Given the difficulties in accessing articular cartilage as a source of chondrocytes to be used in fabricating cartilage constructs, alternative sources are required. The present study examined chondrocytes from costal cartilage for their suitability in cartilage tissue engineering. Chondrocytes isolated from rat knee and rib hyaline cartilage were separately mixed with alginate and placed in a calcium chloride solution as two mm beads. The beads were incubated over 2 months, during which time the structural features, proliferation rates, and gene expression levels were determined by microscopy, [3-(A, 5-dimethylthiazol-2-yl)-1, 5-diphenyl tetrazulium bromide] (MTT) assay, and real-time PCR analysis, respectively. The majority of both articular and costal chondrocytes were observed to be organelle-rich round to oval cells embedded in lacunalike cavities within the alginate beads. The propagation patterns of both cell types were similar, undergoing proliferation during the first 40 days and almost ceasing propagation over the remaining 20 days of the culture period. The levels of aggrecan and type II collagen (cartilage specific) gene expression in costal and articular chondrocyte cultures were comparable; expression levels were very low during the initial days of culturing but were significantly upregulated by study termination (day 60). Interestingly, in contrast to cultured articular cells, the level of collagen I expression was negligible in costal cultures (p<0.05). Collectively, these data suggest that the costal chondrocytes could provide a beneficial and more accessible source of chondrocytes for three dimensional (3D) cartilage constructs.

Aim: The aim of this study was to use carbon nanotube incorporated electrospun chitosan/polyvinyl alcohol (CS/PVA/CNT) to induce neural differentiation of the stem cells for potential neural tissue engineering applications.Material and Methods: P19 embryonal carcinoma (EC) stem cells were cultured on the CS/PVA/CNT scaffold to induce neuronal differentiation. Cresyl violet staining was used to investigate neuronal phenotype and immunoflourescence technique was carried out to evaluate expression of b-tubulin, a neural specific marker.Results: Cresyl violet staining confirmed the neuronal morphology of the differentiated cells. These cells were immunoreactive to neuron specific marker, b-tubulin.Conclusion: the findings suggested the potential use of combined tissue engineering and stem cell therapy to improve deficits in neurodegenerative diseases.

Background: This study aims to evaluate and compare THREE-DIMENSIONAL Conformal Radiotherapy (3D-CRT) versus Helical Tomotherapy (HT) based on treatment planning and selection of the most appropriate method to reduce side effects. Materials and Methods: Treatment planning was performed on images of 20 patients with head and neck cancer with lymph node involvement by HT and 3D-CRT techniques in Seyed Al-Shohada hospital, Isfahan, Iran. The quality of target coverage, the exposure of normal tissue, and radiation delivery efficiency in two studied methods were compared. Results: Tomotherapy showed significant improvement over 3D-CRT in terms of D2%, D50% Dmean, V95%, CI (conformity index), and HI (homogeneity index) for PTV (planning target volume) and in terms of D2%, D98%, Dmean, V95%, CI and HI for PTV Nodal. The mean dose received by 98% of PTV (D98%) increased in HT compared to 3D-CRT. Whereas, higher doses received in organs at risk (OARs) in 3DCRT compared to HT. Conclusion: Results showed improvements in target quality for HT over 3D-CRT, including dosimetric coverage of target volumes, homogeneity and conformity indices, and reduction of the volume of cold and hot spots. Tomotherapy also performed better than that of 3D-CRT in OARs. Overall, with the satisfactory results obtained here, HT technique has considerable promise for treating head and neck cancers with the involvement of regional lymph nodes.