Low-level laser therapy (LLLT) is a treatment that is increasingly used in orthopedics practices. In vivo and in vitro studies have shown that low-level laser therapy (LLLT) promotes angiogenesis, fracture healing and osteogenic differentiation of stem cells. However, the underlying mechanisms during bone formation remain largely unknown. Factors such as wavelength, energy density, irradiation and frequency of LLLT can influence the cellular mechanisms. Moreover, the effects of LLLT are different according to cell types treated. This review aims to summarize the current knowledge of the molecular pathways activated by LLLT and its effects on the bone healing process. A better understanding of the cellular mechanisms activated by LLLT can improve its clinical application.

Introduction: The term ‘chronic inflammatory arthritis’ (IA) can be used to define a group of heterogeneous diseases in which inflammation of the synovium is the common feature while having different pathogenesis and clinical outcomes. This condition can be found in osteoarthritis (OA), rheumatoid arthritis (RA), and hemophilic arthropathy (HA).Aim: The objective is to try to highlight similarities and differences in the three pathological conditions and understand both molecular and physiological mechanisms.Method: We have carried out a systematic review of the available literature following the guidelines Preferred Reporting Items for Systematic Reviews and Meta‐analysis (PRISMA).Results: By comparing the data in the literature on OA, RA, and HA we have shown that the three pathologies differ in initial etiology but they motivate the same molecular pathways.Conclusion: In this review we highlighted the similarities and differences between these diseases, creating ideas for future studies both in vivo and in vitro to develop new therapeutic agents and suggest possible biomarkers to follow the evolution and severity of the disease.

Ossiculoplasty is a surgical operation performed to restore auditory transmission through the reconstruction of the ossicular chain using prosthetics. Tissue bioengineering has assumed a pivotal role in implementing alternatives to conventional ossicular middle ear replacement prostheses, to overcome extrusion while preserving acoustic properties. This in vitro study aims to explore, for the first time in current literature, the feasibility of a biohybrid middle ear prosthesis, composed of titanium surrounded by a bone extracellular matrix as bio-coating. We have hereby studied the adhesion and proliferation of human adipose-derived mesenchymal stem cells (hASC) on titanium scaffolds in vitro. Moreover, we identified the osteogenic differentiation of hASC using an immunofluorescence assay to analyze osteoblasts’ gene expression profiles (Alp, Runx2, Col1a1, Osx, and Bglap), and we counted the presence of collagen as a marker of hASC’s ability to secrete an extracellular matrix. We utilized scanning electron microscopy to evaluate the presence of an extracellular matrix on the scaffolds. Our preliminary data demonstrated the titanium’s ability to support human adipose-derived mesenchymal stem cell colonization, proliferation, and osteoblastic differentiation, in order to obtain a biohybrid device. Our experience seems encouraging; thus, we advocate for further in vivo research to corroborate our results regarding bone transplantation.

Intra-articular blood, iron and hemosiderin, hydroxyl radical cytokines, and neo-angiogenesis cause synovial inflammation, which leads to cartilage and joint damage. Platelet-rich plasma (PRP) inhibits most of the mediators that produce and maintain synovitis. We compile here our work showing the clinical effectiveness of intra-articular PRP injections and their potential role in stopping articular cartilage damage due to bleeding and its possible repair. A total of 116 joints, including knees (63%), elbows (19.8%), and ankles (17.2%), were treated with intra-articular injections of PRP. Moreover, we also show here the number of extracellular DNA traps (ETs) and the PRP effect in the synovial fluid of patients at the time of treatment and six months after. Clinically, it is demonstrated that PRP is effective in reducing bleeding episodes (p < 0.001) and pain (p < 0.0001) and improving the hemophilia joint health score (HJHS) (p < 0.001) at one year of follow-up. Furthermore, our results demonstrate that PRP inhibits ET formation in vitro and reconstitutes the immune system’s cellular components in the synovial fluid of patients after treatment. We conclude that PRP can be considered an effective, safe, and easy treatment for hemophilic synovitis.

Factor VIII (FVIII) is involved in several molecular pathways and biological processes; indeed, it has a role in the coagulative cascade, cardiovascular disease, hypertension, brain and renal function, cancer incidence and spread, macrophage polarization, and angiogenesis. Hemophilic patients usually present an increase in fracture risk, bone resorption, and an excess of osteoporosis as compared to healthy individuals. Several studies have tried to clarify their etiology but unfortunately it is still unclear. This review focuses on the role of FVIII in bone biology by summarizing all the knowledge present in the literature. We carried out a systematic review of the available literature following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Several studies demonstrated that FVIII is involved in different molecular pathways interfering with bone physiology; it exerts interesting effects on OPG/RANK/RANKL pathways and thrombin/PAR1 pathways. These data confirm a relationship between FVIII and bone metabolism; however, there are still many aspects to be clarified. This review highlights the role of the coagulation factor FVIII in bone metabolism, suggesting new hypotheses for future studies both in vitro and in vivo to better understand the important pleiotropic role of FVIII and hopefully to develop new therapeutic agents for skeletal diseases.

Hemophilic arthropathy (HA) is a complication of hemophilia, which is a genetic disorder characterized by a deficiency in blood clotting factors. HA is characterized by joint damage with inflammatory responses, pain, and movement limitations due to recurrent bleeding in the joints. The inflammatory reactions contribute to the activation of coagulation factors, which can exacerbate bleeding and further damage the affected joints. Therefore, the interaction between inflammation and coagulation plays a crucial role in the progression and complications of HA. Management strategies often focus both on inflammation and coagulation to alleviate symptoms and preserve joint function. Temperature can influence the inflammatory response and coagulation. The aim of this work was to understand how temperature management can positively or negatively influence the HA. We have carried out a narrative review of the available literature. This review explores the impacts of temperature on biological processes, and it discusses the possible clinical implications for the HA treatment. Our research shows that cold exposure has anti-inflammatory and analgesic effects, while heat is linked to pro-inflammatory cytokine release. Both hot and cold treatments are ill-advised for hemophilia patients. Heat stimulates neo-angiogenesis, and cold hampers coagulation, posing risks for increased bleeding in individuals with hemophilia.