The construction of functional micro- or nanostructured surfaces is extensively studied since they are able to provide multifunctional properties and for large variety of potential applications in fields such as tissue engineering, wearable electronics or microfluidics. The micro- or nanosized surfaces can be easily prepared by various lithography techniques, also additional modifications (laser exposure, metal deposition and further processing) and which can induce new applicable properties on the basis of synergic effect by combining aforementioned approaches. In this work we have focused on the polytetrafluoroethylene (PTFE) nanotextile with specific bimetallic nanostructures. Our primary target was to find optimal surface modification of silver/gold coated surface, which would induce strong antibacterial response to both gram-positive and/or gram-negative bacteria. We have used plasma-modified polytetrafluoroethylene nanotextile as a substrate, onto which silver and gold nanolayers were deposited by sputtering. The foils were further subjected to "single-shot" exposure to an excimer KrF laser and some samples were also thermally stressed before exposure. Such surfaces were further examined in terms of surface morphology and chemical composition. The surface was investigated for antibacterial properties. Their antimicrobial activity was examined in vitro against the bacteria Escherichia coli and Staphylococcus epidermidis strains. The surface of the prepared materials was replicated into a lactic acid polymer and the properties were again investigated in terms of surface morphology and surface chemistry. The results demonstrated construction of antibacterial surfaces with excellent resistance to bacteria E. coli for bimetallic structures on PTFE. Excimer laser induced bimetallic pattern exhibited also significant antibacterial properties for S. epidermidis. Replication of bimetallic pattern was also demonstrated.

• Klíčová slova
• Antibacterial properties, Bimetallic nanopattern, Laser exposure, Nanostructure, Nanotextile, Noble metal, PTFE, Polymer, Replication,
• Publikační typ
• časopisecké články MeSH

PURPOSE: The present study aims to prepare poly(D,L-lactic acid) (PLA) nanofibers loaded by the immunosuppressant cyclosporine A (CsA, 10 wt%). Amphiphilic poly(ethylene glycol)s (PEG) additives were used to modify the hydrophobic drug release kinetics. METHODS: Four types of CsA-loaded PLA nanofibrous carriers varying in the presence and molecular weight (MW) of PEG (6, 20 and 35 kDa) were prepared by needleless electrospinning. The samples were extracted for 144 h in phosphate buffer saline or tissue culture medium. A newly developed and validated LC-MS/MS method was utilized to quantify the amount of released CsA from the carriers. In vitro cell experiments were used to evaluate biological activity. RESULTS: Nanofibers containing 15 wt% of PEG showed improved drug release characteristics; significantly higher release rates were achieved in initial part of experiment (24 h). The highest released doses of CsA were obtained from the nanofibers with PEG of the lowest MW (6 kDa). In vitro experiments on ConA-stimulated spleen cells revealed the biological activity of the released CsA for the whole study period of 144 h and nanofibers containing PEG with the lowest MW exhibited the highest impact (inhibition). CONCLUSIONS: The addition of PEG of a particular MW enables to control CsA release from PLA nanofibrous carriers. The biological activity of CsA-loaded PLA nanofibers with PEG persists even after 144 h of previous extraction. Prepared materials are promising for local immunosuppression in various medical applications.

• Klíčová slova
• LC-MS/MS, cyclosporine A, drug release kinetics, poly(D,L-lactic acid) nanofibers, poly(ethylene glycol),
• MeSH
• buněčné linie MeSH
• cyklosporin aplikace a dávkování   chemie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• imunosupresiva aplikace a dávkování   chemie   MeSH
• kinetika MeSH
• kultivační média MeSH
• lidé MeSH
• nanovlákna chemie   MeSH
• nosiče léků MeSH
• polyestery chemie   MeSH
• polyethylenglykoly chemie   MeSH
• povrchové vlastnosti MeSH
• slezina cytologie   MeSH
• techniky tkáňových kultur MeSH
• uvolňování léčiv MeSH
• velikost částic MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cyklosporin MeSH
• imunosupresiva MeSH
• kultivační média MeSH
• nosiče léků MeSH
• poly(lactide) MeSH Prohlížeč
• polyestery MeSH
• polyethylenglykoly MeSH

