Black phosphrous quantum dot (BPQD)-loaded erythrocyte membrane vesicles for phothothermal therapy in breast cancer

Objective To investigate the method of preparing black phosphrous quantum dot (BPQD)-loaded erythrocyte membrane nanovesicles (BPQD-EMNVs), and to study its efficiency in photothermal therapy for breast cancer. Methods Fresh red blood cells (RBCs) of healthy mice were extracted to prepare erythrocyte membrane, and BPQD-EMNVs were prepared by sonication method. The morphology of BPQD-EMNVs was observed by a transmission electron microscopy. The particle size distribution was measured by a nano-particle size and Zeta potential meter. The encapsulation efficiency of BPQD was determined by inductively coupled plasma emission spectrometry. The uptake rate of BPQD-EMNVs was observed by a laser scanning confocal microscope. 4T1 tumor-bearing Balb/c mice were randomly divided into PBS, EMNVs, BPQD and BPQD-EMNVs groups, and the tumor sites were irradiated with 808 nm near-infrared light for 10 min after 4 hours of tail vein injection. The growth of the tumors was continually observed. Results The prepared BPQD-EMNVs have a regular spherical shape with an average particle diameter of 228 nm and an encapsulation efficiency of about 47%. Cellular uptake in vitro experiments showed that BPQD-EMNVs were rapidly taken up by 4T1 tumor cells. The results of animal in vivo experiments showed that BPQD-EMNVs had the highest enrichment after 4 h of injection at the tumor site, and BPQD-EMNVs could effectively kill tumor tissues after 10 min of 808 nm near-infrared light irradiation. Conclusions The BPQD-EMNVs are easy to prepare, and the prepared nanovesicles have good biocompatibility and photothermiotherapy effect, which is expected to be a promising method for breast cancer therapy. Key words: Erythrocyte membrane; Breast cancer; Black phosphorous quantum dot; Nanovesicles; Photothermal therapy