A multifunctional albumin/superparamagnetic iron oxide nanoparticle (SPIO) nanocomplex system to deliver IR780, a photothermal agent, for cancer theranostic applications was proposed in this study. Single emulsion method was utilized to fabricate the human albumin/IR780/SPIO (HISP) nanocomplexes with a hydrophobic core (SPIO and IR780) and a hydrophilic shell (human serum albumin (HSA) and poly (ethylene glycol) (PEG)). Effects of PEGylation on the size and surface potential of nanocomplexes were analyzed. Nanospheres containing uniformly dispersed SPIO was observed using Transmission Electron Microscopy (TEM) imaging. As a potential magnetic resonance (MR) imaging agent, the HISP displayed dose-dependent T2-weighted imaging contrast (R2 = 81.6 mM-1s-1). Good colloidal stability was verified from the nanocomplexes under difference circumstances. The nanocomplexes were taken up by cancer cells efficiently and led to significant photothermal-mediated cancer cell death upon short-term near infrared (NIR) irradiation in vitro. Via intravenous injection, PEG-HISP can efficiently deliver IR780 to tumor sites and showed strong photothermal effect compared to free drug on the mice model. Significant tumor suppression by the photothermal treatments using PEG-HISP was demonstrated from the mice CT26 xenograft model. Good safety profile of the PEG-HISP was confirmed from histological examination and liver functional analysis. Taken together, the results suggest that PEG-HISP is a safe and robust nano-theranostic platform for advanced anti-cancer treatment.
Keywords: IR780; colon cancers; magnetic resonance imaging; photothermal therapy; superparamagnetic iron oxide nanoparticles.