take a hierarchical approach, starting with in vitro cell viability and function assays. The selection of cell types and assay systems for the in vitro studies should be broad enough to permit a balanced interpretation. Whenever possible, animal models are recommended for the next hierarchical level of testing, followed by human ex vivo study designs. Designs of the latter sort provide evidence that a new solution formulation is exerting an altered biological response in vivo; the response is not purely an in vitro artifact or restricted to a given animal species. This article discusses the various approaches available for biocompatibility testing during the pre-clinical phase of solution development, with an emphasis on the advantages and drawbacks of each method.

Animals↗

Biocompatibility of new peritoneal dialysis solutions: what can we hope to achieve?

Despite the bioincompatibility of the "old", standard, high glucose, lactate-buffered peritoneal dialysis (PD) solutions, PD is itself a highly successful dialysis modality with patient survival equivalent to that of hemodialysis (HD) during the initial 3 - 5 years of dialysis therapy. Nevertheless, PD technique survival is often limited by infectious complications and alterations in the structure and function of the peritoneal membrane. These local changes also have a negative impact on patient survival owing to systemic effects such as those often seen in patients with high peritoneal transport rate and loss of ultrafiltration (UF) capacity. Patient mortality remains unacceptably high in both HD and PD patients, with most premature deaths being associated with signs of malnutrition, inflammation, and atherosclerotic cardiovascular disease (MIA syndrome). These systemic signs are likely to be influenced by PD solutions both directly and indirectly (via changes in the peritoneal membrane). New, biocompatible PD solutions may have favorable local effects (viability and function of the peritoneal membrane) and systemic effects (for example, on MIA syndrome). Amino acid-based solution [Nutrineal (N): Baxter Healthcare Corporation, Deerfield, IL, U.S.A.] may improve nutritional status as well as peritoneal membrane viability. Bicarbonate/lactate-buffered solution [Physioneal (P): Baxter Healthcare Corporation] may ameliorate local and systemic effects of low pH, high lactate, and high glucose degradation products. Icodextrin-based solution [Extraneal (E): Baxter Healthcare SA, Castlebar, Ireland] may improve hypertension and cardiovascular problems associated with fluid overload and may extend time on therapy in patients with loss of UF capacity. The positive effects of each of these new, biocompatible solutions have been demonstrated in several studies. It is likely that the combined use of N, P, and E solutions will produce favorable synergies in regard to both local effects (peritoneal viability) and systemic effects (less malnutrition, inflammation, and fluid overload). Solution combination is an exciting area for clinical study in the coming years. Furthermore, dialysis fluid additives such as hyaluronan, which protects and improves the function of the peritoneal membrane, may further improve PD solutions. The new, biocompatible PD solutions represent an entirely new era in the evolution of the PD therapy; they are likely to have markedly positive effects on both PD technique and PD patient survival in coming years.

Amino Acids↗

Biocompatibility of dental materials in two human cell lines.

It was the aim of this study to investigate the biocompatibility of metallic (titan, gold, amalgam) and ceramic dental materials in contact with gingival (GF) and epithelial tumour cells (EpiCa). The cells were incubated with the test specimens (5 mg/piece) over a period of six days. Cellular proliferation rate, protein synthesis, and prostaglandin release (PGE2) served as parameters to determine the biocompatibility of the materials. - The investigations showed that the protein values were subject to slight variations following contact with the dental materials. Incubation of the cells with the test materials resulted in material dependent increases in PGE2-values (GF/EpiCa: titan: 187.4%, 131.0%; ceramic: 151.5%, 176.4%; gold: 114.5%, 123.8%; amalgam 150.6%, 159.8%). A comparison of control cells and cells of the test series (GF/EpiCa) after cell stimulation with 10-5M arachidonic acid (AA) showed the following changes in PGE2 on contact with titan (110.0%, 167.5%), ceramic (98.7%, 188.9%), gold (119.5%, 153.1%), and amalgam (68.9%, 179.5%). - Measurement of the proliferation rate (24 hours) further demonstrated that the dental materials used exerted an influence on the growth rates. While amalgam was associated with a marked reduction in the proliferation rate, titan, gold and ceramic induced only slight changes in the growth rate. - The results of the present study demonstrate that the cell culture systems used represent suitable in vitro models for the investigation of the biocompatibility of dental materials. The level of cell irritation was shown to be lowest for titan, closely followed by ceramic and gold. Cell culture; prostaglandin release; titan; ceramic; amalgam

Adult↗

Biomechanical substantiation of design features and physicomechanical characteristics of pins made of biocompatible polymers for intraosseous osteosynthesis.

