Blood Circulation, Biodistribution, and Pharmacokinetics of Dextran-Modified Black Phosphorus Nanoparticles

Black phosphorus (BP) nanostructures have been receiving enormous attention in diverse bioapplications owing to their unique physicochemical properties. However, it is still challenging to investigate their blood circulation, biodistribution, and pharmacokinetics after administration due to the difficulty in quantifying them. Here, we report the quantification of blood circulation, biodistribution, and pharmacokinetics of dextran-modified BP nanoparticles (i.e., BP-DEX NPs) in balb/c mice through the highly sensitive noninvasive photoacoustic (PA) imaging and single-emission computed tomography/computed tomography (SPECT/CT) imaging. We first prepare water-soluble and biocompatible small BP-DEX NPs and label them with radioisotopes 99mTc. We then quantify their half-lives of distribution and elimination phases to be 0.2 and 9.5 h by counting the γ-emissions in the blood of mice administrated with BP-DEX NPs. We also show the dynamic variation of BP-DEX NPs in the tumor, liver, spleen, and kidney through i...