Tissue engineering a fetal membrane

The aim of this study was to construct an artificial fetal membrane (FM) by combination of human amniotic epithelial stem cells (hAESCs) and a mechanically enhanced collagen scaffold containing encapsulated human amniotic stromal fibroblasts (hASFs). Such a tissue-engineered FM may have the potential to plug structural defects in the amniotic sac after antenatal interventions, or to prevent preterm premature rupture of the FM. The hAESCs and hASFs were isolated from human fetal amniotic membrane (AM). Magnetic cell sorting was used to enrich the hAESCs by positive ATP-binding cassette G2 selection. We investigated the use of a laminin/fibronectin (1:1)-coated compressed collagen gel as a novel scaffold to support the growth of hAESCs. A type I collagen gel was dehydrated to form a material mimicking the mechanical properties and ultra-structure of human AM. hAESCs successfully adhered to and formed a monolayer upon the biomimetic collagen scaffold. The resulting artificial membrane shared a high degree of similarity in cell morphology, protein expression profiles, and structure to normal fetal AM. This study provides the first line of evidence that a compacted collagen gel containing hASFs could adequately support hAESCs adhesion and differentiation to a degree that is comparable to the normal human fetal AM in terms of structure and maintenance of cell phenotype

A Tissue Engineering product development pathway

Tissue engineering is a field of inquiry and research that uses engineering techniques and principles of biological sciences to develop functional substitutes for reconstruction of damaged organs. Commercial translation of tissue engineering products is currently in progress all over the world. Many companies are moving their interest towards this market segment that grows by 6% per year. Aim of this thesis is to probe the possibility of developing tissue engineering products in the most cost-effective way, minimizing the industrial risk and developing a specific fund raising model. Tissue engineering is based on three main features: cells, scaffolds and bioreactors. Cells are seeded on a scaffold and cultured in a bioreactor in order to obtain a tissue engineering product. Nevertheless, developing cell carrying products is hampered by certification claims ("advanced therapies" certification rules) that unbearably increase R&D and certification costs and can be faced by either big companies or start-ups of big companies and spin-offs of complex aggregates of research centers involved in advanced cell research. On the other hand, scaffolds (certification class IIb) and bioreactors for tissue engineering (certification class I) can be developed with a lower economic effort, being the competition based on innovation, since their market is in the "growth phase" for scaffolds and in the "introduction phase" for bioreactors in the Levitt's product life cycle theory. Purpose of this thesis is to basically study scaffold and bioreactor features, then to preliminarily design some models of bioreactors and, eventually, to set a business model, based on private and public fund raising, aimed to the development of scaffolds for dental implantology and of bioreactors for cardiovascular and bone tissue engineering. Finally, a business plan of a company being spin-off of Politecnico di Torino and industrial start-up has been elaborate

Bioactive composites for bone tissue engineering

One of the major challenges of bone tissue engineering is the production of a suitable scaffold material. In this review the current composite materials options available are considered covering both the methods of both production and assessing the scaffolds. A range of production routes have been investigated ranging from the use of porogens to produce the porosity through to controlled deposition methods. The testing regimes have included mechanical testing of the materials produced through to in vivo testing of the scaffolds. While the ideal scaffold material has not yet been produced, progress is being made

Big bottlenecks in cardiovascular tissue engineering.

Although tissue engineering using human-induced pluripotent stem cells is a promising approach for treatment of cardiovascular diseases, some limiting factors include the survival, electrical integration, maturity, scalability, and immune response of three-dimensional (3D) engineered tissues. Here we discuss these important roadblocks facing the tissue engineering field and suggest potential approaches to overcome these challenges

Endogenous musculoskeletal tissue engineering - a focused perspective

Two major difficulties facing widespread clinical implementation of existing Tissue Engineering (TE) strategies for the treatment of musculoskeletal disorders are (1) the cost, space and time required for ex vivo culture of a patient’s autologous cells prior to re-implantation as part of a TE construct, and (2) the potential risks and availability constraints associated with transplanting exogenous (foreign) cells. These hurdles have led to recent interest in endogenous TE strategies, in which the regenerative potential of a patient’s own cells is harnessed to promote tissue regrowth without ex vivo cell culture. This article provides a focused perspective on key issues in the development of endogenous TE strategies, progress to date, and suggested future research directions toward endogenous repair and regeneration of musculoskeletal tissues and organs

A mechanistic approach to design smart scaffolds for tissue engineering

This thesis describes a library of novel 3D scaffolds designed and optimized for tissue engineering and regenerative medicine applications. Tissue engineering aims at restoring or regenerating a deamaged tissue by combining cells, derived from a patient biopsy, with a 3D porous matrix, functioning as a scaffold. After isolation\ud and eventual in vitro expansion, cells are seeded on the 3D scaffolds and, depending on the strategy, implanted directly or at a later stage in the patient¿s body

Angiogenesis in tissue engineering : Breathing life into constructed tissue substitutes

Long-term function of three-dimensional (3D) tissue constructs depends on adequate vascularization after implantation. Accordingly, research in tissue engineering has focused on the analysis of angiogenesis. For this purpose, 2 sophisticated in vivo models (the chorioallantoic membrane and the dorsal skinfold chamber) have recently been introduced in tissue engineering research, allowing a more detailed analysis of angiogenic dysfunction and engraftment failure. To achieve vascularization of tissue constructs, several approaches are currently under investigation. These include the modification of biomaterial properties of scaffolds and the stimulation of blood vessel development and maturation by different growth factors using slow-release devices through pre-encapsulated microspheres. Moreover, new microvascular networks in tissue substitutes can be engineered by using endothelial cells and stem cells or by creating arteriovenous shunt loops. Nonetheless, the currently used techniques are not sufficient to induce the rapid vascularization necessary for an adequate cellular oxygen supply. Thus, future directions of research should focus on the creation of microvascular networks within 3D tissue constructs in vitro before implantation or by co-stimulation of angiogenesis and parenchymal cell proliferation to engineer the vascularized tissue substitute in situ

Composite guidance scaffolds for neural tissue engineering

No abstract available

A new educational program on biomedical engineering

At the University of Twente together with the Free University of Amsterdam a new educational program on Biomedical Engineering will be developed. The academic program with a five-year duration will start in September 2001. After a general, broad education in Biomedical Engineering in the first three years, the students specialise in one of the following areas: materials and tissue engineering; technology for restoration of human function; healthcare technolog