Nutrient Regulation by Continuous Feeding for Large-scale Expansion of Mammalian Cells in Spheroids

Abstract

In this demonstration, spheroids formed from the β-TC6 insulinoma cell line were cultured as a model of manufacturing a mammalian islet cell product to demonstrate how regulating nutrient levels can improve cell yields. In previous studies, bioreactors facilitated increased culture volumes over static cultures, but no increase in cell yields were observed. Limitations in key nutrients such as glucose, which were consumed between batch feedings, can lead to limitations in cell expansion. Large fluctuations in glucose levels were observed, despite the increase in glucose concentrations in the media. The use of continuous feeding systems eliminated fluctuations in glucose levels, and improved cell growth rates when compared with batch fed static and SSB culture methods. Additional increases in growth rates were observed by adjusting the feed rate based on calculated nutrient consumption, which allowed the maintenance of physiological glucose over three weeks in culture. This method can also be adapted for other cell types.

Insulinoma-derived pseudo-islets for diabetes research

“…The complexity, cost, and time-consuming nature of primary islets of Langerhans research and training motivated our team to create an accessible, rapidly renewable, and representative model system for isolated islets that could be used to train personnel and inform experiments that require valuable primary islets. Previous work by several groups has shown that insulinoma cell lines form islet-like aggregates or IPIs (13)(14)(15)(16)(17)(18)(19)(20)34). However, previous approaches to create IPIs required relatively complex methodology, often with relatively low yields and limited functional characterization.…”

Co-Microencapsulation of BMSCs and Mouse Pancreatic (3 Cells for Improving the Efficacy of Type I Diabetes Therapy

“…Therefore, co-microencapsulation of BMSCs and mouse pancreatic β cells (beta-TC-6) was performed in the current study. Beta-TC-6 was selected due to its more sensitive response to glucose (21) through the activation of ERK 1/2 signal transduction pathway (22), and the ability for large-scale expansion in spheroids (23). Their insulin secretion and their potential for transplantation for treatment of type I diabetes were then investigated.…”