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Combinatorial chemo-photodynamic therapy is regared as effective cancer therapy strategy, which could be realized via multiple nano-drug delivery system. Herein, novel high payload nanoparticles stabilized by amphiphilic block polymer cholesterol- b -poly(ethylene glycol) (PEG) 2000 (Chol-PEG 2000 ) were fabricated for loading chemotherapeutic drug 10-hydroxycamptothecin (HCPT) and photosensitizer chlorin e6 (Ce6). The obtained HCPT/Ce6 NPs showed uniform rod-like morphology with a hydration diameter of 178.9 ± 4.0 nm and excellent stability in aqueous solution. HCPT and Ce6 in the NPs displayed differential release profile, which was benefit for preferentially exerting the photodynamic effect and subsequently enhancing the sensitivity of the cells to HCPT. Under laser irradiation, the NPs demonstrated fantastic in vitro and in vivo anticancer efficiency due to combinational chemo-photodynamic therapy, enhanced cellular uptake effectiveness, and superb intracellular ROS productivity. Besides, the NPs were proved as absent of systemic toxicity. In summary, this nanoparticle delivery system could be hopefully utilized as effective cancer therapy strategy for synergistically exerting combined chemo-photodynamic therapy in clinic.

As one of the most promising drug delivery carriers, self-assembled DNA nanostructures are characterized of well-defined sizes, excellent biocompatibility, high drug loading and ability to control drug release. Studying the interactions between anticancer drugs and DNA nanostructures can help to associate microstructure-drug loading-release rate-therapeutic effect. Herein AS1411 aptamer-tethered DNA nanotrains (AS1411NTrs) were constructed and used as anthracyclines carrier with high payload for targeted delivery. The bindings of doxorubicin (DOX), epirubicin (EPI), and daunorubicin (DAU) to AS1411NTrs were investigated by isothermal titration calorimetry and fluorescence spectroscopy, and thermodynamic parameters were obtained. The high drug payload capacity of AS1411NTrs was verified by the large number of binding sites (~20). The binding mode was determined by differential scanning calorimetry and potassium iodide (KI) quenching experiments. The release experiment data showed that DNase I facilitated drug release and the release followed the first-order kinetic model. MTT cell viability assay demonstrated that the drug-loaded AS1411NTrs had significantly higher cytotoxicity against target HeLa cells than normal human liver L02 cells. These findings revealed that AS1411NTrs had high payload and targeted release capacity for DOX, EPI, and DAU. This result can provide a theoretical basis for constructing reasonable DNA nanostructures based on drug carriers., Competing Interests: Declaration of Competing Interest The authors declare no competing financial interests., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: The combination of chemo-photodynamic therapy based on nano-technology has emerged as a preferable and promising measure for synergetic antitumor therapy., Purpose: The aim of this study was expected to overcome most of the safety concerns from nano-carriers and improve the chemo-photodynamic synergistic antitumor efficacy., Methods: Herein, we reported a facile and effective approach based on the self-assembly of chemotherapeutic agent 10-hydroxycamptothecin (HCPT) and photosensitizer chlorin e6 (Ce6) for preparing stably dual-functional nanorods (NRs)., Results: The chemical thermodynamic parameters obtained from isothermal titration calorimeter (ITC) and the microcosmic configuration snapshots acquired by molecular dynamics (MD) simulations verified that HCPT and Ce6 molecules tended to assemble with each other through various intermolecular forces. The as-prepared HCPT/Ce6 NRs possessed a relatively uniform size of around 165 nm and zeta potential of about -29 mV, together with good stability in aqueous solution and freeze-dried state. In addition, both the extra- and intracellular reactive oxygen species (ROS) generation capacity of the NRs under laser irradiation was significantly enhanced compared with Ce6 injections. Moreover, the dual-functional HCPT/Ce6 NRs exhibited a substantial in vitro/in vivo synergistic antitumor efficacy under laser irradiation due to the integration of the two therapeutic modalities into one drug delivery system. Besides, no obvious hepatic or renal toxicity was observed in the NRs treatment groups., Conclusion: Taken together, HCPT/Ce6 NRs demonstrated a powerful efficacy in chemo-photodynamic therapy for breast cancer. Therefore, the carrier-free dual-functional NRs prepared in a facile and effective strategy might give inspiration for the development of combined antitumor therapy., Competing Interests: The authors declare no conflicts of interest in this study., (© 2019 Zhao et al.)

DNA nanostructures-based chemotherapy-phototherapy (CTPT) combination therapy can achieve targeted release and effectively overcome multidrug resistance (MDR). The therapeutic effect of CTPT combination drugs loaded in DNA nanostructures is related to the interactions among them. Herein, based on our previous research on AS1411NTrs loading with a single drug of DOX, the interactions between a single drug (toluidine blue O, TBO) or combination drugs (doxorubicin and toluidine blue O, DOX + TBO) and AS1411 aptamer-tethered DNA nanotrains (AS1411NTrs) were investigated. By fluorescence spectroscopy and isothermal titration calorimetry technique, the corresponding thermodynamic parameters were obtained, including the number of binding sites, binding constant, enthalpy change and entropy change. By combining with the differential scanning calorimetry and ferrocyanide ion quenching analysis, the binding mode-thermodynamic parameters were correlated. In addition, the effect of the binding affinity of DOX and TBO to AS1411NTrs on the drugs release rate was studied. Finally, the in vitro cytotoxicity and confocal laser scanning microscopy imaging of AS1411NTrs + TBO + DOX was investigated. The results showed that this drug delivery system could increase its in vitro cytotoxicity and overcome drug resistance in DOX-resistant human breast cancer cells (MCF-7/ADR). The work would provide important information for the combination therapy of DOX and TBO to overcome MDR effectively. Unlabelled Image • Doxorubicin (DOX) and toluidine blue O (TBO) were intercalated into DNA nanotrains. • The binding affinity of DOX with DNA nanotrains was stronger than that of TBO. • The addition order of DOX and TBO could affect the stability of DNA nanotrains. • Due to the stronger binding to DNA nanotrains, DOX released more slowly than TBO. • DOX + TBO combination drugs loaded in DNA nanotrains could overcome drug resistance. [ABSTRACT FROM AUTHOR]