RESUMO
Microneedle (MN) devices comprise of micron-sized structures that circumvent biological barriers in a minimally invasive manner. MN research continues to grow and evolve; the technology was recently identified as one of the top ten overall emerging technologies of 2020. There is a growing interest in using such devices in cosmetology and dermatological conditions where the MNs mechanically disrupt the outer skin barrier layer, creating transient pathways that allow the passage of materials to underlying skin layers. This review aims to appraise the application of microneedle technologies in skin science, provide information on potential clinical benefits, as well as indicate possible dermatological conditions that can benefit from this technology, including autoimmune-mediated inflammatory skin diseases, skin aging, hyperpigmentation, and skin tumors. A literature review was carried out to select studies that evaluated the use of microneedles as drug delivery enhancement for dermatologic purposes. MN patches create temporary pathways that allow the passage of material to deeper layers of the skin. Given their demonstrable promise in therapeutic applications, it will be essential for healthcare professionals to engage with these new delivery systems.
RESUMO
Advanced wound dressings capable of interacting with lesions and changing the wound microenvironment to improve healing are promising to increase the therapeutic efficacy of this class of biomaterials. Aiming at the production of bioactive wound dressings with the ability to control the wound microenvironment, biomaterials of three different chemical compositions, but with the same architecture, were produced and compared. Electrospinning was employed to build up a biomimetic extracellular matrix (ECM) layer consisting of poly(caprolactone) (PCL), 50/50 dl-lactide/glycolide copolymer (PDLG) and poly(l-lactide) (PLLA). As a post-treatment to broaden the bioactivity of the dressings, an alginate coating was applied to sheathe and functionalize the surface of the hydrophobic electrospun wound dressings, in combination with the extract of the plant Arrabidaea chica Verlot, known for its anti-inflammatory and healing promotion properties. Wettable bioactive structures capable to interact with media simulating lesion microenvironments, with tensile strength and elongation at break ranging respectively from 155 to 273â¯MPa and from 0.94 to 1.39% were obtained. In simulated exudative microenvironment, water vapor transmission rate (WVTR) values around 700â¯g/m2/day were observed, while water vapor permeability rates (WVPR) reached about 300â¯g/m2/day. In simulated dehydrated microenvironment, values of WVTR around 200â¯g/m2/day and WVPR around 175â¯g/m2/day were attained.
Assuntos
Bandagens , Materiais Revestidos Biocompatíveis/farmacologia , Fenômenos Mecânicos , Cicatrização , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Liberação Controlada de Fármacos , Íons , Testes de Sensibilidade Microbiana , Permeabilidade , Extratos Vegetais/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Vapor , Termogravimetria , Fatores de Tempo , Água/química , Difração de Raios XRESUMO
The electrochemical behaviour of two commercial titanium alloys Ti-6Al-4 V (ASTM F136) and Ti-13Nb-13Zr (ASTM F1713) was investigated in Ringer physiological solution at two pH values (5.5 and 7.0). The corrosion properties were examined by using electrochemical techniques: Potentiodynamic anodic polarization, cyclic polarization and electrochemical impedance spectroscopy (EIS). The electrochemical corrosion properties of both alloys at different conditions were measured in terms of corrosion potential (E (corr)), corrosion current density (i (corr)) and passivation current density (i (pass)). Equivalent electrical circuits were used to modulate EIS data, in order to characterize alloys surface and better understanding the pH effect on the interface alloy/solution.