Review of titanium surface modification techniques and coatings for antibacterial applications.

Implanted biomaterials play a key role in the current success of orthopedic and dental procedures. Pure titanium and its alloys are the most commonly used materials for permanent implants in contact with bone. However, implant-related infections remain among the leading reasons for failure. The most critical pathogenic event in the development of infection on biomaterials is biofilm formation, which starts immediately after bacterial adhesion. In the last decade, numerous studies reported the ability of titanium surface modifications and coatings to minimize bacterial adhesion, inhibit biofilm formation and provide effective bacterial killing to protect implanted biomaterials. In the present review, the different strategies to prevent infection onto titanium surfaces are reported: surface modification and coatings by antibiotics, antimicrobial peptides, inorganic antibacterial metal elements and antibacterial polymers. STATEMENT OF SIGNIFICANCE: Implanted biomaterials play a key role in the current success of orthopedic and dental procedures. Pure titanium and its alloys are the most commonly used materials for permanent implants in contact with bone. Microbial infection is one of the main causes of implant failure. Currently, the global infection risk is 2-5% in orthopedic surgery. Numerous solutions exist to render titanium surfaces antibacterial. The LBPS team is an expert on the functionalization of titanium surfaces by using bioactive polymers to improve the biologiocal response. In this review, the different strategies to prevent infection are reported onto titanium and titanium alloy surfaces such as surface modification by antibiotics, antimicrobial peptides, inorganic antibacterial metal elements and antibacterial polymers.

Protein selective adsorption properties of a polyethylene terephtalate artificial ligament grafted with poly(sodium styrene sulfonate) (polyNaSS): correlation with physicochemical parameters of proteins.

Immediately after surgical placement of biomaterials, a first step consists in the adsorption of proteins from the biological environment on the artificial surfaces. Because the composition of the adsorbed protein layer modulates the cell response to the implanted material, researchers in the biomaterials field have focused on coating proteins or peptides onto surfaces to improve cell response and therefore the long-term compatibility of the implant. However, some materials used in tissue engineering, mainly synthetic polymers, are too hydrophobic to allow the optimal adsorption of proteins and have to be first submitted to physical or chemical treatments. In our laboratory, we have demonstrated that grafting of poly(sodium styrene sulfonate) (polyNaSS) onto biomaterials can strongly modulate the protein adsorption and the cellular response compared to unmodified surfaces. In this study, we used a liquid chromatography strategy coupled to proteomics to evaluate the adsorptive properties of a polyethylene terephtalate (PET) artificial ligament grafted with polyNaSS, and to identify and analyse proteins adsorbed on PET fibers. Results obtained with platelet rich plasma (PRP) proteins demonstrated that grafting significantly increases the protein adsorption of the PET and also selectively modulates the adsorption of proteins on PET fibers. Finally, regarding physicochemical parameters calculated from the amino acid sequence of identified proteins, we found that the aliphatic index is highly correlated with the selective adsorption of proteins onto the polyNaSS/PET surface. Therefore, the proteomic approach complemented with physicochemical property evaluation could provide a powerful tool for the elaboration of new biomaterials based on protein layer deposition.

Biotribocorrosion (tribo-electrochemical) characterization of anodized titanium biomaterial containing calcium and phosphorus before and after osteoblastic cell culture.

The purpose of this study was to investigate the relationship between the osteoblastic cells behavior and biotribocorrosion phenomena on bioactive titanium (Ti). Ti substrates submitted to bioactive anodic oxidation and etching treatments were cultured up to 28 days with MG63 osteoblast-like cells. Important parameters of in vitro bone-like tissue formation were assessed. Although no major differences were observed between the surfaces topography (both rough) and wettability (both hydrophobic), a significant increase in cell attachment and differentiation was detected on the anodized substrates as product of favorable surface morphology and chemical composition. Alkaline phosphatase production has increased (≈20 nmol/min/mg of protein) on the anodized materials, while phosphate concentration has reached the double of the etched material and calcium production increased (over 20 µg/mL). The mechanical and biological stability of the anodic surfaces were also put to test through biotribocorrosion sliding solicitations, putting in evidence the resistance of the anodic layer and the cells capacity of regeneration after implant degradation. The Ti osteointegration abilities were also confirmed by the development of strong cell-biomaterial bonds at the interface, on both substrates. By combining the biological and mechanical results, the anodized Ti can be considered a viable option for dentistry.

