61 research outputs found
Binding fullerenol C60(OH)24 to dsDNA
The first C60(OH)24-DNA complex and its fluorescence enhancement is reported. The enhanced fluorescence intensity of fullerenol C60(OH)24 is in proportion to the concentration of DNA in the range of 1 × 10−9 to 8 × 10−5 molL−1 and the detection limit was 1.3 ng mL−1. Fullerenol C60(OH)24 binds significantly to the phosphate backbone of native dsDNA and to base-pairs within the major groove of sodium salt of dsDNA
In silico study of PEI-PEG-squalene-dsDNA polyplex formation: the delicate role of the PEG length in the binding of PEI to DNA
Using a two step simulation protocol the atomistic interactions between PEG and b-PEI and the effect of these interactions on DNA binding were determined
Synthetic Approaches to Novel Human Carbonic Anhydrase Isoform Inhibitors Based on Pyrrol-2-one Moiety
New dihydro-pyrrol-2-one compounds, featuring dual sulfonamide groups, were synthesized through a one-pot, three-component approach utilizing trifluoroacetic acid as a catalyst. Computational analysis using density functional theory (DFT) and condensed Fukui function explored the structure-reactivity relationship. Evaluation against human carbonic anhydrase isoforms (hCA I, II, IX, XII) revealed potent inhibition. The widely expressed cytosolic hCA I was inhibited across a range of concentrations (K-I 3.9-870.9 nM). hCA II, also cytosolic, exhibited good inhibition as well. Notably, all compounds effectively inhibited tumor-associated hCA IX (K-I 1.9-211.2 nM) and hCA XII (low nanomolar). Biological assessments on MCF7 cancer cells highlighted the compounds' ability, in conjunction with doxorubicin, to significantly impact tumor cell viability. These findings underscore the potential therapeutic relevance of the synthesized compounds in cancer treatment
Antibacterial Polysiloxane Polymers and Coatings for Cochlear Implants
Within this study, new materials were synthesized and characterized based on polysiloxane modified with different ratios of N-acetyl-l-cysteine (NAC) and crosslinked via UV-assisted thiol-ene addition, in order to obtain efficient membranes able to resist bacterial adherence and biofilm formation. These membranes were subjected to in vitro testing for microbial adherence against S. pneumoniae using standardized tests. WISTAR rats were implanted for 4 weeks with crosslinked siloxane samples without and with NAC. A set of physical characterization methods was employed to assess the chemical structure and morphological aspects of the new synthetized materials before and after contact with the microbiological medium
Dextran Formulations as Effective Delivery Systems of Therapeutic Agents
Dextran is by far one of the most interesting non-toxic, bio-compatible macromolecules, an exopolysaccharide biosynthesized by lactic acid bacteria. It has been extensively used as a major component in many types of drug-delivery systems (DDS), which can be submitted to the next in-vivo testing stages, and may be proposed for clinical trials or pharmaceutical use approval. An important aspect to consider in order to maintain high DDS’ biocompatibility is the use of dextran obtained by fermentation processes and with a minimum chemical modification degree. By performing chemical modifications, artefacts can appear in the dextran spatial structure that can lead to decreased biocompatibility or even cytotoxicity. The present review aims to systematize DDS depending on the dextran type used and the biologically active compounds transported, in order to obtain desired therapeutic effects. So far, pure dextran and modified dextran such as acetalated, oxidised, carboxymethyl, diethylaminoethyl-dextran and dextran sulphate sodium, were used to develop several DDSs: microspheres, microparticles, nanoparticles, nanodroplets, liposomes, micelles and nanomicelles, hydrogels, films, nanowires, bio-conjugates, medical adhesives and others. The DDS are critically presented by structures, biocompatibility, drugs loaded and therapeutic points of view in order to highlight future therapeutic perspectives
Innovative Non-Enzymatic Electrochemical Quantification of Cholesterol
The use of the Liebermann–Burchard reaction in this study has been explored in the development of a simple, reliable, and robust quantitative electrochemical method to assay cholesterol, and hence provide a good alternative to colorimetric methods. The optimization of batch mode operation for electrochemical oxidation of cholesterol in the Liebermann–Burchard reagents included the applied potential and acidic volume. Tested using chronoamperometry, the developed method showed a high sensitivity (14.959 μA mM−1) and low detection limit (19.78 nM) over a 0.025–3 mM concentration range, with remarkable linearity (R2 = 0.999), proving an analytical performance either higher or comparable to most of the cholesterol sensors discussed in literature. The influence of possible interfering bioactive agents, namely, glucose, uric acid, ascorbic acid, KCl and NaCl, has been evaluated with no or negligible effects on the measurement of cholesterol. Our study was directed at finding a new approach to chemical processing arising from the use of external potential as an additional level of control for chemical reactions and the transfer of electrons between surfaces and molecules. Finally, the optimized method was successfully applied for the determination of cholesterol content in real blood samples
Dextran Formulations as Effective Delivery Systems of Therapeutic Agents
Dextran is by far one of the most interesting non-toxic, bio-compatible macromolecules, an exopolysaccharide biosynthesized by lactic acid bacteria. It has been extensively used as a major component in many types of drug-delivery systems (DDS), which can be submitted to the next in-vivo testing stages, and may be proposed for clinical trials or pharmaceutical use approval. An important aspect to consider in order to maintain high DDS’ biocompatibility is the use of dextran obtained by fermentation processes and with a minimum chemical modification degree. By performing chemical modifications, artefacts can appear in the dextran spatial structure that can lead to decreased biocompatibility or even cytotoxicity. The present review aims to systematize DDS depending on the dextran type used and the biologically active compounds transported, in order to obtain desired therapeutic effects. So far, pure dextran and modified dextran such as acetalated, oxidised, carboxymethyl, diethylaminoethyl-dextran and dextran sulphate sodium, were used to develop several DDSs: microspheres, microparticles, nanoparticles, nanodroplets, liposomes, micelles and nanomicelles, hydrogels, films, nanowires, bio-conjugates, medical adhesives and others. The DDS are critically presented by structures, biocompatibility, drugs loaded and therapeutic points of view in order to highlight future therapeutic perspectives
- …