Biofabrication and Bone Tissue Regeneration: Cell Source, Approaches, and Challenges

The growing occurrence of bone disorders and the increase in aging population have resulted in the need for more effective therapies to meet this request. Bone tissue engineering strategies, by combining biomaterials, cells, and signaling factors, are seen as alternatives to conventional bone grafts for repairing or rebuilding bone defects. Indeed, skeletal tissue engineering has not yet achieved full translation into clinical practice because of several challenges. Bone biofabrication by additive manufacturing techniques may represent a possible solution, with its intrinsic capability for accuracy, reproducibility, and customization of scaffolds as well as cell and signaling molecule delivery. This review examines the existing research in bone biofabrication and the appropriate cells and factors selection for successful bone regeneration as well as limitations affecting these approaches. Challenges that need to be tackled with the highest priority are the obtainment of appropriate vascularized scaffolds with an accurate spatiotemporal biochemical and mechanical stimuli release, in order to improve osseointegration as well as osteogenesis

Amniotic fluid-derived stem cells for cardiovascular tissue engineering applications

Recent research has demonstrated that a population of stem cells can be isolated from amniotic fluid removed by amniocentesis that are broadly multipotent and non-tumorogenic. These amniotic fluid-derived stem cells (AFSC) could potentially provide an autologous cell source for treatment of congenital defects identified during gestation, particularly cardiovascular defects. In this review, the various methods of isolating, sorting and culturing AFSC are compared, along with techniques for inducing differentiation into cardiac myocytes and endothelial cells. Though research has not demonstrated complete and high yield cardiac differentiation, AFSC have been shown to effectively differentiate into endothelial cells and can effectively support cardiac tissue. Additionally, several tissue engineering and regenerative therapeutic approaches for the use of these cells in heart patches, injection after myocardial infarction, heart valves, vascularized scaffolds and blood vessels are summarized. These applications show great promise in the treatment of congenital cardiovascular defects, and further studies of isolation, culture, and differentiation of AFSC will help to develop their use for tissue engineering, regenerative medicine, and cardiovascular therapies

Il Diritto: così la Musica, così la Vita

[Law like Music and Life] Luca Orciani reviews the recent book Interpretare. Dialogo tra un musicista e un giurista by Mario Brunello and Gustavo Zagrebelsky (Bologna, il Mulino, 2016). Through a very close dialogue, Authors move across two worlds, two performative disciplines, two passions. With a critical sensitiveness, Orciani points out the important topics focused in the book (interpretation, creativity, virtuosity, perfection, but not only), asking some questions that are essential in Music as in Law

Characterization and phylogenetic epitope mapping of CD38 ADPR cyclase in the cynomolgus macaque

BACKGROUND: The CD38 transmembrane glycoprotein is an ADP-ribosyl cyclase that moonlights as a receptor in cells of the immune system. Both functions are independently implicated in numerous areas related to human health. This study originated from an inherent interest in studying CD38 in the cynomolgus monkey (Macaca fascicularis), a species closely related to humans that also represents a cogent animal model for the biomedical analysis of CD38. RESULTS: A cDNA was isolated from cynomolgus macaque peripheral blood leukocytes and is predicted to encode a type II membrane protein of 301 amino acids with 92% identity to human CD38. Both RT-PCR-mediated cDNA cloning and genomic DNA PCR surveying were possible with heterologous human CD38 primers, demonstrating the striking conservation of CD38 in these primates. Transfection of the cDNA coincided with: (i) surface expression of cynomolgus macaque CD38 by immunofluorescence; (ii) detection of ~42 and 84 kDa proteins by Western blot and (iii) the appearance of ecto-enzymatic activity. Monoclonal antibodies were raised against the cynomolgus CD38 ectodomain and were either species-specific or cross-reactive with human CD38, in which case they were directed against a common disulfide-requiring conformational epitope that was mapped to the C-terminal disulfide loop. CONCLUSION: This multi-faceted characterization of CD38 from cynomolgus macaque demonstrates its high genetic and biochemical similarities with human CD38 while the immunological comparison adds new insights into the dominant epitopes of the primate CD38 ectodomain. These results open new prospects for the biomedical and pharmacological investigations of this receptor-enzyme

Role of IGF1 and IGF1/VEGF on Human Mesenchymal Stromal Cells in Bone Healing: Two Sources and Two Fates.

