Optimizing the Penetration of Nanoparticles into Platelet-Rich Plasma and Whole Blood Clots
Mentor 1
Julie Oliver
Start Date
1-5-2020 12:00 AM
Description
Ischemic stroke patients have a limited number of treatment options available. The only FDA approved drug comes with a significant risk of bleeding complications. We are investigating an alternative treatment that specifically targets activated platelets in occlusive clots using fibrinogen-conjugated gold-coated magnetic nanoparticles for hyperthermia. Previous experiments showed that using silver enhancement (SE) screening methods allows us to rapidly assess differences in clot network and the degree of penetration of fibrinogen conjugated-gold nanoparticles (FGN-cAu18) into clots under light microscopy (LM). We also found that the penetration and concentration of the nanoparticles were limited to the outside of the clot that formed at high thrombin concentrations, especially in whole blood (WB) clots. The success of disrupting the clot require a significant number of nanoparticles localized deep inside occlusive clots. Thus, we hypothesize that increasing label concentration and incubation time will increase the depth of penetration and concentration of nanoparticles into clots. We examined this using an in vitro model in which platelet-rich plasma (PRP) and WB were clotted using a high thrombin concentration followed by soaking in low or high FGN-cAu18 concentration for 15 or 60 minutes. Frozen cross-sections were treated with SE and analyzed by LM. As expected, both short time incubation and low concentration of FGN-cAu18 result in low label concentration and penetration inside clots. By increasing FGN-cAu18 concentration and incubation time, penetration and concentration of nanoparticles improves significantly in PRP clot, but slightly in WB clot. These results suggest that multiple applications of nanoparticles may be necessary for a targeted nanoparticle therapy for ischemic stroke.
Optimizing the Penetration of Nanoparticles into Platelet-Rich Plasma and Whole Blood Clots
Ischemic stroke patients have a limited number of treatment options available. The only FDA approved drug comes with a significant risk of bleeding complications. We are investigating an alternative treatment that specifically targets activated platelets in occlusive clots using fibrinogen-conjugated gold-coated magnetic nanoparticles for hyperthermia. Previous experiments showed that using silver enhancement (SE) screening methods allows us to rapidly assess differences in clot network and the degree of penetration of fibrinogen conjugated-gold nanoparticles (FGN-cAu18) into clots under light microscopy (LM). We also found that the penetration and concentration of the nanoparticles were limited to the outside of the clot that formed at high thrombin concentrations, especially in whole blood (WB) clots. The success of disrupting the clot require a significant number of nanoparticles localized deep inside occlusive clots. Thus, we hypothesize that increasing label concentration and incubation time will increase the depth of penetration and concentration of nanoparticles into clots. We examined this using an in vitro model in which platelet-rich plasma (PRP) and WB were clotted using a high thrombin concentration followed by soaking in low or high FGN-cAu18 concentration for 15 or 60 minutes. Frozen cross-sections were treated with SE and analyzed by LM. As expected, both short time incubation and low concentration of FGN-cAu18 result in low label concentration and penetration inside clots. By increasing FGN-cAu18 concentration and incubation time, penetration and concentration of nanoparticles improves significantly in PRP clot, but slightly in WB clot. These results suggest that multiple applications of nanoparticles may be necessary for a targeted nanoparticle therapy for ischemic stroke.
