Biological Validation of Isorhamnetin Glycosides Loaded Nanofibers as a Drug Release System

Abstract

Nanofibers have emerged as a potential novel platform due to its physicochemical properties for healthcare application. Nanofibers advantage rely in their high specific surface area-tovolume ratio and porosity. Their peculiar assembly allow cell accommodation, nutrient infiltration, gas exchange, waste excretion, high drug release rate and stable structure. Different strategies have been reported to enhance physical and mechanical characteristics of nanofibers and increase their production yield rate. Herbal bioactive compounds have raised special interest due to their prominent beneficial properties in health care. Nanofiber properties let these systems to serve as bioactive compounds carriers to generate functional matrixes. Opuntia ficus-indica (L.) Mill, is commonly consumed in Mexico due to its beneficial properties since ancient times for the treatment of diabetes, hypertension, metabolic syndrome, cardiovascular and neurodegenerative diseases, hypercholesterolemia and asthma. Additionally, O. ficus-indica isorhamnetin glycosides have clinical potential for the treatment of topical injuries.

The following project assessed the release kinetics and the in vitro anti-inflammatory potential of isorhamnetin glycosides loaded to nanofibers with different concentration of gelatin (25% and 30%). Isorhamnetin glycosides were extracted from the plant using acetic acid 80% (v:v) and the resultant solution was mixed with gelatin to create a polymeric solution. Isorhamnetin glycosides loaded nanofibers were fabricated through the ForcespinningTM technique and crosslinked with glutaraldehyde (GTA) vapors. Isorhamnetin glycosides within the nanofibers were quantified by HPLC-UV. SEM and FTIR analysis of nanofibers were used to elucidate nanofibers morphology and chemical interactions between the functional groups of the compounds. Alike, the in vitro drug release assays revealed the role of polymer concentration and chemical interactions between particles to enhance the release of isorhamnetin glycosides. 25% GL+NP and 30% GL+NP nanofibers displayed a release percentage of 37.15% and 62.98%, respectively. Additionally, celular uptake assays demonstrated the feasibility of glycosides to cross human dermal fibroblasts (HDFa cell line) cell membrane according the glycosylation pattern of the flavonoids. Cell proliferation was enhanced by the presence of the matrix and no significant effect on cell viability was observed at the concentration of total isorhamnetin glycosides used in the experiments. Nitric Oxide (NO), Cyclooxigenase-2 (COX-2), tumor necrosis- alpha (TNF- alpha) and Interleuikin-6 (IL-6) were monitored. Isorhamnetin glycosides loaded to nanofibers remarkably decrease the production of NO, 30%GL+NP nanofiber reached a NO inhibition of 93.8% at 8h of isorhamnetin release. Also, they inhibited the production of COX-2, TNF- alpha and IL-6. Among the two nanofibers, 30% GL+NP nanofiber displayed the most adequate physicochemical characteristics such as diameter, non-bead formation and prevalence of non-covalent bonding for ease compound´s release to act as a controlled release system a potential anti-inflammatory system in topical injuries than 25% GL+NP nanofiber.