This paper suggests a biomechanical model for osteosynthesis of tubular bones with the use of pins made of biocompatible polymers for the substantiation of the basic physicomechanical requirements to jointing elements (pins) with regard to functional loads, design features of pins and physicochemical properties of the materials used. It is shown that the known polymers including the biocompatible ones, do not individually possess the necessary strength characteristics for the production of jointing elements for highly loaded tubular bones. The properties of pins, made of biocompatible polymers, can be increased by optimizing their shapes and modifying the materials.

Adolescent↗

[Biocompatibility of poly-l-lysine-modified silica nanoparticles].

BACKGROUND & OBJECTIVE: Poly-l-lysine-modified silica nanoparticle(PMS-NP) was a novel non-viral vector for gene delivery. The current study was designed to evaluate the biocompatibility of PMS-NP for its further utilization in vivo. METHODS: Cell transfection and flow cytometry were used to elucidate the delivery efficiency of plasmid DNA and antisense ODN mediated by PMS-NP in the presence of serum-containing medium. Subsequently, the biocompatibility of PMS-NP in vivo was evaluated using filtration assay of plasma proteins and erythrocyte aggregation assay. RESULTS: The abilities of PMS-NP to deliver plasmid DNA and antisense ODN in vitro clearly decreased in the presence of serum-containing medium. PMS-NP/DNA(ODN)complexes bound plasma proteins and triggered erythrocyte aggregation. CONCLUSION: PMS-NP might interact with plasma proteins, resulting in decreased transfection efficiency in vitro. And filtration assay of plasma proteins and the erythrocyte aggregation assay demonstrated that the interaction of PMS-NP with plasma proteins and erythrocytes might play a negative role in gene transfection efficiency in vivo. And its biocompatibility needs to be further improved.

Animals↗

[Biocompatibility of JJ magnetic retainer metal materials].

OBJECTIVE: The purpose of this study was to evaluate the biocompatibility of new JJ-magnetic retainer metal materials. METHODS: Preliminary biocompatible tests of the metal materials were performed depending on ISO 10.993-12 standard. They were cytotoxicity test, hemolysis test, acute systemic toxicity test, sensitization test and Ames test. RESULTS: The cytotoxicity of the metal material was grade I. The hemolysis rate was 0.45%. There was no abnormal sensitization and irritation actions in the experimental group. The metal had no action of mutagenesis and carcinogenesis. CONCLUSION: The JJ-magnetic retainer metal material showed excellent biocompatibility on the preliminary tests. It would be a good material in the way of biological safety.

English Abstract↗

[Biocompatibility evaluation of chitosan-g-polyvinylpyrrolidone].

OBJECTIVE: To evaluate the biocompatibility of chitosan-g-polyvinylpyrrolidone as a new scaffold material. METHODS: The material was tested and measured for water absorption and contact angle, followed by evaluation of the biocompatibility by implantation into rabbits and in vitro cultured with the corneal epithelial cells. RESULTS: The water absorption rate of the material reached 1 100% with contact angle of 83-86. The results of implantation revealed partial degradation of the material 3 months after implantation, and much collagen and numerous corneal stromal cells appeared on the material without obvious inflammation reactions. In vitro coculture with epithelial cells showed good adhesion of the cells to the material which induced no obvious cytotoxicity. CONCLUSION: The novel chitosan derivative has excellent biocompatibility and can be used as a tissue scaffold material.

Animals↗

[Acute biocompatibility of hemodiafiltration with endogenous reinfusion (HFR)].

