Development and Comparison of Two Immuno-disaggregation Based Bioassays for Cell Secretome Analysis

Cell secretome analysis has gained increasing attention towards the development of effective strategies for disease treatment. Analysis of cell secretome enables the platform to monitor the status of disease progression, facilitating therapeutic outcomes. However, cell secretome analysis is very challenging due to its versatile and dynamic composition. Here, we report the development of two immuno-disaggregation bioassays using functionalized microparticles for the quantitative analysis of the cell secretome. Methods: We evaluated the feasibility of our developed immuno-disaggregation bioassays using antibody-conjugated MPs and protein-conjugated MPs for the detection of target cell secretome protein. The vascular endothelial growth factor (VEGF)-165 protein was tested as a model cell secretome protein in the serum and serum-free conditions. The status of MP aggregates was examined with a light microscopy and AccuSizer^TM 780 Optical Particle Sizer. The accuracy of our bioassays measurement was compared with standard ELISA method. Results: The developed bioassays successfully detected target VEGF protein present in serum-free buffer and serum-containing complete cell culture medium with high sensitivity and specificity. Additionally, the immuno-disaggregation bioassays using antibody-conjugated MPs and protein-conjugated MPs have a wide detection range from 0.01 ng/mL to 100 ng/mL and 0.5 ng/mL to 100 ng/mL, respectively. The sensitivity of the bioassay using antibody-conjugated MPs was approximately one order of magnitude higher than the bioassay using protein-conjugated MPs. Conclusion: Our promising results indicate the potential of the developed bioassays as powerful platforms for the quantitative analysis of cell secretome.