In one aspect, a method of preconditioning stem cells comprising exposing stem cells to low dose radiation (LDR) is provided. In another aspect, a population of preconditioned stem cells is provided, wherein the population of 5 preconditioned stem cells is obtained by exposing stem cells to LDR. Uses of the preconditioned stem cells are also provided. In other aspects, the stem cells are muscle stem cells.

A tissue graft for soft tissue repair or reconstruction comprising a sheet of a biopolymer-based matrix having a plurality of small perforations and a plurality of large perforations. The small perforations are sized to facilitate clotting and granulation tissue development within the perforations which, in turn, facilitates revascularization and cell repopulation in the patient. The large perforations are sized to reduce the occurrence of clotting and granulation tissue development within the perforations so that extravascular tissue fluids accumulating at the implant site can drain through the tissue graft. The large perforations enhance mammal tissue anchoring by permitting mammal tissue to compress into the perforations increasing mammal tissue contact area.

A tissue graft for soft tissue repair or reconstruction comprising a sheet of a biopolymer-based matrix having a plurality of small perforations and a plurality of large perforations. The small perforations are sized to facilitate clotting and granulation tissue development within the perforations which, in turn, facilitates revascularization and cell repopulation in the patient. The large perforations are sized to reduce the occurrence of clotting and granulation tissue development within the perforations so that extravascular tissue fluids accumulating at the implant site can drain through the tissue graft. The large perforations enhance mammal tissue anchoring by permitting mammal tissue to compress into the perforations increasing mammal tissue contact area.

Methods and compositions for making endocardial cells from pluripotent stem cells are described, as are methods and compositions for using such cells.

The present invention provides a means for reconstituting tissues and organs having mature functions. A method of preparing a tissue or an organ, comprising coculturing an organ cell with a vascular endothelial cell and a mesenchymal cell, generating an organ bud, transplanting the organ bud into a non-human animal, and then isolating from the non-human animal the transplanted organ bud-derived tissue or organ.

The present invention provides a means for reconstituting tissues and organs having mature functions. A method of preparing a tissue or an organ, comprising coculturing an organ cell with a vascular endothelial cell and a mesenchymal cell, generating an organ bud, transplanting the organ bud into a non-human animal, and then isolating from the non-human animal the transplanted organ bud-derived tissue or organ.

The present disclosure provides patterned biomaterials having organized cords and extracellular matrix embedded in a 3D scaffold. According, the present disclosure provides compositions and applications for patterned biomaterials. Pre-patterning of these biomaterials can lead to enhanced integration of these materials into host organisms, providing a strategy for enhancing the viability of engineered tissues by promoting vascularization.

The present disclosure provides patterned biomaterials having organized cords and extracellular matrix embedded in a 3D scaffold. According, the present disclosure provides compositions and applications for patterned biomaterials. Pre-patterning of these biomaterials can lead to enhanced integration of these materials into host organisms, providing a strategy for enhancing the viability of engineered tissues by promoting vascularization.

Spheroid microtissues that can mimic native tissue-like structure and function, spheroid production methods that are high-throughput, suitable for efficient production, maintainable over long-term culture, and/or offer repeatable control over size distribution. Spheroids that have blood vessels, including spheroids with functional, blood-perfused vascular networks upon injection in vivo. Dissolvable hydrogel microwell arrays for high throughput parallel formation of spheroids in a single pipetting step and easy retrieval for downstream applications. A method to produce prevascularized microtissues in sufficient numbers to form a macrotissue in vivo for therapeutic purposes. This method is based on sacrificial release of dissolvable microwell templates, a novel and scalable strategy which enables gentle harvesting of microtissues with control over size and composition. The method forms microtissues containing endothelial cells and mesenchymal stem cells, which are co-cultured under dynamic conditions and self-organize into blood-vessel units.

Spheroid microtissues that can mimic native tissue-like structure and function, spheroid production methods that are high-throughput, suitable for efficient production, maintainable over long-term culture, and/or offer repeatable control over size distribution. Spheroids that have blood vessels, including spheroids with functional, blood-perfused vascular networks upon injection in vivo. Dissolvable hydrogel microwell arrays for high throughput parallel formation of spheroids in a single pipetting step and easy retrieval for downstream applications. A method to produce prevascularized microtissues in sufficient numbers to form a macrotissue in vivo for therapeutic purposes. This method is based on sacrificial release of dissolvable microwell templates, a novel and scalable strategy which enables gentle harvesting of microtissues with control over size and composition. The method forms microtissues containing endothelial cells and mesenchymal stem cells, which are co-cultured under dynamic conditions and self-organize into blood-vessel units.