PURPOSE: In order to reduce the hemodialysis (HD)-induced pro-inflammatory activity we need to use a biocompatible dialysis membrane, avoid backfiltration and possibly use adsorbents. Hemodiafiltration reinfusion (HFR) is a new on-line hemodiafiltration (HDF) technique combining these aspects. This study aimed to evaluate the biocompatibility of the single dialysis session comparing standard HD and HFR. METHODS: Eighteen patients on chronic HD were enrolled in five Centers. Patients underwent one standard and two HFR study sessions; in each session we evaluated leukocyte activation at 0, 5, 15, 60 and 240 min; and interleukin-6 (IL-6), C-reactive protein (CRP) and IL-1 receptor antagonist (IL-1Ra) levels at 0, 60 and 240 min. RESULTS: Leukocyte activation was similar in HD and HFR, while the post-dialysis IL-6 increase was lower with HFR; CRP levels were stable during HFR, but increased after HD, and IL-1Ra did not demonstrate any difference. CONCLUSIONS: These preliminary data show that HFR still has a better biocompatibility in the single dialysis session.

Hemodiafiltration↗

Biocompatibility of a peritoneal dialysis solution with amino acids: histological evaluation in the rabbit.

OBJECTIVE: To determine the biocompatibility of a peritoneal dialysis (PD) solution containing amino acids compared to PD solutions containing glucose. DESIGN: The biocompatibility of three dialysis solutions containing 1.1% amino acids, 1.36% glucose, and 3.86% glucose, respectively, was evaluated in vivo in rabbits. METHODS: After 60 days of PD, peritoneal histological changes in rabbits were investigated by light and transmission electron microscopy. The parameters investigated were: (1) mesothelial damage; (2) submesothelial edema; (3) submesothelial cell infiltration; (4) submesothelial fibrosis; and (5) vascular alterations. Semiquantitative evaluations were performed for all the above alterations; quantitative morphometric evaluation was performed for mesothelial damage (cubic transformation of the mesothelium, areas devoid of mesothelium, submesothelial edema) and thickness of peritoneal arteriole walls. RESULTS: (1) Mesothelial damage was practically nonexistent in rabbits dialyzed with the solution containing amino acids, and intermediate and severe with low-glucose and high-glucose solutions, respectively. Both controls and rabbits dialyzed with amino acid solution showed flat continuous mesothelium; rabbits dialyzed with low-glucose solution showed cubic continuous mesothelium; and rabbits dialyzed with high-glucose solution showed cubic discontinuous mesothelium. Cytopathic mesothelial effects were slight with the solution containing amino acids and severe with both the low- and high-glucose solutions. Duplication and thickening of mesothelial basement membrane were never observed. (2) Submesothelial edema showed a worsening trend from controls to rabbits dialyzed with solution containing amino acids, low glucose, and high glucose. (3) No difference in submesothelial infiltration was found between groups. (4) Submesothelial fibrosis was never observed. (5) Vascular alterations were never observed. CONCLUSION: These results are evidence that PD solution with amino acids is more biocompatible than high- and also low-glucose solutions.

Amino Acids↗

Hemocompatibility, biocompatibility, inflammatory and in vivo studies of primary reference materials low-density polyethylene and polydimethylsiloxane: a review.

In 1984, low-density polyethylene (LDPE) and polymethylsiloxane (PDMS), two primary reference materials (PRM), were made available by the National Heart, Lung, and Blood Institute (NHLBI) as discriminatory tools for the validation of standardized and novel in vitro and in vivo tests in the evaluation of biomaterials. This article reviews the results and conclusions obtained by several studies investigating the hemocompatibility, in vitro biocompatibility, inflammatory response, and in vivo tissue reactions of these two reference materials. Variable results obtained with LDPE and PDMS in ex vivo hemocompatibility studies were attributed to the type of animal model used, the flow velocity of the circulating blood, the time of exposure, and the methodology used to measure blood cell adhesion or activation at the surface of the materials. In contrast, both the LDPE and PDMS appeared to be suitable reference materials when used in in vitro biocompatibility, inflammatory response, and in vivo studies. However, caution must be taken when interpreting the results, because gamma sterilization of these two materials as well as their origin (for example PDMS) are two critically important factors. In conclusion, we see a definite need for standardized hemocompatible parameters and better high-quality hemocompatibility studies on PRM. This review also suggests other materials as potential PRM candidates, namely, Biomer and Intramedic polyethylene.

Animals↗