Dermal wound healing involves complex histo-molecular events aimed to repair the discontinuity of the epithelium. Employing nanometric silver particles provides an efficient antimicrobial effect for several dermal infections. The aim is to elucidate imminent advantages of silver nanoparticles, such as the possibility of modulating the epithelial cell repair process. Through the nanostructural implementation of chitosan thin films supporting silver nanoparticles, it was feasible to evaluate in vivo the efficacy and evolution of dermal recuperation after surgical damage. The characterization of chitosan silver nanoparticle films was performed by UV-visible spectra and Fourier transform infrared spectroscopy, X-ray diffraction, and high-resolution electron microscopy. An important dermal healing was accomplished in animals that were treated with chitosan films supporting silver nanoparticles, as confirmed by a histopathological analysis of the skin after 12 days of treatment. The developed chitosan thin film supporting an optimized amount of silver nanoparticles could be employed to treat diseases related to wound healing.

Abstract:The entrapping of physicochemical active molecules inside mesoporous networks is an appealing field of research due to the myriad of potential applications in optics, photocatalysis, chemical sensing, and medicine. One of the most important reasons for this success is the possibility of optimizing the properties that a free active species displays in solution but now trapped inside a solid substrate. Additionally it is possible to modulate the textural characteristics of substrates, such as pore size, specific surface area, polarity and chemical affinity of the surface, toward the physical or chemical adhesion of a variety of adsorbates. In the present document, two kinds of non-silicon metal alkoxides, Zr and Ti, are employed to prepare xerogels containing entrapped tetrapyrrolic species that could be inserted beforehand in analogue silica systems. The main goal is to develop efficient methods for trapping or binding tetrapyrrole macrocycles inside TiO2 and ZrO2 xerogels, while comparing the properties of these systems against those of the SiO2 analogues. Once the optimal synthesis conditions for obtaining translucent monolithic xerogels of ZrO2 and TiO2 networks were determined, it was confirmed that these substrates allowed the entrapment, in monomeric form, of macrocycles that commonly appear as aggregates within the SiO2 OPEN ACCESSMolecules 2015, 20 19464 network. From these experiments, it could be determined that the average pore diameters, specific surface areas, and water sorption capacities depicted by each one of these substrates, are a consequence of their own nature combined with the particular structure of the entrapped tetrapyrrole macrocycle. Furthermore, the establishment of covalent bonds between the intruding species and the pore walls leads to the obtainment of very similar pore sizes in the three different metal oxide (Ti, Zr, and Si) substrates as a consequence of the templating effect of the encapsulated species.

Abstract. While searching for adequate sol-gel methodologies for successfully trapping in monomeric and stable form either porphyrins or phthalocyanines, inside translucent monolithic silica xerogels, it was discovered that the interactions of these trapped tetrapyrrole macrocycles with Si-OH surface groups inhibit or spoil the efficient display of physicochemical, especially optical, properties of the confined species. Consequently, we have developed strategies to keep the inserted macrocycle species as far as possible from these interferences by substituting the surface -OH groups for alkyl or aryl groups or trapping these species inside alternative metal oxide networks, such as ZrO 2 , TiO 2 , and Al 2 O 3 . In the present manuscript, we present, for the first time to our knowledge, a methodology for preserving the spectroscopic characteristics of metal tetrasulfophthalocyanines and cobalt tetraphenylporphyrins trapped inside the pores of ZrO 2 xerogels. The results obtained are contrasting with analogous silica systems and demonstrate that, in ZrO 2 networks, the macrocyclic species remain trapped in stable and monomeric form while keeping their original spectroscopic characteristics in a better way than when captured inside silica systems. This outcome imply a lower hydrophilic character linked to the existence of a smaller amount of surface hydroxyl groups in ZrO 2 Nano HybridsOnline : 2014-08-18 ISSN: 2234-9871, Vol. 7, pp 1-34 doi:10.4028/www.scientific.net/NH.7.1 © 2014 This is an open access article under the CC-BY 4.0 license (https://creativecommons.org/licenses/by/4.0/) networks, if compared to analogous SiO 2 xerogel systems. The development and study of the possibility of trapping or fixing synthetic or natural tetrapyrrole macrocycles inside inorganic networks suggest the possibility of synthesizing hybrid solid systems suitable for important applications in technological areas such as optics, catalysis, sensoring and medicine

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A functionalized epoxy resin (DGEBA) was synthesized from abietic acid, through the esterification and condensation reactions between the carboxyl groups of abietic acid and the basic functional groups of an epoxy resin. This method of synthesis increases the epoxy resin surface adhesion, as well as the chemical and thermal stability, for being used as a protective coating against corrosion of copper plates. Characterization analyses included FTIR and SEM of both raw and functionalized epoxy resin substrates performed. The corrosion performance of these coatings when applied onto Cu and stainless plates was tested in terms of: (i) immersion in a misty saline chamber, under accelerated corrosive conditions; (ii) Taber abrasion and (iii) hardness, adhesion and potentiodynamic polarization. The obtained results indicate the existence of a chemical bond between the epoxy ring and the carboxyl functional groups of abietic acid. This chemical bonding provided an increased adhesion as well as better chemical and thermal stabilities than those of the original resin. The corrosion resistance lining the functionalized epoxy resin films indicated that their anticorrosive efficiency was up to 30% higher than that of the functionalized resin.