PolyNaSS grafting on titanium surfaces enhances osteoblast differentiation and inhibits Staphylococcus aureus adhesion.

Titanium surface modifications to simultaneously prevent bacterial adhesion but promote bone-cell functions could be highly beneficial for improving implant osseointegration. In the present in vitro study, the effect of sulfonate groups on titanium surfaces was investigated with respect to both S. aureus adhesion and osteoblast functions pertinent to new bone formation. Commercial pure titanium (cpTi) squares were oxydized (Tiox), grafted with poly(sodium styrene sulfonate) groups (Tigraft) by covalent bonding using radical polymerization, and were characterized by infrared spectroscopy (HATR-FTIR) and colorimetry. Bacterial adhesion study showed that Tigraft exhibited high inhibition of S. aureus adhesion S at levels >90 %, when compared to cpTi (P < 0.05). In contrast osteoblasts adhesion was similar on all three titanium surfaces. While the kinetics of cell proliferation were similar on the three titanium surfaces, Alkaline phosphatase-specific activity of osteoblasts cultured on Tigraft surfaces was twofold higher than that observed on either on Tiox or cpTi surfaces (P < 0.01). More importantly, the amount and the distribution of calcium-containing nodules was different. The total area covered by calcium-containing nodules was 2.2-fold higher on the Tigraft as compared to either Tiox or cpTi surfaces (P < 0.01). These results provide evidence that poly(sodium styrene sulfonate) groups grafting on cpTi simultaneously inhibits bacteria adhesion but promote osteoblast function pertinent to new bone formation. Such modified titanium surfaces offer a promising strategy for preventing biofilm-related infections and enhancing osteointegration of implants in orthopaedic and dental applications.

The osteogenic differentiation improvement of human mesenchymal stem cells on titanium grafted with polyNaSS bioactive polymer.

Osseointegration of metallic implants used in orthopedic surgery requires that osteoprogenitor cells attach and adhere to the surface, then proliferate, differentiate into osteoblasts, and finally produce mineralized matrix. Because the ability of progenitor cells to attach to a scaffold surface during early stages is important in the development of new tissue structures, we developed in our laboratory, a strategy involving grafting of implants with a polymer of sodium styrene sulfonate (polyNaSS) used as a scaffold which enables human mesenchymal stem cells (hMSCs) interactions. In the present study, we investigated the cellular response of hMSCs to polyNaSS surfaces of titanium (Ti). In particular, cell proliferation, cell viability, cell differentiation, and cell spreading were evaluated. Results showed that cell proliferation and cell viability did not differ with any statistical significance between modified and unmodified Ti surfaces. Interestingly, culture of MSCs on polyNaSS surfaces resulted in a significant increase of cell spreading and cell differentiation compared with the other tested surfaces. These results suggest that titanium surface grafted with polyNaSS is a suitable scaffold for bone tissue engineering.

Characterization of a synthetic bioactive polymer by nonlinear optical microscopy.

Tissue Engineering is a new emerging field that offers many possibilities to produce three-dimensional and functional tissues like ligaments or scaffolds. The biocompatibility of these materials is crucial in tissue engineering, since they should be integrated in situ and should induce a good cell adhesion and proliferation. One of the most promising materials used for tissue engineering are polyesters such as Poly-ε-caprolactone (PCL), which is used in this work. In our case, the bio-integration is reached by grafting a bioactive polymer (pNaSS) on a PCL surface. Using nonlinear microscopy, PCL structure is visualized by SHG and proteins and cells by two-photon excitation autofluorescence generation. A comparative study between grafted and nongrafted polymer films is provided. We demonstrate that the polymer grafting improves the protein adsorption by a factor of 75% and increase the cell spreading onto the polymer surface. Since the spreading is directly related to cell adhesion and proliferation, we demonstrate that the pNaSS grafting promotes PCL biocompatibility.

[Inhibition of Staphylococcus epidermidis adhesion on titanium surface with bioactive water-soluble copolymers bearing sulfonate, phosphate or carboxylate functions]. / Inhibition de l'adhérence de Staphylococcus epidermidis sur des surfaces en titane par des polymères hydrosolubles bioactifs comportant des fonctions sulfonate, phosphate ou carboxylate.

