Poly-ɛ-caprolactone nanocapsules loaded with copaiba essential oil reduce inflammation and pain in mice.

Diverse drugs have been used for the management of inflammation disorders and pain. However, they present many side effects and stimulate the search for new pharmacotherapeutic alternatives. Plant-derived products such as copaiba essential oil (CO) offer beneficial pharmacological effects. On the other hand, essential oil's low water solubility and physical instability hinder its in vivo application. Thus, poly-ɛ-caprolactone (PCL)-based nanocarriers have been used to increase their stability and efficacy. This work aimed to encapsulate CO in PCL nanocapsules and evaluate their effect on inflammation models and pain. The polymeric nanocapsules loading CO (CO-NC) were prepared by nanoprecipitation technique, characterized, and analyzed for their anti-inflammatory effect in vitro and in vivo. The results showed that CO-NC presented a spherical shape, 229.3 ± 1.5 nm diameter, and a negative zeta potential (approximately -23 mV). CO and CO-NC presented anti-inflammatory and antioxidant effects by LPS-activated macrophages (J774 cells). In addition, CO-NC significantly reduced TNF-α secretion (3-fold) compared to CO. In vivo, pre-treatment with CO or CO-NC (50, 100, 200 mg/kg, intraperitoneal; i.p) reduced the mechanical allodynia, paw edema, and pro-inflammatory cytokines induced by intraplantar (i.pl) injection of carrageenan in mice. Specifically, CO-NC (200 mg/kg; i.p.) reduced the production of TNF-α similar to the control group. Our results support using polymeric nanocapsules for CO delivery in inflammatory conditions.

Lecithin-based nanocapsule loading sucupira (Pterodon emarginatus) oil effects in experimental mucositis.

Intestinal mucositis (IM) is a frequent adverse effect in anticancer therapy without standard treatment. The oil obtained from sucupira (Pterodon emarginatus) has anti-inflammatory properties, and the soybean lecithin reduces the intestinal toxicity of several xenobiotics. However, their water insolubility impairs the in vivo application. For this reason, we evaluated if the nanoencapsulation of sucupira oil (SO) in lecithin-based nanocapsules (SO-NC) could be a therapeutically effective system for the treatment of IM in murine cisplatin (CDDP)-induced intestinal mucositis model. SO was analyzed by LC-HRMS/MS and HPLC. SO-NC was prepared by nanoprecipitation and characterized using DLS, HPLC, and AFM. Mice body weight and food consumption were assessed daily during experimental mucositis induced by CDDP. The animals were euthanized, and intestinal permeability, inflammatory mediators, and intestinal histology were performed. SO-NC demonstrated adequate characteristics for oral administration as size under 300 nm, IP < 0.3, high EE, and spherical shape. In vitro cytotoxicity performed against RAW 264.7 cell lines resulted in cell viability above 80 % confirming the non-cytotoxic profile of SO (IC50 268 µg/mL) and SO-NC (IC50 118.5 µg/mL) up to 117.2 µg/mL. The untreated mice showed intestinal toxicity after i.p. of CDDP, principally weight loss, increased intestinal permeability, and MPO and TNF-α levels. Surprisingly, the administration of SO to CDDP-mucositis animals did not circumvent the CDDP effects and increased intestinal permeability. However, SO-NC proved efficient in mitigating the experimental intestinal mucositis by improving intestinal epithelium architecture, reducing intestinal permeability, and improving the MPO levels. In conclusion, SO-NC can positively impact intestinal mucositis by promoting mucosal recovery. This is a promising strategy for developing a new treatment for intestinal mucositis.

"Click" Silica-Supported Sulfonic Acid Catalysts with Variable Acid Strength and Surface Polarity.

Solid acid catalysts are central in our chemical industry and are major players in the valorization of bioresources. However, there is still a need to develop solid acid catalysts with enhanced acid strength and improved, or tunable, physicochemical profile to enhance the efficiency and sustainability of chemical processes. Here, a modular approach to tune the acid strength and surface polarity of silica-supported sulfonic acid catalysts, based on a versatile copper-catalyzed azide-alkyne cycloaddition (CuAAC)-based anchoring scheme, is presented. The CuAAC-formed triazole link was used to enhance the activity of the grafted sulfonic acids and to pair the acid sites with secondary hydrophobic functions. The beneficial effects of both the triazolium link and the paired hydrophobic site, as well as the optimal positioning of the sulfonic moiety on the triazole ring, are discussed in model esterification reactions.

Thicker is better? Synthesis and evaluation of well-defined polymer brushes with controllable catalytic loadings.

Polymer brushes (PBs) have been used as supports for the immobilization of palladium complexes on silicon surfaces. The polymers were grown by surface-initiated atom-transfer radical polymerization (SI-ATRP) and postdecorated with dipyridylamine (dpa) ligands. The pendant dpa units were in turn complexed with [Pd(OAc)(2)] to afford hybrid catalytic surfaces. A series of catalytic samples of various thicknesses (ca. 20-160 nm) and associated palladium loadings (ca. 10-45 nmol cm(-2)) were obtained by adjusting the SI-ATRP reaction time and characterized by ellipsometry, X-ray reflectivity, X-ray photoelectron spectroscopy, and inductively coupled plasma mass spectrometry (ICP-MS). ICP-MS revealed a near-linear relationship between thickness of the polymer brush and palladium content, which confirmed the robustness of the preparation and postmodification sequence presented herein, rendering possible the creation of functional architectures with predefined catalytic potential. The activities of the catalytic PBs were determined by systematically exploring a full range of substrate-to-catalyst ratios in a model palladium(0)-catalyzed reaction. Quantitative transformations were observed for loadings down to 0.03 mol % and a maximum turnover number (TON) of around 3500 was established for the system. Comparison of the catalytic performances evidenced a singular influence of the thickness on conversions and TONs. The limited recyclability of the hairy catalysts has been attributed to palladium leaching.

Grafting control of mainstay terpyridine self-assembled monolayers for the preparation of planar silicon surfaces with variable catalytic loadings.

Monolayers of terpyridine-derivatized silanes were self-assembled, with accurately controlled grafting densities, on single-crystal silicon surfaces. Complexation of the resulting terpyridine monolayers with Pd(OAc)(2) afforded a series of catalytic surfaces covering a full range of Pd loadings (0.14-0.85 nmol.cm(-2)) in the aim to explore their impact on catalysis methodically. X-ray reflectivity (XRR), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma mass spectrometry (ICP-MS) were combined to afford a precise picture of the grafting density, chemical composition, and catalyst loadings of the surfaces investigated here. We report that the control of the terpyridine density and thus the control of catalytic loadings can be achieved through a fine modification of silanization concentrations, which affords surfaces with tunable catalytic activity.

Controlled thermoreversible transfer of poly(oxazoline) micelles between an ionic liquid and water.

Poly(2-nonyl-2-oxazoline-block-2-ethyl-2-oxazoline) block copolymer micelles were investigated as an alternative system to the approach proposed by He and Lodge (Y. He and T. P. Lodge, J. Am. Chem. Soc., 2006, 128, 12666) for the thermoreversible transfer of micelles between a hydrophobic ionic liquid phase and an aqueous phase; this work describes the possibility of thermally triggering and controlling this process.