Preparation of Light-responsive Membranes by a Combined Surface Grafting and Postmodification Process

In order to modify the surface tension of commercial available track-edged polymer membranes, a procedure of surface-initiated polymerization is ...

Empa, Swiss Federal Laboratories for Materials Science and Technology

Biomaterials releasing silver (Ag) are of interest because of their ability to inhibit pathogenic bacteria including antibiotic-resistant strains. In order to investigate the potential of nanometre-thick Ag polymer (Ag/amino-hydrocarbon) nanocomposite plasma coatings, we studied a comprehensive range of factors such as the plasma deposition process and Ag cation release as well as the antibacterial and cytocompatible properties. The nanocomposite coatings released most bound Ag within the first day of immersion in water yielding an antibacterial burst. The release kinetics correlated with the inhibitory effects on the pathogens Pseudomonas aeruginosa or Staphylococcus aureus and on animal cells that were in contact with these coatings. We identified a unique range of Ag content that provided an effective antibacterial peak release, followed by cytocompatible conditions soon thereafter. The control of the in situ growth conditions for Ag nanoparticles in the polymer matrix offers the possibility to produce customized coatings that initially release sufficient quantities of Ag ions to produce a strong adjacent antibacterial effect, and at the same time exhibit a rapidly decaying Ag content to provide surface cytocompatibility within hours/days. This approach seems to be favourable with respect to implant surfaces and possible Ag-resistance/tolerance built-up.

Antibacterial burst-release from minimal Ag-containing plasma polymer coatings.

Biomat&eacute;riaux, lib&eacute;rant l&#39;argent (Ag) est int&eacute;ressantes en raison de leur capacit&eacute; &agrave; inhiber les bact&eacute;ries pathog&egrave;nes, y compris les souches r&eacute;sistantes aux antibiotiques. Afin d&#39;&eacute;tudier le potentiel de nanom&egrave;tres d&#39;&eacute;paisseur Ag polym&egrave;re (Ag/amino-hydrocarbures) nanocomposite plasma rev&ecirc;tements, nous avons &eacute;tudi&eacute; une gamme compl&egrave;te de facteurs telles que le proc&eacute;d&eacute; de d&eacute;p&ocirc;t de plasma et le cation Ag version ainsi que les propri&eacute;t&eacute;s antibact&eacute;riennes et cytocompatible. Les rev&ecirc;tements nanocomposites sorti Ag plus li&eacute; au sein de la premi&egrave;re journ&eacute;e d&#39;immersion dans l&#39;eau, ce qui donne un antibact&eacute;rien &eacute;clater. La cin&eacute;tique de lib&eacute;ration en corr&eacute;lation avec les effets inhibiteurs sur les agents pathog&egrave;nes Pseudomonas aeruginosa ou Staphylococcus aureus et sur des cellules animales qui ont &eacute;t&eacute; en contact avec ces rev&ecirc;tements. Nous avons identifi&eacute; un contenu unique gamme de Ag qui fourni une version pic antibact&eacute;rien efficace, suivie peu apr&egrave;s de cytocompatible conditions. Le contr&ocirc;le des conditions in situ de la croissance pour les nanoparticules Ag dans la matrice polym&egrave;re offre la possibilit&eacute; de produire des rev&ecirc;tements sur mesure qui initialement lib&egrave;rent des quantit&eacute;s suffisantes d&#39;ions Ag pour produire un fort effet antibact&eacute;rien adjacent et &agrave; l&#39;exposition de temps m&ecirc;me une teneur en Ag rapidement en d&eacute;composition pour fournir des cytocompatibility de surface dans les heures/jours. Cette approche semble &ecirc;tre favorable en ce qui concerne les surfaces de l&#39;implant et possible Ag-r&eacute;sistance/tol&eacute;rance b&acirc;tie.

Antibact&eacute;rien rafale-lib&eacute;ration de rev&ecirc;tements de polym&egrave;res plasma Ag contenant un minimum.

Biomateriali rilasciando argento (Ag) sono di interesse a causa della loro capacit&agrave; di inibire i batteri patogeni, compresi i ceppi resistenti agli antibiotici. Al fine di indagare le potenzialit&agrave; dei rivestimenti plasma di nanometro-spessore Ag polimero (Ag/ammino-idrocarburi) nanocompositi, abbiamo studiato una gamma completa di fattori come il processo di deposizione al plasma e il catione Ag rilasciare cos&igrave; come le propriet&agrave; antibatteriche e cytocompatible. I rivestimenti nanocompositi rilasciato pi&ugrave; vincolato Ag entro il primo giorno di immersione in acqua producendo un antibatterico scoppiato. La cinetica di rilascio correlata con gli effetti inibitori sui patogeni Pseudomonas aeruginosa o Staphylococcus aureus e su cellule animali che sono stati a contatto con questi rivestimenti. Abbiamo individuato un contenuto di gamma unica di Ag che ha fornito un rilascio efficace antibatterico picco, seguito poco dopo da cytocompatible condizioni. Il controllo delle condizioni di crescita in situ per le nanoparticelle Ag nella matrice polimerica offre la possibilit&agrave; di produrre rivestimenti personalizzati che inizialmente rilasciare una quantit&agrave; sufficiente di ioni Ag per produrre un forte effetto antibatterico adiacente e presso la stessa esposizione di tempo un contenuto Ag decadere rapidamente a fornire cytocompatibility superficie entro ore o giorni. Questo approccio sembra essere favorevole per quanto riguarda le superfici dell&#39;impianto e possibile Ag-resistenza/tolleranza edificata.

Antibatterico burst-rilascio da minimi rivestimenti polimerici plasma contenente Ag.

As opposed to culture on standard tissue-treated plastic, cell culture on three-dimensional scaffolds impedes additional challenges with respect to substrate preparation, cell seeding, culture maintenance, and analysis. We herewith present a general route for the culture of primary cells, differentiated cells, or stem cells on plasma-coated, electrospun scaffolds. We describe a method to prepare and fix the scaffolds in culture wells and discuss a convenient method for cell seeding and subsequent analysis by scanning electron microscopy or immunohistology.

General protocol for the culture of cells on plasma-coated electrospun scaffolds.

Cardiac tissue engineering approaches can deliver large numbers of cells to the damaged myocardium and have thus increasingly been considered as a possible curative treatment to counteract the high prevalence of progressive heart failure after myocardial infarction (MI). Optimal scaffold architecture and mechanical and chemical properties, as well as immune- and bio-compatibility, need to be addressed. We demonstrated that radio-frequency plasma surface functionalized electrospun poly(ɛ-caprolactone) (PCL) fibres provide a suitable matrix for bone-marrow-derived mesenchymal stem cell (MSC) cardiac implantation. Using a rat model of chronic MI, we showed that MSC-seeded plasma-coated PCL grafts stabilized cardiac function and attenuated dilatation. Significant relative decreases of 13% of the ejection fraction (EF) and 15% of the fractional shortening (FS) were observed in sham treated animals; respective decreases of 20% and 25% were measured 4weeks after acellular patch implantation, whereas a steadied function was observed 4weeks after MSC-patch implantation (relative decreases of 6% for both EF and FS).

Dirk Hegemann

Laboratory of Advanced Fibers

Empa, Swiss Federal Laboratories for Materials Science and Technology

Preparation of Light-responsive Membranes by a Combined Surface Grafting and Postmodification Process

Dirk Hegemann

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Laboratory of Advanced Fibers

Empa, Swiss Federal Laboratories for Materials Science and Technology

Preparation of Light-responsive Membranes by a Combined Surface Grafting and Postmodification Process

Laboratory of Advanced Fibers