Szczegóły: Diffusion and Defect Data – Solid State Data. Part B 227 (2015) 499–502
Szczegóły: Acta of Bioengineering and Biomechanics 17(3) (2015) 41–48
Since there are more and more cases of multiresistance among microorgani sms, rational use of antibiotics (especially their systemic vs. local application)is of great importance. Here we propose polymeric nanoparticles as locally applied gentamicin delivery system useful in osteomyelitis therapy. Gentamicin sulphate (GS) was encapsulated in the poly(lactide-co-glycolide)(PLGA 85:15)nanoparticles by double emulsification (water/oil/water, W1/O/W2). The nanoparticles were characterized by dynamic light scattering, laser electrophoresis and atomic force microscopy. UV-vis spectroscopy (O-phthaldialdehyde assay, OPA) and Kirby-Bauer tests were used to evaluate drug release and antimicrobial activity, respectively. Physicochemical characterization showed that size, shape and drug solubilization of the nanoparticles mainly depended on GS content and concentration of surface stabilizer (polyvinyl alcohol, PVA). Laser electrophoresis demonstrated negative value of zeta potential of the nanoparticles attributed to PLGA carboxyl end group presence. Drug release studies showed initial burst release followed by prolonged 35-day sustained gentamicin delivery.Agar-diffusion tests performed with pathogens causing osteomyelitis (Staphylococcus aureus and Staphylococcus epidermidis, both reference strains and clinical isolates) showed antibacterial activity of GS loaded nanoparticles (GS-NPs). It can be concluded that GS-NPs are a promising form of biomaterials useful in osteomyelitis therapy.
Szczegóły: Surface and Coatings Technology 276 (2015) 23–30
The surface of Ti–13Nb–13Zr alloy was modified in 0.1 M calcium hypophosphite (Ca(H2PO2)2) solutions via the addition of tricalcium phosphate, wollastonite or silica powders using a plasma electrolytic oxidation process. Depending on the anodizing bath chemical composition and applied voltage, various oxide layers were formed on the substrate. The water contact angle of the oxide layer was measured. The biological investigations using osteoblast-like cells MG-63 showed that the suspensions utilized during anodization strongly influenced the oxide layer bioactivity. Only the traces of the alloy elements were involved in Ringer solution after 5 months of immersion.
Szczegóły: Materials Letters 139 (2015) 344–347
In the current study, the effect of post-plasma grafting of 2-aminoethyl methacrylate (AEMA) and the subsequent covalent immobilization of gelatin (GelB) on poly(-lactide-co-glycolide) (PLGA) thin films were investigated. The applied modification resulted in surface chemistry changes of PLGA. More specifically, an increase of nitrogen from 0 at% to 14 at% with a concomitant decrease in carbon and oxygen concentration was observed. The samples were more hydrophilic after the treatment as reflected by a decrease of the water contact angle from 72° to 33° and more rough at the nanoscale as shown by atomic force microscopy (increase of Ra roughness from 0.7 nm to 10 nm). The growth of osteoblast-like MG-63 cells was enhanced on biofunctionalised PLGA-AEMA-GelB surfaces and the cells were more homogenously distributed than on non-modified PLGA. Our findings are especially important for tissue engineering applications, where substrates supporting homogenous cell cultures are particularly promising.