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Poly(thioether‐ester) (PTEe) nanoparticles obtained by thiol‐ene polymerization have received attention of many researchers due to several advantages, including, biocompatibility and biodegradability. The search for new nanomaterials requires toxicity studies to assess potential toxic effects of their administration. Therefore, the aim of this study was to evaluate the in vivo acute toxicity of PTEe and poly(thioether‐ester)‐coated magnetic nanoparticles prepared by thiol‐ene polymerization in miniemulsion. These nanoparticles presented a mean size of approximately 120 nm, spherical morphology, and negative surface charge. Doses of 40 mg/kg were administered intraperitoneally to Swiss mice and nociceptive, behavioral and biochemical parameters were investigated in five different organs. None of the nanoparticles led to any alterations in the nociceptive and behavioral responses. Biochemical alterations were observed in liver, decreasing the sulfhydryl and glutathione (GSH) levels, suggesting the dependence of the GSH metabolism in the elimination of the nanoparticles. In general, both nanoparticle types did not cause disturbances in biochemical parameters analyzed in others organs. These results suggest that both nanoparticle types did not induce acute toxicity to the different organs evaluated, reinforcing the biocompatibility of PTEe nanoparticles synthetized by thiol‐ene polymerization. [ABSTRACT FROM AUTHOR]

In this work, magnetic nanoparticles were encapsulated in PUU by miniemulsion polymerization resulting in particles with an average diameter of 164 nm and superparamagnetic proprieties. The hemocompatibility was confirmed by hemolysis and flow cytometry analyses. When an AC magnetic field was applied under superparamagnetic PUU nanoparticles the temperature reached the threshold temperature required for cancer hyperthermia, decreasing the HeLa cells viability at all concentrations tested. On the other hand, when the NIH3T3 cells were submitted to hyperthermia no cytotoxic effect was observed. In particular, the hyperthermia assay proved to be effective in destroying cancer cells while preserving non-tumor ones. [ABSTRACT FROM AUTHOR]

Thiol‐ene polymerization has been pointed out as a promising technique to produce biobased polymers for biomedical applications due to its advantages, including mild conditions and rapid reaction rates without the formation of byproducts. Therefore, in this study different concentrations of magnetic nanoparticles (MNPs) were incorporated in poly(thioether‐ester) (PTEE) nanoparticles by thiol‐ene miniemulsion polymerization of biobased monomers to form both linear and branched cross‐linked polymers. Loading efficiencies up to approximately 95% (thermogravimetric analysis) of the MNPs within the polymer matrix were obtained. In addition, the substitution of the dithiol 1,4‐butanedithiol (64.2%) for the tetrathiol PTEMP (95.8%), increased the encapsulation efficiency by about 30%. Hybrid nanoparticles presented average mean diameters between 95 and260 nm with polydispersity index between 0.13 and 0.42 by DLS, negative zeta potentials around −45 mV and superparamagnetic behavior. The hyperthermia assays performed on breast cells (MDA‐MB 231) have shown that the cell death was dependent on the exposure time to the AC magnetic field and the reduction in cell viability was approximately 35%. These results demonstrated the production of superparamagnetic PTEE nanoparticles via thiol‐ene polymerization and highlight the promising application of these biobased materials for cancer treatment by hyperthermia. [ABSTRACT FROM AUTHOR]

The demand for environmentally friendly products allied with the depletion of natural resources has increased the search for sustainable materials in chemical and pharmaceutical industries. Polyesters are among the most widely used biodegradable polymers in biomedical applications. In this work, aliphatic polyesters (from globalide and ω-pentadecalactone) were synthesized using a new commercial biocatalyst, the low-cost immobilized NS 88011 lipase (lipase B from Candida antarctica immobilized on a hydrophobic support). Results were compared with those obtained under the same conditions using a traditional, but more expensive, commercial biocatalyst, Novozym 435 (lipase B from C. antarctica immobilized on Lewatit VP OC). When NS 88011 was used in the polymerization of globalide, longer reaction times (240 min)-when compared to Novozym 435-were required to obtain high yields (80-90 wt%). However, higher molecular weights were achieved. When poly(ω-pentadecalactone) was synthesized, high yields and molecular weights (130,000 g mol) were obtained and the enzyme concentration showed strong influence on the polyester properties. This is the first report describing NS 88011 in polymer synthesis. The use of this cheaper enzymatic preparation can provide an alternative for polyester synthesis via enzymatic ring-opening polymerization. [ABSTRACT FROM AUTHOR]

Biocompatible polymeric nanoparticles are obtained via thiol-ene polymerization of a biobased monomer in miniemulsion. The α,ω-diene-diester monomer is synthesized through esterification reaction of a glycerol derivative, namely 1,3-propanediol, with 10-undecenoic acid, a long-chain diene carboxylic acid. In order to investigate how different monomeric structures behave toward thiol-ene polymerization in miniemulsion, two types of thiols are investigated: 1,4-butanedithiol and 2-mercaptoethyl ether. Poly(thioether-ester)s with weight average molecular weight up to 15 kDa (Mn) are obtained, depending on initiator concentration and types of surfactant and dithiol employed. Finally, biobased poly(thioether-ester) nanoparticles are submitted to cytotoxicity and hemolysis analyses. High cell viability and no significant changes in cell morphology are observed after the incubation on murine fibroblast (L929) and human cervical cancer cells (HeLa). Last, hemolysis assays revealed blood compatibility and therefore polymeric nanoparticles have been shown to be a potential alternative drug delivery vector for intravenous administration. Practical Applications: There is a great demand for polymeric systems that fulfill a number of requirements, such as biodegradability and biocompatibility, for biomedical applications. In this context, biobased polymers obtained from vegetable oils are a very attractive sustainable alternative to fossil-derived polymeric materials, presenting potential biodegradability and low toxicity. By thiol-ene reactions, polymeric materials containing ester groups in the main chain-which can undergo hydrolysis-can be prepared in miniemulsion, enabling their degradation in physiological environment and, therefore, being interesting for biomedical applications and material disposal. Such novel materials could be used in temporary implants, tissue engineering, and drug delivery systems. Biocompatible polymeric nanoparticles are obtained via thiol-ene polymerization of a biobased monomer in miniemulsion. Nanoparticles revealed to be a potential alternative controlled release drug delivery vector for intravenous administration. [ABSTRACT FROM AUTHOR]

The use of enzymes as catalyst in polyesters production enables the creation of new materials for use in biomedical applications. In this work, a polyester derived from ω-pentadecalactone was synthesized. The polymer synthesis was performed using lipase Novozym 435 as catalyst and several solvents at 70 °C. The use of a closed variable volume reactor allowed the use of solvents with a boiling point lower than the reaction temperature, without affecting the ratio of solvent to monomer. Yields above 49 wt% and high molecular weights were obtained for all tested solvents. Dichloromethane (DCM) and chloroform were used as solvents for the evaluation of water content on enzyme and reaction time over the properties of final polymer. The amount of water on enzyme has a direct influence on reaction yields though higher molecular weights were obtained in reactions with lower water content. Yields of around 90 wt% were obtained in 6 h of reaction and molecular weights up to 42,300 and 51,900 g mol-1 were obtained in 2 h of reactions using DCM and chloroform as solvents. [ABSTRACT FROM AUTHOR]