RESUMO
BACKGROUND: Tretinoin or all-trans retinoic acid is used in the treatment of acne vulgaris and photo-aging. This work aims to develop tretinoin-loaded nanofibers as a potential anti-acne patch and to investigate its physicochemical characteristics. METHOD: Nanofibers were produced via electrospinning method and surface topography was evaluated by Field Emission Scanning Electron Microscopy (FESEM). The functional groups of polymer and the drug molecule and the possible interactions were studied by Fourier Transform Infrared Spectroscopy (FTIR). Drug release studies were carried out by total immersion method at 25 °C and 32 °C. Tretinoin stability was evaluated at room temperature and fridge for 45 days. The possibility of synergistic antibacterial activity of tretinoin and erythromycin combination was investigated on Staphylococcus aureus (ATCC® 25923™) and (ATCC® 29213™) by Kirby Bauer disc diffusion method. RESULTS: Uniform fibers without drug crystals were fabricated via electrospinning. Drug-loaded nanofibers show inherent stability under various storage conditions. Electrospun nanofibers showed a prolonged release of tretinoin. The stability of formulations in FT was higher than RT. Disc diffusion tests did not show any synergism in the antibacterial activity of erythromycin when used in combination with tretinoin. CONCLUSION: It can be anticipated that the easy fabrication, low costs and dosing frequency of the construct reported here provide a platform that can be adapted for on-demand delivery of tretinoin.
RESUMO
In this study, boric acid (BA) is employed as a crosslinking agent to improve the characteristics of two commonly used polymeric films, ethyl cellulose (EC) and polyvinyl alcohol (PVA), for topical drug delivery applications. The developed films are characterized by FTIR spectroscopy and SEM analysis. The results show that the surfaces of the prepared films are even and transparent, except for the BA-modified EC sample. The initial cumulative release for erythromycin (EM) is found to be 0.30 and 0.36 mg/mL for EC and PVA films, which drops to 0.25 and 0.20 mg/mL after BA crosslinking, respectively, after 1 h at 25 °C. Further, the developed formulations are stable for 75 days. Also, the antibacterial activity of the developed formulations is investigated against S. aureus (ATCC® 25923™ and ATCC® 29213™). The obtained data confirm that the application of BA as the crosslinking agent extends the release of EM from EC and PVA polymeric films. The findings of this study suggest that BA-crosslinked EC and PVA films are promising carriers for controlled topical drug delivery applications.
RESUMO
Nowadays, human dental pulp stem cells (hDPSCs) became more attractive for therapeutic purposes because of their high proliferation and differentiation potential. Thus, coupling the desired cellular characteristics of hDPSCs with good biomaterial properties of the chitosan scaffolds provide an interesting approach for tissue engineering applications. On the other hand, scaffold surface modification is also needed to promote stem cell adhesion since chitosan lacks adhesion motifs to support direct cell anchorage. In this study, hDPSCs were isolated from third molars of healthy female individuals (aged 16-25) with enzymatic digestion. For cell culture studies, the chitosan scaffolds which have approximately 9 mm diameter and 2 mm thickness with interconnected structure were prepared by freeze-drying. To support cellular attachment the scaffolds were covalently immobilized with either RGD (arginine-glycine-aspartic acid) or fibronectin (Fn) molecules. Cells were seeded on chitosan scaffolds with or without immobilized RGD and fibronectin. Cell attachment, spreading, adhesion behaviors and proliferation capacity were examined by scanning electron microscopy, immunofluorescence staining and PrestoBlue® assays, respectively. In addition, differentiation potential of hDPSCs on Fn immobilized chitosan scaffolds was determined with real time reverse transcriptase polymerase chain reaction analysis. The results showed that chitosan scaffolds were not able to support stem cell attachment. hDPSCs on chitosan scaffolds formed spheroids more quickly and the size of spheroids were smaller than on chitosan-RGD while Fn-immobilized chitosan scaffolds strongly supported cellular attachment but not odontogenic differentiation. The results suggest that the Fn-immobilized chitosan scaffolds may serve as good three-dimensional substrates for dental pulp stem cell attachment and proliferation. In the case of dental regeneration, they must be supported by appropriate biosignals to induce odontogenic differentiation.
