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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 thiolene 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 (M n ) 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.

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Summary: The objective this work was the synthesis, characterization and evaluation of cytotoxicity poly(methyl methacrylate), PMMA, nanoparticles (NPs) produced using miniemulsion polymerization technique adopting azobisisobutylonitrile (AIBN) as initiator and biocompatible and biodegradable surfactant, lecithin and co-stabilizer, miglyol 812 The NPs showed high stability during one year and an average diameter of 89 nm with polydispersity index of 0.11 and a zeta potential À48 mV. The PMMA NPs were tested for cytotoxicity in acute monocytic leukemia cells (THP1) and in human lung adenocarcinoma cells (A549). The PMMA NPs did not show any adverse effect on cell viability indicating their potential to encapsulate antitumor agents.

Healing is the process responsible for restoring the integrity of the body’s internal or external structures when they rupture. Photobiomodulation (PBM) stands out as one of the most efficient resources in the treatment of epithelial lesions, as well as hyaluronic acid (HA), which has been emerging as a new molecule for the treatment of dermal and epidermal lesions. The biological application of gold nanoparticles (GNPs) shows promising results. This study aimed to investigate the possible anti-inflammatory and antioxidant effects of the association between PBM and GNPs-linked HA in an epithelial lesion model. Fifty Wistar rats were randomly distributed in the Control Group (CG); (PBM); (PBM + HA); (PBM + GNPs); (PBM + GNPs-HA). The animals were anesthetized, trichotomized, and induced to a surgical incision in the dorsal region. Topical treatment with HA (0.9%) and/or GNPs (30 mg/kg) occurred daily associated with 904 nm laser irradiation, dose of 5 J/cm2, which started 24 h after the lesion and was performed daily until the seventh day. The levels of proinflammatory (IL1 and TNFα), anti-inflammatory (IL10 and IL4) and growth factors (FGF and TGFβ) cytokines and oxidative stress parameters were evaluated, besides histological analysis through inflammatory infiltrate, fibroblasts, new vessels, and collagen production area. Finally, for the analysis of wound size reduction, digital images were performed and subsequently analyzed by the IMAGEJ software. The treated groups showed a decrease in proinflammatory cytokine levels and an increase in anti-inflammatory cytokines. TGFβ and FGF levels also increased in the treated groups, especially in the combination therapy group (PBM + GNPs-HA). Regarding the oxidative stress parameters, MPO, DCF, and Nitrite levels decreased in the treated groups, as well as the oxidative damage (Carbonyl and Thiol groups). In contrast, antioxidant defense increased in the groups with the appropriate therapies proposed compared to the control group. Histological sections were analyzed where the inflammatory infiltrate was lower in the PBM + GNPs-HA group. The number of fibroblasts was higher in the PBM and PBM + HA treated groups, whereas collagen production was higher in all treated groups. Finally, in the analysis of the wound area contraction, the injury group presented a larger area in cm2 compared to the other groups. Taken together, these results allow us to observe that the combination of PBM + GNPs-HA optimized the secretion of anti-inflammatory cytokines, proliferation and cell differentiation growth factors, and made an earlier transition to the chronic phase, contributing to the repair process.

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