Abstract: Provided are stem cell biomimetic microparticles comprised of at least one stem cell-derived paracrine polypeptide or growth factor embedded in a polymer core particle that further comprises an outer layer of at least one fragment of a cell membrane of a stem cell disposed on the core particle. The polymer core may be constituted of any biocompatible and biodegradable polymer or copolymer, or a combination thereof that allows the embedding of the paracrine factors and their prolonged release from the core. The core and hence the microparticles can be biodegradable, allowing eventual elimination from the recipient animal or human subject. The core particles are sized to allow both transport through blood vessels and extravasation from the blood vessels into the surrounding tissues. The core particle may further include at least one polypeptide or peptide growth factor to induce the generation and proliferation of a population of stem cells.

Abstract: Provided are engineered cells fused with platelet membrane vesicles and capable of specifically targeting a subendothelial site of vascular injury. Also provided are methods of generating a modified cell or extracellular vesicle fused with platelet membrane vesicles or fragments thereof. Further provided are methods for using these engineered cells and vesicles for the treatment of injured tissue accompanied by vascular injury by engraftment with modified cells fused with platelet membrane vesicles. Cells fused with the platelet vesicles can be engineered stem cells such as cardiac or mesenchymal stem cells; the extracellular vesicles fused with the platelet vesicles can be exosomes such as exosomes derived from cardiac or mesenchymal stem cells. The use of the platelet vesicles for targeting sites of vascular injury may also be usefully applied to engineering cells and exosomes that have therapeutic activity for the treatment of vascular injury.

Abstract: Provided are stem cell biomimetic microparticles comprised of at least one stem cell-derived paracrine polypeptide or growth factor embedded in a polymer core particle that further comprises an outer layer of at least one fragment of a cell membrane of a stem cell disposed on the core particle. The polymer core may be constituted of any biocompatible and biodegradable polymer or copolymer, or a combination thereof that allows the embedding of the paracrine factors and their prolonged release from the core. The core and hence the microparticles can be biodegradable, allowing eventual elimination from the recipient animal or human subject. The core particles are sized to allow both transport through blood vessels and extravasation from the blood vessels into the surrounding tissues. The core particle may further include at least one polypeptide or peptide growth factor to induce the generation and proliferation of a population of stem cells.