In order to quantify the binding capacities of polymeric, biodegradable and biocompatible poly(lactic-co-glycolic acid)
(PLGA) nanoparticles (NPs), conjugated with either R11 peptides or Folic Acid, the strength by detach from prostate
cancer cells (PCCs) was measured via optical tweezers based measurements. Specific nanoparticle drug delivery
eliminates the previously used diffuse, full-body application of potent cancer drugs by localizing drug delivery to
malignant cells. Precise monitoring of NP position in the trap near the PCC membrane using a fluorescence imaging
based method enabled calibration of the trap stiffness and subsequent force measurements. By defining the force with
which the many diverse conjugates and coatings of different types of NPs bind the vast array of cancer cell types,
chemotherapeutic drugs can be delivered in a specific manner with the optimal particle and corresponding conjugates.
Further, and most significantly, the rupture force measurements will reveal whether or not targeted nanoparticles can
overcome the force of blood attempting to pull the particle from designated cells. Our preliminary study revealed that the
binding between PLGA-NPs and prostate cancer cells is enhanced by coating with folic acid or R11 peptides. These
conjugates increase the force required to detach the particle thus allowing particles to overcome drag force of the blood
in prostate capillary systems.