Nanofiber scaffolds influence organelle structure and function in bone marrow stromal cells

Abstract

Tutak, Wojtek; Jyotsnendu, Giri; Bajcsy, Peter; and Simon, Carl G. Jr., "Nanofiber scaffolds influence organelle structure and function in bone marrow stromal cells" (2016 Abstract: Recent work demonstrates that osteoprogenitor cell culture on nanofiber scaffolds can promote differentiation. This response may be driven by changes in cell morphology caused by the three-dimensional (3D) structure of nanofibers. We hypothesized that nanofiber effects on cell behavior may be mediated by changes in organelle structure and function. To test this hypothesis, human bone marrow stromal cells (hBMSCs) were cultured on poly(e-caprolactone) (PCL) nanofibers scaffolds and on PCL flat spuncoat films. After 1 dayculture, hBMSCs were stained for actin, nucleus, mitochondria, and peroxisomes, and then imaged using 3D confocal microscopy. Imaging revealed that the hBMSC cell body (actin) and peroxisomal volume were reduced during culture on nanofibers. In addition, the nucleus and peroxisomes occupied a larger fraction of cell volume during culture on nanofibers than on films, suggesting enhancement of the nuclear and peroxisomal functional capacity. Organelles adopted morphologies with greater 3D-character on nanofibers, where the Z-Depth (a measure of cell thickness) was increased. Comparisons of organelle positions indicated that the nucleus, mitochondria, and peroxisomes were closer to the cell center (actin) for nanofibers, suggesting that nanofiber culture induced active organelle positioning. The smaller cell volume and more centralized organelle positioning would reduce the energy cost of inter-organelle vesicular transport during culture on nanofibers. Finally, hBMSC bioassay measurements (DNA, peroxidase, bioreductive potential, lactate, and adenosine triphosphate (ATP)) indicated that peroxidase activity may be enhanced during nanofiber culture. These results demonstrate that culture of hBMSCs on nanofibers caused changes in organelle structure and positioning, which may affect organelle functional capacity and transport.

Polycaprolactone–chitosan nanofibers influence cell morphology to induce early osteogenic differentiation

“…6 In this study, a significant difference in the minor axis length (72.50 ± 22.32 on TCPS and 205.72 ± 61.93 on NF) was observed which again indicated osteogenic differentiation. We also observed a substantial difference in the aspect ratio of cells on both substrates (4.69 on TCPS and 1.32 on NF), as supported by Tutak et al 46 Apart from cytoskeletal features, nucleus area was also measured. Mean nucleus area of cells on nanofibers was 560.55 ± 191.42 compared to 383.70 ± 143.15 on TCPS.…”

“…The increase in nucleus size indicated the enhancement in nuclear functional activity occurring during cell differentiation. 46 Thus, the morphological changes in pre-osteoblasts at as early as seven days suggested that nanofibers promoted early osteogenic differentiation.…”

Enhanced Differentiation of Human Preosteoblasts on Electrospun Blend Fiber Mats of Polydioxanone and Anionic Sulfated Polysaccharides

“…An increase in cell spread area has been correlated with osteogenic differentiation 46 − 48 and an increase in nucleus size was concluded to translate into enhanced nuclear functional activity occurring during cell differentiation. 49 The mean area of SaOS-2 cells cultured in osteogenic medium on the electrospun fibers was found to be almost twice that of cells cultured in normal proliferation conditions. Furthermore, cells grown in the normal proliferation medium were larger on the electrospun blend fibers compared to the PDX fibers.…”

Machine learning metrology of cell confinement in melt electrowritten three-dimensional biomaterial substrates

“…The principle of controlling cell function through cell shape manipulation has led to the development of engineered culture models made from natural or synthetic polymers 7 – 11 . In general, hydrogel-based systems with tunable stiffness parameter are considered the gold standard for three-dimensional (3D) cell culture 12 , 13 .…”