RESUMEN
Human mesenchymal stromal cells (hMSCs), whether used alone or together with three-dimensional scaffolds, are the best-studied postnatal stem cells in regenerative medicine. In this study, innovative composite scaffolds consisting of a core-shell architecture were seeded with bone-marrow-derived hMSCs (BM-hMSCs) and tested for their biocompatibility and remarkable capacity to promote and support bone regeneration and mineralization. The scaffolds were prepared by grafting three different amounts of gelatin-chitosan (CH) hydrogel into a 3D-printed polylactic acid (PLA) core (PLA-CH), and the mechanical and degradation properties were analyzed. The BM-hMSCs were cultured in the scaffolds with the presence of growth medium (GM) or osteogenic medium (OM) with differentiation stimuli in combination with fetal bovine serum (FBS) or human platelet lysate (hPL). The primary objective was to determine the viability, proliferation, morphology, and spreading capacity of BM-hMSCs within the scaffolds, thereby confirming their biocompatibility. Secondly, the BM-hMSCs were shown to differentiate into osteoblasts and to facilitate scaffold mineralization. This was evinced by a positive Von Kossa result, the modulation of differentiation markers (osteocalcin and osteopontin), an expression of a marker of extracellular matrix remodeling (bone morphogenetic protein-2), and collagen I. The results of the energy-dispersive X-ray analysis (EDS) clearly demonstrate the presence of calcium and phosphorus in the samples that were incubated in OM, in the presence of FBS and hPL, but not in GM. The chemical distribution maps of calcium and phosphorus indicate that these elements are co-localized in the same areas of the sections, demonstrating the formation of hydroxyapatite. In conclusion, our findings show that the combination of BM-hMSCs and PLA-CH, regardless of the amount of hydrogel content, in the presence of differentiation stimuli, can provide a construct with enhanced osteogenicity for clinically relevant bone regeneration.
RESUMEN
Extracellular vesicles (EVs) are various sets of cell-derived membranous structures containing lipids, nucleic acids, and proteins secreted by both eukaryotic and prokaryotic cells. It is now well recognized that EVs are key intercellular communication mediators, allowing the functional transfer of bioactive chemicals from one cell to another in both healthy and pathological pathways. It is evident that the condition of the producer cells heavily influences the composition of EVs. Hence, phenotypic changes in the parent cells are mirrored in the design of the secreted EVs. As a result, EVs have been investigated for a wide range of medicinal and diagnostic uses in different hematological diseases. EVs have only recently been studied in the context of Chronic Myeloid Leukemia (CML), a blood malignancy defined by the chromosomal rearrangement t(9;22) and the fusion gene BCR-ABL1. The findings range from the impact on pathogenesis to the possible use of EVs as medicinal chemical carriers. This review aims to provide for the first time an update on our understanding of EVs as carriers of CML biomarkers for minimal residual disease monitoring, therapy response, and its management, as well as the limited reports on the use of EVs as therapeutic shuttles for innovative treatment approaches.
RESUMEN
Introducción: La colonización por Staphylococcus aureus meticilino resistente adquirido en la comunidad (SAMR-AC) ha ido en aumento desde su aparición. El objetivo de este trabajo fue conocer la prevalencia de colonización por SAMR-AC en soldados, determinar los factores predisponentes y conocer la dinámica de colonización a los seis meses de convivencia. Materiales y métodos: Estudio descriptivo, de corte transversal. Se incluyó una muestra de los soldados ingresantes a un establecimiento militar. Se tomó una muestra de hisopado nasal y, en caso de aislamiento de Staphylococcus aureus, se determinó la frecuencia de la cepa meticilino resistente de la comunidad. Se realizó una encuesta sobre los posibles factores predisponentes para la colonización. Luego de seis meses de convivencia se efectuó un nuevo hisopado y se analizó el cambio en la prevalencia y la dinámica de colonización. Resultados: Se incluyeron 346 soldados provenientes de diferentes provincias de Argentina. La prevalencia inicial de colonización por Staphylococcus aureus meticilino resistente de la comunidad fue 7,8% y, luego de seis meses, 9,5% (aumento del 21,8%). Los factores que mostraron asociación con la colonización por SAMR-AC fueron los antecedentes de un conviviente con forunculosis (p=0,02), forunculosis previa (p=0,04) y forunculosis en familiar de primer grado no conviviente (p=0.03). Se constató persistencia de colonización en el 79% del grupo inicial. Conclusiones: Se observó una prevalencia de colonización por Staphylococcus aureus meticilino resistente de la comunidad del 7,8%, superior a la encontrada en la mayoría de los estudios publicados
Introduction: Colonization by community-acquired methicillin-resistant Staphylococcus aureus has been on the rise since its appearance. The objective of this study was to estimate the prevalence of colonization by community-acquired methicillin-resistant staphylococcus aureus in soldiers, determine the predisposing factors and know the dynamics of colonization during coexistence. Materials and methods: descriptive, cross-sectional study. A sample of the incoming soldiers in a military establishment was included. A nasal swab was taken and, in case of isolation of Staphylococcus aureus, the frequency of the resistant meticillin strain in the community was determined. A survey was made on possible predisposing factors for colonization by this germ. After 6 months of cohabitation, a new swab was performed and the change in prevalence and colonization dynamics was analyzed. Results: 346 soldiers from different provinces of the country were included. The initial prevalence of soldiers colonized by community-acquired methicillin-resistant was 7.8%, and after 6 months, 9.5% (21.8% increase). The factors associated with SAMR-AC colonization were the antecedent of a household members with forunculosis (p=0.02), history of forunculosis (p=0.04) and the antecedent of forunculosis in a non-cohabiting first-degree relative (p=0.03). Persistence of colonization was found in 79% of the initial group.Conclusion: a prevalence of 7.8% community methicillin resistant Staphylococcus aureus colonization was observed, superior to that found in the majority of published studies.