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Biology subjects

Palchesko, R. N.

Publications and source records attributed to Palchesko, R. N..

2 recordsLinked to original sources

Injury-Free In Vivo Delivery and Engraftment into the Cornea Endothelium Using Extracellular Matrix Shrink-Wrapped Cells

Cell injection is a common clinical approach for therapeutic delivery of cells into diseased and damaged tissues in order to achieve regeneration. However, cell retention, viability, and engraftment at the injection site has generally been poor, driving the need for improved approaches. Here, we developed a technique to shrink-wrap micropatterned islands of corneal endothelial cells in a basement membrane-like layer of extracellular matrix (ECM) that enables the cells to maintain their cell-cell junctions and cytoskeletal structure while in suspension. These Monolayers exhibited the ability to rapidly engraft into intact, high-density corneal endothelial monolayers in both in vitro and in vivo model systems. Importantly, the engrafted Monolayers increased local cell density, something that the clinical-standard single cells in suspension failed to do. These results show that shrink-wrapping cells in ECM dramatically improves engraftment and provides a potential alternative to cornea transplant when low endothelial cell density is the cause of corneal blindness. One Sentence SummaryShrink-wrapped patches of endothelial cells can rapidly attach and integrate into an intact cornea endothelium when injected into the anterior chamber, increasing cell density.

bioengineering

Dynamic Loading of Human Engineered Heart Tissue Enhances Contractile Function and Drives Desmosome-linked Disease Phenotype

The role mechanical forces play in shaping the structure and function of the heart is critical to understanding heart formation and the etiology of disease but is challenging to study in patients. Engineered heart tissues (EHTs) incorporating human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes have the potential to provide insight into these adaptive and maladaptive changes in the heart. However, most EHT systems are unable to model both preload (stretch during chamber filling) and afterload (pressure the heart must work against to eject blood). Here, we have developed a new dynamic EHT (dyn-EHT) model that enables us to tune preload and have unconstrained fractional shortening of >10%. To do this, 3D EHTs are integrated with an elastic polydimethylsiloxane (PDMS) strip that provides mechanical pre- and afterload to the tissue in addition to enabling contractile force measurements based on strip bending. Our results demonstrate in wild-type EHTs that dynamic loading is beneficial based on the magnitude of the forces, leading to improved alignment, conduction velocity, and contractility. For disease modeling, we use hiPSC-derived cardiomyocytes from a patient with arrhythmogenic cardiomyopathy (ACM) due to mutations in desmoplakin. We demonstrate that manifestation of this desmosome-linked disease state requires the dyn-EHT conditioning and that it cannot be induced using 2D or standard 3D EHT approaches. Thus, dynamic loading strategy is necessary to provoke a disease phenotype (diastolic lengthening, reduction of desmosome counts, and reduced contractility), which are akin to primary endpoints of clinical disease, such as chamber thinning and reduced cardiac output. Single Sentence SummaryDevelopment of a dynamic mechanical loading platform to improve contractile function of engineered heart tissues and study cardiac disease progression.

bioengineering