Hypothermic and cryogenic preservation of cardiac tissue-engineered constructs.

Cardiac tissue engineering (cTE) has already advanced towards the first clinical trials, investigating safety and feasibility of cTE construct transplantation in failing hearts. However, the lack of well-established preservation methods poses a hindrance to further scalability, commercialization, and transportation, thereby reducing their clinical implementation. In this study, hypothermic preservation (4 °C) and two methods for cryopreservation (, a slow and fast cooling approach to -196 °C and -150 °C, respectively) were investigated as potential solutions to extend the cTE construct implantation window.

Orthotopic equine study confirms the pivotal importance of structural reinforcement over the pre-culture of cartilage implants.

In articular cartilage (AC), the collagen arcades provide the tissue with its extraordinary mechanical properties. As these structures cannot be restored once damaged, functional restoration of AC defects remains a major challenge. We report that the use of a converged bioprinted, osteochondral implant, based on a gelatin methacryloyl cartilage phase, reinforced with precisely patterned melt electrowritten polycaprolactone micrometer-scale fibers in a zonal fashion, inspired by native collagen architecture, can provide long-term mechanically stable neo-tissue in an orthotopic large animal model.

Fusogenic Coiled-Coil Peptides Enhance Lipid Nanoparticle-Mediated mRNA Delivery upon Intramyocardial Administration.

Heart failure is a serious condition that results from the extensive loss of specialized cardiac muscle cells called cardiomyocytes (CMs), typically caused by myocardial infarction (MI). Messenger RNA (mRNA) therapeutics are emerging as a very promising gene medicine for regenerative cardiac therapy. To date, lipid nanoparticles (LNPs) represent the most clinically advanced mRNA delivery platform.

Convergence of melt electrowriting and extrusion-based bioprinting for vascular patterning of a myocardial construct.

To progress cardiac tissue engineering strategies closer to the clinic, thicker constructs are required to meet the functional need following a cardiac event. Consequently, pre-vascularization of these constructs needs to be investigated to ensure survival and optimal performance of implantable engineered heart tissue. The aim of this research is to investigate the potential of combining extrusion-based bioprinting (EBB) and melt electrowriting for the fabrication of a myocardial construct with a precisely patterned pre-vascular pathway.

Generation, High-Throughput Screening, and Biobanking of Human-Induced Pluripotent Stem Cell-Derived Cardiac Spheroids.

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are of paramount importance for human cardiac disease modeling and therapeutics. We recently published a cost-effective strategy for the massive expansion of hiPSC-CMs in two dimensions (2D). Two major limitations are cell immaturity and a lack of three-dimensional (3D) arrangement and scalability in high-throughput screening (HTS) platforms.

Small molecule-mediated rapid maturation of human induced pluripotent stem cell-derived cardiomyocytes.

Background: Human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs) do not display all hallmarks of mature primary cardiomyocytes, especially the ability to use fatty acids (FA) as an energy source, containing high mitochondrial mass, presenting binucleation and increased DNA content per nuclei (polyploidism), and synchronized electrical conduction. This immaturity represents a bottleneck to their application in (1) disease modelling-as most cardiac (genetic) diseases have a middle-age onset-and (2) clinically relevant models, where integration and functional coupling are key. So far, several methods have been reported to enhance iPSC-CM maturation; however, these protocols are laborious, costly, and not easily scalable.

Rapid and cytocompatible cell-laden silk hydrogel formation riboflavin-mediated crosslinking.

Bioactive hydrogels based on naturally-derived polymers are of great interest for regenerative medicine applications. Among naturally-derived polymers, silk fibroin has been extensively explored as a biomaterial for tissue engineering due to its unique mechanical properties. Here, we demonstrate the rapid gelation of cell-laden silk fibroin hydrogels by visible light-induced crosslinking using riboflavin as a photo-initiator, in presence of an electron acceptor.

Simultaneous Micropatterning of Fibrous Meshes and Bioinks for the Fabrication of Living Tissue Constructs.

Fabrication of biomimetic tissues holds much promise for the regeneration of cells or organs that are lost or damaged due to injury or disease. To enable the generation of complex, multicellular tissues on demand, the ability to design and incorporate different materials and cell types needs to be improved. Two techniques are combined: extrusion-based bioprinting, which enables printing of cell-encapsulated hydrogels; and melt electrowriting (MEW), which enables fabrication of aligned (sub)-micrometer fibers into a single-step biofabrication process.

Hypoxia impedes vasculogenesis of in vitro engineered bone.

To ensure the survival of engineered bone after implantation, we combined human endothelial colony forming cells (ECFCs) and multipotent stromal cells (MSCs) as a proof of concept in a co-culture model to create in vitro prevascularized bone constructs. We hypothesized that a hypoxic stimulus will contribute to prevascularization of engineered bone. Bone marrow-derived MSCs and ECFCs from human adult peripheral blood were allowed to form co-culture pellets containing ECFCs and MSCs (1:4) or MSCs only in controls.