surface properties
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The control of the surface properties is an important issue for applicability of polymer membranes interacting with cells. In this work, the influence of surface roughness and stiffness of two polymer membranes on viability and mechanical properties of keratinocytes was studied. Terpolimer polyglicolide, polycaprolactone and polylactide, (PGA-PCL-PLA) and copolymer polycaprolactone, polyglicolide (PGA-PCL) substrates were used for membranes fabrication. Surface modification - the hydrolysis of the obtained membranes was carried out. The analysis of membranes' surface properties revealed that RMS surface roughness and roughness factor of PGA-PCL-PLA membrane decreased after hydrolysis while its stiffness increased. In contrast, the PGA-PCL membrane stiffness was only slightly affected by NaOH treatment. Immortalized human keratinocytes (HaCaT) were grown under standard conditions on the surface of the studied membranes and characterized by means of atomic force microscopy and fluorescence microcopy. The results showed the substrate-dependent effect on cells' properties.
- MeSH
- buněčné linie MeSH
- fluorescenční mikroskopie MeSH
- keratinocyty účinky léků fyziologie MeSH
- lidé MeSH
- membrány chemie MeSH
- mikroskopie atomárních sil MeSH
- polymery chemická syntéza toxicita MeSH
- povrchové vlastnosti * MeSH
- testování materiálů * MeSH
- viabilita buněk MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
In this work we evaluate the applicability of different atomic force microscopy (AFM) modes, such as Phase Shift Imaging, Atomic Force Acoustic Microscopy (AFAM) and Force Spectroscopy, for mapping of the distribution pattern of low-molecular-weight biomimetic groups on polymer biomaterial surfaces. Patterns with either random or clustered spatial distribution of bioactive peptide group derived from fibronectin were prepared by surface deposition of functional block copolymer nano-colloids and grafted with RGDS peptide containing the sequence of amino acids arginine-glycine-aspartic acid-serine (conventionally labeled as RGDS) and carrying biotin as a tag. The biotin-tagged peptides were labeled with 40nm streptavidin-modified Au nanospheres. The peptide molecules were localized through the detection of bound Au nanospheres by AFM, and thus, the surface distribution of peptides was revealed. AFM techniques capable of monitoring local mechanical properties of the surface were proved to be the most efficient for identification of Au nano-markers. The efficiency was successfully demonstrated on two different patterns, i.e. random and clustered distribution of RGDS peptides on structured surface of the polymer biomaterial.
Silver doped diamond-like carbon layers were deposited by dual pulsed laser deposition using two KrF excimer lasers. The concentration of Ag, determined by XPS and WDS, moved from zero to ~10at%. We found that the sp2/sp3ratio, film roughness and the number of droplets (SEM and AFM) increased with increasing silver concentration. The sp3content measurement (XPS) was influenced by ion cluster surface sputtering and varied from 71.0% (undoped DLC) to 36.2% (for 9.3at% Ag). Transmission was measured on the scale from 200nm to 1100nm, and decreased with increasing silver content. An increase of Ag content has an effect on the decrease of the storage modulus (E') and the indentation hardness (HIT). The highest values HIT=51.9GPa and E'=270.6GPa were measured on a sample with 0at% Ag. The lowest values HIT=26.0GPa and E'=180.2GPa were measured on a sample of 9.3at% Ag. Film adhesion was studied using the scratch test and was up to 20.8N for the highest Ag concentration. The contact angle (CA) measurements for water showed that the CA of Ag-DLC films was higher (78°-98°) that of DLC film (77°). The surface free energy of DLC and of Ag-DLC was about 40mJ·m-2. Antibacterial properties were studied using gram positive and gram negative bacteria. The antibacterial effects increased with the Ag concentration and were ~99.9% after 24h for the layers with the highest silver content (9.3at%). Our results demonstrate that the Ag-doped DLC films are potentially useful biomaterials having both good mechanical properties and antimicrobial characteristics. PRIME NOVELTY STATEMENT: Unique manufacturing technique dual pulsed laser deposition was applied on hydrogen-free diamond-like carbon doped by Ag including topological, physical and antibacterial characterization.
- MeSH
- antibakteriální látky chemie MeSH
- diamant MeSH
- povrchové vlastnosti MeSH
- pyridoxal analogy a deriváty MeSH
- stříbro MeSH
- uhlík MeSH
- Publikační typ
- časopisecké články MeSH
