дата: 16 мая 2017 года
время: 14:30-16:00, Ауд. Б607
В данной лекции будут рассказы новейшие достижения в области применения плазменных полимеров для антибактериальных покрытий и биосенсоров.
The biodegradable nanofibers exhibiting antibacterial properties demonstrate a great potential for wound dressing and smart drug delivery applications. A high surface/volume ratio of nanofibers allows to immobilize sufficient amount of biomolecules including antibiotics on their surface. The adjustable leaching of antibiotics can be achieved by tuning the nanofiber-antibiotic linkage and the degradation rate of the nanofibers.
In this work we demonstrate the substrate-independent environment-friendly plasma process aimed at coating of biodegradable nanofibers for immobilization of the antibiotics on their surface. In the first step, the electrospun polycaprolactone (PCL) nanofibers were prepared at optimized conditions leading to the formation of the nanofibrous mesh with an average fibers diameter of 200 nm. The PCL nanofibers were coated by COOH-rich layer using atmospheric plasma co-polymerization of maleic anhydride and acetylene. The modified surface of PCL nanofibers exhibited 8 at.% of COOH- groups measured by trifluoroethylamine chemical derivatization combined with X-ray photoelectron spectroscopy (XPS). The antibiotic (gentamicin) was immobilized on the nanofiber surface using two types of coupling: a covalent bonding between amine group of gentamicin and COOH- group at the modified surface of nanofibers or an ionic bonding of gentamicin to the modified nanofibers. The XPS analysis revealed different chemical states of nitrogen, namely amino groups NH2, amides N-C=O and protonated amines NH3+ . In case of the covalent bonding, a slow long-time drug release is expected, whereas the release of gentamicin immobilized via ionic bond appears to be faster. XPS analysis revealed that gentamicin was immobilized both on the top of nanofibers and inside the nanofibrous foil. Hence, a high capacity of the drug loading was achieved. The plasma-coated biodegradable nanofibers were also characterized in terms of their biocompatibility and antibacterial activity.