Anticorrosion and Antimicrobial Tannic Acid-Functionalized Ti-Metallic Glass Ribbons for Dental Abutment.

In this study, a recently reported Ti-based metallic glass (MG), without any toxic element, but with a significant amount of metalloid (Si-Ge-B, 18 atom %) and minor soft element (Sn, 2 atom %), was produced in ribbon form using conventional single-roller melt-spinning. The produced Ti60Zr20Si8Ge7B3Sn2 ribbons were investigated by differential scanning calorimetry and X-ray diffraction to confirm their amorphous structure, and their corrosion properties were further investigated by open-circuit potential and cyclic polarization tests. The ribbon's surface was functionalized by tannic acid, a natural plant-based polyphenol, to enhance its performance in terms of corrosion prevention and antimicrobial efficacy. These properties can potentially be exploited in the premucosal parts of dental implants (abutments). The Folin and Ciocalteu test was used for the quantification of tannic acid (TA) grafted on the ribbon surface and of its redox activity. Fluorescent microscopy and ζ-potential measurements were used to confirm the presence of TA on the surfaces of the ribbons. The cytocompatibility evaluation (indirect and direct) of TA-functionalized Ti60Zr20Si8Ge7B3Sn2 MG ribbons toward primary human gingival fibroblast demonstrated that no significant differences in cell viability were detected between the functionalized and as-produced (control) MG ribbons. Finally, the antibacterial investigation of TA-functionalized samples against Staphylococcus aureus demonstrated the specimens' antimicrobial properties, shown by scanning electron microscopy images after 24 h, presenting a few single colonies remaining on their surfaces. The thickness of bacterial aggregations (biofilm-like) that were formed on the surface of the as-produced samples reduced from 3.5 to 1.5 µm.

Voriconazole incorporated nanofiber formulations for topical application: preparation, characterization and antifungal activity studies against Candida species.

In this study, voriconazole (VCZ) incorporated polyvinyl alcohol/sodium alginate electrospun nanofibers were produced and, then crosslinked with glutaraldehyde for topical antifungal treatment. The nanofibers were characterized in terms of fiber size, surface morphology, and compatibility between drug-polymer and polymer-polymer using scanning electron microscopy, atomic force microscopy, attenuated total reflection-Fourier transform infrared spectroscopy, and high pressure liquid chromatography. After optimization studies, in vitro drug release, skin penetration, and deposition studies were performed using Franz diffusion cells. Antifungal activities of the nanofiber formulations against Candida albicans, Candida tropicalis, and Candida parapysilosis strains were evaluated using susceptibility test and subsequently time-kill study was performed against C. albicans. The cytotoxicity study was performed using 4-succinate dehydrogenase viability assay on mouse fibroblast cell line. The release rate of VCZ from crosslinked nanofibers was slower than that of non-crosslinked nanofibers and Higuchi kinetic model best fitted to the in vitro release data of both of formulations. VCZ deposited in deeper skin layers from nanofiber formulations was higher than that of the control formulation (VCZ solution in propylene glycol (1% (w/v)). According to the susceptibility and time-kill studies, all of the nanofiber formulations showed antifungal activity against C. albicans with confirming no cytotoxicity on mouse fibroblast cells.

A multifunctional long-term release system for treatment of hypothyroidism.

Hypothyroidism is an autoimmune disease associated with underactive thyroid gland. In this study, a dual effect polymeric system was designed to release Cepharanthine (CEP) to block T cell activation and Selenium (Se) to decrease the anti-thyroid peroxidase (TPOAb) concentration in order to treat hypothyroidism. For this purpose, poly(ethylene-vinyl acetate) (PEVA) and polyethylene glycol (PEG) nanoparticles (NPs) including CEP were synthesized by emulsion solvent evaporation method and they were loaded to polyurethane (PU)/PEG-PUSe-PEG block copolymer blends which were fabricated by particulate leaching technique as porous sponges. Fourier-Transform Infrared (FTIR), Raman, and Nuclear Magnetic Resonance (NMR) analysis showed successful synthesis of PEG-PUSe-PEG block copolymer. A long-term zero-order release profile was obtained for CEP. Se release rate from matrices showed an oxidative stress-mediated release which can be used to adjust Se amount. According to MTS results conducted by NIH 3T3 fibroblasts, both NPs and matrices have no adverse effect on cell viability. Fluorescence microscopy and SEM images confirm the MTS results. The dual release system has potential to be effectively used in long-term treatment of hypothyroidism by addressing both auto-immune response and hormone regulation.