Polydopamine-coated i-motif DNA/Gold nanoplatforms for synergistic photothermal-chemotherapy

The combination of photothermal therapywith chemotherapy has gradually developed into promising cancer therapy.Here,a synergistic photothermal-chemotherapy nanoplatform based on polydopamine(PDA)-coated gold nanoparticles(AuNPs)were facilely achieved via the in situ polymerization of dopamine(DA)on the surface of AuNPs.This nanoplatform exhibited augmented photothermal conversion efficiency and enhanced colloidal stability in comparison with uncoated PDA shell AuNPs.The i-motif DNA nanostructure was assembled on PDA-coated AuNPs,which could be transformed into a C-quadruplex structure under an acidic environment,showing a characteristic pH response.The PDA shell served as a linker between the AuNPs and the i-motif DNA nanostructure.To enhance the specific cellular uptake,the AS1411 aptamer was introduced to the DNA nanostructure employed as a targeting ligand.In addition,Dox-loaded NPs(DAu@PDA-AS141)showed the pH/photothermal-responsive release of Dox.The photothermal effect of DAu@PDA-AS141 elicited excellent photothermal performance and efficient cancer cell inhibition under 808 nm near-infrared(NIR)irradiation.Overall,these results demonstrate that the DAu@PDA-AS141 nanoplatform shows great potential in synergistic photothermal-chemotherapy.

Molecularly engineered truncated tissue factor with therapeutic aptamers for tumor-targeted delivery and vascular infarction

Selective occlusion of tumor vasculature has proven to be an effective strategy for cancer therapy.Among vascular coagulation agents,the extracellular domain of coagulation-inducing protein tissue factor,truncated tissue factor(tTF),is the most widely used.Since the truncated protein exhibits no coagulation activity and is rapidly cleared in the circulation,free tTF cannot be used for cancer treatment on its own but must be combined with other moieties.We here developed a novel,tumor-specific tTF delivery system through coupling tTF with the DNA aptamer,AS1411,which selectively binds to nucleolin receptors overexpressing on the surface of tumor vascular endothelial cells and is specifically cytotoxic to target cells.Systemic administration of the tTF-AS1411 conjugates into tumor-bearing animals induced intravascular thrombosis solely in tumors,thus reducing tumor blood supply and inducing tumor necrosis without apparent side effects.This conjugate represents a uniquely attractive candidate for the clinical translation of vessel occlusion agent for cancer therapy.