New and Improved Tissue Engineering Techniques: Production of Exogenous Material-Free Stroma by the Self-Assembly Technique

Tissue engineering results from the use of cells and scaffolds to reproduce structural and spatial organization or function of a tissue. The Production of an ideal engineered tissue depends on its designed purpose. For clinical applications, the main concerns are biocompatibility and the generation of a tissue able to mimic most of its original biological functions. Moreover, the viability of an implanted tissue is associated with its stability to support vascular networks. This chapter summarizes the theory of the self-assembly approach for tissue engineering. Adjustments and modifications in stromal thickness and extracellular matrix composition for various self-assembled tissues are discussed. Methods developed to generate tissue closely mimicking the native morphology and structure, to incorporate capillary-like networks, and to reduce production time and costs are also reviewed. The self-assembly technique leads to the production of a stroma free of exogenous material and can be adapted to generate fastest, inexpensive, and near-to-native tissue bioengineering for medical and fundamental research applications

Anticancer properties of chitosan on human melanoma are cell line dependent

Purpose: Chitosan, a natural macromolecule, is widely used in medical and pharmaceutical fields because of its distinctive properties such as bactericide, fungicide and above all its antitumor effects. Although its antitumor activity against different types of cancer had been previously described, its mechanism of action was not fully understood. Materials and methods: Coating of chitosan has been used in cell cultures with A375, SKMEL28, and RPMI7951 cell lines. Adherence, proliferation and apoptosis were investigated. Results: Our results revealed that whereas chitosan decreased adhesion of primary melanoma A375 cell line and decreased proliferation of primary melanoma SKMEL28 cell line, it had potent pro-apoptotic effects against RPMI7951, a metastatic melanoma cell line. In these latter cells, inhibition of specific caspases confirmed that apoptosis was effected through the mitochondrial pathway and Western blot analyses showed that chitosan induced an up regulation of pro-apoptotic molecules such as Bax and a down regulation of anti-apoptotic proteins like Bcl-2 and Bcl-XL. More interestingly, chitosan exposure induced an exposition of a greater number of CD95 receptor at RPMI7951 surface, making them more susceptible to FasL-induced apoptosis. Conclusion: Our results indicate that chitosan could be a promising agent for further evaluations in antitumor treatments targeting melanoma

Tissue Engineering in Gynecology

Female gynecological organ dysfunction can cause infertility and psychological distress, decreasing the quality of life of affected women. Incidence is constantly increasing due to growing rates of cancer and increase of childbearing age in the developed world. Current treatments are often unable to restore organ function, and occasionally are the cause of female infertility. Alternative treatment options are currently being developed in order to face the inadequacy of current practices. In this review, pathologies and current treatments of gynecological organs (ovaries, uterus, and vagina) are described. State-of-the-art of tissue engineering alternatives to common practices are evaluated with a focus on in vivo models. Tissue engineering is an ever-expanding field, integrating various domains of modern science to create sophisticated tissue substitutes in the hope of repairing or replacing dysfunctional organs using autologous cells. Its application to gynecology has the potential of restoring female fertility and sexual wellbeing

A rare testicular solid mass in children: juvenile granulosa cell tumour of testis

Juvenile granulosa cell tumour (JGCT) of the testis is a benign neoplasm rarely seen in children. It usually presents as a unilateral scrotal mass and can be associated with genital ambiguity and chromosomal anomalies. Radical orchiectomy is the treatment of choice. We present an infant with a JGCT of the testis and we review the typical findings of the disease

Engineering Tissues without the Use of a Synthetic Scaffold: A Twenty-Year History of the Self-Assembly Method

Twenty years ago, Dr. François A. Auger, the founder of the Laboratory of Experimental Organogenesis (LOEX), introduced the self-assembly technique. This innovative technique relies on the ability of dermal fibroblasts to produce and assemble their own extracellular matrix, differing from all other tissue-engineering techniques that use preformed synthetic scaffolds. Nevertheless, the use of the self-assembly technique was limited for a long time due to its main drawbacks: time and cost. Recent scientific breakthroughs have addressed these limitations. New protocol modifications that aim at increasing the rate of extracellular matrix formation have been proposed to reduce the production costs and laboratory handling time of engineered tissues. Moreover, the introduction of vascularization strategies in vitro permits the formation of capillary-like networks within reconstructed tissues. These optimization strategies enable the large-scale production of inexpensive native-like substitutes using the self-assembly technique. These substitutes can be used to reconstruct three-dimensional models free of exogenous materials for clinical and fundamental applications