Efficient Recovery of Rare Earth Elements from Acidic Wastewater by a Green ß-CDs-Functionalized Nanosponge.

The recovery of rare earth elements (REEs) from acidic wastewater is crucial to sustainable development, industrial processes, and human health. In this research, ß-cyclodextrin-based nanosponges (ß-CD/PVA-SA NSs) have been proposed as potential adsorbents for europium (Eu), dysprosium (Dy), and gadolinium (Gd) recovery. The nanosponges are synthesized by cross-linking ß-cyclodextrin (ß-CD) functionalized polyvinyl alcohol (PVA) and sodium alginate (SA). Experimental results indicate that ß-CD/PVA-SA NSs exhibit favorable selectivity for Eu, Dy, and Gd, with the maximum adsorption capacity of 222, 217, and 204 mg/g, respectively, in addition to stability and cyclicity. ß-CD/PVA-SA NSs maintain selective adsorption effects towards RE ions that are present in acidic mine drainage (AMD), thereby highlighting their potential for practical applications. Furthermore, density functional theory (DFT) simulations have unveiled the fundamental interactions between the functional groups anchored in ß-CD/PVA-SA NSs and the REEs, providing vital insights into their adsorption mechanism. Hence, the utilization of ß-CD/PVA-SA NSs has the potential to advance initiatives in remediating acidic water pollution and facilitating the sustainable recycling of RE resources.

Enzyme-activated binary assembly for targeted, controlled delivery of anti-liver cancer compounds.

Liver cancer is the third leading cause of cancer deaths globally. The use of Hydroxycamptothecin (HCPT) as a first-line chemotherapeutic agent for liver, lung, and gastric cancers is often hampered by its low activity, limited targeting, and poor water solubility. This results in a low accumulation of HCPT in tumor cells, as well as the inability to maintain continuous treatment. Consequently, there is an urgent need to develop an accessory method that can enhance the therapeutic efficacy of HCPT while exhibiting good biocompatibility and targeted delivery ability. To address this critical issue, an enzyme-triggered supramolecular nanocarrier, refer as SCD/LCC SNCs, has been successfully developed, leveraging the aggregation of the negatively charged sulfate-modified ß-CDs and positively charged lauroylcholine chloride (LCC). This nanocarrier demonstrates acetylcholinesterase (LCC) triggered decomposition behavior, making it a promising drug carrier for HCPT. The cellular assays conducted have demonstrated that HCPT loaded into these SCD/LCC SNCs exhibit reduced cytotoxicity towards normal cells while maintaining robust tumor inhibitory activity and inducing apoptosis. Therefore, this study offers a promising strategy for the effective use of HCPT in the treatment of liver cancer.

Reactive oxygen species responsive chitooligosaccharides based nanoplatform for sonodynamic therapy in mammary cancer.

Sonodynamic therapy (SDT) has been extensively studied as a new type of non-invasive treatment for mammary cancer. However, the poor water solubility and defective biocompatibility of sonosensitizers during SDT hinder the sonodynamic efficacy. Herein, a nanoplatform has been developed to achieve high efficient SDT against mammary cancer through the host-guest interaction of ß-cyclodextrin/5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin (ß-CD-TPP) and ferrocenecarboxylic acid/chitooligosaccharides (FC-COS). Moreover, the glucose oxidase (GOx) was loaded through electrostatic adsorption, which efficiently restricts the energy supply in tumor tissues, thus enhancing the therapeutic efficacy of SDT for tumors. Under optimal conditions, the entire system exhibited favorable water solubility, suitable particle size and viable biocompatibility. This facilitated the integration of the characteristics of starvation therapy and sonodynamic therapy, resulting in efficient inhibition of tumor growth with minimal side effects in vivo. This work may provide new insights into the application of natural oligosaccharides for construct multifunctional nanocarrier systems, which could optimize the design and development of sonodynamic therapy strategies and even combination therapy strategies.

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.

Codelivery of High-Molecular-Weight Poly-porphyrins and HIF-1α Inhibitors for In Vivo Synergistic Anticancer Therapy.

Photodynamic therapy (PDT) is showing great potential in the treatment of cancer diseases, and photosensitizers play crucial roles in absorbing the energy of light and generating reactive oxygen species (ROS) during PDT. Most of the photosensitizers bearing macrocyclic structures have strong hydrophobicity and suffer from the π-π interaction and undesired aggregation caused quenching (ACQ), which severely limit the PDT efficacy. Moreover, the continuous oxygen consumption during PDT also leads to the upregulated expression of hypoxia-inducible factor-1α (HIF-1α), which can aggravate the growth of tumors. To overcome the abovementioned problems, polymerized photosensitizers repelled by flexible thioketal linkers were designed and synthesized using a multicomponent polymerization (MCP) method to afford the poly-porphyrins with high molecular weight (Mw > 20 000 g/mol) under room temperature. The ACQ effect could be significantly inhibited by introducing flexible chains and increasing Mw, leading to the improvement in the singlet oxygen quantum yield and phototoxicity simultaneously. An HIF-1α inhibitor, Lificiguat (YC-1) was synthesized as a chemodrug and codelivered with poly-porphyrins to decrease the expression of HIF-1α and inhibit tumor growth under hypoxia. With the synergistic PDT and chemotherapy, poly-porphyrin/YC-1 micelles showed excellent therapeutic antitumor efficacy both in vitro and in vivo.

Copper-catalyzed tandem annulation/enol nucleophilic addition to access multisubstituted indoles.

A method to access various multisubstituted indoles from propargylic alcohols and readily available enol nucleophiles by copper-catalyzed tandem annulation/enol nucleophilic addition has been developed. Compared to the expensive metal catalysts such as platinum, gold, silver, and palladium used previously, the most economical copper(i) catalyst could achieve this reaction efficiently. The fused heterocyclic compounds, pyrrolo[1,2-a] indoles, could be afforded by further transformation of the products. The allyl cation intermediate may be involved in the mechanism.