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OBJECTIVE: The objective of this research was to examine the effects of topical ciprofloxacin on cultured nasal epithelial cells of human origin. MATERIALS AND METHODS: H uman n asal epithelial cells were collected from patients who voluntarily donated tissue left over following septorhinoplasty. The samples were from individuals without any indication of rhinosinusitis. An assay that may be employed to investigate toxic effects at the cellular level is MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). This test reveals where DNA becomes fragmented, the nuclei condense, the outer cell membrane is altered, or the cytoskeleton appears disrupted. The present study employed this technique. Nasal epithelium in cell culture was exposed to ciprofloxacin for 24 hours at a temperature of 37°C, following which the MTT assay was undertaken before examining the cells by confocal microscopy to look for alterations indicating cytotoxicity. Another test of toxicity, the artificial scratch technique, was also used. Cells treated in this way were assessed using a light microscope. RESULTS: The nasal epithelial cells in culture that were exposed to topical ciprofloxacin for 24 hours were less viable than controls and this result was statistically significant. For this length of exposure, the IC50 was calculated as 1.565 mg/mL. The peak reductions in cellular viability occurred with exposure at a concentration of 1.25 mg/mL and 0.625 mg/mL. These was only a mild decrease in viability at other concentrations, but these results were of statistical significance. The MTT assay and confocal microscopy confirmed this result. Cultured nasal epithelium not exposed to ciprofloxacin (i.e., controls) exhibited a compact morphological appearance when examined with confocal microscopy. The epithelial cells had a regular fusiform boundary, and the nuclei were intact. By contrast, the cultures with exposure to the antibiotic were of decreased size and their outline changed from fusiform to round. The epithelial cells cultures where scratch injury was induced were examined by light microscopy, the extent of closure of the denuded area being assessed after 24 hours. It was noted that the area opened up by the experimental scratch was not closed completely by 24 hours later. This result shows that ciprofloxacin decreases the viability of nasal epithelial cells. CONCLUSIONS: Topical application of cipro- floxacin to the nasal lining is not recommended, since this resulted in decreased cellular viability, cellular shrinking and alteration in outline from fusiform to round in cultured nasal epithelial cells. These changes indicate that topically applied ciprofloxacin is toxic to nasal epithelial cells. The outcomes of this study should be studied and correlated in vivo models. [ABSTRACT FROM AUTHOR]

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Transplantation of immuno-isolated islets is a promising strategy to restore insulin-secreting function in patients with Type 1 diabetes. However, the clinical translation of this treatment approach remains elusive due to the loss of islet viability resulting from hypoxia at the avascular transplantation site. To address this challenge, we designed non-spherical islet-like microtissues and investigated the effect of their geometries on cellular viability. Insulin-secreting microtissues with different shapes were fabricated by assembly of monodispersed rat insulinoma beta cells on micromolded nonadhesive hydrogels. Our study quantitatively demonstrated that toroid microtissues exhibited enhanced cellular viability and metabolic activity compared to rod and spheroid microtissues with the same volume. At a similar level of cellular viability, toroid geometry facilitated efficient packing of more cells into each microtissue than rod and spheroid geometries. In addition, toroid microtissues maintained the characteristic glucose-responsive insulin secretion of rat insulinoma beta cells. Furthermore, toroid microtissues preserved their geometry and structural integrity following their microencapsulation in immuno-isolatory alginate hydrogel. Our study suggests that adopting toroid geometry in designing therapeutic microtissues potentially reduces mass loss of cellular grafts and thereby may improve the performance of transplanted islets towards a clinically viable cure for Type 1 diabetes. Transplantation of therapeutic cells is a promising strategy for the treatment of a wide range of hormone or protein-deficiency diseases. However, the clinical application of this approach is hindered by the loss of cell viability and function at the avascular transplantation site. To address this challenge, we fabricated hydrogel-encapsulated islet-like microtissues with non-spheroidal geometry and optimal surface-to-volume ratio. This study demonstrated that the viability of therapeutic cells can be significantly increased solely by redesigning the microtissue configuration without requiring any additional biochemical or operational accessories. This study suggests that the adoption of toroid geometry provides a possible avenue to improve the long-term survival of transplanted therapeutic cells and expedite the translation of cell-based therapy towards clinical application. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Polyhydroxybutyrate (PHB), a promising biopolymer with significant potential in the dental field, is an immunologically compatible substance derived from natural and viable sources. Recognized as lipid acid polymers produced intracellularly by bacteria, PHB holds promise for various dental applications. If combined with dental stem cells (DPSCs), its unique properties could further enhance its suitability for innovative and biocompatible scaffold development. MATERIALS AND METHODS: The production of PHB fibrillar membranes utilized the electrospinning method, employing an aluminum foil-covered copper plate as the collector. A solution of PHB at a concentration of 8% (w/v) was prepared by dissolving it in chloroform: 2-fluoroethanol (20:1 v/v) at 60°C using a heated magnetic stirrer. The resulting PHB solution was loaded into a 20 ml syringe connected to a syringe pump, set at a flow rate of 0.3 ml/hour. Electrospinning was performed on a copper plate with the power supply set to 10 kV. The isolation and characterization of dental pulp stem cells (DPSCs) were conducted following previously established protocols. Cytotoxicity testing was carried out using the MTT assay, and cellular adhesion was assessed through immunocytochemical staining with DAPI. RESULTS AND DISCUSSION: The MTT results demonstrated consistently high cell viability comparable to the control group. This indicates that the PHB membranes did not induce cytotoxic effects on DPSCs over the assessed time points (1, 3 and 7 days). The immunocytochemical images obtained after 1, 3, and 7 days of treatment exhibited robust cellular adhesion. This suggests that the PHB scaffolds provided a conducive environment for DPSC adhesion and growth. This consistency in cellular response underscores the biocompatibility of the PHB scaffolds. The absence of adverse effects on cell viability and adhesion supports the potential of PHB as a suitable material for dental applications. The positive outcomes of this study suggest that PHB fibrillar membranes hold promise for use in dental applications, particularly in the context of DPSC interactions. Further investigations are warranted to explore the long-term effects, structural integrity, and specific molecular interactions between PHB and dental stem cells. These findings contribute valuable insights to the development of biocompatible materials for dental tissue engineering and regenerative medicine. CONCLUSIONS: In summary, our study demonstrates the sustained viability, lack of cytotoxic effects, and robust cellular adhesion of dental pulp stem cells on PHB fibrillar membranes, affirming the promising biocompatibility of PHB for dental applications. [ABSTRACT FROM AUTHOR]

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Copyright of Acta Universitaria is the property of Universidad de Guanajuato/Acta Universitaria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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