Biology subjects

Lesher-Perez, S. C.

Publications and source records attributed to Lesher-Perez, S. C..

3 recordsLinked to original sources

bioRxiv2025

MAP hydrogel promotes revascularization of human ovarian graft and integration with the hypothalamic-pituitary axis in a mouse model of primary ovarian insufficiency

Ovarian tissue cryopreservation and autotransplantation (OTCT) is a crucial fertility preservation strategy for patients facing gonadotoxic cancer treatments, but its clinical success is hampered by ischemic injury and follicle loss following transplantation. This study aimed to enhance OTCT outcomes by employing microporous annealed particle (MAP) hydrogels to promote human ovarian graft revascularization. Unlike non-encapsulated tissue grafts, which exhibited early but transient and disorganized host vascular infiltration followed by regression, tissue grafts encapsulated in MAP hydrogels (OvaMAPs) demonstrated delayed yet organized and stable, long-term revascularization. OvaMAPs had significantly greater mouse CD31+ tissue area and vessel length after 3 and 6 weeks post-transplantation in ovariectomized immunodeficient mice compared to non-encapsulated grafts. By 20 weeks, both groups restored physiological estradiol levels (with OvaMAPs reaching 158 pg/mL) and suppressed follicle-stimulating hormone, confirming integration of the grafts with the hosts hypothalamic-pituitary axes. Notably, OvaMAPs achieved comparable endocrine function restoration with reduced estradiol variability, indicating more consistent graft function. In conclusion, MAP hydrogel encapsulation promoted long-term graft revascularization and vascular stability after OTCT, ultimately supporting consistent endocrine integration with host physiology.

bioengineering↗

bioRxiv2025

Membrane Geometric Confinement Reshapes the Lateral Electric Field Distribution and Intracellular Cargo Transport in Nanopore Electroporation

Nanopore electroporation (NanoEP) is an emerging transfection method that enables efficient and safe intracellular delivery and removal of biomolecular cargo for applications in disease modeling, tissue engineering, and therapeutic biologics manufacturing. Conventional device designs assume uniform vertical cargo flux across nanoporous membranes; however, we demonstrate that the lateral electric field distributions introduce a pronounced edge effect, with enhanced cargo delivery and depletion along the membrane perimeters. We identify and characterize the presence of this edge effect in NanoEP systems, and develop a modified Nernst-Planck model to guide the design of membrane geometries that either promote delivery uniformity or create prescribed spatial gradients within cell monolayers. By varying the internal angles formed by the membrane edges (60{degrees}C, 90{degrees}C, 120{degrees}C), we create predictable intracellular cargo gradients, while concave "serpentine" geometries with high perimeter-to-area ratios amplify delivery efficiency and minimize spatial heterogeneity compared to circular membranes. These findings establish membrane geometry as a tunable design parameter in NanoEP, enabling control over both uniform and patterned intracellular payload delivery or depletion. This geometric design principle offers a scalable strategy for next-generation transfection platforms and synthetic tissue constructs.

bioengineering↗

bioRxiv2024

Clickable PEG-norbornene microgels support suspension bioprinting and microvascular assembly

The development of perfusable and multiscale vascular networks remains one of the largest challenges in tissue engineering. As such, there is a need for the creation of customizable and facile methods to produce robustly vascularized constructs. In this study, secondarily crosslinkable (clickable) poly(ethylene glycol)-norbornene (PEGNB) microbeads were produced and evaluated for their ability to sequentially support suspension bioprinting and microvascular self-assembly towards the aim of engineering hierarchical vasculature. The clickable PEGNB microbead slurry exhibited mechanical behavior suitable for suspension bioprinting of sacrificial bioinks, could be UV crosslinked into a granular construct post-print, and withstood evacuation of the bioink and subsequent perfusion of the patterned void space. Endothelial and stromal cells co-embedded within jammed RGD-modified PEGNB microbead slurries assembled into capillary-scale vasculature after secondary crosslinking of the beads into granular constructs, with endothelial tubules forming within the interstitial space between microbeads and supported by the perivascular association of the stromal cells. Microvascular self-assembly was not impacted by printing sacrificial bioinks into the cell-laden microbead support bath before UV crosslinking. Collectively, these results demonstrate that clickable PEGNB microbeads are a versatile substrate for both suspension printing and microvascular culture and may be the foundation for a promising methodology to engineer hierarchical vasculature.

bioengineering↗