Microphysiologic Systems of Lymphatic Vasculatures in Health and Disease
Breakthroughs in lymphatic biology have traditionally relied on animal models, ex-vivo studies, and molecular discoveries. However, these approaches often fall short in capturing the complexity of human disease. At the Lymphatic Biology & Bioengineering Lab (LLBB), we are pioneering microphysiological systems (MPS) that bridge this gap by mimicking the in-vivo lymphatic microenvironment.
We have developed a pro-lymphangiogenic hydrogel platform based on PEG-4MAL, enabling the growth of both ex-vivo lymphatic tissues and patient-derived organoid models. This cutting-edge system promotes lymphatic sprouting, demonstrated by our ability to cultivate collecting lymphatic vessels from isolated rat tissues (Hooks et al., 2022). More recently, we have reverse-engineered lymphatic tissues from primary cells across multiple species (rat, sheep, and human), accelerating lymphatic research by overcoming the long-standing challenge of isolating and maintaining lymphatic endothelial cells (LECs) in culture.
A major focus of our lab is advancing translational research in Lymphatic Malformations (LMs), a congenital vascular anomaly driven by PIK3CA mutations. Many cancer drugs targeting the PI3K/Akt/mTOR pathway show potential for LMs but remain poorly tolerated by pediatric patients. To accelerate preclinical drug testing, we have established LM patient-specific MPS using PEG- 4MAL hydrogels. These hydrogels support long-term lymphangiogenic growth, allowing patient biopsy-derived LM tissues to expand while maintaining their native transcriptional profile, as confirmed by single-cell RNA sequencing.
For the first time, our lab has successfully developed in vitro patient-derived LM organoid (PDO) models, engineered from biopsies of LM patients. These models enable us to test targeted PI3K/AKT/mTOR inhibitors in a physiologically relevant setting. Alpelisib treatment induced significantly higher sprout regression than sirolimus in two LM organoid models, while a third model exhibited resistance. Additionally, transcriptomic analysis revealed that alpelisib-treated LMOs upregulated pro-apoptotic genes while downregulating cell cycle progression genes, shedding light on drug mechanisms and potential resistance factors.
Our research is pushing the boundaries of lymphatic tissue engineering, creating a new paradigm for precision medicine in LM and related vascular anomalies. Future research in our lab will refine these models, enhance patient-specific drug screening, and expand our understanding of LM pathophysiology.
Contact: Yarelis Gonzalez-Vargas