Our approach is to induce vessel network assembly within 3D tissue constructs in vitro by multicellular culturing of endothelial cells (ECs) and vascular mural cells with cells specific to the tissue of interest.
Levenberg has shown that such in vitro pre-vascularization of engineered tissue can promote its survival and vascularization upon implantation.
The ongoing projects in the lab focus on:
1. Creating vascularized engineered tissues for regeneration;
2. Characterizing the mechanisms of in vitro vascularization and vessel-network formation in multi-cellular tissue constructs by using defined biomaterials and mechanical stimulation designed to mimic in vivo settings;
3. Cell-grown meat.
Engineering blood vessel networks
In this project we explored the effects of mechanical forces, scaffold type and supporting cells on angiogenesis. We examined different endothelial cells and support cells under various conditions, with a particular focus on how engineered vessels align in response to mechanical forces, and integrate in-vivo.
This study was supported by the FP7 ERC starting Grant, Engvasc.
Engineering Composite Tissues for Facial Reconstruction
Facial reconstruction usually involves the use of autologous grafts or composite tissue allografts, which are highly complex tissues that pose significant challenges to tissue engineering experts. Tissue engineering of independent facial elements, e.g., bone, adipose, skin and muscle tissues, has been demonstrated. However, to date, no composite soft tissues composed of multiple facial layers have been created. Composite facial tissue engineering will require proper innervation and vascularization, essential to support generation of large thick implants. However, techniques for effective innervation of engineered tissues are currently insufficient and generation of well-vascularized large and thick engineered tissues is still one of the major obstacles limiting their translation to the clinic. Our goal is to engineer thick, composite, human-scale, facial tissues (muscle-adipose-dermis composite, and bone) of a personally adaptable shape, that will be vascularized invitro, and innervated upon transplantation. Our concept is to create in-vitro a functional vascular network (VesselNet), within engineered constructs, which will allow for the generation of thick engineered tissues under continuous flow conditions. 3D bio-printing techniques will be applied to create the engineered tissues. These tissues will serve as a model to study mechanisms involved in vessel anastomosis, and tissue organization and stabilization.
This study is supported by the Horizon 2020 ERC Consolidator Grant, VesselNet.
For more information, please visit the The ERC VesselNet Project web page
3D Bioprinting of Pancreatic Tissue
Developing therapies for pancreatic diseases, such as diabetes and pancreatic cancer, is hampered by a limited access to pancreatic tissue in vivo. Engineering three-dimensional (3D) tissue models, which accurately mimic the native organ, have great potential in biomedical applications, by both providing powerful platforms for studying tissue development and homeostasis and for modeling diseases in pharmaceutical testing. Our research establishes a multi-disciplinary European consortium with the goal of developing an innovative bio-printing approach for generating pancreatic tissue. Tissues and organs comprise multiple cell types with specific biological functions that must be recapitulated in the printed tissue. We aim at bio-mimicking developmental processes to fabricate 3D bio-printed pancreatic tissue units that allow sustained cell viability, expansion and functional differentiation ex vivo.
This study is supported by Horizon 2020, FET-Open – Novel ideas for radically new technologies, Pan3D.
Restoring Insulin Sensitivity in Type 2 Diabetes Patients using Engineered Muscle Tissue
Type 2 Diabetes (DM2) is a complex metabolic disease, characterized by adipose and muscle insulin resistance accompanied by defects in pancreatic insulin secretion or loss of function of insulin-secreting cells. Present therapeutic modalities include lifestyle modification and pharmaceutical agents, however many patients fail to achieve blood glucose homeostasis.
This research proposes to overcome peripheral tissue insulin resistance by genetically modifying skeletal muscle cells and use them to construct engineered muscle tissue. Upon implantation of such engineered muscle, overall glucose uptake of the animal is expected to be enhanced, therefore improving diabetic state.
This study is supported by the The Rina and Avner Schneur Center of Diabetes Research (http://schneur-diabetic-center.net.technion.ac.il/)
Bone Tissue Repair
The main hurdle in bone tissue repair is maintaining appropriate vascularization for regeneration of large-scaled defects. We fabricate engineered constructs, capable of soft and hard tissue repair. These pre-vascularized composite grafts are fabricated from FDA approved and biocompatable biomaterials, which undergo an induction phase by differential seeding with diverse cellular components. Our bone tissue engineering (BTE) models are treated from a clinical perspective, utilizing in vivo imaging and CAD-CAM interfaces to produce defect-specific grafts. These engineered constructs are implanted in live animal models to assess their ability to regenerate complex anatomical structures.
This study is supported by the Israel science foundation.
Spinal Cord Injury Regeneration
Stem cell-based therapies hold great potential to treat spinal cord injury and additional nervous system traumatic syndromes due to lack of regeneration in the adult nervous system. Our research focuses on delivering stem cells into a complete spinal cord injury. We utilize tissue engineering methods to enhance stem cell integration and survival post implantation. In addition we study the effect of vascularization on spinal cord regeneration. Alternatively, we exploit the regenerative effects of stem cell-derived exosomes as therapeutics and drug delivery platforms to target the spinal cord lesion.
This study was supported by the J&J Shervington Fund (SL), and the Israel Foundation for Spinal Cord Injury (SL).
Cardiac Muscle Regeneration using a Perfusable Cardiac Patch
The aim of this project is to create a perfusable cardiac patch, intended for repairing damaged areas of the cardiac muscle. The patch is created using 3D bioprinting technology, which allows for the controlled and automatic deposition of biological and structural materials that will form the construct. Endothelial cells are deposited within an extracellular matrix mimicking material, enabling them to spontaneously organize into vascular networks. Cardiomyocytes are obtained by differentiating induced pluripotent stem cells (iPSCs) and seeded along the endothelial cells, creating a more complex tissue.
Geometric and Mechanical Patterning of Hierarchical Vascular Networks
This research focuses on exploring the biophysical factors controlling vascular architecture, remodeling, and integration upon implantation. Using cutting edge methods to pattern the organization of cells, and to map and control mechanical forces within the 3D constructs, the role of cell-generated forces, initial endothelial cell organization and external mechanical forces in the location, orientation and extent of sprouting is studied. In addition, the impact of hierarchical network geometry, rationally designed, on implant integration in-vivo is assessed.
This research is supported by United States-Israel BSF grant in collaboration with Prof. Christopher Chen from Boston University.
Effect of scaffold geometry on vascular networks
Many environmental factors can affect the behavior of newly sprouting vessels. Among them, scaffold geometry provides mechanical cues that are translated into chemical and physical cell signaling, which impacts on the decisions made by migrating vessels. This research studies how different scaffold geometries can help control the behavior and orientation of sprouting vessels during network formation.
This research is supported by funding from the University of Michigan – Israel Partnership for Research.
The aim of this project is to produce meat from cell cultures, using tissue engineering techniques. We isolate stem cells from a bovine origin, expand them, and seed them on 3D scaffolds, to develop bovine skeletal muscle tissues.
We study food-related properties of bovine skeletal muscle tissues under different cell combinations, scaffolds and media composition.
This study is supported by Aleph Frams (Aleph Farms)
Nano-liter Microfluidic device
AST (Antimicrobial susceptibility testing ) system on a microfluidic device capable of delivering results in under 6 hours was developed in the Levenberg’s lab. Using an automated algorithm for data analysis, the system is capable of determining whether bacteria from an infection site is resistant or susceptible to the tested antibiotic. This technology was licensed to Nanosynex, and now-a-days, Nanosynex takes this proof of concept from the lab to the market.