Tissue Engineering

Despite remarkable developments in vascular medicine in the last decades and intensive research on the improvement of bypass materials, an ideal bypass graft comparable to autologous veins or arteries is still not available for peripheral vascular and coronary artery bypass grafting. This article reviews established bypass materials and provides an overview over interesting new technologies particularly those associated with tissue-engineering and those already adopted clinically.

Book (in French) published in 2003 at the occasion of the first exhibition staging exclusively biomedia art works at the national art center Le Lieu Unique in Nantes/France. Hauser Jens (ed.): L'Art Biotech. Nantes/Trézélan, 2003.

The publication has not been available anymore since 2008; this PDF is made accessible with the agreement and the kind support of the Filigranes publishing house, until an augmented new edition will be be available. Great thanks to Filigranes and Patrick Le Bescont! https://www.filigranes.com

Periodontal diseases are among the most common diseases affecting humans. Dental biofilm is a contributor to the etiology of most periodontal diseases. It is also widely accepted that immunological and inflammatory responses to biofilm components are manifested by signs and symptoms of periodontal disease. The outcome of such interaction is modulated by risk factors (modifiers), either inherent (genetic) or acquired (environmental), significantly affecting the initiation and progression of different periodontal disease phenotypes. While definitive genetic determinants responsible for either susceptibility or resistance to periodontal disease have yet to be identified, many factors affecting the pathogenesis have been described, including smoking, diabetes, obesity, medications, and nutrition. Currently, periodontal diseases are classified based upon clinical disease traits using radiographs and clinical examination. Advances in genomics, molecular biology, and personalized medicine ...

Three dimensional (3D) bioplotting requires appropriate crosslinkers to crosslink the hydrogel precursor while simultaneously maintaining the viability of embedded cells. However, the evaluation and comparison of various types of crosslinkers in bioplotting remains underexplored to date. This paper presents our study of the inuence of three ionic crosslinkers—calcium chloride (CaCl 2), barium chloride (BaCl 2), and zinc chloride (ZnCl 2)—on the mechanical and biological properties of 3D bioplotted alginate scaolds. The scaold mechanical properties characterized included the elastic modulus, swelling, and degradation while the biological properties considered included Schwann cell viability and surface morphology. The mechanical and biological properties of the bioplotted scaolds were both dependent on the crosslinkers used for fabrication; speciically, crosslinking ions resulted in the elastic modulus of the hydrogels decreasing in the order BaCl 2 >CaCl 2 >ZnCl 2 over 42 days while Schwann cell viability decreased in the order CaCl 2 >BaCl 2 >ZnCl 2 over 7 days. Taken together, these results ooer insights that are eeective in terms of manipulating the 3D bioplotting process so as to tune and optimize the mechanical and biological performance of the plotted scaaolds for tissue engineering applications.

Phosphate-based glasses have been examined in many studies as a potential biomaterial for bone repair because of its degradation properties, which can be controlled and allow the release of various elements to promote osteogenic tissue growth. However most of these experiments studied either tertiary or quaternary glass systems. This study investigated a qinternary system that included titanium dioxide for degradation rate control and zinc that is considered to have a role in bone formation. Zinc and titanium phosphate glass discs of different compositions were melt synthesized and samples of each composition was tested for different physical, chemical and biological characteristics via density measurement, X-ray diffraction, differential thermal analysis, mass loss, ion release, scanning electron microscopy, biocompatibility studies via live/dead assays at three time points (day 1, 4, and 7). The results showed that the glass was amorphous and that the all thermal variables decreas...

Tissue engineering is an interdisciplinary field that applies the principles and methods of engineering and the cell culture toward the development of biomaterials that restore, maintain or improve tissue function. The amalgamation of engineering and medicine has interested many scientists for at last two hundred years. What was the goal of cell culture? First, for progress in life sciences achievement and subsequent for virology and toxicology development. In vitro studies are done because of many problems with carrying out animal experiments. In this work the authors present the attempts of physicians, anatomopathologists, embryologists and biologists which contributed to fast development of new area in medicine--tissue engineering.

T issue engineering (TE) has the potential of improving the quality of life for many thousands of people throughout the world. One particular area which presents an exciting challenge in this field is the repair and regeneration of cartilage where traumatic injuries and arthritis result in pain and restriction of movement. In order to achieve this goal of tissue engineering cartilage, there are three necessary components: cells for the generation of tissue, a scaffold to support growth and that degrades as the extracellular matrix is generated and a bioactive factor to stimulate the correct biological signals in vivo for tissue growth and integration with native cartilage. Over the last number of years there has been significant interest in progenitor stem cells for TE applications. Mesenchymal stem cells (MSCs) have been shown to differentiate into a range of tissues including bone, cartilage, muscle, tendon, skin and fat. Furthermore, a number of biocompatible biodegradable materi...

Summary A cute liver failure (ALF) patients have a high risk of mortality. The elective treatment for ALF still is orthotopic liver transplantation. Donor organ scarcity and the associated high costs make transplantation possible for only about one third of the patients on the transplantation waiting list. Engineering a biological liver substitute is an interesting alternative to the traditional ALF

Glial-derived neurotrophic factor (GDNF) promotes both sensory and motor neuron survival. The delivery of GDNF to the peripheral nervous system has been shown to enhance regeneration following injury. In this study we evaluated the effect of affinity-based delivery of GDNF from a fibrin matrix in a nerve guidance conduit on nerve regeneration in a 13 mm rat sciatic nerve defect. Seven experimental groups were evaluated which received GDNF or nerve growth factor (NGF) with the delivery system within the conduit, control groups excluding one or more components of the delivery system, and nerve isografts. Nerves were harvested 6 weeks after treatment for analysis by histomorphometry and electron microscopy. The use of the delivery system (DS) with either GDNF or NGF resulted in a higher frequency of nerve regeneration vs. control groups, as evidenced by a neural structure spanning the 13 mm gap. The GDNF DS and NGF DS groups were also similar to the nerve isograft group in measures of nerve fiber density, percent neural tissue and myelinated area measurements, but not in terms of total fiber counts. In addition, both groups contained a significantly greater percentage of larger diameter fibers, with GDNF DS having the largest in comparison to all groups, suggesting more mature neural content. The delivery of GDNF via the affinity-based delivery system can enhance peripheral nerve regeneration through a silicone conduit across a critical nerve gap and offers insight into potential future alternatives to the treatment of peripheral nerve injuries.

Over the past few years, substantial progress has been made in the field of stem cell regeneration of the intervertebral disc. Autogenic mesenchymal stem cells in animal models can arrest intervertebral disc degeneration or even partially regenerate it and the effect is suggested to be dependent on the severity of degeneration. Mesenchymal stem cells (MSCs) are able to escape alloantigen recognition which is an advantage for allogenic transplantation. A number of injectable scaffolds have been described and various methods to pre-modulate MSCs’ activity have been tested. In future, work will need to address the use of mesenchymal stem cells in large animal models and the fate of the implanted mesenchymal stem cells, particularly in the long term, in animals. This review examines the state-of-the-art in the field of stem cell regeneration of the intervertebral disc, and critically discusses, with scientific support, the issues involved, before stem cells could be used in human subjects.