جستجوی مقالات مرتبط با کلیدواژه « استخوان » در نشریات گروه « زیست شناسی »

Occurrence of various types of incidents such as road accidents, damage and injuries during sports activities as well as some diseases can lead to the destruction and resorption of osteochondral tissue and cause many problems in health and quality of life of the patient, therefore control and repairing these defects is one of the major challenges in the field of regenerative medicine. Since osteochondral defects involve damage to both articular cartilage and underlying subchondral bone, the demands of bone, cartilage, and bone cartilage interface should be taken into account for repair. Current clinical therapies are more palliative and less therapeutic. Hence, due to the limitations of existing treatment methods over the past decade, the use of tissue engineering as an effective and low-risk treatment method for the treatment of many diseases, especially bone-cartilage lesions has been introduced. In this approach, some of the limitations of previous methods could be overcome by transplanting osteochondral composite tissues, which have been obtained by combining patient's own cells with three-dimensional porous biomaterials of predetermined shape and size. So far, various strategies for scaffold fabrication have been used to repair osteochondral defects, including single-phase, multilayer, and graded structures. In this study, some common strategies in tissue engineering as well as the challenges ahead are briefly discussed.

Bone tissue engineering is a promising approach to develop new appropriate treatments for bone tissue damage. One of the important goals in this field is to fabricate the scaffolds by mimicking the extracellular matrix. The aim of this study was to study the fabrication of polylactic acid/Laponite (PLA/LAP) scaffold and to investigate the behavior of human bone marrow mesenchymal stem cells (hBMSCs) on it. First, PLA scaffold was fabricated by electrospinning technique, and then LAP (0.8 wt%) was coated on it. The morphology of the scaffold was examined by scanning electron microscopy (SEM) and Energy-dispersive X-ray (EDX) spectroscopy. The chemical structure of the scaffold was evaluated by ATR-FTIR spectroscopy and its hydrophilicity was tested by measuring the water contact angle. Finally, the biocompatibility of the scaffold and cell viability tested with MTT assay was performed on hBMSCs. The results of scaffold morphology showed a successful coat of LAP 0.8% on the surface of PLA scaffold. Furthermore, the hydrophilicity of PLA scaffold improved after coating with LAP 0.8%. The Biocompatibility of scaffold up to 24 hours and hMSCs viability up to 72 hours after cell culture were confirmed (p≤0.001). Based on the results of this study, it seems that PLA/LAP of 0.8% scaffold can be a promising candidate for bone tissue engineering applications by maintaining biocompatibility and cell viability due to the presence of ions in LAP nanoparticles.

Comparison of morphological structures is a key element in evolutionary biology and taxonomy, as well as in the studies concerning variation and biodiversity either at interspecific or intraspecific levels. This study aimed to compare the bony structures of Chondrostoma orientale and C. nasus. For this purpose, three specimens of C. orientale from the Kor River (passing through Iran), and five specimens of C. nasus from the Danube (passing through Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova and Ukraine), Dnieper (passing through Russia, Belarus and Ukraine) and Rhône river basins (passing through Switzerland and France), as well as Lake Ohrid (Located between Macedonia and Albania) were analysed. The results showed that the two anterior lateral processes of supraethmoid bone were more distant in C. orientale than those in C. nasus. The anterior profile of the supraetmoid bone was concave in C. orientale, while it was almost flat in C. nasus. The posterior pharyngeal process in the basioccipital was wide and triangular in C. orientale and narrow and rectangular in C. nasus. The maxillary mid-lateral ascending process was slightly inclined forward in C. orientale, while it was slightly inclined backward in C. nasus. The maxillary distal process was long in C. orientale and it was short in C. nasus. The premaxillary had a rostral ascending process in C. orientale, while it was missing in C. nasus. The anterior portion of the dentary was narrow and elongated in C. orientale and the coronoid process was perpendicular and located in the middle of the dentary; in contrast, the anterior portion of the dentary was short and wide in C. nasus and the coronoid process was inclined forward.