Implanted prostheses are sometimes subject to bacterial infections, which can threat their benefit rule on a long-term basis. Various methods are studied to fight against these infections. Among them, the grafting of bioactive polymers onto the prosthesis surface shows up as a promising way to the problem of infections. This work presents the influence of various water-soluble bioactive polymers on the inhibition of the Staphylococcus epidermidis adhesion on the titanium samples surfaces initially preadsorbed with various proteins. Whatever the studied protein is, it is shown that the bioactive polymer containing sulfonate functions generates an inhibition of the adhesion of Staphylococcus epidermidis. For a plasma preadsorption, the inhibition rate rises up to 68% when the concentration of sulfonate function is 2.5µmol/L. Titanium surfaces grafted with the bioactive polymer were also tested. We find an inhibitive activity of the adhesion close to that of the previous case. These preliminary results can point up a clinical interest in the fight against the medical devices infection, because they highlight a clear local effect of S. epidermidis adhesion inhibition. Copolymers containing other functional groups (phosphate or carboxylate) were dissolved in a bacterial suspension to monitor the influence of the composition on the adhesion inhibition. Their inhibition rates are not significantly lower than those of pNaSS homopolymers, as much as the sulfonate function proportion remains higher than 50%. Thus, the sulfonate function is the main responsible for the inhibition of the S. epidermidis adhesion.

Development of proteomic tools to study protein adsorption on a biomaterial, titanium grafted with poly(sodium styrene sulfonate).

It is known that protein adsorption is the initial interaction between implanted biomaterials and biological environment. Generally, a complex protein layer will be formed on material surfaces within a few minutes and the composition of this layer at the interface determines the biological response to the implanted material, and therefore the long-term compatibility of the biomaterial. Despite different techniques exist to observe protein adsorption on biomaterials, none of them led to the identification of adsorbed proteins. In this paper, we report a chromatographic technique coupled to proteomics to analyse and identify proteins from complex biological samples adsorbed on biomaterial surfaces. This approach is based on (1) elaboration of the chromatographic support containing the biomaterial (2) a chromatography step involving adsorption of proteins on the biomaterial (3) the high-resolution separation of eluted proteins by 2-DE gel and (4) the identification of proteins by mass spectrometry. Experiments were performed with proteins from platelets rich plasma (PRP) adsorbed on a biomaterial which consist in titanium bioactivated with PolyNaSS. Our results show that chromatographic approach combined to 2-DE gels and mass spectrometry provides a powerful tool for the analysis and identification of proteins adsorbed on various surfaces.

Effect of blasting treatment and Fn coating on MG63 adhesion and differentiation on titanium: a gene expression study using real-time RT-PCR.

Biomaterial surface properties, via alterations in the adsorbed protein layer, and the presence of specific functional groups can influence integrin binding specificity, thereby modulating cell adhesion and differentiation processes. The adsorption of fibronectin, a protein directly involved in osteoblast adhesion to the extracellular matrix, has been related to different physical and chemical properties of biomaterial surfaces. This study used blasting particles of different sizes and chemical compositions to evaluate the response of MG63 osteoblast-like cells on smooth and blasted titanium surfaces, with and without fibronectin coatings, by means of real-time reverse transcription-polymerase chain reaction (qRT-PCR) assays. This response included (a) expression of the α(5), α(v) and α(3) integrin subunits, which can bind to fibronectin through the RGD binding site, and (b) expression of alkaline phosphatase (ALP) and osteocalcin (OC) as cell-differentiation markers. ALP activity and synthesis of OC were also tested. Cells on SiC-blasted Ti surfaces expressed higher amounts of the α(5) mRNA gene than cells on Al(2)O(3)-blasted Ti surfaces. This may be related to the fact that SiC-blasted surfaces adsorbed higher amounts of fibronectin due to their higher surface free energy and therefore provided a higher number of specific cell-binding sites. Fn-coated Ti surfaces decreased α(5) mRNA gene expression, by favoring the formation of other integrins involved in adhesion over α(5)ß(1). The changes in α(5) mRNA expression induced by the presence of fibronectin coatings may moreover influence the osteoblast differentiation pathway, as fibronectin coatings on Ti surfaces also decreased both ALP mRNA expression and ALP activity after 14 and 21 days of cell culture.

Synthesis and in vitro evaluation of gelatin/hydroxyapatite graft copolymers to form bionanocomposites.

