Magnetic Supramolecular Nanofibers of Gold Nanorods for Photothermal Therapy

Recent Development of Supramolecular Cancer Theranostics Based on Cyclodextrins: A Review

With the development of personalized medical demands for precise diagnosis, rational management and effective cancer treatment, supramolecular theranostic systems have received widespread attention due to their reversibly switchable structures, sensitive response to biological stimuli and integration ability for multiple capabilities in a single platform with a programmable fashion. Cyclodextrins (CDs), benefiting from their excellent characteristics, such as non-toxicity, easy modification, unique host-guest properties, good biocompatibility, etc., as building blocks, serve as an all-purpose strategy for the fabrication of a supramolecular cancer theranostics nanodevice that is capable of biosafety, controllability, functionality and programmability. This review focuses on the supramolecular systems of CD-bioimaging probes, CD-drugs, CD-genes, CD-proteins, CD-photosensitizers and CD-photothermal agents as well as multicomponent cooperation systems with regards to building a nanodevice with functions of diagnosis and (or) therapeutics of cancer treatment. By introducing several state-of-the-art examples, emphasis will be placed on the design of various functional modules, the supramolecular interaction strategies under the fantastic topological structures and the hidden "bridge" between their structures and therapeutic efficacy, aiming for further comprehension of the important role of a cyclodextrin-based nanoplatform in advancing supramolecular cancer theranostics.

Cyclodextrin-Based Nanoplatforms for Tumor Phototherapy: An Update

Tumor phototherapies are light-mediated tumor treatment modalities, which usually refer to tumor photothermal therapy (PTT) and photodynamic therapy (PDT). Due to the outstanding spatial-temporal control over treatment through light irradiation, tumor phototherapies display extremely low side effects during treatment and are believed to be a tumor treatment method with a clinical translation potential. However, current tumor phototherapy nanoplatforms face obstacles, including light irradiation-induced skin burning, tumor hypoxia microenvironments, limited light penetration depth, et al. Therefore, one important research direction is developing a tumor phototherapy nanoplatform with multifunctionality and enhanced pharmacological effects to overcome the complexity of tumor treatment. On the other hand, cyclodextrins (CDs) are starch-originated circular oligosaccharides with negligible toxicity and have been used to form supermolecular nanostructures through a host–guest interaction between the inner cavity of CDs and functional biomolecules. In the past few years, numerous studies have focused on CD-based multifunctional tumor phototherapy nanoplatforms with an enhanced photoeffect, responsive morphological transformation, and elevated drug bioavailability. This review focuses on the preparation methods of CD-based tumor phototherapy nanoplatforms and their unique physiochemical properties for improving anti-tumor pharmacological efficacy.

Cyclodextrin-Activated Porphyrin Photosensitization for Boosting Self-Cleavable Drug Release

Supramolecular prodrugs that combine the merits of stimuli-responsiveness and targeting ability in a controllable manner have shown appealing prospects in disease diagnostics and therapeutics. Herein, we report that a new theranostic agent with the host-guest-binding-activated photosensitization has been fabricated by a binary supramolecular assembly consisting of the permethyl-β-cyclodextrin-grafted hyaluronic acid and a combretastatin A-4-appended porphyrin derivative. Illuminated by a red-light source, the production efficiency of singlet oxygen (¹O₂) pronouncedly increases by ∼60-fold once the porphyrin core is encapsulated by cyclodextrins. Consequently, the cell-selective fluorescence emission is dramatically enhanced, the microtubule-targeted drug is rapidly and completely released, and the ¹O₂-involved combinational treatment is simultaneously achieved both in vitro and in vivo. To be envisaged, this complexation-boosted light-activatable photosensitizing prodrug delivery system with improved photophysical performance and remarkable phototheranostic outcomes will make a significant contribution to the creation of more advanced stimulus-based biomaterials.

