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Medical applications stimulate the need for materials with broad potential. Chitosan, the partially deacetylated derivative of chitin, offers many interesting characteristics, such as biocompatibility and chemical derivatization possibility. In the present study, porous scaffolds composed of electrospun interwoven nanometric fibers are produced using chitosan or chitosan functionalized with aliphatic chains of twelve, fourteen or sixteen methylene groups. The scaffolds were thoroughly characterized by SEM and XPS. The length of the aliphatic tail influenced the physico-chemical and dynamic mechanical properties of the functionalized chitosan. The electrospun membranes revealed no interaction of Gram+ or Gram− bacteria, resulting in neither antibacterial nor bactericidal, but constitutively sterile. The electrospun scaffolds demonstrated the absence of cytotoxicity, inflammation response, and eryptosis. These results open the door to their application for blood purification devices, hemodialysis membranes, and vascular grafts.

Tissue engineering or tissue reconstruction/repair/regeneration may be considered as a guiding strategy in oral and maxillofacial surgery, as well as in endodontics, orthodontics, periodontics, and daily clinical practice. A wide range of techniques has been developed over the past years, from tissue grafts to the more recent and innovative regenerative procedures. Continuous research in the field of natural and artificial materials and biomaterials, as well as in advanced scaffold design strategies has been carried out. The focus has also been on various growth factors involved in dental tissue repair or reconstruction. Benefiting from the recent literature, this review paper illustrates current innovative strategies and technological approaches in oral and maxillofacial tissue engineering, trying to offer some information regarding the available scientific data and practical applications. After introducing tissue engineering aspects, an overview on additive manufacturing technologies will be provided, with a focus on the applications of superparamagnetic iron oxide nanoparticles in the biomedical field. The potential applications of magnetic fields and magnetic devices on the acceleration of orthodontic tooth movement will be analysed.

The aim of this study was to evaluate the effect of a time-dependent magnetic field on the biological performance of periodontal ligament stem cells (PDLSCs). A Western blot analysis and Alamar Blue assay were performed to investigate the proliferative capacity of magnetically stimulated PDLSCs (PDLSCs MAG) through the study of the MAPK cascade (p-ERK1/2). The observation of ALP levels allowed the evaluation of the effect of the magnetic field on osteogenic differentiation. Metabolomics data, such as oxygen consumption rate (OCR), extracellular acidification rate (ECAR) and ATP production provided an overview of the PDLSCs MAG metabolic state. Moreover, the mitochondrial state was investigated through confocal laser scanning microscopy. Results showed a good viability for PDLSCs MAG. Magnetic stimulation can activate the ERK phosphorylation more than the FGF factor alone by promoting a better cell proliferation. Osteogenic differentiation was more effectively induced by magnetic stimulation. The metabolic panel indicated significant changes in the mitochondrial cellular respiration of PDLSCs MAG. The results suggested that periodontal ligament stem cells (PDLSCs) can respond to biophysical stimuli such as a time-dependent magnetic field, which is able to induce changes in cell proliferation and differentiation. Moreover, the magnetic stimulation also produced an effect on the cell metabolic profile. Therefore, the current study demonstrated that a time-dependent magnetic stimulation may improve the regenerative properties of PDLSCs.

The concept of magnetic guidance is still challenging and has opened a wide range of perspectives in the field of tissue engineering. In this context, magnetic nanocomposites consisting of a poly(ε-caprolactone) (PCL) matrix and iron oxide (Fe3O4) nanoparticles were designed and manufactured for bone tissue engineering. The mechanical properties of PCL/Fe3O4 (80/20 w/w) nanocomposites were first assessed through small punch tests. The inclusion of Fe3O4 nanoparticles improved the punching properties as the values of peak load were higher than those obtained for the neat PCL without significantly affecting the work to failure. The effect of a time-dependent magnetic field on the adhesion, proliferation, and differentiation of human mesenchymal stem cells (hMSCs) was analyzed. The Alamar Blue assay, confocal laser scanning microscopy, and image analysis (i.e., shape factor) provided information on cell adhesion and viability over time, whereas the normalized alkaline phosphatase activity (ALP/DNA) demonstrated that the combination of a time-dependent field with magnetic nanocomposites (PCL/Fe3O4 Mag) influenced cell differentiation. Furthermore, in terms of extracellular signal-regulated kinase (ERK)1/2 phosphorylation, an insight into the role of the magnetic stimulation was reported, also demonstrating a strong effect due the combination of the magnetic field with PCL/Fe3O4 nanocomposites (PCL/Fe3O4 Mag).

Triple Negative Breast Cancers (TNBC) subtype is an aggressive disease with poor clinical outcome. The only treatment available is surgery followed by chemotherapy or radiotherapy. Programmed death-ligand 1 (PD-L1) is a trans-membrane protein expressed on a wide variety of cells including immune cells, epithelial and vascular endothelial cells. Recently, PD-1/PD-L1 pathway signaling was described as an adaptive immune resistance mechanism enacted by the tumor cells to evade the immune response. Its presence on tumor cell membranes, acquired for this reason, through time, is an important prognostic value. However, data available in the literature about PD-L1 immunohistochemical expression in breast cancer are often discordant and not uniform, probably for the use of different antibodies clones and the high molecular heterogeneity of the different tumor types. The absence of target therapies, in particular for TNBC, has shifted the clinical attention mainly on the role of PD-L1 in this subtype of breast cancer. In this study, we evaluated tumor and TIL (tumor infiltrating lymphocytes) PDL-1 expression in a series of TNBC, included in Tissue Micro Arrays (TMAs), to define its real prognostic value, optimizing immunohistochemistry method with an “approved for diagnostic assay” antibody. PD-L1 expression directly correlated with proliferation index (Ki-67), glycemia, the presence of diabetes and indirectly with menopausal status, presence of lymph node metastasis and relapse. The analysis of Kaplan–Meier showed that an increased PD-L1 expression was strongly associated with better disease-free survival (DFS) but not correlated with overall survival (OS). Our data confirmed that PD-L1 could be an important marker for prognostic stratification and for planning immune checkpoint inhibitors therapies in patients with TNBC.