Probing the pH microenvironment of mesenchymal stromal cell cultures on additive-manufactured scaffolds

TL;DR

This study introduces a capsule-based optical sensor system integrated with 3D scaffolds to monitor pH changes during mesenchymal stromal cell growth, providing spatial and temporal insights into tissue regeneration microenvironments.

Contribution

The paper presents a novel method combining optical sensors and additive-manufactured scaffolds for real-time pH monitoring in 3D cell cultures, advancing tissue engineering techniques.

Findings

pH decreases over time in 3D scaffolds

pH change is more prominent at scaffold edges

3D scaffolds show higher pH variation than 2D cultures

Abstract

Despite numerous advances in the field of tissue engineering and regenerative medicine, monitoring the formation of tissue regeneration and its metabolic variations during culture is still a challenge and mostly limited to bulk volumetric assays. Here, a simple method of adding capsules based optical sensors in cell seeded 3D scaffolds is presented and the potential of these sensors to monitor the pH changes in space and time during cell growth is demonstrated. It is shown that the pH decreased over time in the 3D scaffolds, with a more prominent decrease at the edges of the scaffolds. Moreover, the pH change is higher in 3D scaffolds compared to monolayered 2D cell cultures. The results suggest that this system, composed by capsules based optical sensors and 3D scaffolds with predefined geometry and pore architecture network, can be a suitable platform for monitoring pH variations during 3D cell growth and tissue formation. This is particularly relevant for the investigation of 3D cellular microenvironment alterations occurring both during physiological processes, such as tissue regeneration, and pathological processes, such as cancer evolution.