Polarization of Stem Cells Directed by Magnetic Field-Manipulated Supramolecular Polymeric Nanofibers

Precise assembly of the cytoskeleton (e.g., actin, tubulin, and intermediate filaments) is of great importance for stem cell polarization and tissue regeneration. Recently, artificial manipulation of cytoskeleton assembly for remodeling stem cell polarization and ultimate cell fates attracts more and more interest of both chemists and biologists. Herein, we report the magnetic field-directed formation of biocompatible supramolecular polymeric nanofibers composed of two subunits: a β-cyclodextrin-bearing hyaluronic acid host polymer (HACD) and magnetic nanoparticles modified with actin-binding peptide and adamantane (MS-ABPAda). Transmission electron microscopy indicated that when HACD and MS-ABPAda were exposed to a magnetic field, they self-assembled into long nanofibers along the direction of the magnetic field, and the rate of nanofiber formation was linearly correlated with the strength of the magnetic field. Interestingly, when incubated with dental pulp stem cells, the nanofibers specifically drove tip extension and polarization of the cells, a phenomenon that can be attributed to targeting of actin-binding peptide to the actin cytoskeleton and subsequent polarization of the nanofibers. The successful application of these magnetic field-responsive supramolecular polymers on accurately driving polarization of mammalian cells is expected to be of great value for artificially manipulating cell fate and developing intelligent responsive materials in regenerative medicine.

Facile construction of noncovalent graft copolymers with triple stimuli-responsiveness for triggered drug delivery

A triple stimuli-responsive noncovalent graft copolymer was designed and synthesized by the host–guest interactions between β-CD grafted dextran and ferrocene-terminated poly(lactide).

Efficient removal of 17α-ethinylestradiol from secondary wastewater treatment effluent by a biofilm process incorporating biogenic manganese oxide and Pseudomonas putida strain MnB1

This study proposes a biofilm process to immobilize biogenic manganese oxide (BMO) and Pseudomonas putida MnB1 (BMO-MnB1), which shows excellent synergistic effects for 17α-ethinylestradiol (EE2) from secondary wastewater treatment effluent (WWTE). Modified granular activated carbon (M-GAC) was used as the packing carrier, inoculated with Pseudomonas putida MnB1 and Mn(II) to form the BMO-MnB1 biofilm. Feasibility tests were performed to compare the EE2 removal efficiency with that of the conventional biofilm process (BAC) for heterogeneous microbial communities. Results show that in the BAC, EE2 was removed mainly by adsorption, with biodegradation contributing only slightly to the overall performance. In contrast, the BMO-MnB1 biofilter outperformed the BAC. Furthermore, less than 4% of the total EE2 removed was extracted from the biofilter medium over 150 days of operation, confirming that EE2 was biodegraded by P. putida MnB1 or chemically oxidized by BMO. Our results suggest that BMO-MnB1 biofilm processes have high potential for practical applications in removal of endocrine disrupting compounds from wastewater effluent.

Polysaccharide-Based Nanoparticles for Two-Step Responsive Release of Antitumor Drug

A novel two-step in situ method for targeted antitumor drug release by supramolecular assembly (Fc-CPT@HACD) was constructed using camptothecin prodrug (Fc-CPT) and β-cyclodextrin (β-CD)-modified hyaluronic acid (HACD). Benefiting from the overexpressed H₂O₂ and glutathione (GSH) in tumor cells, Fc-CPT@HACD can be disassembled by oxidation of ferrocene (Fc) to Fc⁺, leading to an efficient release of the anticancer drug camptothecin (CPT) to induce tumor cell apoptosis without affecting normal cells. The in vivo experiment results also demonstrated that Fc-CPT@HACD possessed higher anticancer efficiency than free CPT, accompanied by negligible side effects.

Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization

Magnetic nanofibers are of great interest in basic research, as well as for possible applications in spintronics and neuromorphic computing. Here we report on the preparation of magnetic nanofiber mats by electrospinning polyacrylonitrile (PAN)/nanoparticle solutions, creating a network of arbitrarily oriented nanofibers with a high aspect ratio. Since PAN is a typical precursor for carbon, the magnetic nanofiber mats were stabilized and carbonized after electrospinning. The magnetic properties of nanofiber mats containing magnetite or nickel ferrite nanoparticles were found to depend on the nanoparticle diameters and the potential after-treatment, as compared with raw nanofiber mats. Micromagnetic simulations underlined the different properties of both magnetic materials. Atomic force microscopy and scanning electron microscopy images revealed nearly unchanged morphologies after stabilization without mechanical fixation, which is in strong contrast to pure PAN nanofiber mats. While carbonization at 500 °C left the morphology unaltered, as compared with the stabilized samples, stronger connections between adjacent fibers were formed during carbonization at 800 °C, which may be supportive of magnetic data transmission.

