Poly(lactic acid) (PLA) has shown much success in the preparation of tissue engineering scaffolds as it can be fabricated with a tailored architecture. However, the PLA surface has drawbacks including the lack of biofunctional motifs which are essential for high affinity to biological cells. Therefore, this study describes a multistep physicochemical approach for the immobilization of d-glucosamine (GlcN), a naturally occurring monosaccharide having many biological functions, on the PLA surface aiming at enhancing the cell proliferation activity. In this approach, poly(acrylic acid) (PAAc) spacer arms are first introduced into the PLA surface via plasma post-irradiation grafting technique. Then, covalent coupling or physical adsorption of GlcN with/on the PAAc spacer is carried out. Factors affecting the grafting yield are controlled to produce a suitable spacer for bioimmobilization. X-ray photon spectroscopic (XPS) analyses confirm the immobilization of GlcN on the PLA surface. The XPS results reveal also that increasing the yield of grafted PAAc spacer on the PLA surface increases the amount of covalently immobilized GlcN, but actually inhibits the immobilization process using the physical adsorption method. Contact angle measurements and atomic force microscopy (AFM) show a substantial increase of surface energy and roughness of PLA surface, respectively, upon the multistep modification procedure. The cytocompatibility of the modified surfaces is assessed using a mouse embryonic fibroblast (MEF) cell line. Observation from the cell culture basically demonstrates the potential of GlcN immobilization in improving the cytocompatibility of the PLA surface. Moreover, the covalent immobilization of GlcN seems to produce more cytocompatible surfaces if compared with the physical adsorption method. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3176-3188, 2017.
- MeSH
- adsorpce MeSH
- biokompatibilní materiály chemie MeSH
- buněčné linie MeSH
- fibroblasty cytologie MeSH
- glukosamin chemie MeSH
- kinetika MeSH
- mikroskopie atomárních sil MeSH
- myši MeSH
- polyestery chemie MeSH
- povrchové vlastnosti MeSH
- proliferace buněk MeSH
- tkáňové podpůrné struktury chemie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The aim of this study was to develop the potential tissue engineering applications of d-glucosamine (GlcN) immobilized onto the surface of a biodegradable matrix in order to induce a desired biological effect at biointerfaces. Thus, for sample preparation we used a novel multistep physicochemical approach. In the first step the poly(lactic acid) (PLA) films were exposed to a low pressure plasma in air atmosphere, followed by radical graft copolymerization with acrylic acid to yield a carboxyl-functionalized spacer layer on the PLA surface. The carboxyl groups were then coupled to GlcN molecules via the carbodiimide chemistry. The developed surfaces were characterized by X-ray Photoelectron Spectroscopy (XPS), Contact angle measurements and Atomic Force Microscopy (AFM). A preliminary study on the proliferation of fibroblasts on the developed surfaces was performed using the NIH/3T3 cell line.
- MeSH
- biokompatibilní materiály chemie MeSH
- fotoelektronová spektroskopie MeSH
- glukosamin chemie MeSH
- mikroskopie atomárních sil MeSH
- polyestery chemie MeSH
- povrchové vlastnosti MeSH
- proliferace buněk MeSH
- regenerace * MeSH
- smáčivost MeSH
- tkáňové inženýrství * MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- generika MeSH
- léčivé přípravky * ekonomika klasifikace normy MeSH
- lékové předpisy MeSH
- lidé MeSH
- zákonodárství lékové MeSH
- Check Tag
- lidé MeSH
- Geografické názvy
- Slovenská republika MeSH
The increase in surface Gibbs energy of polypropylene (PP) by cold barrier plasma is a promising alternative to chemical modification. The advantage of using this discharge method compared with other types such as corona or glow discharge, consists in a better process control by homogenous plasma formation and in an efficient deposition of thin layers. As a result of the reactive site formation by plasma treatment, it is possible to initiate graft radical polymerization of acrylic acid, acrylamide or methyl methacrylate on PP surface, which leads to films with new physico-chemical properties such as morphology, thickness, polarity, and surface chemical composition. On the films thus formed it is possible to efficiently immobilize antibacterial polysaccharides, such as chitosan, pectin and cyclodextrin copolymers, which increase the PP biocompatibility by reducing the biofilm formation. This method can be used in food and textile industries, biomedicine and in production of new composites and nanocomposites.
- MeSH
- antibakteriální látky * chemie MeSH
- biomedicínský výzkum MeSH
- chemické jevy MeSH
- chitosan chemie MeSH
- lidé MeSH
- polypropyleny * chemie MeSH
- protézy a implantáty využití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Alginic acid coated polyethylene films were examined in terms of surface properties and bacteriostatic performance against two most representative bacterial strains, that is, Escherichia coli and Staphylococcus aureus. Microwave plasma treatment followed by brush formation in vapor state from three distinguished precursors (allylalcohol, allylamine, hydroxyethyl methacrylate) was carried out to deposit alginic acid on the substrate. Surface analyses via various techniques established that alginic acid was immobilized onto the surface where grafting (brush) chemistry influenced the amount of alginic acid coated. Moreover, alginic acid was found to be capable of bacterial growth inhibition which itself was significantly affected by the brush type. The polyanionic character of alginic acid as a carbohydrate polymer was assumed to play the pivotal role in antibacterial activity. The cell wall composition of two bacterial strains along with the substrates physicochemical properties accounted for different levels of bacteriostatic performance.
