Construction Of Degradable Mesoporous Carbon-silica-based Nanoparticles For Bioapplication

Phototherapy,typically implemented in the forms of photothermal therapy(PTT)and photodynamic therapy(PDT),is a promising strategy for cancer therapy owing to its noninvasiveness and high selectivity.Many nanomaterials have been currently reported for dual-modality PTT and PDT.Among them,carbon nanomaterials have flourished for cancer therapy for decades due to their easy fabrication and high photothermal conversion efficiency.However,their practical applications on clinical bases still pose a challenge to address the dilemma of metabolism in vivo.Herein,we successfully designed and synthesized an enzyme-free degradable carbon-silica nanocomposite(denoted as CSN)based on the three-dimensional dendritic biodegradable mesoporous silica nanoparticle(MSN),which has specific advantages as follows:(1)CSN can be degraded into small nanoparticles of?5 nm in 16 days in both simulated body fluid(SBF)and simulated lysosomal fluid(SLF)after NIR light irradiation without the participation of enzymes.(2)CSN alone has photothermal/photodynamic performance,as well as photoacoustic(PA)imaging ability for imaging-guided dual-mode phototherapy to improve the therapeutic effect.(3)The intrinsic immunoadjuvant property of CSN can mature DCs and induce the generation of tumor-associated antigens after combination with NIR light to provoke the subsequent antitumor immune response in no need of additional exogenous antigen.Besides the cell line-derived xenograft model(4T1 tumor model),patient-derived xenograft(PDX)model as a more clinically relevant tumor model,was also established to assess the in vivo therapeutic effect of CSN.And tumor inhibition efficiencies of CSN were 93.2%in 4T1 tumor model and 92.5%in PDX tumor model,respectively.We believe this strategy would develop the way for the design of biodegradable nanomaterials and facilitate the further clinical translation of carbon-silica-based nanomaterials with immunoadjuvant property.