The combination of gelatin (Gel) with a bioactive component hydroxyapatite (HA) and cartilage powder (CP) to form biocomposites takes advantage of the osteoconductivity and osteoinductivity properties. The studies on bionanocomposites containing HA, CP fillers and Gel are still being conducted. In this present study, the bioactive fillers were loaded onto poly(hydroxylethylmethacrylate) and poly(hydroxylethylmethacrylate-co-methyl methacrylate) grafted gelatin copolymers to produce novel bionanocomposites having osteoconductive and osteoinductive properties. The resulting bionanocomposites were assessed by ATR-IR and SEM-EDX techniques to prove the interaction between different matrices. In vitro behavior of these bionanocomposites was performed in SBF for 21 days at pH 7.4 to verify formation of the apatite layer on the surfaces and its enhancement. The results confirmed the formation of thick plentiful aggregated (hexagonal or spherical) nanoparticles with a bright color (apatite layer) containing carbonate ions onto the surface of composites especially these containing CP and P(HEMA-co-MMA) having bone cement formation in their structure. These novel bionanocomposites have unique bioactivity that can be applied in bone implants as scaffolds and tissue engineering in future.

Bioactive polymer grafting onto titanium alloy surfaces.

Bioactive polymers bearing sulfonate (styrene sodium sulfonate, NaSS) and carboxylate (methylacrylic acid, MA) groups were grafted onto Ti6Al4V alloy surfaces by a two-step procedure. The Ti alloy surfaces were first chemically oxidized in a piranha solution and then directly subjected to radical polymerization at 70 degrees C in the absence of oxygen. The grafted surfaces were characterized by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and the toluidine blue colorimetric method. Toluidine blue results showed 1-5microgcm(-2) of polymer was grafted onto the oxidized Ti surfaces. Grafting resulted in a decrease in the XPS Ti and O signals from the underlying Ti substrate and a corresponding increase in the XPS C and S signals from the polymer layer. The ToF-SIMS intensities of the S(-) and SO(-) ions correlated linearly with the XPS atomic percent S concentrations and the ToF-SIMS intensity of the TiO(3)H(2)(-) ion correlated linearly with the XPS atomic per cent Ti concentration. Thus, the ToF-SIMS S(-), SO(-) and TiO(3)H(2)(-) intensities can be used to quantify the composition and amount of grafted polymer. ToF-SIMS also detected ions that were more characteristic of the polymer molecular structure (C(6)H(4)SO(3)(-) and C(8)H(7)SO(3)(-) from NaSS, C(4)H(5)O(2)(-) from MA), but the intensity of these peaks depended on the polymer thickness and composition. An in vitro cell culture test was carried out with human osteoblast-like cells to assess the influence of the grafted polymers on cell response. Cell adhesion after 30min of incubation showed significant differences between the grafted and ungrafted surfaces. The NaSS grafted surfaces showed the highest degree of cell adhesion while the MA-NaSS grafted surfaces showed the lowest degree of cell adhesion. After 4 weeks in vivo in rabbit femoral bones, bone was observed to be in direct contact with all implants. The percentage of mineralized tissue around the implants was similar for NaSS grafted and non-grafted implants (59% and 57%). The MA-NaSS grafted implant exhibited a lower amount of mineralized tissue (47%).

Bone tissue response to titanium implant surfaces modified with carboxylate and sulfonate groups.

The present study assessed in vivo new bone formation around titanium alloy implants chemically grafted with macromolecules bearing ionic sulfonate and/or carboxylate groups. Unmodified and grafted Ti-6Al-4V exhibiting either 100% carboxylate, or 100% sulfonate, or both carboxylate and sulfonate groups in the percent of 50/50 and 80/20 were bilaterally implanted into rabbit femoral condyle. Neither toxicity nor inflammation were observed for all implants tested. After 4 weeks, peri-implant new bone formation varied as a function of the chemical composition of the titanium surfaces. The percent bone-implant contact (BIC) was the lowest (13.4 +/- 6.3%) for the implants modified with grafted carboxylate only. The value of BIC on the implants with 20% sulfonate (24.6 +/- 5.2%) was significantly (P < 0.05) lower than that observed on 100% sulfonate (38.2 +/- 13.2%) surfaces. After both 4 and 12 weeks post-implantation, the BIC value for implants with more than 50% sulfonate was similar to that obtained with the unmodified Ti-6Al-4V. The grafted titanium alloy exhibiting either 100% sulfonate or carboxylate and sulfonate (50% each) groups promoted bone formation. Such materials are of clinical interest because, they do not promote bacteria adhesion but, they support new bone formation, a condition which can lead to osseointegration of bone implants while preventing peri-implant infections.

