Biodegradable Poly(amino Acid)-gold Nanoparticle For Multimodal Imaging-Guided Synergistic Chemo-photothermal Therapy

Gold nanoparticles serve as efficient agents for non-invasive photothermal therapy due to their unique surface plasmon resonance performance.However,their non-biodegradability has limited practical biomedical application.In this work,a biodegradable poly(amino acid)-gold nanoparticle for synergistic chemo-photothermal therapy was developed by a green and facile synthesis method.Monodisperse magnetic nanoparticles loaded with chemotherapeutic drugs were obtained in the aqueous phase by self-assembly with poly(?-glutamic acid)(y-PGA)and poly(L-arginine)(PA).And the near-infrared region-responsive gold nanoshell(170 nm)was obtained by in situ reduction on the surface of amino groups.By the precisely guiding of computed tomography(CT),photoacoustic tomography(PAT),and magnetic resonance(MRI)imaging,a synergistic chemo-photothermal therapy had been achieved.This nanoparticle has the follows attractive advantages:1)the guanidine groups in PA facilitate the endocytosis and lysosomal escape of nanoparticle in cancer cells,resulting from the formation of bidentate hydrogen bonds and electrostatic interaction with cell membrane constituents such as sulfate,phosphate,and carboxylate;2)under the stimulate/induce of near infrared(NIR),hot electron resonance driven by the surface plasmon of gold nanoshell destroyed the electrostatic interaction of the polyion complex,which leaded to the effective DOX release,presenting excellent synergistic chemo-photothermal therapy with an anti-tumor rate of 94%;3)the poly(amino acid)-gold nanoparticle was degraded into around 3 nm Au nanoparticle in 4 days in body fluid through poly(amino acid)complex destruction,providing a new method and approache for body clearance.In summary,we had designed a biodegradable multifunctional poly(amino acid)-gold nanoparticle by a green and simple method,which is believed to have an attractive application prospect in the clinical transformation of gold nanoparticles.