Self-targeting visualizable hyaluronate nanogel for synchronized intracellular release of doxorubicin and cisplatin in combating multidrug-resistant breast cancer

Multidrug-resistance(MDR)featuring complicated and poorly defined mechanisms is a major obstacle to the success of cancer chemotherapy in the clinic.Compound nanoparticles comprising multiple cytostatics with different mechanisms of action are commonly developed to tackle the multifaceted nature of clinical MDR.However,the different pharmacokinetics and release profiles of various drugs result in inconsistent drug internalization and suboptimal drug synergy at the tumor sites.In the present study,a type of self-targeting hyaluronate(HA)nanogels((CDDPH)^ANG/DOX)to reverse drug resistance through the synchronized pharmacokinetics,intratumoral distribution,and intracellular release of topoisomerase II inhibitor doxorubicin(DOX)and DNA-crosslinking agent cisplatin(CDDP)is developed.With prolonged circulation time and enhanced intratumoral accumulation in vivo,(CDDP)^HANG/DOX shows efficient drug delivery into the drug-resistant MCF-7/ADR breast cancer cells and enhanced antitumor activity.Besides,fluorescence imaging of DOX combined with the micro-computed tomography(micro-CT)imaging of CDDP facilitates the visualization of this combination tumor chemotherapy.With visualizable synchronized drug delivery,the self-targeting in situ crosslinked nanoplatform may hold good potential in future clinical therapy of advanced cancers.

Tumor acid microenvironment-activated self-targeting&splitting gold nanoassembly for tumor chemo-radiotherapy

Low accumulation and penetration of nanomedicines in tumor severely reduce therapeutic efficacy.Herein,a pH-responsive gold nanoassembly is designed to overcome these problems.Polyethylene glycol linked raltitrexed(RTX,target ligand and chemotherapy drug)and two tertiary amine molecules(1-(2-aminoethyl)pyrrolidine and N,N-dibutylethylenediamine)are modified on the surface of the 6-nm gold nanoparticles by lipoic acid to form gold nanoassembly defined as Au-NNP(RTX).The Au-NNP(RTX)nanoassembly could remain at about 160 nm at the blood circulation(pH 7.4),while split into 6-nm gold nanoparticles due to tertiary amine protonation at tumor extracellular pH(pH 6.8).This pH-responsive disassembly behavior endows Au-NNP(RTX)better tumor tissue permeability through the better diffusion brought by the size reduction.Meanwhile,after disassembly,more RTXs on the surface of gold nanoparticles are exposed from the shielded state of assembly along with 2.25-fold augment of cellular uptake capability.Most importantly,the results show that Au-NNP(RTX)possesses of high tumor accumulation and effective tumor penetration,thereby enhancing the tumor chemo-radiotherapy efficiency.