[New antitumor agent: In vitro activity on breast carcinoma cells]. / Nouvel agent antitumoral : activité in vitro sur les cellules de carcinomes mammaires.

Previous work showed that established interactions between water-soluble polymers and cell membrane receptors can lead to modulate cell proliferation and differentiation in vitro. These polymers can be considered as bioactive. The aim of this work was to establish the consequences of the interactions between human breast cancer cells MCF7 and polymers of various chemical compositions regarding cell adhesion and proliferation onto tissue culture plate. Water soluble copolymers were synthesized by radical polymerization and are composed of methacrylic acid and sodium styrene sulphonate units. The modulation of the MCF7, biological-induced by these polymers of various compositions, was evaluated. The influence of the polymers chemical composition on the kinetics of cell proliferation, as well as cell morphology and spreading, were studied. A polymer concentration-dependent inhibition effect was observed. One hundred microgram per liter polymers solutions induced strong inhibition of cell proliferation, as well as a change of the MCF7 cells morphology, which can be related to an inhibition of cell spreading. The polymers/MCF7 cells interactions are modulated by the chemical composition of the copolymers and then the respective rate in sulphonate and carboxylate groups distributed along the macromolecular chain.

Morphology and adhesion of human fibroblast cells cultured on bioactive polymer grafted ligament prosthesis.

The anterior cruciate ligament (ACL) is the most important ligament for the knee stabilization. Unfortunately, it is also the most commonly injured. Synthetic polymers such as polyethylene terephthalate (PET) are widely used to fabricate ligament prostheses. In this study, we reported how to graft poly(sodium styrene sulfonate) (pNaSS) onto PET fabrics used to prepare ligament at a rate of about 4.5 x 10(-6) mol/g. In this study, we analyzed the morphology of human fibroblast MacCoy adhering onto the pNaSS grafted fabrics. Cell adhesion strength onto grafted and non grafted fabrics previously adsorbed with serum proteins was also evaluated after the application of shear stresses. Results showed that human fibroblast MacCoy adhered more strongly on the pNaSS grafted fabric compared to the non grafted one. The cell spreading is well on the grafted fiber even after the shear stress application: about 65% of cells remained adhered on the pNaSS grafted fabric as compared to 32% on the non grafted one. We concluded that Mac Coy human fibroblast cells strongly adhered onto the pNaSS functionalized PET prosthesis surface and showed a better spread cell morphology as well as a more homogeneous distribution than on the non grafted sample surfaces.

Grafting of bioactive polymers onto titanium surfaces and human osteoblasts response.

In this paper, the adhesion of human osteoblast-like cells (line MG63) onto functionalized pure Titanium (Ti cp) has been studied. The Titanium surfaces were functionalized by grafting bioactive polymers bearing anionic groups such as sodium sulfonate. The grafting was achieved under inert atmosphere, by radical polymerization of sodium styrene sulfonate NaSS after the activation of the surface. ATR/FTIR and XPS were used to analyse the chemical composition of the grafted and non grafted titanium surfaces. The efficiency of the grafting was evidenced by the high amounts of grafted polyNaSS (5 microg/cm(2)), measured by Toluidin Blue colorimetric method. Biological tests have been investigated to highlight the influence of the grafting polymer on the cell response. Human osteoblast-like cells were cultured on titanium surfaces. Differences in the adhesion strength of cells were observed. Mineralization of osteoblast-like cells was studied after 28 days of culture and the amount of calcium formed were evaluated. Surface modification by bioactive polymers bearing anionic groups appears as an effective way to stimulate the bone regeneration over that, as provided by titanium as suggested by basic studies and in vitro results.

Bioactive poly(ethylene terephthalate) fibers and fabrics: grafting, chemical characterization, and biological assessment.

