Understanding the Role of Scavenger Receptor A1 in Nanoparticle Uptake by Murine Macrophages: Version 2

Phagocytic cells take up nanoparticles via multiple routes, including phagocytosis and pinocytosis [1]. Nanoparticles with an anionic surface or made of anionic polymers are often phagocytosed via scavenger receptor A1 (SR-A1); multiple uptake routes may also be involved in the uptake of the same particle [2]. Understanding the route of nanoparticle uptake helps provide mechanistic insight into biological responses to and biodistribution of nanoparticles. The protocol described herein utilizes the murine macrophage cell line RAW 264.7 and its genetically engineered clone ½. The engineered cells were transduced with a lentivirus encoding SR-A1 specific siRNA; as the result, these cells do not express SR-A1 [2]. A decrease in the nanoparticle uptake by the SR-A1 deficient cells compared to the parent cells indicates the involvement of the SR-A1 pathway, as was verified using various models and inhibitors [2]. This protocol is intended for mechanistic studies.