Effect of angiotensin II and angiotensin-(1-7) on proliferation of stem cells from human dental apical papilla.

The effects of the renin-angiotensin system (RAS) on stem cells isolated from human dental apical papilla (SCAPs) are completely unknown. Therefore, the aim of this study was to identify RAS components expressed in SCAPs and the effects of angiotensin (Ang) II and Ang-(1-7) on cell proliferation. SCAPs were collected from third molar teeth of adolescents and maintained in cell culture. Messenger RNA expression and protein levels of angiotensin-converting enzyme (ACE), ACE2, and Mas, Ang II type I (AT1) and type II (AT2) receptors were detected in SCAPs. Treatment with either Ang II or Ang-(1-7) increased the proliferation of SCAPs. These effects were inhibited by PD123319, an AT2 antagonist. While Ang II augmented mTOR phosphorylation, Ang-(1-7) induced ERK1/2 phosphorylation. In conclusion, SCAPs produce the main RAS components and both Ang II and Ang-(1-7) treatments induced cell proliferation mediated by AT2 activation through different intracellular mechanisms.

Application of the adverse outcome pathway framework for investigating skin sensitization potential of nanomaterials using new approach methods.

BACKGROUND: Currently, considerable efforts to standardize methods for accurate assessment of properties and safety aspects of nanomaterials are being made. However, immunomodulation effects upon skin exposure to nanomaterial have not been explored. OBJECTIVES: To investigate the immunotoxicity of single-wall carbon nanotubes, titanium dioxide, and fullerene using the current mechanistic understanding of skin sensitization by applying the concept of adverse outcome pathway (AOP). METHODS: Investigation of the ability of nanomaterials to interact with skin proteins using the micro-direct peptide reactivity assay; the expression of CD86 cell surface marker using the U937 cell activation test (OECD No. 442E/2018); and the effects of nanomaterials on modulating inflammatory response through inflammatory cytokine release by U937 cells. RESULTS: The nanomaterials easily internalized into keratinocytes cells, interacted with skin proteins, and triggered activation of U937 cells by increasing CD86 expression and modulating inflammatory cytokine production. Consequently, these nanomaterials were classified as skin sensitizers in vitro. CONCLUSIONS: Our study suggests the potential immunotoxicity of nanomaterials and highlights the importance of studying the immunotoxicity and skin sensitization potential of nanomaterials to anticipate possible human health risks using standardized mechanistic nonanimal methods with high predictive accuracy. Therefore, it contributes toward the applicability of existing OECD (Organisation for Economic Co-operation and Development) testing guidelines for accurate assessment of nanomaterial skin sensitization potential.

In Vivo Vaginal Fungal Load Reduction After Treatment with Itraconazole-Loaded Polycaprolactone-Nanoparticles.

Itraconazole (ITZ) has a broad spectrum of action and is commonly used for the treatment of fungal infections. Topic administration of ITZ is a promising strategy to improve vulvovaginal candidiasis treatment, which can be further optimized by its encapsulation in nanoparticles to increase drug delivery and reduce ITZ toxicity. In this work, we designed polycaprolactone nanoparticles containing ITZ and evaluated in vivo the efficacy of this yet unexplored approach. Nanocapsules (ITZ-NC) and nanospheres (ITZ-NS) were obtained by nanoprecipitation. ITZ-NC presented encapsulation efficiency of 99%, mean diameter of 190 nm, PDI 0.1 and zeta potential of -15 mV. ITZ-NS showed encapsulation efficiency of 97%, mean diameter of 120 nm, PDI 0.1 and zeta potential of -10 mV. Both particles were efficiently freeze-dried using 10% trehalose + 10% sucrose. Nanoparticles were then incorporated in a viscous formulation for vaginal application in female Balb/C mice infected with Candida albicans. Fungal load was significantly reduced in infected animals after treatment with ITZ-NC but not with ITZ-NS, compared to animals treated with ITZ solution. Histological analysis showed a clear difference between vaginal tissues of ITZ-NC and ITZ-NS and ITZ solution-treated animals, which correlated with IL-1ß and TNF-α quantification. Animals treated with ITZ-NC showed reduced cytokine levels and healthy tissue characteristics, while animals treated with ITZ-NS and ITZ solution showed increased IL-1ß and TNF-α levels and typical tissue inflammation. Our results demonstrate the potential of ITZ-NC to improve the treatment of vulvovaginal candidiasis after topical application in the vagina, opening new perspectives for the treatment of this disease.