Biodegradable Electrospun Nanofibers: A New Approach For Rhinosinusitis Treatment.

Biodegradable polymeric nanofibers containing mometasone furoate can be a new approach to drug delivery to treat chronic rhinosinusitis, providing controlled steroid delivery to the sinonasal mucosa. This study aimed to develop biodegradable polymeric nanofibers and explore the safety of these fibers in an in vivo rabbit model. The nanofibers' development has been optimized using the Response Surface Methodology (RSM) obtained with Design of Experiments (DoE) with the best conditions related to the polymer concentration and proportion of solvents used in the electrospinning process. The nanofibers were prepared, operating as a determinant factor, the nanofiber formation and its diameter evaluated by Scanning Electron Microscopy (SEM). The ideal system obtained was assessed by SEM, thermogravimetric analysis (TGA), X-ray diffraction (XRD), differential scanning calorimetry (DSC), assay, and drug delivery by UHLPC validated method. The results showed that the drug is dispersed in the polymeric matrix, is stable, and showed sustained release kinetics in a bio-relevant nasal environment (Higuchi model kinetics). In vivo tests, the level of inflammation at the animals' mucosa which received the nanofiber with the mometasone furoate was lower than those that received the nanofibers without the drug (α = 0.05). Histopathology analysis showed that the polymeric nanofibers containing mometasone are safe when topically applied on the sinonasal mucosa, opening a new horizon in chronic rhinosinusitis treatment.

Bevacizumab-loaded polyurethane subconjunctival implants: effects on experimental glaucoma filtration surgery.

PURPOSE: Vascular endothelial growth factor (VEGF) may contribute to the scarring process resulting from glaucoma filtration surgery, since this cytokine may stimulate fibroblast proliferation. The aim of this study was to describe a new bevacizumab-loaded polyurethane implant (BPUI) and to evaluate its effectiveness as a new drug delivery system of anti-VEGF antibody in a rabbit model of glaucoma filtration surgery. METHODS: An aqueous dispersion of polyurethane was obtained via the conventional process. Bevacizumab (1.5 mg) was then incorporated into the dispersion and was subsequently dried to form the polymeric films. Films with dimensions of 3×3×1 mm that either did (group BPUI, n=10) or did not contain bevacizumab (group PUI, n=10) were implanted in the subconjunctival space, at the surgical site in 1 eye of each rabbit. The in vitro bevacizumab release was evaluated using size-exclusion high-performance liquid chromatography (HPLC), and the in vivo effects of the drug were investigated in a rabbit experimental trabeculectomy model by examining the bleb characteristics and collagen accumulation, and by performing immunohistological analyses of VEGF expression. RESULTS: HPLC showed that only 10% of the bevacizumab in the implants had been released by postoperative day 5. In vivo studies demonstrated that the drug had no adverse effects; however, no significant differences in either the bleb area score or the collagen deposit intensity between the group PUI and the group that BPUI were observed. Moreover, the group BPUI presented a significantly lower proportion of VEGF-expressing fibroblasts than group PUI (0.17±0.03 vs. 0.35±0.05 cells/field, P=0.005). CONCLUSIONS: This study demonstrated that bevacizumab release from the BPUIs only occurred for a short time probably from the surface of the films. Nevertheless, they were well tolerated in rabbit eyes and reduced the number of VEGF-expressing fibroblasts.