Search

Abstract Severe infectious diseases, such as coronavirus disease 2019 (COVID‐19), can induce hypercytokinemia and multiple organ failure. In spite of the growing demand for peptide therapeutics against infectious diseases, current small molecule‐based strategies still require frequent administration due to limited half‐life and enzymatic digestion in blood. To overcome this challenge, a strategy to continuously express multi‐level therapeutic peptide drugs on the surface of immune cells, is established. Here, chimeric T cells stably expressing therapeutic peptides are presented for treatment of severe infectious diseases. Using lentiviral system, T cells are engineered to express multi‐level therapeutic peptides with matrix metallopeptidases‐ (MMP‐) and tumor necrosis factor alpha converting enzyme‐ (TACE‐) responsive cleavage sites on the surface. The enzymatic cleavage releases γ‐carboxyglutamic acid of protein C (PC‐Gla) domain and thrombin receptor agonist peptide (TRAP), which activate endothelial protein C receptor (EPCR) and protease‐activated receptor‐1 (PAR‐1), respectively. These chimeric T cells prevent vascular damage in tissue‐engineered blood vessel and suppress hypercytokinemia and lung tissue damages in vivo, demonstrating promise for use of engineered T cells against sepsis and other infectious‐related diseases.

Abstract The use of engineered scaffolds or stem cells is investigated widely in the repair of injured musculoskeletal tissue. However, the combined regeneration of hierarchical osteochondral tissue remains a challenge due to delamination between cartilage and subchondral bone or difficulty in spatial control over differentiation of transplanted stem cells. Here, two types of composite spheroids are prepared using adipose‐derived stem cells (hADSCs) and nanofibers coated with either transforming growth factor‐β3 or bone morphogenetic growth factor‐2 for chondrogenesis or osteogenesis, respectively. Each type of spheroid is then cultured within a 3D‐printed microchamber in a spatially arranged manner to recapitulate the bilayer structure of osteochondral tissue. The presence of inductive factors regionally modulates in vitro chondrogenic or osteogenic differentiation of hADSCs within the biphasic construct without dedifferentiation. Furthermore, hADSCs from each spheroid proliferate and sprout and successfully connect the two layers mimicking the osteochondral interface without apertures. In vivo transplantation of the biphasic construct onto a femoral trochlear groove defect in rabbit knee joint results in 21.2 ± 2.8% subchondral bone volume/total volume and a cartilage score of 25.0 ± 3.7. The present approach can be an effective therapeutic platform to engineer complex tissue.