RESUMO

Nanocomposites formed by clay and lipid carriers (NLCs) show a high potential for providing controlled release and specific delivery of bioactive molecules and have recently gained attention in the pharmaceutical sector due to their ability to transport hydrophilic and hydrophobic drugs. Recent studies have recognized the biological activity of the oil of Bixa orellana L. (AO) with regards to its healing, antioxidant, antibacterial, and anti-leishmanial properties. Therefore, the purpose of this study is the preparation and characterization of hybrid systems based on lipid nanocarriers and laponite for the delivery of AO. NLCs were prepared by the fusion-emulsification method, using cetyl palmitate (CP) or myristyl myristate (MM), AO, and Poloxamer 188. The morphology, hydrodynamic diameters, zeta potential (ZP), polydispersity index (PDI), thermal analysis, X-ray diffraction analysis (XRD), viscosity behavior, and cytotoxicity testing of the hybrid systems were performed. The thermal study and X-ray diffraction analyses (XRD) revealed polymorphic structural changes compatible with the amorphization of the material. Rheological assays highlighted a typical pseudoplastic behavior in all systems (MM and CP with LAP). The hybrid systems' morphology, size diameters, and PDIs were similar, preset spherical and monodisperse structures (≈200 nm; <0.3), without significant change up to sixty days. The ZP values differed from each other, becoming higher with increasing AO concentration. XEDS spectra and elemental X-ray maps show peaks of lipids (organic components, C and O) and inorganic components O, Mg, and Si. All samples showed cell viability above 60%. The results indicated a stable, biocompatible hybrid system that can be an alternative for topical application.

RESUMO

Fucoxanthin (FUCO) is a marine carotenoid characterized by antiproliferative properties against hyperproliferative cells. The aim of this work was to design and develop nanostructured lipidic carriers (NLCs) based on bacuri butter and tucumã oil and loaded with FUCO, intended for skin application to prevent skin hyperproliferative diseases and in particular psoriasis. The presence of FUCO should control the hyperproliferation of skin diseased cells and the lipids forming the NLC core, rich in antioxidants and characterized by wound healing properties, should favor the restoring of skin integrity. NLCs were coated with chitosan (CS) to improve their biopharmaceutical properties (bio/mucoadhesion and wound healing) and to combine the advantages of lipidic nanoparticles with the biological properties of CS. Chitosan coated and non-coated NLC were prepared by means of high shear homogenization and characterized for chemico-physical and biopharmaceutical properties (in vitro biocompatibility and cell uptake towards normal dermal human fibroblasts). Moreover, the pharmacological activity of FUCO loaded in NLCs was assessed in psoriatic-like cellular model. NLCs were characterized by dimensions ranging from about 250 to 400 nm. Moreover, the CS coating and FUCO loading determined an increase of size. Moreover, TEM and zeta potential analysis confirmed the presence of CS coating on nanoparticle surface, thus conferring to nanoparticle good bioadhesion properties. NLCs uptake in fibroblasts was observed and NLC-FUCO-CS caused a reduction of cell viability with a less marked effect in fibroblasts rather than in psoriatic cells, highlighting the capability of this system to control skin hyperproliferation and inflammation. The loading of NLC-FUCO-CS in pullulan film should render NLCs application easy, without impair prompt interaction of the drug with the skin. Considering the overall results skin application of CS coated NLCs loaded with FUCO seems a promising approach to control skin hyperproliferation and to preserve skin integrity in psoriatic skin.

Assuntos

RESUMO

In healthy individuals, wound healing is a highly efficient process. However, interruptions of normal healing give rise to chronic wounds, characterized by inflammation with impaired angiogenesis and re-epithelialization. The aim of this work was the design and the development of electrospun nanofibrous scaffolds based on sodium alginate (SA) and pullulan (PUL) and loaded with human platelet lysate (PL) intended for skin reparation, to take the advantage of nanofibrous scaffolds (with improved physical structure) and of SA as biopolymer. Two preparation approaches have been used to load PL in the scaffolds: as component of the PUL/SA matrix, to be electrospun, or as coating component, to cover the previously prepared electrospun PUL based membranes. A preformulation study to assess pullulan entanglement concentration and alginate or citric acid critical concentration, to obtain electrospun nanofibers, has been performed. The preparation process allowed to obtain insoluble systems starting from aqueous solutions and these were able to act as scaffolds for tissue engineering with suitable mechanical properties and PL release. PL loading in PUL/SA matrix nanofibers did not substantially modify the nanofiber morphology before crosslinking, while the crosslinking process, in presence of PL, determined less sharp nanofibers probably due to an increase in hydrophilicity caused by PL proteins. On the contrary, the coated nanofibers showed an increase in diameters due to PL loading. The two different approaches affected the fiber dimension and scaffold elasticity, especially for PL loaded systems. Anyhow, these differences were not crucial for fibroblast adhesion and proliferation which were mainly influenced by PL loading. In particular, fibroblasts presented different conformation and orientation mainly due to the presence of PL. This caused a cell random orientation compatible to a fibroblast-to-myofibroblast transition that could enhance wound healing.

Assuntos