Disclosed are tissue graft compositions made of particles having different densities, methods of making these compositions, and methods of using these compositions for promoting tissue restoration in a patient.

An object of the present invention is to provide a cell structure which does not contain glutaraldehyde and can form blood vessels after transplantation, and a method for producing the above-described cell structure. According to the present invention, there is provided a cell structure which contains a biocompatible macromolecular block and at least one kind of cell and has voids and in which a plurality of the biocompatible macromolecular blocks are arranged in gaps between a plurality of the cells, in which a ratio of the volume of the biocompatible macromolecular blocks with respect to the volume of the cell structure is 10% to 30%, a ratio of the volume of the cells with respect to the volume of the cell structure is 20% to 50%, and a ratio of the volume of the voids with respect to the volume of the cell structure is 35% to 60%.

The present invention finds out find out the requirements necessary for preparing a cell condensate in vitro from a large number of cells (several ten thousand to several million cells) and provides a method of forming a cell condensate for self-organization which is capable of realizing complex higher structures (such as liver and kidney) and interactions with other organs.

A method of preparing a cell condensate in vitro, comprising culturing a mixture of cells and/or tissues of a desired type in a total cell count of 400,000 or more and 100,000 to 400,000 mesenchymal cells to form a cell condensate of 1 mm or more in size. A cell condensate prepared by the above-described method. A method of preparing a three-dimensional tissue structure, comprising allowing self-organization of a cell condensate prepared by the above-described method to form a three-dimensional tissue structure that has been provided with higher structures. A gel-like support wherein the side on which culture is to be performed has a U- or V-shaped cross-section.

Disclosed are tissue graft compositions made of particles having different densities, methods of making these compositions, and methods of using these compositions for promoting tissue restoration in a patient.

Described are methods for producing tissue constructs, tissue constructs produced by the methods, and their use. The described method of producing a tissue construct comprises providing a granular tissue, depositing one or more filaments on or in the granular tissue, each filament comprising an ink, and gelling or fusing the granular tissue, thereby producing the tissue construct.

Methods for decellularizing organs and tissues in vitro and in vivo are provided, as are methods of maintaining organ and tissue frameworks and methods of recellularizing organs and tissues, thereby providing an approach to needed organs or tissues.

Described are methods for producing tissue constructs, tissue constructs produced by the methods, and their use. The described method of producing a tissue construct comprises providing a granular tissue, depositing one or more filaments on or in the granular tissue, each filament comprising an ink, and gelling or fusing the granular tissue, thereby producing the tissue construct.

Compositions and methods of transplanting cells by grafting strategies into solid organs (especially internal organs) are provided. These methods and compositions can be used to repair diseased organs or to establish models of disease states in experimental hosts. The method involves attachment onto the surface of a tissue or organ, a patch graft, a bandaid-like covering, containing epithelial cells with supporting early lineage stage mesenchymal cells. The cells are incorporated into soft gel-forming biomaterials prepared under serum-free, defined conditions comprised of nutrients, lipids, vitamins, and regulatory signals that collectively support stemness of the donor cells. The graft is covered with a biodegradable, biocompatible, bioresorbable backing used to affix the graft to the target site. The cells in the graft migrate into and throughout the tissue such that within a couple of weeks they are uniformly dispersed within the recipient (host) tissue. The mechanisms by which engraftment and integration of donor cells into the organ or tissue involve multiple membrane-associated and secreted forms of MMPs.

An aspect provides a biodegradable polymer scaffold for kidney regeneration, including basic ceramic particles, an extracellular matrix, zinc particles, a kidney regeneration-inducing material, and a biodegradable polymer. A biodegradable polymer scaffold for kidney regeneration, according to an aspect, includes a kidney regeneration-inducing material and/or extracellular vesicles that secrete a stem cell recruitment-inducing factor, thereby inducing stem cells to a damaged tissue site and enhancing kidney regenerative capacity, and thus can effectively induce the regeneration of kidney tissue. Therefore, the biodegradable polymer scaffold can contribute to the medical device industry, including the bioimplant market.