Platelet Disguises Could Aid Drug Delivery

Abstract

The usual job of the blood cells known as platelets is stopping bleeding. They rush to sites of vascular injury and signal other platelets to join them in forming blood clots. But circulating tumor cells and bacterial invaders can hijack platelets to help them evade the body’s immune system. These other cells bind to proteins on the surfaces of the blood cells. Once the cells hitch a ride with the platelets, they attract less attention from the immune system. This may speed the spread of cancer. Platelets’ abilities to bind cells related to disease and evade immune responses have encouraged researchers to put platelets to work for a different use—drug delivery. Multiple research teams have recently shown that they can use membranes from platelets isolated from whole blood of humans and other species to disguise and target drug-containing silica or polymer particles. These platelet-mimicking particles could become a new type

Nano-Biomimetic Drug Delivery Vehicles: Potential Approaches for COVID-19 Treatment

“…The interaction between platelets and pathogens shields pathogens from an immune response by host organisms [120], and this challenge can be overcome by use of platelet-mimetic nanoparticle (PMNP) technology to treat infections. PMNP technology makes use of platelet membranes to disguise API-containing nanoparticles and decrease clearance of such particles, which would otherwise be regarded as antigenic [120].…”

“…The interaction between platelets and pathogens shields pathogens from an immune response by host organisms [120], and this challenge can be overcome by use of platelet-mimetic nanoparticle (PMNP) technology to treat infections. PMNP technology makes use of platelet membranes to disguise API-containing nanoparticles and decrease clearance of such particles, which would otherwise be regarded as antigenic [120]. API-containing silica or poly (lactic-co-glycolic acid) (PLGA) polymeric nanoparticles, incorporated into platelet membranes isolated from whole blood by centrifugation, are functionalized with a specific receptor for a target pathogen [120].…”

“…PMNP technology makes use of platelet membranes to disguise API-containing nanoparticles and decrease clearance of such particles, which would otherwise be regarded as antigenic [120]. API-containing silica or poly (lactic-co-glycolic acid) (PLGA) polymeric nanoparticles, incorporated into platelet membranes isolated from whole blood by centrifugation, are functionalized with a specific receptor for a target pathogen [120]. The target pathogen binds to the specific receptors on the platelet, and the API-containing composite enters the infecting virus and destroys it [120,121].…”

“…API-containing silica or poly (lactic-co-glycolic acid) (PLGA) polymeric nanoparticles, incorporated into platelet membranes isolated from whole blood by centrifugation, are functionalized with a specific receptor for a target pathogen [120]. The target pathogen binds to the specific receptors on the platelet, and the API-containing composite enters the infecting virus and destroys it [120,121]. Specific receptors can be attached to platelet mimetics to ensure death of pathogens [120], and this approach has been investigated for the treatment of cancer [122,123], bacterial infection [124], and vascular damage [125].…”

“…Surface modifiers and specific proteins, when added to nanoparticles, can improve recognition by target cells; however, if these do not match endogenous compounds, the result is removal of the nanoparticles via an immune response [123]. The use of a PMNP ensures longer residence time for the payload in-vivo, thereby enhancing therapeutic outcomes by providing a specific target for the platelet-binding pathogen, and by shielding the technology from destruction by macrophage phagocytosis due to the presence of specific membrane proteins [120,123]. The usual platelet induced inflammatory response is eliminated when using platelet membranes alone as opposed to whole platelets [126].…”