The Construction And Application Of Multifunctional Tumor Theranostic Nanoplatform Via Hyaluronic Acid-Based Self-Assembly

Traditional nano drug delivery systems（NDDSs）often lead to large individual differences in therapeutic effects due to tumor heterogeneity.Multifunctional theranostic nanoplatforms（MFNTPs）integrated of specific targeting,tumor microenvironment response,multi-drug synergy,combined imaging and novel photothermal/photodynamic therapy functions can improve the therapeutic effectiveness and achieve precise diagnosis and treatment.Hyaluronic acid（HA）,a natural polysaccharide,not only has the excellent biocompatibility and biodegradability,but also has the tumor targeting ability which endows the HA-based NDDSs self-targeting capability.Herein,we report two HA-based MFNTPs which integrated targeting,imaging,stimulus responsiveness and multimodal therapy functions via the designed functional groups and supramolecular assembly strategy.The main content can be divided into the following three parts:In the first part,histidine（His）was firstly grafted onto HA to form HA-His by amidation reaction.Subsequently a multifunctional nanogel（HANG）with targeting,imaging and stimulus response functions was prepared via one-step self-assembly strategy by employing magnetic resonance imaging（MRI）agent Mn²⁺as a reversible crosslinker via interaction with imidazole and carboxyl group in HA-His.The p H/GSH responsiveness,Mn²⁺-mediated MRI capability,biocompatibility and tumor targeting ability of HANG were fully characterized.The drug release curve suggested the p H/GSH responsiveness of the nanogels.T₁-weighted MR imaging was achieved under a 7T magnetic field,with longitudinal relativity coefficient（r₁）calculated to be 10.4 m M^-1s^-1.Negligible cytotoxicity of HANG was observed both for CD44-overexpressed B16 melanoma cells and L02 healthy liver cells.The CD44 overexpressed B16 cell targeting capability was verified at cellular level.Therefore,the MFNTPs constructed by drug loaded HANG have great potential to achieve efficient tumor diagnosis and treatment.In the second part,the prepared HANG was used to simultaneously load the chemotherapeutic drug doxorubicin（DOX）and the photosensitizer chlorin e6（Ce6）to construct a multifunctional drug-loaded theranostic nanoplatform ^Ce6HANG/DOX.The tumor-targeting capability,MRI capability and the combined chemotherapy and photodynamic therapy were fully characterized by using B16melanoma tumor model.The constructed MFNTPs exhibited the active targeting ability and the MRI capability in vivo,which improved the accumulation of free drugs at the tumor site and reduced the cardiotoxicity of DOX.The combined chemo-photodynamic therapy efficiently suppressed B16tumor growth in vivo,with the inhibition rate of 89.2%.The prepared MFNTPs exhibited great clinical transformation potential due to non-extra toxicity reagents used during fabrication process.In the third part,a multifunctional nanoplatform（NGH）composed of HA and nanographene oxide（NGO）was prepared by using the host-guest assembly strategy.Meanwhile,MFNTPs(ACNGH^OX)were constructed by co-loading Ce6 and hypoxia responsiveness prodrug AQ4N viaπ-πstacking and non-aromatic drug oxaliplatin OX via host-guest interaction.The versatility and tumor therapeutic effect were well studied.The modification of HA was found to increase the solvent storage stability of NGO and endowed NGO with CD44 overexpressed B16 cell targeting capability.The loaded drugs exhibited a photothermal release manner under 808 nm laser irradiation.The activation of Ce6photodynamic therapy enhanced tumor hypoxia,resulted in the transformation of nontoxic prodrug AQ4N into toxic AQ4.The combined chemo-photothermal-photodynamic therapy efficiently induced B16 cell death in vitro,with the Cell viability decreased to 13.6%.Near-infrared thermal imaging was achieved at the tumor site of B16 mice upon 808 nm irradiation.ACNGH^OX will become a novel supramolecular inorganic/organic hybrid multifunctional theranostic nanoplatform.