As an example, a microfluid system consisting of PDMS was used to grow multicellular tumor spheroids to evaluate the PTT performance of hollow Au nanoshells modified with an anti-MUC1 aptamer (HGNs@anti-MUC1) (Fig. 4A1–A3).272 Human lung epithelial carcinoma cells (A549) and human breast adenocarcinoma cells (MCF-7) were used to assemble the tumor spheroids. Here, MUC1 is linked to breast adenocarcinoma.