Actin Cytoskeleton-Disrupting and Magnetic Field-Responsive Multivalent Supramolecular Assemblies for Efficient Cancer Therapy

Actin cytoskeleton disruption is a promising and intriguing anticancer strategy, but their efficiency is frequently compromised by severe side effects of the actin cytoskeleton-disrupting agents. In this study, we constructed the biocompatible actin cytoskeleton-targeting multivalent supramolecular assemblies that specifically target and disrupt the tumor actin cytoskeleton for cancer therapy. The assemblies were composed of β-cyclodextrin-grafted hyaluronic acid (HACD) and iron oxide magnetic nanoparticles (MNPs) grafted by an actin-binding peptide (ABP) and adamantane (Ada)-modified polylysine. Owing to the multivalent binding between cyclodextrin and Ada, HACD, and peptide-grafted MNPs (MNP-ABP-Ada) could self-assemble to form MNP-ABP-Ada⊂HACD nanofibers in a geomagnetism-dependent manner. Furthermore, the presence of ABP rendered the assemblies to efficiently target the actin cytoskeleton. Interestingly, with the acid of a low-frequency alternating magnetic field (200 Hz), the actin cytoskeleton-targeting nanofibers could induce severe actin disruption, leading to a remarkable cell cycle arrest and drastic cell death of tumor cells both in vitro and in vivo, but showed no obvious toxicity to normal cells. The actin cytoskeleton-targeting/disrupting supramolecular assembly implies an excellent strategy for realizing efficient cancer therapy.

Repeated administrations of Mn3O4 nanoparticles cause testis damage and fertility decrease through PPAR-signaling pathway

Potential health hazards of nanomaterials on male reproductive system have received raising concerns. Even though Mn₃O₄ nanoparticles (Mn₃O₄-NPs) is highly effective in clinical diagnostic and therapeutic applications of human disease, its potential toxic effect on the male reproductive system has not been reported. In this study, the testis damage and fertility decrease of male rats were conducted to testify the experimental reproductive injury induced by Mn₃O₄-NPs. After repeated tail vein injection with 10 mg/kg/week Mn₃O₄-NPs for 0, 60 and 120 days, Mn₃O₄-NPs accumulated in the testes resulted in oxidative stress and disorder of normal serum sex hormones. Experiments in vivo and in vitro indicated that mitochondria-mediated cell apoptosis were triggered via oxidative stress, demonstrated by the upregulation of malondialdehyde (MDA) and the depolarization of mitochondrial membrane potential. Notably, Mn₃O₄-NPs significantly resulted in a reduction of the quantity/quality of sperm and finally caused astonishing fertility decrease. Our preliminary result implied that the application of Mn₃O₄-NPs could be a double-edged sword and careful consideration should be given to the clinical uses.

Polyethyleneimine coated Fe3O4 magnetic nanoparticles induce autophagy, NF-κB and TGF-β signaling pathway activation in HeLa cervical carcinoma cells via reactive oxygen species generation

Fe₃O₄ magnetic nanoparticles (MNPs), as one of the most intensively researched NPs, have a range of applications in cancer treatments. In current research, we have focused on the influences of MNPs on cancer cells. We chose polyethyleneimine (PEI) coated MNPs (PEI-MNPs) as a model and they are colloidally stable in biological media. It can be proved that PEI-MNPs result in autophagy induction via mTOR-Akt-p70S6 K and ATG7 signaling pathways. For the first time, we have reported that PEI-MNPs activate both NF-κB and TGF-β signaling, two key pro-inflammatory pathways, in cancer cells. More significantly, we have found that autophagy induction and NF-κB and TGF-β activation can be efficiently suppressed through the inhibition of PEI-MNP dependent reactive oxygen species (ROS) over-production. ROS are deemed as a 'double edge sword' for cancer cells, owing to the cancer-suppressing and cancer-promoting actions. Our findings would be useful for designing MNPs induced ROS anti-cancer strategies or diminishing long-term toxic effects.