1,720,996 research outputs found
Repurposing of Loperamide as a New Drug With Anticancer Activity for Human Osteosarcoma
No full textBackground/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
Multimodal transfer of MDR by exosomes in human osteosarcoma
No full textExosomes are extracellular vesicles released by both normal and tumour cells which are involved in a new intercellular communication pathway by delivering cargo (e.g., proteins, microRNAs, mRNAs) to recipient cells. Tumour-derived exosomes have been shown to play critical roles in different stages of tumour growth and progression. In this study, we investigated the potential role of exosomes to transfer the multidrug resistance (MDR) phenotype in human osteosarcoma cells. Exosomes were isolated by differential centrifugation of culture media from multidrug resistant human osteosarcoma MG-63DXR30 (Exo/DXR) and MG-63 parental cells (Exo/S). Exosome purity was examined by transmission electron microscopy and confirmed by immunoblot analysis for the expression of specific exosomal markers. Our data showed that exosomes derived from doxorubicin-resistant osteosarcoma cells could be taken up into secondary cells and induce a doxorubicin-resistant phenotype. The incubation of osteosarcoma cells with Exo/DXR decreased the sensitivity of parental cells to doxorubicin, while exposure with Exo/S was ineffective. In addition, we demonstrated that Exo/DXR expressed higher levels of MDR-1 mRNA and P-glycoprotein compared to Exo/S (p=0.03). Interestingly, both MDR-1 mRNA and P-gp increased in MG-63 cells after incubation with Exo/DXR, suggesting this as the main mechanism of exosome-mediated transfer of drug resistance. Our findings suggest that multidrug resistant osteosarcoma cells are able to spread their ability to resist the effects of doxorubicin treatment on sensitive cells by transferring exosomes carrying MDR-1 mRNA and its product P-glycoprotein
Cell-based Assay System for Predicting Bone Regeneration in Patient Affected by Aseptic Nonunion and Treated with Platelet Rich Fibrin
No full textRegenerative strategies based on the use of platelet concentrates as an autologous source of growth factors (GF) has been proposed to promote the healing of long bone nonunions. However, the relatively high failure rate stimulates interest in growing knowledge and developing solutions to obtain the best results from the regenerative approach
Association between Bone Turnover Markers and Fracture Healing in Long Bone Non-Union: A Systematic Review
Full text linkBackground: 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
No full text: 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 nanorods 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 anex vivomodel 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 OC 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 OBs, and reducing OC differentiation. Thus, the bioactive and biomimetic system promoted an enhanced cellular response, highlighting its potential application in BTE
Mesenchymal Stem Cells‐Derived Small Extracellular Vesicles and Their Validation as a Promising Treatment for Chondrosarcoma in a 3D Model in Vitro
Full text linkChondrosarcomas (CHS) constitute approximately 20% of all primary malignant bone tumors, characterized by a slow growth ratewith initial manifestation of few signs and symptoms. These malignant cartilaginous neoplasms, particularly those with dediffer-entiated histological subtypes, pose significant therapeutic challenges, as they exhibit high resistance to both radiation andchemotherapy. Ranging from relatively benign, low‐grade tumors (grade I) to aggressive high‐grade tumors with the potential forlung metastases and a grim prognosis, there is a critical need for innovative diagnostic and therapeutic approaches, particularly forpatients with more aggressive forms. Herein, small extracellular vesicles (sEVs) derived from mesenchymal stem cells are presentedas an efficient nanodelivery tool to enhance drug penetration in an in vitro 3D model of CHS. Employing high‐pressure homoge-nization (HPH), we achieved unprecedented encapsulation efficiency of doxorubicin (DXR) in sEVs derived from mesenchymal stemcells (MSC‐EVs). Subsequently, a comparative analysis between free DXR and MSC‐EVs encapsulated with DXR (DXR‐MSC‐EVs)was conducted to assess their penetration and uptake efficacy in the 3D model. The results unveiled a higher incidence of necroticcells and a more pronounced toxic effect with DXR‐MSC‐EVs compared to DXR alone. This underscores the remarkable ability ofMSC‐EVs to deliver drugs in complex environments, highlighting their potential application in the treatment of aggressive CHS
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Ultrasound-guided injection of platelet-rich plasma or cord blood platelet-rich plasma in nonunion: a randomized controlled trial
No full textPlain language summary Although the regenerative capacity of bone tissue is well recognized, the fracture repair process may be impaired by unfavorable conditions resulting in delayed union or complete nonunion. In this scenario, the use of autologous blood derivates to accelerate bone healing has been proposed. The aim of this study was to compare the therapeutic efficacy of autologous platelet-rich plasma (PRP) and cord blood PRP (PRPc) in bone nonunion. PRPc contains high levels of cytokines and growth factors, has low immunogenicity and can be successfully stored until use. This study verified that bone consolidation was similar in PRP and PRPc treatments, thus supporting PRPc as a valid therapeutic option when clinical conditions discourage the use of autologous blood derivates.Aim: To compare the ability of autologous platelet-rich plasma (PRP) and cord blood PRP (PRPc) to accelerate bone healing. Patients & methods: 71 patients with mechanically stable nonunion were treated weekly (3 consecutive weeks) with ultrasound-guided percutaneous injections of PRP or PRPc in a controlled randomized clinical trial. The primary outcome was healing (12 months) and secondary outcomes were radiological evolution (2 and 6 months) and changes in pain intensity (6 months). Results & conclusion: Bone consolidation was assessed over time without significant differences between PRP and PRPc treatment. In patients with persistent nonunion, pain perception decreased more after PRP treatment. PRPc appears to be a valid alternative when specific clinical conditions suggest avoiding the use of autologous blood products
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