Aiming to improve the sensitivity and specificity of environmental analysis of sertraline residues, we investigated the use of molecularly imprinted polymers (MIPs) as the solid phase extraction sorbents for rebinding of the parent drug, its metabolite norsertaline and its transformation product (TP) sertraline ketone. MIPs were synthesized using the antidepressant sertraline as the target, where two polymerisation approaches were used: polymerisation in solvent and two-stage polymerisation. Leaching of sertraline from the imprinted material presented a major problem in case of MIPs polymerised in solvent. On the contrary, by synthetizing MIPs with the two-stage polymerisation approach, sertraline was removed to below the limit of quantification (LOQ). Two MIPs were selected that showed the best binding characteristics during the solid phase extraction rebinding experiments: one was prepared by polymerisation in solvent and another one by two-stage polymerisation. The former bound norsertraline and sertraline ketone in a high binding ratio compared to its non-imprinted analogue, while the latter had the highest imprinting factor for sertraline. Based on the proved cross-selectivity of MIPs, we propose their use in enrichment, purification and isolation of transformation products, including novel compounds that have before not been recognised
COBISS.SI-ID: 31632679
A combination of hard sphere and high internal phase emulsion templating gives a platform for synthesizing hierarchically porous polymers with a unique topology exhibiting interconnected spherical features on multiple levels. Polymeric spheres are fused by thermal sintering to create a 3D monolithic structure while an emulsion with a high proportion of internal phase and monomers in the continuous phase is added to the voids of the previously constructed monolith. Following polymerization of the emulsion and dissolution of the templating structure, a down-replicating topology is created with a primary level of pores as a result of fused spheres of the 3D monolithic structure, a secondary level of pores resulting from the emulsion's internal phase, and a tertiary level of interconnecting channels. Thiol-ene chemistry with divinyladipate and pentaerythritol tetrakis(3-mercaptopropionate) is used to demonstrate the preparation of a crosslinked polyester with overall porosity close to 90%. Due to multilevel porosity, such materials are interesting for applications in bone tissue engineering, possibly simulating the native sponge like bone structure. Their potential to promote ossteointegration is tested using human bone derived osteoblasts. Material-cell interactions are evaluated and they reveal growth and proliferation of osteoblasts both on surface and in the bulk of the scaffold.
COBISS.SI-ID: 21006358
For the isolation of selected phenolic compounds from dried chokeberries, natural deep eutectic solvents (NADESs) were investigated as a green alternative to conventionally used extraction solvents. Four types of NADESs were synthesised, with choline chloride as the hydrogen bond acceptor in combination with different hydrogen bond donors (sugars, organic acid and urea). Ultrasound-assisted extraction was used to improve the extractability of the phenolic compounds and the results were compared to those obtained with 80% methanol as the extraction media. The highest values of total phenols and total flavonoids were found in the extract obtained with choline chloride–fructose NADES (36.15 ± 3.39 mg gallic acid g-1 dry weight (DW) and 4.71 ± 0.33 mg rutin g-1 DW, respectively). The extraction recoveries for the individual phenolic compounds depended strongly on the phenolic compound’s structure, with relative mean values between 70% and 97%.
COBISS.SI-ID: 1538563011
Magnesium (Mg) and its alloys are third-generation biomedical implant material in the biomedical field. The limitation of using Mg in medical applications is its rapid corrosion rate. In the present work, for the first time, AZ91 magnesium alloy surface treated with the inductively coupled Ar/O2 Plasma process to decrease the corrosion rate of the alloy. The oxidation mechanism and surface analysis have been investigated in detail. The electrochemical studies in SBF solution reveal that plasma modified surface increases the corrosion resistance of the alloy compared to the untreated surface.
COBISS.SI-ID: 22992662
AAA+ disaggregases solubilize aggregated proteins and confer heat tolerance to cells. Their disaggregation activities crucially depend on partner proteins, which target the AAA+ disaggregases to protein aggregates while concurrently stimulating their ATPase activities. Here, we report on two potent ClpG disaggregase homologs acquired through horizontal gene transfer by the species Pseudomonas aeruginosa and subsequently abundant P. aeruginosa clone C. ClpG exhibits high, stand-alone disaggregation potential without involving any partner cooperation. Specific molecular features, including high basal ATPase activity, a unique aggregate binding domain, and almost exclusive expression in stationary phase distinguish ClpG from other AAA+ disaggregases. Consequently, ClpG largely contributes to heat tolerance of P. aeruginosa primarily in stationary phase and boosts heat resistance 100-fold when expressed in Escherichia coli. This qualifies ClpG as a potential persistence and virulence factor in P. aeruginosa.
COBISS.SI-ID: 23563528