RESEARCH ARTICLE

Cellular uptake and distribution of black phosphorus nanosheets in A549 cells: Effects on cellular metabolism and mitochondrial function

¹ State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Chemistry and Biomedicine Innovation Center, Nanjing University, Nanjing 210093, China
² Nanjing Qixia District Hospital, Nanjing 210033, China
³ School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
⁴ SCIEX, Analytical Instrument Trading Co., Ltd., Shanghai 201100, China

^* Corresponding author (email: lmao@nju.edu.cn)

Received: 21 June 2025
Revised: 17 August 2025
Accepted: 4 September 2025

Abstract

Black phosphorus nanosheets (BPNSs) show great potential in medical applications; however, their intracellular behavior and toxic effects should not be ignored once they are introduced into the human body. Fluorescence labeling technology was utilized to visualize their uptake and distribution in A549 (human non-small cell lung cancer cells) cells, and the influence of their sizes was also investigated. This study reveals that small-sized BPNS (SBPNS) and large-sized BPNS (LBPNS) enter cells through macropinocytosis and caveolae-dependent endocytosis, respectively. Moreover, BPNS were found to localize in lysosomes (4.17 ± 0.69 μg), the Golgi apparatus (7.65 ± 1.20 μg), and mitochondria (37.20 ± 7.10 μg). Next, the transfer of BPNS to mitochondria causes mitochondrial dysfunction and metabolic disorders, as evidenced by decreased Ca²⁺ levels, decreased mitochondrial membrane potential, cell cycle arrest in S and G2/M phases, and increased ROS (reactive oxygen species) levels. The above conclusions provide important basic data to promote the application of BPNS in biomedical fields.