Abstract: Objective To prepare semiconductor polymer nanoparticles (SPNs) for photoacoustic imaging. Methods SPNs was prepared by using poly(cyclopentadithiophene-alt-benzothiadiazole) according to nanoprecipitation method. The characteristics and biosecurity of the SPNs were assessed, and the photoacoustic imaging capability of SPNs was also evaluated in vivo. Results The mean size of SPNs was (61±3)nm, and its mean potential was (-38±2)mV. In vitro cytotoxicity test showed the reactive viability of Hela cell was not affected. The enhanced photoacoustic signal in vivo murine tumor model was achieved by using the SPNs under 680nm laser-activation. Conclusion The preliminary study developed a type of SPNs with small size, biosafety and stability. The stronger photoacoustic signals in murine tumor model were obtained by using the SPNs.

Key words: semiconducting polymer, nanoparticle, photoacoustic imaging