(6gu) Cell Shape: An Overlooked Factor at the Nanobio Interfaces

Morteza Mahmoudi¹, Saeid Zanganeh²

¹Center for Nanomedicine, Department of Anesthesiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, United States

²Sloan Kettering Institute for Cancer Research, New York, New York 10065, USA

Introduction:

It is now a well-known fact that cells in their native tissue show different morphologies than those grown on a culture plate. In vivo, cells maintain their specific 3D structure, while they almost have a flat body when cultured on the conventional 2D culture plates. Here, we show that the way cells respond to the exact same type of nanoparticles is strongly dependent on their shape. Therefore, the nanoparticles uptake and toxicology data from 2D culture plates cannot exactly predict how the cells would respond in their 3D structures in vivo. In order to better predict the efficacy of the 2D cell culture plates, we propose the use of “pseudo-3D” substrates that could partially mimic the in vivo cell shapes.

Materials and Methods: The polydimethylsiloxane (PDMS) polymer was used as a molding agent. The imprints were prepared from two different kinds of cells; the normal fibroblast cells (HU02), and the cancerous epithelial cells (MCF-7) with spindle and polygonal shapes respectively. To evaluate the GNRs-mediated toxicological responses on the HU02 cells, which were cultured either on the cell-imprinted substrates or the conventional polystyrene culture plate, a wide range of assays were conducted as following: (i) cellular uptake, (ii) cell viability, (iii) reactive oxygen species (ROS) production assay, (iv) comet assay, (v) apoptosis-necrosis detection assay, and (vi) cell cycle assessment. The wells’ bed had been covered with the polymeric substrates, including HU02-imprinted (“autologous”), MCF-7-imprinted (“allogeneic”), plain polydimethylsiloxane (PDMS) substrates or without polymeric substrates (control group, conventional polystyrene culture plate).

Results and Discussion: In this study, we clarify that cells cultured on the cell-imprinted substrates presumably receive similar signals from the milieu to that of their natural niche signal and that these cells behave more naturally. Furthermore, this research well explains the fact that the cell toxicity that results from different substrates, is strongly depending on the cells’ bed. So, it is safe to say that preparing a topographically optimized niche microenvironment on cell culture substrate, by patterning the natural cell shapes, could be a promising way to simulate the extracellular matrix and to mimic the natural cell architecture, which may further extend our capabilities to investigate and predict the biological effects of nanoparticles such as cell toxicity in a more precise way.

Conclusions: In this study, we draw biomedical communities’ attention to another major factor that could diminish the gap between in vitro and in vivo outcomes, the cell shape. We show that the cellular uptake and toxicity of exact same nanoparticles are strongly dependent on the cell shape (i.e., cells which are being cultured on 2D- and cell- imprinted-substrates). Our results suggest that the cell shape effects should be considered in nanobiointerfaces’ protocols, enabling them to provide more accurate and precise outcomes.

Research Interests: My research goals are directed toward use of superparamagnetic iron oxide nanoparticles (SPIONs) for various biomedical applications (such as targeted delivery of therapeutic biomolecules to the desired cells, targeted imaging of the cells, protein/gene delivery, and hyperthermia) for earlier detection and better treatment of diseases (such as cancer and neurodegenerative disease).

Teaching Interests: My teaching interests lie at the interface of materials science and engineering, nanotechnology, cell biology, and medicine. I particularly enjoy teaching introductory biomaterials and bioengineering courses to majors and non-majors alike