In this research project, synthesis and characterization of ionic liquids and their subsequent utilization as facilitators of transdermal delivery of human insulin was pursued. Choline geranate and choline oleate ionic liquids (and their deep eutectic solvents) were produced and characterized by nuclear magnetic resonance ( 1 H NMR), water content, oxidative stability, cytotoxicity and genotoxicity assays, and ability to promote transdermal protein permeation. The results gathered clearly suggest that all ionic liquids were able to promote/facilitate transdermal permeation of insulin, although to various extents. In particular, choline geranate 1:2 combined with its virtually nil cytoand geno-toxicity was chosen to be incorporated in a biopolymeric formulation making it a suitable facilitator aiming at transdermal delivery of insulin.

Development and optimization of a bioorigami film with silk sericin was pursued for skin regeneration. Several formulations were produced, with varying integrated sericin contents, viz. 0, 1, 2, 5, 10, 20 and 50 mg sericin mL film-1. The physico-chemical characteristics of the bioorigami films produced were evaluated via infrared spectrophotometry, X-ray diffraction, X-ray transmission, X-ray fluorescence, thermogravimetry, differential scanning calorimetry, transdermal protein permeation, kinetics of protein release from the bioorigami films and free radical scavenging activities. The mechanical resistance was also evaluated. The results by 2,2-diphenyl-1-picrylhydrazil (DPPH) assay suggest that the bioorigami films integrating crude sericin extract had capacity to sequester free radicals, exhibited prolonged release of the bioactive protein, good physico-chemical characteristics and adequate mechanical resistance. Specifically, the bioorigami film with 10 mg sericin mL film-1 proved to be able to release all the bioactive protein in a 12 h timeframe. The results suggest potential for use in biopharmaceutical application, specifically, as material for use in hydrogels.

Production of bacterial nanocellulose was pursued as a matrix system for the stabilization of human insulin. The biomembranes produced by Gluconacetobacter hansenii were washed with 2% aqueous sodium dodecylsulfate solution, rinsed with ultrapure water and immersed in 1 mol L -1 NaOH aqueous solution at 60 °C for 90 min until neutralization. For the insulin adsorption assays, the biomembranes were soaked in a buffered solution of human insulin until no protein could be detected in the supernatant. The membranes with adsorbed insulin were characterized via mechanical resistance (resilience, relaxation, perforation), Differential Scanning Calorimetry (DSC), Thermal Gravimetrical Analysis (TGA), Fourier Transform Infrared Spectrophotometry (FTIR), X-ray diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) analyses. The FESEM photomicrographs of the surface of the biomembranes showed a rugged surface without cracks. The biomembranes exhibited adequate mechanical characteristics. The infrared spectra indicated that the chemical aspect of the protein moiety was preserved during adsorption onto the BNC biomembranes. According to the XRD analyses, the biomembranes showed a generalized amorphous behavior. Thermal analyses indicated an adequate thermal stability for a pharmaceuticals product. Hence, an elastic and malleable biomembrane was produced, suitable for incorporation of human insulin, aiming at transdermal delivery.