Fabrication of multifunctional core-shell structured nanocarriers for chemo-photothermal therapy of breast cancer
Black titanium dioxide(BT)was first obtained by the hydrogenation and reduction of white titanium dioxide(TiO2),then a core-shell structured nanocomposite(BT@M)consisting of BT core and degradable mesoporous organosilica(MON)shell containing bisulfide bonds was prepared as redox-responsive drug delivery nanocarriers.Subsequently,chemotherapeutic drug doxorubicin hydrochloride(DOX·HCl)was loaded in the mesoporous BT@M,followed by introducing the pH-responsive polydopamine(PDA)coating to the surface as a"nanovalve",to fabricate a dual stimulus-responsive drug delivery nanosystem(BT@M/D-P)for tumor chemo-photothermal therapy.Transmission electron microscopy(TEM)images of BT@M nanoparticles exhibited a distinct core-shell structure with a size of about 100 nm.In a reductive environment containing 10 mmol·L-1 glutathione(GSH),BT@M nanoparticles underwent the redox-triggered decomposition of the outer mesoporous organosilica shell,due to the breakage of disulfide bonds in the organosilica framework.Furthermore,BT@M/D-P displayed pH/redox dual stimuli-responsive drug release in simulated tumor microenvironment and physiological environments.Under 808 nm laser illumination,BT@M exhibited excellent photothermal stability and high photothermal conversion efficiency up to 35.5%.Under specific-wavelength light irradiation,BT@M/D-P exerted significantly higher toxicity against tumor cells than normal cells,via effective combination of conventional chemotherapy and photothermal therapy which"heated up"tumor cells.Compared with chemotherapy or photothermal therapy alone,the nanocomplex-based drug delivery system displayed combined chemo-photothermal therapeutic effects for breast cancer cells.Meanwhile,BT@M/D-P nanoparticles did not induce hemolysis at the concentration range of 50-200 µg‧mL-1,suggesting good blood compatibility.
black titanium dioxidedegradable mesoporous organosilicacontrolled drug releasechemo-photothermal combination therapy
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