2.5 VLP-GOx surface functionalization
The VLP-GOx nanoreactors were prepared by functionalizing their surface to improve their affinity to breast cancer cells. Hence, the outer surface of the VLP-GOx nanocages was covered with human serum albumin (HSA) protein. First, the HSA was activated with reduced glutathione as reported by Chauhan, et al, 2020. Second, the VLP-GOx nanoreactors (synthesized at 1:3 molar ratio) and reduced HSA were mixed at 1:8 VLP:HSA w/w ratio and stirred overnight at 4°C for the coating reaction. Next, the HSA functionalized nanoreactors were centrifuged at 40,000 rpm, 4°C for 2 h. After centrifugation, the supernatant was discarded and a pellet containing the HSA functionalized VLP-GOx nanoreactors (VLP-GOx@HSA) was resuspended in the assembly buffer. Finally, the VLP-GOx@HSA suspension was purified by HPLC to get rid of free-HAS and aberrant capsids.