In the repair of skeletal defects one of the major obstacles still remains an efficient vascularization of engineered scaffolds. We have examined the ability of insulin growth factor-1, alone or in association with vascular endothelial growth factor, to modulate the osteoblastic or endothelial commitment of periosteum-derived progenitor cells (PDPCs) and skin-derived multipotent stromal cells (S-MSCs). A selected gene panel for endothelial and osteoblastic differentiation as well as genes that can affect MAPK and PI3K/AKT signaling pathways were investigated. Moreover, gene expression profile of Sox2, Oct4, and Nanog transcription factors was assessed. Our results showed that under growth factor stimulation PDPCs are induced toward an osteoblastic differentiation, while S-MSCs seem to move along an endothelial phenotype. This different commitment seems to be linked to a diverse MAPK or PI3K/AKT signaling pathway activation. The analysis of genes for stemness evidenced that at least in PDPCs multipotency and differentiation could coexist. These results open interesting perspective for the development of innovative bone tissue engineering approaches based on a good network of angiogenesis and osteogenesis processes

mRNAs and miRNAs profiling of Mesenchymal Stem Cells derived from amniotic fluid and skin

Mesenchymal Stem Cells (MSCs) may be isolated from different adult sources and even if the minimal criteria for defining MSCs have been reported, the scientific question about the potential distinctions among MSCs derived from different sources is still opened. In particular, it is debated if MSCs of different origin have the same grade of stemness or if the source affects their undifferentiated status. Here we report not only the isolation and the traditional characterization of MSCs derived from amniotic fluid (AF-MSCs) [1] and skin (S-MSCs) [2], but also a molecular characterization based on mRNAs and miRNAs profiling. Our results show that even if both AF- and S-MSCs are regulated by the same pathways (such as Wnt, MAPK and TGF-β), there is a fine and different control of them as suggested by altered levels of expression of some member of these pathways. In conclusion, it will be necessary to improve the knowledge about the role of each dysregulated miRs/gene because, actually, these differences may strengthen the question about the importance of tissue origin. This work was supported by grant FIRB-RBAP10MLK7_003 from Ministero dell’Istruzione, dell’Università e della Ricerca, Rome, Ital

3D bioactive composite scaffolds for bone tissue engineering

Bone is the second most commonly transplanted tissue worldwide, with over four million operations using bone grafts or bone substitute materials annually to treat bone defects. However, significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma, cancer, infection and arthritis. Developing bioactive three-dimensional (3D) scaffolds to support bone regeneration has therefore become a key area of focus within bone tissue engineering (BTE). A variety of materials and manufacturing methods including 3D printing have been used to create novel alternatives to traditional bone grafts. However, individual groups of materials including polymers, ceramics and hydrogels have been unable to fully replicate the properties of bone when used alone. Favourable material properties can be combined and bioactivity improved when groups of materials are used together in composite 3D scaffolds. This review will therefore consider the ideal properties of bioactive composite 3D scaffolds and examine recent use of polymers, hydrogels, metals, ceramics and bio-glasses in BTE. Scaffold fabrication methodology, mechanical performance, biocompatibility, bioactivity, and potential clinical translations will be discussed

Role of 11β-Hydroxysteroid Dehydrogenase and Mineralocorticoid Receptor on Alzheimer's Disease Onset: A Systematic Review

The role of 11β-HSD1 in Alzheimer's disease (AD) has garnered significant attention due to its involvement in glucocorticoid metabolism, neuroinflammation, and cognitive decline. This review explores the current understanding of 11β-HSD1 in AD, examining genetic, preclinical, and clinical research. Genetic studies have identified 11β-HSD1 polymorphisms that may influence AD risk, although findings remain inconsistent. Mechanistically, 11β-HSD1 promotes neurodegeneration through the dysregulation of glucocorticoid activity, contributing to hippocampal atrophy, amyloid plaque formation, and tau pathology. Preclinical studies have shown that 11β-HSD1 inhibitors offer neuroprotective effects, including enhanced cognitive function, reduced inflammation, and improved mitochondrial activity. However, clinical trials, including those involving ABT-384 and Xanamem, have produced mixed results, with no substantial cognitive improvements despite effective enzyme inhibition. These inconsistencies highlight the complexity of AD and the challenges in translating preclinical findings into clinical outcomes. Moreover, while 11β-HSD1 inhibition holds therapeutic potential, other strategies targeting neuroinflammation, autophagy, and glucocorticoid signaling are also being explored. Ongoing research is focusing on optimizing 11β-HSD1 inhibitors, identifying biomarkers for patient selection, and investigating combination therapies to enhance treatment efficacy. Ultimately, 11β-HSD1's role in AD presents a promising therapeutic target, but further studies are required to fully understand its potential in managing the disease