Journal of Tissue Science and Engineering

Objective: The use of autologous cortical and cancellous bone remains the gold standard of bone-grafting. However, donor side morbidity, limited availability, and the risk of infections lead surgeons and researchers to seek suitable alternatives. Human fibroblasts are potent immunoregulatory cells with multipotent differentiation potential, which are easy to harvest and proliferate in vitro, which makes them attractive tools for bone tissue engineering. But for an autologous application in cell-based therapies, attention should be paid to the effect of donor age on differentiation potential. Culture senescence must also be considered, as some proliferation steps are necessary to obtain a sufficient cell number for therapeutic use.

Methods: The results of this study reveal that an additional supplementation of insulin-like growth factor 1 is more suitable for osteogenic differentiation of foreskin fibroblasts, evaluated with an alkaline phosphatase assay, and quantification of calcium deposition in the extracellular matrix.

Results: Our findings demonstrate that increasing donor age and culture senescence negatively affect the proliferation and osteogenic differentiation capacity of foreskin fibroblasts. These results suggest that the best approach to increase cell numbers is to optimize the seeding density, while additional growth factor application has no beneficial effect on the proliferation in early passages, analysed with a cell viability assay.

Furthermore, commonly used osteogenic differentiation strategies consist of an application of ascorbate- 2-phosphate, dexamethasone, and β-glycerophosphate. However, phenotypic and differentiation potential discrepancies exist between multipotent mesenchymal stromal cells from different tissue origins as well as among fibroblasts from different dermal origins.

Conclusion: This work illustrates, that human fibroblasts, provided by young donors and in early cell culture passages, are a viable cell source for bone tissue engineering.

Breast tissue displacements estimation in static ultrasound elastography, is a medical imaging technique which provides information on the local rigidity of tissues. Despite the fact that this technique has a major interest in clinical diagnosis, it suffers from increased deterioration due to the presence of speckle noise, artifacts and poor detail accuracy which appeared during the B-mode image acquisition process. Therefore, the application of Block Matching (BM) technique will greatly amplify the speckle noise and deteriorate the image quality. In this perspective, the implementation of an optimal technique is crucial for optimizing the quality of mammary displacements tissue. In this paper, we propose a new method based on the BM model that is to improve the old BM (OBM) technique. In this respect, an improvement of pre-processing step is satisfactory, in order to establish accurate tissue displacement estimation. The research was validated on a database of 20 patients with breast malignant tumor. Biophysical parameters has been adapted and used to eliminate artifacts and speckle noise, once the images are filtered; the BM model is implemented after to estimate tissue displacements. Based on the clinical results, quantitative analysis verifies that the tissue displacements estimated by our proposed strategy are more efficient than the OBM and Bilinear Deformable Block Matching (BDBM) techniques, our proposed approach gives better values in term of standard deviation (SD), higher contrast to noise ratio (CNR), greater peak signal-to-noise ratio (PSNR) and excellent structural similarity (SSIM) than OBM and BDBM techniques. The results of the proposed model are encouraging, allowing excellent estimates. The proposed model provides a new and appropriate solution for improving estimation of mammary tissue displacements. The proposed new strategy could be a powerful diagnostic tool to be used in clinical evaluation dedicated to breast ultrasound elastography.

The increasing demand of organs for transplantation necessitates the development of substitutes to meet the structural and physiological functions. Tissue decellularization and recellularization aids in retaining the three-dimensional integrity, biochemical composition, tissue ultra-structure, and mechanical behavior, which makes them functionally suitable for organ transplantation. Herein, we attempted to rebuild functional liver grafts in small animal model (Wistar rat) with a potential of translation. A soft approach was adopted using 0.1% SDS (Sodium Dodecyl Sulfate) for decellularization and primary hepatocytes were used as potential cell source for recellularization. The decellularization process was evaluated and confirmed using histology, DNA content, ultra-structure analysis. The resultant scaffold was re-seeded with the rat hepatocytes and their biocompatibility was assessed by its metabolic functions and gene expression. The structural components of the ECM (Laminins, Collagen type I, Reticulins) were conserved and the liver cell specific proteins like CK18, alpha fetoprotein, albumin were expressed in the recellularized scaffold. The functionality and metabolic activity of the repopulated scaffold was evident from the albumin and urea production. Expression of Cytokeratin-19 (CK-19), Glucose 6- Phosphatase (G6P), Albumin, Gamma Glutamyl Transferase (GGT) genes has distinctly confirmed the translational signals after the repopulation process. Our study clearly elucidates that the native extracellular matrix of rat liver can be utilized as scaffold for effective recellularization for whole organ regeneration.