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The aim of this work was to synthesize a series of semi-interpenetrating polymer networks (semi-IPNs) of 2-hydroxyethyl acrylate and itaconic acid, in the presence of poly(N-vinylpyrrolidone). Samples were synthesized by free radical copolymerization with constant PVP and variable IA content and characterized for structural, morphological, thermal, swelling, drug release, antibacterial and cytotoxic properties. The chemical structure of samples was confirmed by Fourier-transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) was used to examine morphology of samples and glass transition temperatures were determined by differential scanning calorimetry (DCS). The pH and temperature sensitivity was confirmed by measuring the dependence of the degree of swelling on pH and temperature. All samples show volume phase transition temperature (VPTT) around 47 °C. Drug release profiles were investigated using vitamin B3 as a model drug. The vitamin B3 transport mechanism was studied by fitting experimental data to five different model equations and calculating the corresponding parameters. It was also observed that IA content has a marked influence on the release profiles of vitamin B3, so the rate of drug release can be designed by changing the HEA/IA ratio. Cell viability, performed using MTT test, was high for all samples and all concentration of extract used. The antibacterial activity of hydrogels was determined against Pseudomonas aeruginosa. It turns out that IA content and time of exposure have an influence on the antibacterial potential. All samples showed satisfied cell viability. Due to these characteristics, P(HEA/IA)/PVP semi-IPNs represent interesting biomaterials for biomedical applications.

The aim of this study was the development of a non-toxic, biosynthetic antimicrobial agent which selectively acts on only one type of microorganism, and preserves the microbiota. Antimicrobial performance of biosynthesized silver nanoparticles (Ag NPs) by horsetail (Equisetum arvense L.) extract was examined against Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus, as well as yeasts Candida albicans and Saccharomyces boulardii. Also, the cytotoxicity of Ag NPs was examined toward pre-osteoblast cells. The synthetic conditions—concentration of extract, temperature, and pH—were optimized to prepare silver colloids with different particle size distributions and long-term stability. The obtained samples were characterized using transmission electron microscopy, X-ray diffraction analysis, and absorption spectroscopy. The smaller-sized Ag NPs (~ 10–20 nm), prepared at a lower temperature (20 °C), showed better antimicrobial performance against E. coli compared to larger ones (~ 40–60 nm), prepared at high temperature (100 °C). On the other hand, both samples did not display any toxic action against bacteria S. aureus, or yeasts C. albicans and S. boulardii. Non-cytotoxic behavior of Ag NPs toward pre-osteoblast cells was observed for the concentrations of silver ≤ 2.25 and ≤ 4.5 mg L−1 for 10–20 and 40–60 nm-sized Ag NPs, respectively. Biosynthesized Ag NPs by horsetail extract display selective toxic action against E. coli at the ecologically acceptable concentration level., Financial support for this study was granted by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Projects III 45020 and TR 31035).

The antibacterial ability of in situ prepared nanometer-sized silver particles, immobilized in agar-agar films, was studied as a function of the concentration of co-dopant, magnesium ions. Content of inorganic components in hybrid films was determined using inductively coupled plasma optic emission spectroscopy, and found to be low (

This study was aimed to highlight the possibility of cotton fabric impregnation with silver nanoparticles synthesized by dextran isolated from Leuconostoc mesenteroides T3 in order to obtain antimicrobial properties. The fabrication of dextran was proved by FTIR spectroscopy. Particle sizes of synthesized dextran and silver nanoparticles were measured by dynamic light scattering method. The presence of silver nanoparticles on the surface of cotton fabric was confirmed by scanning electron microscopy, X-ray diffraction measurements and reflectance spectrophotometry. Antimicrobial activity of cotton fabric impregnated with silver nanoparticles was tested against bacteria Escherichia coli and Staphylococcus aureus, and fungus Candida albicans. The results indicated that synthesized silver nanoparticles can provide satisfactory antimicrobial activity. However, maximum reduction (99.9%) of all tested microorganisms can be obtained only when 1.0mmolL(-1) colloid consisting of silver nanoparticles is applied.

In this study, three series of hydrogels based on 2-hydroxyethyl acrylate and itaconic acid, unloaded, with incorporated copper(II) ions and reduced copper, were successfully prepared, characterized and evaluated as novel wound healing materials. Fourier transform infrared spectroscopy (FTIR) confirmed the expected structure of obtained hydrogels. Scanning electron microscopy (SEM) revealed porous morphology of unloaded hydrogels, and the morphological modifications in case of loaded hydrogels. Thermal characteristics were examined by differential scanning calorimetry (DSC) and the glass transition temperatures were observed in range of 12-50 degrees C. Swelling study was conducted in wide range of pHs at 37 degrees C, confirming pH sensitive behaviour for all three series of hydrogels. The in vitro copper release was investigated and the experimental data were analysed using several models in order to elucidate the transport mechanism. The antimicrobial assay revealed excellent antimicrobial activity, over 99% against Escherichia coli, Staphylococcus aureus and Candida albicans, as well as good correlation with the copper release experiments. In accordance with potential application, water vapour transmission rate, oxygen penetration, dispersion characteristics, fluid retention were observed and the suitability of the hydrogels for wound healing application was discussed.

The TiO2 based hybrid supports with different functional groups (amino, glutaraldehyde or epoxy) were prepared and their influence on immobilization of dextransucrase (DS) was studied. Novel synthetic route for surface modification of TiO2 with amino and glutaraldehyde groups was developed taking advantage of charge transfer complex (CTC) formation between surface Ti atoms and salicylate-type of ligand (5 aminosalicylic acid (5-ASA)). The proposed coordination of 5-ASA to the surface of TiO2 powder and optical properties of CTC was presented. The pristine TiO2 and amino functionalized TiO2 have higher sorption capacity for DS (12.6 and 12.0 mg g(-1), respectively) compared to glutaraldehyde and epoxy activated supports (9.6 and 9.8 mg g(-1) respectively). However, immobilized enzyme to either glutaraldehyde or epoxy functionalized TiO2 have almost two times higher expressed activities compared to pristine TiO2 support (258, 235 and 142 IU g(-1), respectively). Thermal stability of enzyme immobilized on glutaraldehyde and epoxy functionalized supports was studied at 40 degrees C, as well as operational stability under long-run working conditions in repeated cycles. After five cycles, DS imobilized on glutaraldehyde activated support retained almost 70% of its initial expressed activity, while, after five cycles, performance of DS immobilized on epoxy activated support was significantly lower (15%).

In this work, antimicrobial bioinspired films made from chitosan incorporated with triclosan were investigated. The tensile strenght of these films were in the range of 33 and 39 MPa, which presented satisfied mechanical stability comparable to the synthetic-based packages commonly used in industry. The addition of triclosan enhanced thermal stability and antimicrobial activity of chitosan films against Escherichia coli and Staphylococus aureus . Results obtained in this work demonstrated that chitosan/triclosan films could be potentially used as an eco-sustainable package in healthcare sector to prevent infections/contaminations.