- MeSH
- algináty chemie MeSH
- antibakteriální látky chemie farmakologie MeSH
- Escherichia coli účinky léků MeSH
- kyselina glukuronová chemie MeSH
- kyseliny hexuronové chemie MeSH
- mikrobiální testy citlivosti MeSH
- polyethylen chemie MeSH
- Staphylococcus aureus účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Medical-grade polyvinyl chloride was coated by polysaccharides through a novel physicochemical approach. An initial surface activation was performed foremost via diffuse coplanar surface barrier discharge plasma in air at ambient temperature and pressure. Then, radical graft copolymerization of acrylic acid through grafting-from pathway was directed to render a well-defined brush of high density, and finally a chitosan monolayer and chitosan/pectin alternating multilayer were bound onto the functionalized surfaces. Surface characteristics were systematically investigated using several probe techniques. In vitro bacterial adhesion and biofilm formation assays indicated that a single chitosan layer was incapable of hindering the adhesion of a Staphylococcus aureus bacterial strain, while up to 30% reduction was achieved by the chitosan/pectin layered assembly. On the other hand, chitosan and chitosan/pectin multilayer could retard Escherichia coli adhesion by 50% and 20%, respectively. Furthermore, plasma treated and graft copolymerized samples were also found effective to diminish the degree of adherence of Escherichia coli.
- MeSH
- absorpce účinky léků MeSH
- bakteriální adheze účinky léků MeSH
- biofilmy účinky léků MeSH
- biokompatibilní potahované materiály farmakologie MeSH
- Escherichia coli cytologie účinky léků fyziologie MeSH
- fotoelektronová spektroskopie MeSH
- mikroskopie elektronová rastrovací MeSH
- molekulární modely MeSH
- polysacharidy farmakologie MeSH
- polyvinylchlorid farmakologie MeSH
- smáčivost účinky léků MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- Staphylococcus aureus cytologie účinky léků fyziologie MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Medical-grade polyvinyl chloride was surface modified by a multistep physicochemical approach to improve bacterial adhesion prevention properties. This was fulfilled via surface activation by diffuse coplanar surface barrier discharge plasma followed by radical graft copolymerization of acrylic acid through surface-initiated pathway to render a structured high density brush. Three known antibacterial agents, bronopol, benzalkonium chloride, and chlorhexidine, were then individually coated onto functionalized surface to induce biological properties. Various modern surface probe techniques were employed to explore the effects of the modification steps. In vitro bacterial adhesion and biofilm formation assay was performed. Escherichia coli strain was found to be more susceptible to modifications rather than Staphylococcus aureus as up to 85% reduction in adherence degree of the former was observed upon treating with above antibacterial agents, while only chlorhexidine could retard the adhesion of the latter by 50%. Also, plasma treated and graft copolymerized samples were remarkably effective to diminish the adherence of E. coli.
- MeSH
- antiinfekční látky farmakologie MeSH
- bakteriální adheze MeSH
- benzalkoniové sloučeniny chemie MeSH
- biofilmy MeSH
- biokompatibilní materiály chemie MeSH
- chemické modely MeSH
- chlorhexidin chemie MeSH
- Escherichia coli metabolismus MeSH
- polyvinylchlorid chemie MeSH
- povrchové vlastnosti MeSH
- propylenglykoly chemie MeSH
- racionální návrh léčiv MeSH
- smáčivost MeSH
- Staphylococcus aureus metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Práca sa zaoberá hodnotením rizika liekov s dôrazom na skupinu psychofarmák. Autori hodnotia percepciu rizika v súvislosti s faktormi ovplyvňujúcimi preskripciu liekov a so systémom monitorovania nežiaducich účinkov v medicínskej praxi. Poukazujú na nízku frekvenciu hlásením nežiaducich účinkov v Slovenskej republike, kde pretrváva v spontánnom monitorovaní veľmi nízka aktivita psychiatrov a neurológov. Analyzujú niektoré príčiny nízkej percepcie rizika liekov a hľadajú možnosti prevencie.
An article concerns on drugs risks evaluation with emphasis to psychopharmaceuticals. Authors evaluate perception of risk connected with drug-s prescription influencing factors and a system of adverse events monitoring in medical practice. They refer to low adverse events reports level in Slovak Republic, where low activity of psychiatrists and neurologists persists in spontaneous monitoring. Authors analyse some reasons for low perception of drug risks and seek for possibilities of prevention.
- MeSH
- brániční hernie diagnóza chirurgie komplikace MeSH
- chybná diagnóza MeSH
- dítě MeSH
- klinické laboratorní techniky MeSH
- laparotomie MeSH
- lidé MeSH
- plastická chirurgie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- kazuistiky MeSH
