Microfluidic platforms for multiplexed functional testing of intact tumor tissues

Thesis (Ph.D.)--University of Washington, 2021Despite advances in targeted therapies, cancer treatment continues to face significant challenges as it moves toward the goal of rationally chosen personalized therapy. There is a great need for functional testing platforms that use human, intact tumor tissue to predict patient outcomes to cancer therapy. The successful development of such platforms would advance both drug development and identification of optimal treatments for a given patient (i.e., precision oncology). However, current approaches that solely use patient-derived cells from dissociated tissue typically lack most of the tumor microenvironment (TME) and are not rapid enough to guide patient-specific therapy decisions. Furthermore, the response of each individual to a given treatment can vary widely across the population. This report outlines the progress we have made in developing two digitally fabricated microfluidic platforms that utilize intact patient-derived tumor tissue to solve critical challenges related to the advancement of personalized therapy. The first chapter outlines an introduction to digital manufacturing and laser micromachining through CO2 laser ablation and compatible bonding techniques for microfluidic applications. The second chapter summarizes the development of a digitally fabricated microfluidic platform (Oncoslice) that allows for selective spatiotemporal exposure of organotypic slice cultures to dozens of drug conditions. The chapter includes published demonstrations of successful microfluidic delivery of small-molecule cancer drug panels to glioblastoma (GBM) xenograft slices and GBM and colorectal cancer patient tumor slices. Furthermore, it includes preliminary results that spear our future aims to utilize the platform to evaluate combination immunotherapies and their interaction with the TME. Finally, the third chapter summarizes our most recent advances in developing a microfluidic platform that enables drug treatment, exogenous T cell therapy, and high-content analysis using hundreds to thousands of similarly sized, precision-sliced cuboidal micro-tissues (“cuboids”) produced from a single tumor sample. The chapter incorporates published results related to cuboid sectioning and characterization (i.e., size, viability, TME), microfluidic platform prototype development and functionality, and pilot drug delivery experiments. Despite advances in targeted therapies, cancer treatment continues to face significant challenges as it moves toward the goal of rationally chosen personalized therapy. There is a great need for functional testing platforms that use human, intact tumor tissue to predict patient outcomes to cancer therapy. The successful development of such platforms would advance both drug development and identification of optimal treatments for a given patient (i.e., precision oncology). However, current approaches that solely use patient-derived cells from dissociated tissue typically lack most of the tumor microenvironment (TME) and are not rapid enough to guide patient-specific therapy decisions. Furthermore, the response of each individual to a given treatment can vary widely across the population. This report outlines the progress we have made in developing two digitally fabricated microfluidic platforms that utilize intact patient-derived tumor tissue to solve critical challenges related to the advancement of personalized therapy. The first chapter outlines an introduction to digital manufacturing and laser micromachining through CO2 laser ablation and compatible bonding techniques for microfluidic applications. The second chapter summarizes the development of a digitally fabricated microfluidic platform (Oncoslice) that allows for selective spatiotemporal exposure of organotypic slice cultures to dozens of drug conditions. The chapter includes published demonstrations of successful microfluidic delivery of small-molecule cancer drug panels to glioblastoma (GBM) xenograft slices and GBM and colorectal cancer patient tumor slices. Furthermore, it includes preliminary results that spear our future aims to utilize the platform to evaluate combination immunotherapies and their interaction with the TME. Finally, the third chapter summarizes our most recent advances in developing a microfluidic platform that enables drug treatment, exogenous T cell therapy, and high-content analysis using hundreds to thousands of similarly sized, precision-sliced cuboidal micro-tissues (“cuboids”) produced from a single tumor sample. The chapter incorporates published results related to cuboid sectioning and characterization (i.e., size, viability, TME), microfluidic platform prototype development and functionality, and pilot drug delivery experiments