Repurposing of Loperamide as a New Drug With Anticancer Activity for Human Osteosarcoma.

BACKGROUND/AIM: Osteosarcoma is an aggressive malignant bone tumor, with unfavorable outcomes in patients with metastatic and recurrent disease. To improve patient survival new treatment options are needed. By using the drug repurposing approach, which takes advantage of already approved drugs with non-oncology primary use, we investigated the activity of loperamide, a peripheral opiate receptor agonist, a drug widely used in clinical practice to treat acute non-specific and chronic diarrhea, on human osteosarcoma. MATERIALS AND METHODS: Human osteosarcoma cell lines (143B, Saos-2, HOS and MG-63) and multidrug-resistant MG-63DXR30 cells were treated with loperamide. Proliferation and cell viability were determined by viable cell count and acid phosphatase assay. Loperamide activity on cell cycle and apoptosis induction were evaluated by flow cytometry and a luminescence assay testing caspase 3/7 activity, respectively. RESULTS: Loperamide significantly inhibited cell proliferation, through alteration of cell cycle profile at G0/G1 phase and apoptotic death in human osteosarcoma cells. Furthermore, loperamide significantly inhibited the growth of multidrug-resistant osteosarcoma cells. CONCLUSION: Our findings provide new perspectives for loperamide and its therapeutic repositioning for the treatment of osteosarcoma.

Association between Bone Turnover Markers and Fracture Healing in Long Bone Non-Union: A Systematic Review.

Background: Fracture healing is a very complex and well-orchestrated regenerative process involving many cell types and molecular pathways. Despite the high efficiency of this process, unsatisfying healing outcomes, such as non-union, occur for approximately 5-10% of long bone fractures. Although there is an obvious need to identify markers to monitor the healing process and to predict a potential failure in callus formation to heal the fracture, circulating bone turnover markers' (BTMs) utility as biomarkers in association with radiographic and clinical examination still lacks evidence so far. Methods: A systematic review on the association between BTMs changes and fracture healing in long bone non-union was performed following PRISMA guidelines. The research papers were identified via the PubMed, Cochrane, Cinahl, Web of Science, Scopus, and Embase databases. Studies in which the failure of fracture healing was associated with osteoporosis or genetic disorders were not included. Results: A total of 172 studies were collected and, given the inclusion criteria, 14 manuscripts were included in this review. Changes in circulating BTMs levels were detected during the healing process and across groups (healed vs. non-union patients and healthy vs. patients with non-union). However, we found high heterogeneity in patients' characteristics (fracture site, gender, and age) and in sample scheduling, which made it impossible to perform a meta-analysis. Conclusions: Clinical findings and radiographic features remain the two important components of non-union diagnosis so far. We suggest improving blood sample standardization and clinical data collection in future research to lay the foundations for the effective use of BTMs as tools for diagnosing non-union.

Osteoblast and osteoclast activity on collagen-based 3D printed scaffolds enriched with strontium-doped bioactive glasses and hydroxyapatite nanorods for bone tissue engineering.

Bone tissue engineering (BTE) aims to promote bone regeneration by means of the synergistic effect of biomaterials, cells, and other factors, as potential alternative to conventional treatments for bone fractures. To this aim, a composite material was developed, based on collagen type I, strontium-enriched mesoporous bioactive glasses, and hydroxyapatite nanoparticles as bioactive and biomimetic components. Nanostructured scaffolds were 3D printed and subsequently chemically crosslinked with genipin to improve mechanical properties and stability. The developed nanostructured system was maintained in culture until 3 weeks with a co-culture of human bone cells to provide an ex vivo model of bone microenvironment and examine the cellular crosstalk and signaling pathways through paracrine cell activities. Human osteoblasts (OBs), derived from trabecular bone, and human osteoclast precursors (OCs), isolated from buffy coat samples were involved, with OBs seeded on the scaffold and OCs precursors seeded in a transwell device. When compared to the material without inorganic components, the bioactive and biomimetic scaffold positively influenced cell proliferation and cell metabolic activity, boosting alkaline phosphatase activity of osteoblasts, and reducing osteoclast differentiation. Thus, the bioactive and biomimetic system promoted an enhanced cellular response, highlighting its potential application in bone tissue engineering. .

Cell culture-derived extracellular vesicles: Considerations for reporting cell culturing parameters.

Cell culture-conditioned medium (CCM) is a valuable source of extracellular vesicles (EVs) for basic scientific, therapeutic and diagnostic applications. Cell culturing parameters affect the biochemical composition, release and possibly the function of CCM-derived EVs (CCM-EV). The CCM-EV task force of the Rigor and Standardization Subcommittee of the International Society for Extracellular Vesicles aims to identify relevant cell culturing parameters, describe their effects based on current knowledge, recommend reporting parameters and identify outstanding questions. While some recommendations are valid for all cell types, cell-specific recommendations may need to be established for non-mammalian sources, such as bacteria, yeast and plant cells. Current progress towards these goals is summarized in this perspective paper, along with a checklist to facilitate transparent reporting of cell culturing parameters to improve the reproducibility of CCM-EV research.