Porphyrin-Implanted Carbon Nanodots for Photoacoustic Imaging and in Vivo Breast Cancer Ablation

The incorporation of intensive light absorbing porphyrins macrocycles with biocompatible nanoparticles would lead to new nanomaterials with multiple imaging and therapeutic modalities. Herein, a facile synthetic strategy has been applied to prepare porphyrin-implanted carbon nanodots (PNDs) by partial and selective pyrolysis of 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP) and citric acid (CA) at an appropriate temperature. As-prepared PNDs exhibit not only the excellent stability and biocompatibility characteristic of carbon nanodots but also the unique properties of porphyrin macrocycle such as strong UV-visible and near-infrared absorption, specifically, high photodynamic therapy efficiency. More importantly, the PNDs with near-infrared absorption could act as a contrast agent for photoacoustic molecular imaging with deep tissue penetration and fine spatial resolution. The Cetuximab-conjugated porphyrin-based carbon nanodots (C225-PNDs) have been further prepared to precisely target the cancer cells (HCC827 and MDA-MB-231 cells) with overexpression of EGFR, leading to highly efficient photodynamic therapy upon two-photo excitation at 800 nm. A complete ablation of tumor together with an enhanced photoacoustic contrast ability for C225-PNDs have been further validated in mice bearing MDA-MB-231 breast cancer.