A novel method is successfully tested for non-covalent imprinting. Conditions are used which practically exclude the formation of prepolymerization complexes. The template is cholesterol, and no so-called functional monomer is used. The polymers contain only an acrylic diester crosslinker. The porogen isopropanol prevents even hydrogen bonding between the template and the monomer in the prepolymerization solution. Despite of these apparently very disadvantageous conditions, appreciable imprinting factors for cholesterol and imprinted selectivity against some other steroids are observed, similar to other cholesterol MIPs with proven analytical usefulness.

High fatty acid (FA) levels are deleterious to pancreatic β-cells, largely due to the accumulation of biosynthetic lipid intermediates, such as ceramides and diglycerides, which induce ER stress and apoptosis. Toxicity of palmitate (16:0) and oleate (18:1 cis-Δ9) has been widely investigated, while very little data is available on the cell damages caused by elaidate (18:1 trans-Δ9) and vaccenate (18:1 trans-Δ11), although the potential health effects of these dietary trans fatty acids (TFAs) received great publicity. We compared the effects of these four FAs on cell viability, apoptosis, ER stress, JNK phosphorylation and autophagy as well as on ceramide and diglyceride contents in RINm5F insulinoma cells. Similarly to oleate and unlike palmitate, TFAs reduced cell viability only at higher concentration, and they had mild effects on ER stress, apoptosis and autophagy. Palmitate increased ceramide and diglyceride levels far more than any of the unsaturated fatty acids; however, incorporation of TFAs in ceramides and diglycerides was strikingly more pronounced than that of oleate. This indicates a correlation between the accumulation of lipid intermediates and the severity of cell damage. Our findings reveal important metabolic characteristics of TFAs that might underlie a long term toxicity and hence deserve further investigation.

Dietary trans fatty acids (TFAs) have been implicated in serious health risks, yet little is known about their cellular effects and metabolism. We aim to undertake an in vitro comparison of two representative TFAs (elaidate and vaccenate) to the best-characterized endogenous cis-unsaturated FA (oleate). The present study addresses the possible protective action of TFAs on palmitate-treated RINm5F insulinoma cells with special regards to apoptosis, endoplasmic reticulum stress and the underlying ceramide and diglyceride (DG) accumulation. Both TFAs significantly improved cell viability and reduced apoptosis in palmitate-treated cells. They mildly attenuated palmitate-induced XBP-1 mRNA cleavage and phosphorylation of eukaryotic initiation factor 2α (eIF2α) and stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK), but they were markedly less potent than oleate. Accordingly, all the three unsaturated FAs markedly reduced cellular palmitate incorporation and prevented harmful ceramide and DG accumulation. However, more elaidate or vaccenate than oleate was inserted into ceramides and DGs. Our results revealed a protective effect of TFAs in short-term palmitate toxicity, yet they also provide important in vitro evidence and even a potential mechanism for unfavorable long-term health effects of TFAs compared to oleate.

Recent studies have shown anomalies with the most studied non-covalent molecularly imprinted polymer, the propranolol imprinted one. This imprinted polymer, like many others, binds more template than the non-imprinted control polymer, but its selectivity in template adsorption is only slightly or not at all improved by imprinting, depending on the compound compared. The reasons for this anomaly are discovered here. Simple experiments show that acid homoassociation in the prepolymerisation complex is the likely cause of the anomaly. The specific conductivity of prepolymerization mixtures at different functional monomer to template ratios follows a pattern observed in homoassociating systems. Analysis of the optimal prepolymerization mixture shows that on average two molecules of the functional monomer are complexed to the basic template, even if the template lacks any other hydrogen bonding functional group than the amino group. Molecular modeling calculations provide the structure and stability of the homoassociated prepolymerization complexes. These results lead to a plausible interpretation of the anomaly, which may not be unique for the propranolol imprinted polymer, but may affect all imprinted polymers made for basic templates by using acidic functional monomers. The analytical applications of the new imprinting model are demonstrated.

One of the main reasons for making molecularly imprinted polymers (MIPs) has been that MIPs interact selectively with a specific target compound. This claim is investigated here with the example of a widely used type of noncovalent MIP, the MIP for the beta blocker propranolol. Adsorption isotherms of this MIP and of a nonimprinted control polymer (NIP), respectively, have been measured with a series of compounds in the porogen solvent acetonitrile. The results, visualized as “selectivity ladders”, show that the MIP binds propranolol and many other amines better than the NIP does, but the selectivity of the MIP is actually inferior to that of the NIP. The selectivity of either polymer for propranolol is modest against many amines, but is remarkable with respect to other compounds. The contribution of imprinting towards selectivity can be better appreciated when three MIPs, made with different amine templates, are compared among themselves. Each MIP is seen to bind its own template slightly better than the other two MIPs do. In media different from the porogen, the selectivity patterns may change substantially. Propranolol seems to have properties that make it stand high on the selectivity scale in different solvents, albeit for different reasons.

SZV 1287 (3-(4,5-diphenyl-1,3-oxazol-2-yl)propanal oxime) is a novel multi-target candidate under preclinical development for neuropathic pain. It inhibits amine oxidase copper containing 3, transient receptor potential ankyrin 1 and vanilloid 1 (TRPV1) receptors. Mainly under acidic conditions, it is transformed to the cyclooxygenase inhibitor oxaprozin, which is ineffective for neuropathy. Therefore, an enterosolvent capsule is suggested for oral formulation, which we investigated for nociception, basic kinetics, and thermoregulatory safety in mice. The antihyperalgesic effect of SZV 1287 (10, 20, 50, and 200 mg/kg, p.o.) was determined in partial sciatic nerve ligation-induced traumatic neuropathy by aesthesiometry, brain and plasma concentrations by HPLC, and deep body temperature by thermometry. Its effect on proton-induced TRPV1 activation involved in thermoregulation was assessed by microfluorimetry in cultured trigeminal neurons. The three higher SZV 1287 doses significantly, but not dose-dependently, reduced neuropathic hyperalgesia by 50% of its maximal effect. It was quickly absorbed; plasma concentration was stable for 2 h, and it entered into the brain. Although SZV 1287 significantly decreased the proton-induced TRPV1-mediated calcium-influx potentially leading to hyperthermia, it did not alter deep body temperature. Oral SZV 1287 inhibited neuropathic hyperalgesia and, despite TRPV1 antagonistic action and brain penetration, it did not influence thermoregulation, which makes it a promising analgesic candidate.