The grafting of poly(sodium styrene sulfonate) (pNaSS) onto ozone-treated poly(ethylene terephthalate) (PET) fabric surfaces was characterized by X-ray photoelectron spectroscopy and toluidine blue colorimetry. Significant amounts of pNaSS were grafted over the range of experimental conditions examined in this study (30-120 min of ozonation, reaction at 65 or 70 degrees C, and reaction times up to 240 min). Within these ranges the amount of grafted pNaSS increased with both ozonation time and reaction temperature. The amount of grafted pNaSS increased over the first 60 min of reaction, then remained relatively constant from 60 to 240 min. For the biological experiments pNaSS-grafted samples were prepared with 30 min of ozonation and 60 min of reaction at a grafting temperature of 70 degrees C. The ozonation time was limited to 30 min to minimize any possible degradation of the PET fabrics by the ozonation treatment. The pNaSS-grafted PET surface adsorbed a factor of 4 more compared to the nongrafted surfaces. The strength of fibroblast adhesion was an order of magnitude higher on pNaSS-grafted PET fabrics compared to that on nongrafted PET fabrics. This difference in the cell attachment was correlated to the cell spreading, which was better and more homogeneous on the grafted fibers compared to the nongrafted fibers. Fibroblasts adhered more strongly on surfaces precoated with normal human plasma compared to surfaces precoated with 10% fetal calf serum in Dulbecco's modified Eagle's medium.

Radical graft polymerization of styrene sulfonate on poly(ethylene terephthalate) films for ACL applications: "grafting from" and chemical characterization.

The purpose of this study is to develop a reliable method of functionalizing poly(ethylene terephthalate) with bioactive polymers to produce a "biointegrable" artificial anterior cruciate ligament. Radical graft polymerization of the sodium salt of styrene sulfonate (NaSS) onto poly(ethylene terephthalate) (PET) films was performed using the "grafting from" technique. Prior to the grafting, the surfaces of poly(ethylene terephthalate) films were activated by ozonation to generate peroxide and hydroperoxide reactive species on the PET film surfaces. The radical polymerization of NaSS was initiated by thermal decomposition of the hydroperoxides. The grafted PET surfaces were characterized by a toluidin blue colorimetric method, X-ray photoelectron spectroscopy, contact angle measurements, and atomic force microscopy. The influence of ozonation time, monomer concentration, and temperature on NaSS grafting ratios was examined. A total of 30 min of ozonation followed by grafting from a 15% NaSS solution at 70 degrees C for 90 min or more resulted in attachment of poly(NaSS) chains to the PET film surfaces.

Surface modification of hydrogel intraocular lenses to prevent cell proliferation.

Intraocular lenses made from a hydrogel matrix were coated with a bioactive polymer exhibiting sulfonate and carboxylate groups. The anchorage of the macromolecular chains bearing the anionic groups to the hydrogel implant surface was obtained by an intermolecular reaction of the photosensitive groups attached to the ionic polymer, in order to obtain a pseudo-interpenetrated network. Cell proliferation assays performed on coated and uncoated hydrogel lenses showed an inhibiting effect of the bioactive polymer coating by up to 40% at day 6. The inhibiting effect was due to the presence and the distribution of both sulfonate and carboxylate groups along the macromolecular chains, which led to the appearance of ""bioactive sites"" allowing controlled interactions of surface, adhesive proteins and cells. (Journal of Applied Biomaterials & Biomechanics 2004; 2: 183-9).

Bioactive polymers grafted on silicone to prevent Staphylococcus aureus prosthesis adherence: in vitro and in vivo studies.

As joint prostheses become infected preventive strategies are needed. Silicone prostheses were coated with a COO - and SO3 - bearing bioactive copolymer, Q5, synthesized by radical polymerization and the adherence of Staphylococcus aureus (S. aureus)to them was evaluated in vitro and in vivo. Copolymer Q5 contains tris(trimethylsiloxy) methacryloxy propyl silane favoring the compatibility with the silicone matrix, cinnamoyl ethyl methacrylate allowing a network formation at the surface of the silicone prostheses, two ionic monomers: methacrylic acid and sodium styrene sulfonate. In vitro experiments were conducted on Q5-coated silicone lenses and on Q5-coated silicone prostheses. In both cases, materials were incubated with fi-bronectin (Fn) because of its important role in S. aureus adherence to implant surfaces. The percentage of adhesion inhibition was observed at approximately 40% for the coated materials compared to the untreated silicone. Rabbits underwent double-blind partial knee replacements with Q5-coated or control implants fitted into the intramedullary canal of the tibia, and 10 7 bacteria were injected into the knees. The number of bacteria adherent on the prostheses was determined 24 hr later. Signifi-cantly fewer bacteria adhered to Q5-coated than control prostheses (2.26 +/- 0.76 vs 3.86 +/- 0.54 log10 CFU/ml; p < 0.0035). Bioactive polymer coating could provide a new method of preventing joint-prosthesis infections. (Journal of Applied Biomaterials & Biomechanics 2003; 1: 178-85).