Peptide Bioink: Self-Assembling Nanofibrous Scaffolds for Three-Dimensional Organotypic Cultures.

Printable scaffolds with adequate mechanical strength and stiffness are sought after to ensure viability of printed cells and tissues. We report the first peptide bioinks-lysine-containing hexapeptides that self-assemble into stable, nanofibrous three-dimensional hydrogels with unprecedented stiffness of up to 40 kPa. These biocompatible scaffolds support the three-dimensional culture of human stem cells and differentiation of primary cells into organotypic (gastrointestinal and skin) structures for high-throughput screening, diagnosis, and tissue engineering.

Generation of "Off-the-Shelf" Natural Killer Cells from Peripheral Blood Cell-Derived Induced Pluripotent Stem Cells.

Current donor cell-dependent strategies can only produce limited "made-to-order" therapeutic natural killer (NK) cells for limited patients. To provide unlimited "off-the-shelf" NK cells that serve many recipients, we designed and demonstrated a holistic manufacturing scheme to mass-produce NK cells from induced pluripotent stem cells (iPSCs). Starting with a highly accessible human cell source, peripheral blood cells (PBCs), we derived a good manufacturing practice-compatible iPSC source, PBC-derived iPSCs (PBC-iPSCs) for this purpose. Through our original protocol that excludes CD34+ cell enrichment and spin embryoid body formation, high-purity functional and expandable NK cells were generated from PBC-iPSCs. Above all, most of these NK cells expressed no killer cell immunoglobulin-like receptors (KIRs), which renders them unrestricted by recipients' human leukocyte antigen genotypes. Hence, we have established a practical "from blood cell to stem cells and back with less (less KIRs)" strategy to generate abundant "universal" NK cells from PBC-iPSCs for a wide range of patients.