ABSTRACT
We present data and analyses concerning the adhesion of clinically relevant Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa (bacteria) and Candida albicans (yeast) to Zircaloy-2 (Zry-2) and Zircadyne-705 (Zr705) surfaces. These zirconium-based materials are similar to those now being used in total hip and knee replacements. Here we study clinical strains of microbes under shaken and stationary exposure conditions, and their ability to adhere to Zr surfaces having different oxide thicknesses. We use X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), viable counts, endotoxin assays, and statistical analysis methods, and demonstrate a predictive model for microbial adhesion based on XPS data.
Subject(s)
Bacterial Adhesion , Coated Materials, Biocompatible , Zirconium , Alloys , Candida albicans/physiology , Cell Adhesion , Colony Count, Microbial , Endotoxins/analysis , Materials Testing , Microscopy, Electron, Scanning , Models, Biological , Pseudomonas aeruginosa/physiology , Spectrum Analysis , Staphylococcus aureus/physiology , Staphylococcus epidermidis/physiology , Surface Properties , X-RaysABSTRACT
Two Gram-positive coryneform bacteria that degraded p-chlorophenol isolated from a continuous culture system are characterized. Isolate B (probably and Arthrobacter sp.) completely removed the p-chlorophenol from a medium with a concomitant increase in cell density within 16 h. Isolate F similarly removed the p-chlorophenol within 28 h but without an increase in cell density. Isolates B and F also removed the p-chlorophenol from a medium with p-chlorophenol as the sole carbon source within 32 and 48 h, respectively. The optimal temperature for p-chlorophenol degradation by both organisms was 25 to 30 degrees C. The optimal pH range for p-chlorophenol degradation was pH 7-9 for isolate B and pH 8-9 for isolate F. Since these native environmental bacteria can degrade p-chlorophenol, they may have an important application in waste water treatment processes.
Subject(s)
Chlorophenols/metabolism , Gram-Positive Bacteria/metabolism , Arthrobacter/growth & development , Arthrobacter/isolation & purification , Arthrobacter/metabolism , Bacteriological Techniques , Biodegradation, Environmental , Gram-Positive Bacteria/growth & development , Gram-Positive Bacteria/isolation & purification , Hydrogen-Ion Concentration , Temperature , Xenobiotics/metabolismABSTRACT
Biocompatibility and diffusional characteristics of recently synthesized unique amphiphilic networks, i.e., copolymers of methacryloyl-capped polyisobutylene (MA-PIB-MA) with 2-(dimethylamino)-ethyl methacrylate (DMAEMA) have been examined. Excellent biocompatibility and biostability were obtained after 7 weeks with films containing 53-58% MA-PIB-MA implanted dorsally or abdominally in rats. In contrast, networks with higher or lower MA-PIB-MA contents showed decreased biocompatibility. These amphiphilic networks were also studied as potential implantable drug release systems. Bromophenol blue and folic acid were used as model compounds for drug release. Diffusion of these chemicals from loaded networks into water showed a marked pH dependence. Under specific well-defined conditions (MA-PIB-MA/DMAEMA content, pH, time range) release was observed to be independent of time (zero-order release).
