Transient MyoD overexpression in concert with small molecule treatment reprograms mouse fibroblasts into induced myogenic progenitor cells (iMPCs). However, the molecular landscape and mechanisms orchestrating this cellular conversion remain unknown. Here, we undertook an integrative multiomics approach to delineate the process of iMPC reprogramming in comparison to myogenic transdifferentiation mediated solely by MyoD. Using transcriptomics, proteomics, and genome-wide chromatin accessibility assays, we unravel distinct molecular trajectories that govern the two processes. Notably, only iMPC reprogramming is characterized by gradual up-regulation of muscle stem cell markers, unique signaling pathways, and chromatin remodelers in conjunction with exclusive chromatin opening in core myogenic promoters. In addition, we determine that the Notch pathway is indispensable for iMPC formation and self-renewal and further use the Notch ligand Dll1 to homogeneously propagate iMPCs. Collectively, this study charts divergent molecular blueprints for myogenic transdifferentiation or reprogramming and underpins the heightened capacity of iMPCs for capturing myogenesis ex vivo.

The plasticity and regenerative capacity of skeletal muscle arise from quiescent stem cells activated upon overload, injury, or disease state. Developing in vitro muscle models to study these properties can advance muscle disease modeling and pre‐clinical evaluation. Here, Filamented Light (FLight) bioprinting is leveraged as a high‐throughput approach for producing mini‐muscle tissues. Using paired box protein 7 (Pax7)‐nGFP primary myoblasts, mini‐muscles are bioprinted from pristine collagen‐fibrinogen (ColFib). The FLight hydrogel consist of aligned microstructures which guide the formation of aligned myotubes. Mini‐muscles demonstrates in vivo‐like tissue organization, including multinucleated myotubes and a Pax7 ⁺ cell pool embedded in newly deposited laminin. Both spontaneous and electrically stimulated contractions are observed. ColFib matrix is promising for maintenance of the Pax7 ⁺ cell pool. Damage from cardiotoxin‐induced injury of the mini‐muscles led to a massive proliferation of Pax7 ⁺ cells and restoration of the contractile properties of myotubes. Notably, small molecules such as Repsox can enhance regeneration. FLight printed mini‐muscles have potential for applications in muscle biology, exercise/atrophy, disease models, and drug screening.

Musculoskeletal (MSK) disorders—osteoporosis, osteoarthritis, rheumatoid arthritis, intervertebral disc degeneration, tendinopathy, and skeletal muscle injury—contribute the largest share of years lived with disability worldwide. Conventional therapy relies on systemic dosing or repeated intra-articular and peri-tissue injections, which suffer from off-target toxicity, poor lesional bioavailability, and low adherence. Polymer microneedles (MNs)—micron-scale projections of biodegradable, dissolving, hydrogel-forming, or composite polymers—have rapidly matured into a versatile platform for minimally invasive, spatially localized, and temporally programmable delivery of small molecules, biologics, nucleic acids, extracellular vesicles, and cells to MSK tissues. This review synthesizes 2018–2026 advances in polymer MN systems engineered specifically for MSK regeneration. We classify dominant polymer chemistries and MN architectures; map fit-for-purpose across bone, cartilage, joint, intervertebral disc, tendon, and skeletal muscle; and survey “smart” MN designs that exploit reactive oxygen species, pH, mechanical, triboelectric, optogenetic, and ultrasonic triggers. We close with a concise conclusion and forward perspective that identifies the key design levers—hybrid MN–scaffold combination products, stimuli-responsive platforms tuned to the MSK micro-environment, and cell- and EV-loaded formats—most likely to have clinical impact.

Severe cardiac bleeding requires rapid and stable sealing in highly dynamic and continuously wet environments, where most existing hemostatic agents fail to provide sufficient performance. In this work, we introduce a multifunctional polyacrylamide/gelatin/tannic acid hydrogel (PGT) engineered to deliver strong wet adhesion, rapid coagulation, robust mechanical stability, and antibacterial activity simultaneously. The tannic acid(TA) coating strengthens the polymer network by promoting multivalent hydrogen bonding and metal–phenolic coordination, thereby improving both mechanical integrity and interfacial adhesion to moist biological tissues. Among the hydrogel formulations, the PGT10, coated with 10% TA solution, exhibited exceptional performance, achieving instantaneous sealing of a porcine cardiac defect without initial leakage and maintaining stable adhesion under continuous pressure and physiological movement. PGT10 also demonstrated superior hemostatic efficacy in in vivo liver puncture models and porcine whole‐blood assays, markedly reducing blood loss and accelerating clot formation. Additionally, the PGT exhibited excellent cytocompatibility, low hemolysis, and strong antibacterial effects against E. coli and S. aureus . Collectively, these findings highlight the promise of the PGTs as rapidly deployable, biocompatible bioadhesive patches capable of enabling effective bleeding control in high‐motion organs such as the heart and liver. These advantages collectively support its clinical translation potential in critical emergency care settings.

Cultured meat aims to manufacture genuine animal tissue from cells in vitro, displacing the environmental and ethical liabilities of livestock slaughter. Because the final product must reproduce the fibre architecture, fat marbling, and nutrition of conventional meat, the cell—its identity, proliferative ceiling, and differentiation fidelity—is the central determinant of feasibility. This review consolidates the stem cell biology of cultured meat from a tissue engineering perspective. We first compare the principal cell sources: muscle satellite cells, which offer authentic myogenicity but limited expansion; pluripotent stem cells, which are effectively immortal but require directed differentiation; and mesenchymal, adipogenic, and fibro-adipogenic progenitors that supply fat and connective tissue. We then examine how myogenic and adipogenic commitment is controlled through growth-factor and small-molecule signalling, serum-free medium design, and co-culture strategies that recreate the multicellular composition of meat. We next survey biomaterial scaffolds—edible microcarriers, hydrogels, and decellularized plant matrices—that organize stem cells into anisotropic, perfusable, macroscale constructs, drawing on scaffold-design principles from regenerative medicine. Finally, we address bioreactor scale-up, medium cost, cell-line stability, and regulatory translation. We argue that cultured meat will advance fastest when cell source, differentiation protocol, and scaffold architecture are co-designed rather than optimized in isolation.