Recently, infrapatellar fat pad (IFP) has been considered as a source of stem cells for cartilage regeneration in osteoarthritis (OA) due to their ability for differentiation into chondrocytes. However, stressful conditions, like that related to OA, may induce a pathogenic reprograming. The aim of this study was to characterize the structural and functional properties of a new population of stem cells isolated from osteoarthritic infrapatellar fat pad (OA-IFP). Nine OA patients undergoing total knee arthroplasty (TKA) were enrolled in this study [median age = 74 years, interquartile range (IQR) = 78.25-67.7; median body mass index = 29.4 Kg/m², IQR = 31.7-27.4]. OA-IFP stem cells were isolated and characterized for morphology, stemness, metabolic profile and multi-differentiative potential by transmission electron microscopy, flow cytometric analysis, gene expression study and cytochemistry. OA-IFP stem cells displayed a spindle-like morphology, self-renewal potential and responsiveness (CD44, CD105, VEGFR2, FGFR2, IL1R, and IL6R) to microenvironmental stimuli. Characterized by high grade of stemness (STAT3, NOTCH1, c-Myc, OCT-4, KLF4, and NANOG), the cells showed peculiar immunophenotypic properties (CD73⁺/CD39⁺/CD90⁺/CD105⁺/CD44^–/+/CD45^–). The expression of HLA-DR, CD34, Fas and FasL was indicative of a possible phenotypic reprograming induced by inflammation. Moreover, the response to mechanical stimuli together with high expression level of COL1A1 gene, suggested their possible protective response against in vivo mechanical overloading. Conversely, the low expression of CD38/NADase was indicative of their inability to counteract NAD⁺-mediated OA inflammation. Based on the ultrastructural, immunophenotypic and functional characterization, OA-IFP stem cells were hypothesized to be primed by the pathological environment and to exert incomplete protective activity from OA inflammation.

Xeroderma Pigmentosum (XP) is a rare genetic syndrome with a defective DNA nucleotide excision repair. It is characterized by (i) an extreme sensitivity to ultraviolet (UV)-induced damages in the skin and eyes; (ii) high risk to develop multiple skin tumours; and (iii) neurologic alterations in the most severe form. To date, the management of XP patients consists of (i) early diagnosis; (ii) a long-life protection from ultraviolet radiation, including avoidance of unnecessary UV exposure, wearing UV blocking clothing, and use of topical sunscreens; and (iii) surgical resections of skin cancers. No curative treatment is available at present. Thus, in the last decade, in order to prevent or delay the progression of the clinical signs of XP, numerous strategies have been proposed and tested, in some cases, with adverse effects. The present review provides an overview of the molecular mechanisms featuring the development of XP and highlights both advantages and disadvantages of the clinical approaches developed throughout the years. The intention of the authors is to sensitize scientists to the crucial aspects of the pathology that could be differently targeted. In this context, the exploration of the process underlining the conception of liposomal nanocarriers is reported to focus the attention on the potentialities of liposomal technology to optimize the administration of chemoprotective agents in XP patients.

Astrocyte proliferation and migration toward injured Central Nervous System (CNS) areas are key features of astrogliosis and glial scar formation. Even though it is known that intracellular and environmental Reactive Oxygen and Nitrogen Species (RONS) affect astrocyte behaviour in physiological and pathophysiological conditions, their effects on the migration and growth of astrocytes are still unclear. Plasma-technologies are emerging in medicine as a tool to generate RONS for treating cells directly or through Plasma Activated Liquid Media (PALM). In this paper, we show for the first time how the use of PALM can modulate both astrocyte growth and migration as a function of active species produced by plasma in liquids. Our results show that PALM, generated by means of cold atmospheric pressure plasmas fed with N_2, air or O₂, can modulate astrocyte behaviour depending on the content of hydrogen peroxide and nitrite in the liquid. In particular, H₂O₂ enriched PALM induced a negative effect on cell growth associated with the mild wound healing improvement of primary astrocytes, in a scratch assay. Nitrite enriched PALM induced a selective effect on the wound healing without affecting cell growth. PALM containing a more balanced level of H₂O₂ and NO₂⁻ were able to affect cell growth, as well as significantly ameliorate wound healing. None of the PALM investigated induced upregulation of the gliotic inflammatory marker glial fibrillary acidic protein (GFAP), or of the astrocyte markers Aquaporin-4 (AQP4) and Connexin-43 (Cx-43) analysed by Western blot. Finally, immunofluorescence analysis revealed the presence of NO₂^- able to induce elongated protrusions at the front end of wounded astrocytes in the direction of cell migration. With our study we believe to have shown that PALM offer a novel tool to modulate astrocyte behaviour and that they are promising candidates for controlling astrogliosis in the case of CNS injuries.

Nanocomposite scaffolds combining carbon nanomaterials (CNMs) with a biocompatible matrix are able to favor the neuronal differentiation and growth of a number of cell types, because they mimic neural-tissue nanotopography and/or conductivity. We performed comparative analysis of biomimetic scaffolds with poly-L-lactic acid (PLLA) matrix and three different p-methoxyphenyl functionalized carbon nanofillers, namely, carbon nanotubes (CNTs), carbon nanohorns (CNHs), and reduced graphene oxide (RGO), dispersed at varying concentrations. qRT-PCR analysis of the modulation of neuronal markers in human circulating multipotent cells cultured on nanocomposite scaffolds showed high variability in their expression patterns depending on the scaffolds’ inhomogeneities. Local stimuli variation could result in a multi- to oligopotency shift and commitment towards multiple cell lineages, which was assessed by the qRT-PCR profiling of markers for neural, adipogenic, and myogenic cell lineages. Less conductive scaffolds, i.e., bare poly-L-lactic acid (PLLA)-, CNH-, and RGO-based nanocomposites, appeared to boost the expression of myogenic-lineage marker genes. Moreover, scaffolds are much more effective on early commitment than in subsequent differentiation. This work suggests that biomimetic PLLA carbon-nanomaterial (PLLA-CNM) scaffolds combined with multipotent autologous cells can represent a powerful tool in the regenerative medicine of multiple tissue types, opening the route to next analyses with specific and standardized scaffold features.