Surface Plasmon Resonance for Human Bone Marrow Cells Imaging

Thomas Wilkop,W Balachandran,N Manivannan,Asim K Ray

doi:10.1109/jsen.2020.2997742

Abstract

Surface plasmon resonance imaging (SPRI) detects the changes in refractive index in close proximity to the surface of a thin metal film as variations in light intensity reflected from the back of the film and thus does not require labeling for visualization of the structures under investigation. While traditionally, the wave vector scanning is performed via angular rotations, the wave vector can also be scanned though tuning of the wavelength. Here we demonstrate that a combination of a non-monochromatic electrically tunable bandpass filter in conjunction with highly chromatically corrected imaging objectives can yield subcellular resolution for imaging of the interior refractive index of human mesenchymal stem cells.

Highlights

H UMAN mesenchymal stem cells are nonhaematopoietic multipotent cells with the ability to differentiate into three lineage types such as ectoderm, mesoderm and endoderm
Depending on the refractive index distribution in the cell adhering to the substrate surface varying Surface plasmon resonance (SPR) coupling efficiencies can be observed across the cell [21]
Using custom made smaller prism could increase the lateral resolution or increasing the imaging distance can enlarge the field of view

Summary

INTRODUCTION

H UMAN mesenchymal stem cells (hMSCs) are nonhaematopoietic multipotent cells with the ability to differentiate into three lineage types such as ectoderm (neurocytes), mesoderm (osteocytes, adipocytes and chondrocyte) and endoderm (hepatocytes). The bone morphogenetic proteins are found from X-ray imaging studies to promote differentiation of human dermal-derived fibroblast cells in vivo [6]. Using the vascular endothelial-cadherin (VE) protein as a biomarker, SPR has been successfully employed to monitor the hMSC differentiation into endothelial lineage over fourteen days with the detectability of 27cells/mm. In-situ increase of the SPR signal with the VE on the cell surface during the differentiation indicates the possibility of real-time live cell diagnostic treatment without any need for cell breakage [16]. The real-time identification of mesenchymal stem cells has proven to be both problematic and WILKOP et al.: SPR FOR HUMAN BONE MARROW CELLS IMAGING. Surface plasmon resonance (SPR), a highly surface-sensitive technique, may be used for the real time high throughput examination of specific cell types based on their dielectic/refractive index properties [17]. Depending upon the relaxation time of the liquid crystal, the scan speed can exceed that of a goniometer based angular rotation SPR system [18]

EXPERIMENTAL DETAILS

RESULTS

CONCLUDING REMARKS