UNLABELLED: Stem cell-based therapy has become an attractive and promising approach for the treatment of severe injuries or thus-far incurable diseases. However, the use of stem cells is often limited by a shortage of available tissue-specific stem cells; therefore, other sources of stem cells are being investigated and tested. In this respect, mesenchymal stromal/stem cells (MSCs) have proven to be a promising stem cell type. In the present study, we prepared MSCs from bone marrow (BM-MSCs) or adipose tissue (Ad-MSCs) as well as limbal epithelial stem cells (LSCs), and their growth, differentiation, and secretory properties were compared. The cells were grown on nanofiber scaffolds and transferred onto the alkali-injured eye in a rabbit model, and their therapeutic potential was characterized. We found that BM-MSCs and tissue-specific LSCs had similar therapeutic effects. Clinical characterization of the healing process, as well as the evaluation of corneal thickness, re-epithelialization, neovascularization, and the suppression of a local inflammatory reaction, were comparable in the BM-MSC- and LSC-treated eyes, but results were significantly better than in injured, untreated eyes or in eyes treated with a nanofiber scaffold alone or with a nanofiber scaffold seeded with Ad-MSCs. Taken together, the results show that BM-MSCs' therapeutic effect on healing of injured corneal surface is comparable to that of tissue-specific LSCs. We suggest that BM-MSCs can be used for ocular surface regeneration in cases when autologous LSCs are absent or difficult to obtain. SIGNIFICANCE: Damage of ocular surface represents one of the most common causes of impaired vision or even blindness. Cell therapy, based on transplantation of stem cells, is an optimal treatment. However, if limbal stem cells (LSCs) are not available, other sources of stem cells are tested. Mesenchymal stem cells (MSCs) are a convenient type of cell for stem cell therapy. The therapeutic potential of LSCs and MSCs was compared in an experimental model of corneal injury, and healing was observed following chemical injury. MSCs and tissue-specific LSCs had similar therapeutic effects. The results suggest that bone marrow-derived MSCs can be used for ocular surface regeneration in cases when autologous LSCs are absent or difficult to obtain.

• Klíčová slova
• Alkali-injured ocular surface, Corneal regeneration, Limbal stem cells, Mesenchymal stem cells, Stem cell-based therapy,
• MeSH
• biologické markery metabolismus   MeSH
• buněčná a tkáňová terapie metody   MeSH
• buněčná diferenciace MeSH
• buňky kostní dřeně cytologie   fyziologie   MeSH
• chemické popálení patologie   terapie   MeSH
• epitelové buňky cytologie   fyziologie   transplantace   MeSH
• exprese genu MeSH
• fyziologická neovaskularizace MeSH
• králíci MeSH
• limbus corneae krevní zásobení   zranění   MeSH
• mezenchymální kmenové buňky cytologie   fyziologie   MeSH
• primární buněčná kultura MeSH
• proliferace buněk MeSH
• reepitalizace fyziologie   MeSH
• rohovkový epitel krevní zásobení   zranění   MeSH
• tkáňové podpůrné struktury MeSH
• transplantace mezenchymálních kmenových buněk * MeSH
• tuková tkáň cytologie   fyziologie   MeSH
• tukové buňky cytologie   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• biologické markery MeSH

Polyvinyl alcohol nanofibers incorporating the wide spectrum antibiotic gentamicin were prepared by Nanospider™ needleless technology. A polyvinyl alcohol layer, serving as a drug reservoir, was covered from both sides by polyurethane layers of various thicknesses. The multilayered structure of the nanofibers was observed using scanning electron microscopy, the porosity was characterized by mercury porosimetry, and nitrogen adsorption/desorption measurements were used to determine specific surface areas. The stability of the gentamicin released from the electrospun layers was proved by high-performance liquid chromatography (HPLC) and inhibition of bacterial growth. Drug release was investigated using in vitro experiments with HPLC/MS quantification, while the antimicrobial efficacy was evaluated on Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa. Both experiments proved that the released gentamicin retained its activity and showed that the retention of the drug in the nanofibers was prolonged with the increasing thickness of the covering layers.

• Klíčová slova
• drug release, electrospinning, gentamicin, morphology, multilayered structure, nanofibers,
• MeSH
• antibakteriální látky aplikace a dávkování   chemie   MeSH
• difuze MeSH
• elektrochemie metody   MeSH
• gentamiciny aplikace a dávkování   MeSH
• grampozitivní bakterie účinky léků   fyziologie   MeSH
• léky s prodlouženým účinkem aplikace a dávkování   chemie   MeSH
• nanokapsle chemie   ultrastruktura   MeSH
• rotace MeSH
• testování materiálů MeSH
• velikost částic MeSH
• viabilita buněk účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibakteriální látky MeSH
• gentamiciny MeSH
• léky s prodlouženým účinkem MeSH
• nanokapsle MeSH