3D Cellular Morphotyping of Scaffold Niches

Abstract

There is currently no method for assessing the nature of the cell niche provided by 3D biomaterial scaffolds. Analyzing human bone marrow stromal cell (hBMSC) 3D cell shape in response to different biomaterial scaffolds allowed the 3D cell niche promoted by biomaterial scaffolds to be evaluated. Primary hBMSCs (p5) were seeded (5,000 cells/cm2) in 10 different biomaterial scaffolds and cultured for 24 h. Samples were fixed and stained for actin and nucleus, imaged with confocal microscopy to obtain a 3D volume (z-stack), and 3D cell shape was analyzed with computational approaches. Over 100 cells were imaged per scaffold group (10 scaffold groups, ~1250 cells total), resulting in the largest known 3D stem cell dataset (~135,000 files, ~135 GB) and enabling a high degree of statistical rigor. The images were segmented using an automated algorithm and a final dataset of 969 well-segmented cells were analyzed with 79 shape metrics, which enabled 3D cellular morphotyping of scaffold niches. The variety of scaffolds studied promoted different cell morphologies during culture and there were significant differences in shape metrics, particularly for cell depth, surface area, and volume. This study demonstrated a quantitative approach to analyze 3D cell shape and morphotype and is the largest known study analyzing 3D cell shape in response to a variety of biomaterial scaffolds. The dataset is publically accessible with an online 3D viewer. These results could inform the selection of prospective scaffolds for applications based on 3D cell shape in the tissue of interest.