49 research outputs found
Serotonin Exposure Improves Stress Resistance, Aggregation, and Biofilm Formation in the Probiotic Enterococcus faecium NCIMB10415
Novel silverâfunctionalized poly(Éâcaprolactone)/biphasic calcium phosphate scaffolds designed to counteract postâsurgical infections in orthopedic applications
In this study, we designed and developed novel poly(Δâcaprolactone) (PCL)âbased biomaterials, for use as bone scaffolds, through modification with both biphasic calcium phosphate (BCP), to impart bioactive/bioresorbable properties, and with silver nitrate, to provide antibacterial protection against Staphylococcus aureus, a microorganism involved in prosthetic joint infections (PJIs). Field emission scanning electron microscopy (FESEM) showed that the samples were characterized by squareâshaped macropores, and energy dispersive Xâray spectroscopy analysis confirmed the presence of PCL and BCP phases, while inductively coupled plasmaâmass spectrometry (ICPâMS) established the release of Ag+ in the medium (~0.15â0.8 wt% of initial Ag content). Adhesion assays revealed a significant (p < 0.0001) reduction in both adherent and planktonic staphylococci on the Agâfunctionalized biomaterials, and the presence of an inhibition halo confirmed Ag release from enriched samples. To assess the potential outcome in promoting bone integration, preliminary tests on sarcoma osteogenicâ2 (Saosâ2) cells indicated PCL and BCP/PCL biocompatibility, but a reduction in viability was observed for Agâadded biomaterials. Due to their combined biodegrading and antimicrobial properties, the silverâenriched BCP/PCL-based scaffolds showed good potential for engineering of bone tissue and for reducing PJIs as a microbial antiâadhesive tool used in the delivery of targeted antimicrobial molecules, even if the amount of silver needs to be tuned to improve osteointegration
Antibacterial, anti-swarming and anti-biofilm formation activities of Chamaemelum nobile against Pseudomonas aeruginosa
Activin A Induces Langerhans Cell Differentiation In Vitro and in Human Skin Explants
Langerhans cells (LC) represent a well characterized subset of dendritic cells located in the epidermis of skin and mucosae. In vivo, they originate from resident and blood-borne precursors in the presence of keratinocyte-derived TGFÎČ. În vitro, LC can be generated from monocytes in the presence of GM-CSF, IL-4 and TGFÎČ. However, the signals that induce LC during an inflammatory reaction are not fully investigated. Here we report that Activin A, a TGFÎČ family member induced by pro-inflammatory cytokines and involved in skin morphogenesis and wound healing, induces the differentiation of human monocytes into LC in the absence of TGFÎČ. Activin A-induced LC are Langerin+, Birbeck granules+, E-cadherin+, CLA+ and CCR6+ and possess typical APC functions. In human skin explants, intradermal injection of Activin A increased the number of CD1a+ and Langerin+ cells in both the epidermis and dermis by promoting the differentiation of resident precursor cells. High levels of Activin A were present in the upper epidermal layers and in the dermis of Lichen Planus biopsies in association with a marked infiltration of CD1a+ and Langerin+ cells. This study reports that Activin A induces the differentiation of circulating CD14+ cells into LC. Since Activin A is abundantly produced during inflammatory conditions which are also characterized by increased numbers of LC, we propose that this cytokine represents a new pathway, alternative to TGFÎČ, responsible for LC differentiation during inflammatory/autoimmune conditions
Role of osteopontin in dendritic cell shaping of immune responses
Osteopontin (OPN) is a pleiotropic cytokine produced both by immune and non-immune cells and active on different cellular targets. OPN production has been associated with several pathological conditions, including autoimmune diseases (e.g. lupus, multiple sclerosis and rheumatoid arthritis) and cancer. Emerging evidence suggests that the role of OPN has been underestimated, as it seems to be working at multiple levels of immune regulation, such as the shaping of T cell effector responses, the regulation of the tumor microenvironment, and the functional interaction with mesenchymal stromal cells. In this context, dendritic cells (DCs) play a crucial role being both an important source and a cellular target for OPN action. DC family is composed by several cell subsets endowed with specific immune functions. OPN exerts its biological functions through multiple receptors and is produced in different intracellular and secreted forms. OPN production by DC subsets is emerging as a crucial mechanism of regulation in normal and pathological conditions and starts to be exploited as a therapeutic target. This review will focus on the role of DC-derived OPN in shaping immune response and on the complex role of this cytokines in the regulation in immune response