Background/Objectives: Ibrutinib (IBR) is a tyrosine kinase inhibitor under investigation in preclinical and clinical settings as an alternative treatment for melanoma. Nevertheless, the limited oral bioavailability of IBR and the need for high doses of the drug to kill melanoma cells are major drawbacks for this purpose. Considering that melanoma is restricted to the skin at early stages, the topical application of IBR might constitute an effective and safer administration route. In this study, we determined IBR’s toxicity and dermatokinetics using human primary cells and human organotypic skin explant cultures (hOSECs). Methods: After demonstrating that human primary fibroblasts and keratinocytes present IBR target genes, the cytotoxicity of the drug was determined using the MTT and annexin V/PI staining assays. IBR toxicity in the skin was assessed using the TTC assay, and the irritation potential was established using histological assessment. Finally, IBR cutaneous permeation was assessed ex vivo to determine the drug dermatokinetics. Results: Our findings reveal that IBR exerts dose-dependent toxicity towards skin cells, presenting an IC₅₀ in the same range as melanoma cells. The topical application of the drug successfully reduced irritation and toxicity in the skin, and the drug was shown to successfully permeate the stratum corneum and reach the viable skin layers in therapeutic concentrations. Conclusions: Overall, our data encourage the topical application of IBR to treat melanoma, paving the way for future studies in this theme.

Inflammation contributes to the onset and exacerbation of numerous age-related diseases, often manifesting as a chronic condition during aging. Given that cellular senescence fosters local and systemic inflammation, senotherapeutic interventions could potentially aid in managing or even reducing inflammation. Here, we investigated the immunomodulatory effects of the senotherapeutic Peptide 14 (Pep 14) in human peripheral blood mononuclear cells (PBMCs), monocytes, and macrophages. We found that, despite failing to significantly influence T cell activation and proliferation, the peptide promoted a Th2/Treg gene expression and cytokine signature in PBMCs, characterized by increased expression of the transcription factors GATA3 and FOXP3, as well as the cytokines IL-4 and IL-10. These observations were partially confirmed through ELISA, in which we observed increased IL-10 release by resting and PHA-stimulated PBMCs. In monocytes from the U-937 cell line, Pep 14 induced apoptosis in lipopolysaccharide (LPS)-stimulated cells and upregulated IL-10 expression. Furthermore, Pep 14 prevented LPS-induced activation and promoted an M2-like polarization in U-937-derived macrophages, evidenced by decreased expression of M1 markers and increased expression of M2 markers. We also showed that the conditioned media from Pep 14-treated macrophages enhanced fibroblast migration, indicative of a functional M2 phenotype. Taken together, our findings suggest that Pep 14 modulates immune cell function towards an anti-inflammatory and regenerative phenotype, highlighting its potential as a therapeutic intervention to alleviate immunosenescence-associated dysregulation.

Introduction: The development of ex vivo skin tumor models represents a relevant alternative to animal use, allowing the investigation of melanoma progression under physiological conditions closer to human skin

Dengue is endemic in Brazil, and several Brazilian cities are affected by frequent seasonal outbreaks of the disease. During the outbreaks the possibility of transfusion-transmitted dengue (TTD) is increased, mainly by the presence of asymptomatic or oligosymptomatic infections in eligible blood donors. The retrospective assessment of anti-DENV IgM and NS1 seroprevalence during a given time interval may indicate the need for measures for the previous screening of DENV infection in blood donors. In this context, we performed retrospective screening for anti-DENV IgM and NS1 in blood donors from the Federal District of Brazil during the early outbreak that occurred in 2019, the largest outbreak in recent years. In total, 450 blood donations were screened for anti-DENV IgM and DENV NS1 using commercial enzyme-linked immunosorbent assay kits (Panbio Dengue IgM Capture ELISA and Platelia Dengue NS1 Ag, respectively). Among the tested plasma samples, 16 % (72/450) presented anti-DENV IgM; no samples presented DENV NS1. Despite the apparent absence of antigenaemia in tested blood donations, the high prevalence of anti-DENV IgM highlights the importance of DENV screening in blood donors, principally during outbreak periods.