A 3D culture platform enables development of zinc-binding prodrugs for targeted proliferation of β cells
Kisuk Yang, Miseon Lee, Peter A. Jones, Sophie S. Liu, A.X. Zhou, Jun Xu, Vedagopuram Sreekanth, Jamie L. Y. Wu, Lillian Vo, Eunjee A. Lee, Ramona Pop, Yuhan Lee, Bridget K. Wagner, Douglas A. Melton, Amit Choudhary, Jeffrey M. Karp
Abstract
Advances in treating β cell loss include islet replacement therapies or increasing cell proliferation rate in type 1 and type 2 diabetes, respectively. We propose developing multiple proliferation-inducing prodrugs that target high concentration of zinc ions in β cells. Unfortunately, typical two-dimensional (2D) cell cultures do not mimic in vivo conditions, displaying a markedly lowered zinc content, while 3D culture systems are laborious and expensive. Therefore, we developed the Disque Platform (DP)-a high-fidelity culture system where stem cell-derived β cells are reaggregated into thin, 3D discs within 2D 96-well plates. We validated the DP against standard 2D and 3D cultures and interrogated our zinc-activated prodrugs, which release their cargo upon zinc chelation-so preferentially in β cells. Through developing a reliable screening platform that bridges the advantages of 2D and 3D culture systems, we identified an effective hit that exhibits 2.4-fold increase in β cell proliferation compared to harmine.