Facile Fabrication of Dual-Activatable Gastrointestinal-Based Nanocarriers for Safe Delivery and Controlled Release of Methotrexate.

Colon cancer is emerging as one of the most common cancers worldwide, ranking in the top three in morbidity and mortality. Oral methotrexate (MTX) has been employed as a first-line treatment for various cancers, such as colon, breast, and lung cancer. However, the complexity and particularity of the gastrointestinal microenvironment and the limitations of MTX itself, including severe adverse effects and instability, are the main obstacles to the safe delivery of MTX to colon tumor sites. Herein, an innovative oral administrated anticancer therapeutic MTX@Am7CD/SDS NPs equipped with both pH and temperature sensitivity, which could effectively prevent MTX@Am7CD/SDS NPs from being degraded in the acidic environment mimicking the stomach and small intestine, thus harboring the potential to accumulate at the site of colon lesions and further release intestinal drug under mild conditions. In cellular assays, compared with free MTX, MTX@Am7CD/SDS NPs showed a favorable tumor inhibition effect on three tumor cell lines, as well as excellent cell uptake and apoptosis-inducing effect on SW480 cells. Therefore, this work provides a feasible solution for the safe use of MTX in the treatment of colon cancer and even other intestinal diseases.

pH-Activatable Charge-Reversal Polymer-Based Nanocarriers for Targeted Delivery of Antihepatoma Compound.

Chemotherapy is one of the available cancer treatments which has been successfully employed to prolong the survival of cancer patients. However, it remains a major challenge to develop effective chemotherapeutic agents by reducing off-target toxicity, improving bioavailability, and effectively prolonging blood circulation. The pH profile of tumor cells is abnormal to that of normal cells, making it a potential breakthrough for designing effective chemotherapeutic drug agents. Here, the pH-activatable charge-reversal supramolecular nanocarriers, named MI7-ß-CD/SA NPs, were prepared through a simple and "green" constructive process. MI7-ß-CD/SA NPs possess both pH-induced charge-reversal and disassembly properties that were exploited to investigate the loading, delivery, and pH-responsive controlled release of the antitumor compound celastrol (CSL). CSL@MI7-ß-CD/SA NPs displayed low hemolysis, good biocompatibility, and targeted uptake. Furthermore, CSL@MI7-ß-CD/SA NPs exhibited superior apoptosis rates against SMMC-7721 cell lines compared with CSL, when CSL@MI7-ß-CD/SA NPs and CSL were administered at a mass concentration of 5.0 µg/mL, i.e., the CSL content in CSL@MI7-ß-CD/SA NPs was relatively lower than that of intact CSL. We expected that MI7-ß-CD/SA NPs featuring pH-triggered charge reversal could offer a promising controlled release strategy that would then facilitate the clinical conversion of antitumor drugs.

A Supramolecular Nanovehicle Featuring a pH/Enzyme Co-Response for Targeted Delivery of the Antitumor Compound.

Triptolide (TPL) has gained much attention as an antitumor compound with potential applications. However, TPL suffers from low bioavailability, severe toxic side effects, and limited targeted uptake by tumor cells, thus restricting the conversion of its clinical application. Here, a supramolecular nanovehicle, named TSCD/MCC NPs, featuring pH/AChE co-response was designed and prepared for loading, delivery, and targeted release of TPL. The cumulative release rate of TPL from TPL@TSCD/MCC NPs reached ∼90 % within 60 h at pH 5.0 and AChE co-stimulation. Bhaskar model is used to study TPL release procedure. In cell experiments, TPL@TSCD/MCC NPs showed high toxicity to the four tumor cells lines A549, HL-60, MCF-7, and SW480, and favorable biosafety to normal cells BEAS-2B. Furthermore, TPL@TSCD/MCC NPs containing relatively small amounts of TPL presented similar apoptosis rates to those of intrinsic TPL. We anticipate that TPL@TSCD/MCC NPs may facilitate the conversion of TPL into clinical applications through further studies.

Hyaluronidase-trigger nanocarriers for targeted delivery of anti-liver cancer compound.

Chemotherapy is recognized as one of the significant treatment methods for liver cancer. The compound celastrol (CSL) could effectively inhibit the proliferation, migration, and invasion of liver cancer cells, which is regarded as a promising candidate to become a mainstream anti-liver cancer drug. However, the application of CSL in liver cancer chemotherapy is limited due to its systemic toxicity, poor water solubility, multidrug resistance, premature degradation, and lack of tumor targeting. Meanwhile, in order to comply with the current concept of precision medicine, precisely targeted delivery of the anti-liver compound CSL was desired. This paper takes into account that liver cancer cells were equipped with hyaluronic acid (HA) receptors (CD44) on their surface and overexpressed. Hyaluronidase (HAase) capable of degrading HA, HAase-responsive nanocarriers (NCs), named HA/(MI)7-ß-CD NCs, were prepared based on the electrostatic interaction between HA and imidazole moieties modified ß-cyclodextrin (MI)7-ß-CD. HA/(MI)7-ß-CD NCs showed disassembly properties under HAase stimuli, which was utilized to trap, deliver, and the controllable release of the anti-liver cancer compound CSL. Furthermore, cytotoxicity assay experiments revealed that CSL-trapped HA/(MI)7-ß-CD NCs not only reduced cytotoxicity for normal cells but also effectively inhibited the survival for five tumor cells, and even the apoptotic effect of CSL-trapped NCs with a concentration of 5 µg mL-1 on tumor cells (SMMC-7721) was consistent with free CSL. Cell uptake experiments demonstrated HA/(MI)7-ß-CD NCs possessed the capability of targeted drug delivery to cancerous cells. HA/(MI)7-ß-CD NCs exhibited site-specific and controllable release performance, which is anticipated to proceed further in precision-targeted drug delivery systems.