Tumor tissues are composed of tumor cells and complicate microenvironment. Tumor associated macrophages (TAMs) as an important component in tumor microenvironment, play fundamental roles in tumor progression, metastasis and microenvironment regulation. Recently, studies have found that nanotechnology, as an emerging platform, provides unique potential for cancer imaging and therapy. With the nanotechnology, TAMs imaging presents direct evidence for cancer development, progression, and the effectiveness of cancer treatments; it also can regulate the immunosuppression of tumor microenvironment and improve therapeutic efficiency through TAMs targeted killing or phenotypic transformation. In this article, we illustrate the function of TAMs and review the latest development in nano-carriers and their applications in tumor associated macrophage targeting cancer imaging and therapy.

To design and synthesize photosensitizers with different substituents and to identify its physicochemical characteritics and photodynamic effect on cancer cells.Two kinds of BODIPY photosensitizers BPOI and BPCI were synthesized through condensation reaction between aldehyde and reactive hydrogen of pyrrole, followed with electrophilic substitution reaction. Physicochemical properties were characterized byH NMR, FT-IR and UV-visible absorption spectra and fluorescence emission spectra. The ability to produce reactive oxygen species was detected by BPDF and DCFH-DA. Photodynamic therapy effect on rat glioma C6 cellswas determined by MTT method.Two kinds of BODIPY photosensitizers BPOI and BPCI were successfully synthesized with different substituents, which were confirmed byH NMR, FT-IR. Both materials had low toxicity and could be readily taken up by tumor cells. The ability of synthesized photosensitizers to produce reactive oxygen species was strongly influenced by solvent polarity when the substituent was electron-donating group, while no effect was found when the substituent was electron-withdrawing group.Photosensitizer BPOI with electron-donating substituent produces reactive oxygen species with a slow rate in a highly polar environment, while greatly enhanced this effect in a low polarity environment, which is expected to be used for environmental-selective photodynamic therapy in tumor cells.