The fragility of organisms is largely compensated by their ability to self-repair and renew. From wound healing to regeneration of entire organs, organisms have develop a variety of mechanisms to surpass damage. This section groups EPFL’s research projects that get inspired from this amazing properties to create smart, self-maintained materials with prolonged life span and develop new therapeutic approaches to enhance our already innate ability to regenerate in order to fight disease.
The SHeMat project is a training and research network funded within the scope of the “Seventh Framework Programme” by the European Commission’s “Marie Curie” programme. SHeMat involves 9 partners from 6 different countries as well as 4 associated partners from the private sector.
The research activities of SHeMat are situated in the field of self-healing materials. The partners address both fundamental research in material development as well as the complementary aspects of conceptual process chain analysis from a more industrial perspective. Concepts found in nature, for example regarding wound healing in plants are analyzed, and their application into ceramics, polymers and composites are considered. EPFL researchers focused on self-healing coatings and composites based on supramolecular hybrid networks.
Functional composites with active sensing and repair
This project, funded by the Swiss National Foundation, focuses on the analysis and development of functional composite materials with damage control and repair abilities. These composite materials are manufactured by Liquid Composite Molding and integrate healing agents to control and repair damage, under the form of capsules, or of a polymeric second phase. In this project, emphasis is placed on the combination of healing and toughness improvement in fiber reinforced composites, through the combined use of thermoplastic polymers (in the form of discrete powders or fibers or thermoplastic/thermoset blends that phase separate upon polymerization, principally based on PCL polymers). Heating and crack closure, required to activate healing in composites, will be achieved with the help of SMA wires introduced in the reinforcement. The desired outcome of this research is, through analysis of the mechanisms underlying toughness, healing and processing, to propose structural materials with improved properties, with the added capability of repair, assisted by heat and local crack closure, and to propose guidelines and tools to optimize the materials composition and processing route according to the final requirements.
Stem cell niches: tissue self renewal and therapeutics
Tissue homeostasis and regeneration are critically dependent on a limited number of adult stem cells, their self-renewal capability and their commitment to differentiated cells. Due to these unique properties, stem cells hold enormous potential for the treatment of many diseases. Arguably one of the greatest challenges is controlling stem cell behavior outside of the body, as this would for example allow expanding them to sufficient numbers. Adult stem cells reside in specialized niches, comprised of complex mixtures of extracellular cues delivered by support cells in close proximity. Niches protect stem cells from rapid differentiation and regulate the delicate balance between self-renewal and differentiation. The mechanisms by which niches regulate stem cells remain poorly defined in mammals, mainly because of the difficulties in manipulating these intricate microenvironments in vivo.
We develop novel technologies to biochemically and structurally deconstruct in vivo niches, and reconstruct them in vitro, creating well-defined artificial stem cell niches as novel paradigms to decipher adult stem cell regulation. This research will yield insights into the dynamics of stem cell fate changes in response to extrinsic protein signals, and may spawn new strategies for tissue engineering and stem cell-based therapies, for example the robust expansion of rare hematopoietic stem cells for the treatment of blood cancers.
For additional information, please read a review paper in Nature.
Biomimetic Models for Fibrous Tissue Repair
Individual cells, each with the capacity to migrate autonomously and interact with the extracellular matrix, work collectively to maintain integrity of adult tissues. We are engineering biomimetic tissue models and robotic microsurgery platforms to investigate the mechanics of multicellular organization and wound healing. These studies will lead to the development of advanced synthetic systems with tissue-like self-regulation and plasticity
Reference: M. S. Sakar*, J. Eyckmans*, et al, 2016, Cellular Forces and Matrix Assembly Coordinate Fibrous Tissue Repair, Nature Communications, 7:11036 (*equally contributed) (pdf)