Copper sulfide-loaded microspheres for breast cancer theranostics

Objectives: ompared to conventional cancer treatment, combination therapy based on well-designed nanoscale platforms may offer an opportunity for eradication of tumors and reduce recurrence and metastasis. In this study, we prepared the multifunctional microspheres loading ¹³¹I-labeled hollow copper sulfide nanoparticles and paclitaxel (¹³¹I-HCuSNPs-MS-PTX) for imaging and therapeutics of orthopic W256/B breast tumor in rats. ¹⁸F-fluordeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) imaging detected that the expansion of the tumor volume was delayed (p < 0.05) following intra-tumoral (i.t.) injection with ¹³¹I-HCuSNPs-MS-PTX plus near-infrared (NIR) irradiation. The immunohistochemical analysis further confirmed the anti-tumor effect. The single photon emission computed tomography (SPECT)/photoacoustic imaging mediated by ¹³¹I-HCuSNPs-MS-PTX demonstrated that microspheres were mainly distributed in the tumors with a relatively low distribution in other organs. Our results revealed that ¹³¹I-HCuSNPs-MS-PTX offered combined photothermal, chemo- and radio-therapies, eliminating tumors at a relatively low dose, as well as SPECT/CT and photoacoustic imaging to monitor distribution of the injected agents non-invasively. The copper sulfide-loaded microspheres, ¹³¹I-HCuSNPs-MS-PTX, can serve as a versatile theranostic agent in breast cancer orthopic model. Key Words: Microspheres, Theranostics, Combination therapy, Single photon emission computed tomography/computed tomography (SPECT/CT), Photoacoustic imaging