Evaluation of antigen-induced synovitis in a porcine model: Immunological, arthroscopic and kinetic studies

Abstract Background Synovitis is an inflammation-related disease linked to rheumatoid arthritis, osteoarthritis, infections and trauma. This inflammation is accompanied by immune cells infiltration which initiates an inflammatory response causing pain, discomfort and affecting the normal joint function. The treatment of synovitis is based on the administration of anti-inflammatory drugs or biological agents such as platelet rich plasma and mesenchymal stem cells. However, the evaluation and validation of more effective therapies of synovitis requires the establishment of clinically relevant animal models. Results In this study, Large White pigs were pre-immunized to evaluate an antigen-induced synovitis. The immune monitoring of synovial fluids in this model allowed us the identification of IL-12p40 and T cell subsets as immune biomarkers. Moreover, the evolution of synovitis was performed by arthroscopic procedures and kinetic analysis. In summary, this paper describes an animal model of antigen-induced synovitis to be used in the evaluation of anti-inflammatory therapies. Conclusions The novelty of this paper lies in the development of a clinically relevant model of synovitis which permits the simultaneous evaluation of synovitis from an immunological, surgical and kinetic point of view

Stem cells for osteochondral regeneration

Stem cell research plays a central role in the future of medicine, which is mainly dependent on the advances on regenerative medicine (RM), specifically in the disciplines of tissue engineering (TE) and cellular therapeutics. All RM strategies depend upon the harnessing, stimulation, or guidance of endogenous developmental or repair processes in which cells have an important role. Among the most clinically challenging disorders, cartilage degeneration, which also affects subchondral bone becoming an osteochondral (OC) defect, is one of the most demanding. Although primary cells have been clinically applied, stem cells are currently seen as the promising tool of RM-related research because of its availability, in vitro proliferation ability, pluri- or multipotency, and immunosuppressive features. Being the OC unit, a transition from the bone to cartilage, mesenchymal stem cells (MSCs) are the main focus for OC regeneration. Promising alternatives, which can also be obtained from the patient or at banks and have great differentiation potential toward a wide range of specific cell types, have been reported. Still, ethical concerns and tumorigenic risk are currently under discussion and assessment. In this book chapter, we revise the existing stem cell-based approaches for engineering bone and cartilage, focusing on cell therapy and TE. Furthermore, 3D OC composites based on cell co-cultures are described. Finally, future directions and challenges still to be faced are critically discussed.H2020-MSCA-RISE program, as this work is part of developments carried out in BAMOS project, funded from the European Union's Horizon 2020 research and innovation program under grant agreement Nº 734156. Thanks are also due to the Portuguese Foundation for Science and Technology (FCT) for the distinction attributed to J. M. Oliveira (IF/00423/2012 and IF/01285/2015) and to Rogério Pirraco (IF/00347/2015) under the Investigator FCT program. The authors also thank FCT for the Ph.D. scholarship provided to R. F. Canadas (SFRH/BD/92565/2013)info:eu-repo/semantics/publishedVersio