Preparation of pyrenyl-based multifunctional nanocomposites for biomedical applications.

Nanocomposites are widely used to obtain an accurate diagnosis of, and to provide effective therapy for, a number of diseases, because they can be easily formulated by introducing therapeutic agents (e.g., drugs and genes) and imaging agents (e.g., magnetic nanocrystals). Furthermore, nanocomposites can be developed as all-in-one systems, which enable cancer diagnosis and therapy, as well as the simultaneous monitoring of drug behavior. In this protocol, we describe the synthesis of four pyrenyl-based polymers (pyrenyl polyethylene glycol (Py-PEG), pyrenyl dextran (Py-DEX), pyrenyl hyaluronan (Py-HA) and pyrenyl-conjugated heterofunctional PEG (pyrenyl PEG)) and their subsequent use in the preparation of multifunctional nanocomposites for different applications including multimodal imaging, targeted cancer detection and pH-sensitive drug delivery. Notably, these nanocomposites can be used to simultaneously perform multiple tasks--for example, delivering magnetic particles for early cancer detection by MRI, efficient cataloging of patient groups for personalized therapy and real-time monitoring of disease progress. Starting from the synthesis of pyrenyl-based polymers, this protocol can be completed in ∼15 d.