Investigation of PDGF-BB aptamer binding using growth factor-coated particles and flow cytometry

Platelet-derived growth factor-BB (PDGF-BB), a multifunctional growth factor secreted by platelets, endothelial and cancer cells, functions as an efficient and accurate biomarker. PDGF- BB has been employed in various therapeutic applications. Tuning its bioactivity via a specific binding ligand could enhance the PDGF-BB functionality. Aptamer, a single-stranded oligonucleotide that exhibits a selective binding to PDGF-BB, is the molecule of our interest. This research aims to evaluate the PDGF-BB aptamer binding by growth factor-coated particles. PDGF-BB-coated particles were confirmed by ELISA, and aptamer binding evaluation was investigated by flow cytometry. To optimize the condition for binding evaluation, the washing cycle and concentration of PDGF-BB, polystyrene particle and aptamer were studied using flow cytometer. Based on the flow cytometry results, the concentration of PDGF-BB showed an optimal level on the number of fluorescent particles. The percentage of fluorescent particles increased when the washing cycle was reduced and the particle concentration was decreased. The percentage of fluorescent particles also increased proportionally with the aptamer concentration. Using a flow cytometer to detect fluorescent signal from growth factor-coated particle is a promising strategy to study biomolecular binding.