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1.
Top Curr Chem (Cham) ; 382(3): 27, 2024 Jul 20.
Article in English | MEDLINE | ID: mdl-39033235

ABSTRACT

Supramolecular polymers are polymeric materials of monomeric fragments, held jointly by reversible and directional non-covalent interactions such as multiple hydrogen-bonding, charge transfer effects, host-guest interactions, metal coordination, and aromatic stacking. This review article on the Hamilton-based supramolecular polymers aims to shed light on the molecular recognition achievements by the Hamilton-based polymeric systems, evaluate Hamilton receptor's future prospects, and capitalize its potential applications in supramolecular chemistry. To the best of our knowledge, this is the first elaborative and sole manuscript in which polymeric Hamilton receptors are being exposed in detail. The first portion of this manuscript is related to the importance and urgency of polymers along with the historic background of Hamilton receptors. The middle section discloses the potential applications of Hamilton-type receptors in various fields, e.g., dendrimers, mechanically polymeric rotaxanes, and self-assemblies. The final section of the manuscript discloses the future aspects and the importance of novel polymer-based Hamilton-type receptors in the modern era. We believe that this first review in this emerging yet immature field will be useful to inspire scientists around the world to find the unseen future prospects, thereby boosting the field related to this valued artificial receptor in the province of supramolecular chemistry and also in other domains of scientific fields and technology, as well.


Subject(s)
Polymers , Polymers/chemistry , Macromolecular Substances/chemistry , Rotaxanes/chemistry , Dendrimers/chemistry , Molecular Structure , Receptors, Artificial/chemistry , Receptors, Artificial/metabolism , Hydrogen Bonding
2.
ACS Appl Mater Interfaces ; 16(28): 37041-37051, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-38950151

ABSTRACT

Slide-ring hydrogels containing polyrotaxane structures have been widely developed, but current methods are more complex, in which modified cyclodextrins, capped polyrotaxanes, and multistep reactions are often needed. Here, a simple one-pot method dissolving the pseudopolyrotaxane (pPRX) in a mixture of acrylamide and boric acid to form a slide-ring hydrogel by UV light is used to construct a tough, puncture-resistant antibacterial polyrotaxane hydrogel. As a new dynamic ring cross-linking agent, boric acid effectively improves the mechanical properties of the hydrogel and involves the hydrogel with fracture toughness. The polyrotaxane hydrogel can withstand 1 MPa compression stress and maintain the morphology integrity, showing 197.5 mJ puncture energy under a sharp steel needle puncture. Meanwhile, its significant antibacterial properties endow the hydrogel with potential applications in the biomedical field.


Subject(s)
Anti-Bacterial Agents , Cyclodextrins , Escherichia coli , Hydrogels , Poloxamer , Rotaxanes , Rotaxanes/chemistry , Rotaxanes/pharmacology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/chemical synthesis , Hydrogels/chemistry , Hydrogels/pharmacology , Hydrogels/chemical synthesis , Poloxamer/chemistry , Escherichia coli/drug effects , Cyclodextrins/chemistry , Boric Acids/chemistry , Boric Acids/pharmacology , Microbial Sensitivity Tests , Staphylococcus aureus/drug effects
3.
Biomacromolecules ; 25(6): 3661-3670, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38807574

ABSTRACT

Rotaxane cross-linkers enhance the toughness of the resulting rotaxane cross-linked polymers through a stress dispersion effect, which is attributed to the mobility of the interlocked structure. To date, the compositional diversity of rotaxane cross-linkers has been limited, and the poor compatibility of these cross-linkers with peptides and proteins has made their use in such materials challenging. The synthesis of a rotaxane composed of peptides may result in a biodegradable cross-linker that is compatible with peptides and proteins, allowing the fortification of polypeptides and proteins and ultimately leading to the development of innovative materials that possess excellent mechanical properties and biodegradability. However, the chemical synthesis of all-peptide-based rotaxanes has remained elusive because of the absence of strong binding motifs in peptides, which prevents an axial peptide from penetrating a cyclic peptide. Here, we synthesized all-peptide-based rotaxanes using an active template method for proline-containing cyclic peptides. The results of molecular dynamics simulations suggested that cyclic peptides with an expansive inner cavity and carbonyl oxygens oriented toward the center are favorable for rotaxane synthesis. This rotaxane synthesis method is expected to accelerate the synthesis of peptides and proteins with mechanically interlocked structures, potentially leading to the development of peptide- and protein-based materials with unprecedented functionalities.


Subject(s)
Peptides, Cyclic , Proline , Rotaxanes , Rotaxanes/chemistry , Rotaxanes/chemical synthesis , Proline/chemistry , Peptides, Cyclic/chemistry , Peptides, Cyclic/chemical synthesis , Molecular Dynamics Simulation
4.
Carbohydr Polym ; 337: 122143, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38710552

ABSTRACT

Cyclodextrins (CDs) are essential in the pharmaceutical industry and have long been used as food and pharmaceutical additives. CD-based interlocked molecules, such as rotaxanes, polyrotaxanes, catenanes, and polycatenanes, have been synthesized and have attracted considerable attention in supramolecular chemistry. Among them, CD polyrotaxanes have been employed as slide-ring materials and biomaterials. CD polycatenanes are new materials; therefore, to date, no examples of applied research on CD polycatenanes have been reported. Consequently, we expect that applied research on CD polycatenanes will accelerate in the future. This review article summarizes the syntheses and structural analyses of CD polyrotaxanes and polycatenanes to facilitate their applications in the pharmaceutical industry. We believe that this review will promote further research on CD-based interlocked molecules.


Subject(s)
Cyclodextrins , Poloxamer , Rotaxanes , Rotaxanes/chemistry , Rotaxanes/chemical synthesis , Cyclodextrins/chemistry , Cyclodextrins/chemical synthesis , Catenanes/chemistry , Catenanes/chemical synthesis , Biocompatible Materials/chemistry , Biocompatible Materials/chemical synthesis
5.
Int J Biol Macromol ; 267(Pt 2): 131667, 2024 May.
Article in English | MEDLINE | ID: mdl-38636761

ABSTRACT

A thiolated RGD was incorporated into the threaded allyl-ß-cyclodextrins (Allyl-ß-CDs) of the polyrotaxane (PR) through a thiol-ene click reaction, resulting in the formation of dynamic RGD ligands on the PR surface (dRGD-PR). When maintaining consistent RGD density and other physical properties, endothelial cells (ECs) cultured on dRGD-PR exhibited significantly increased cell proliferation and a larger cell spreading area compared to those on the non-dynamic RGD (nRGD-PCL). Furthermore, ECs on dRGD-PR demonstrated elevated expression levels of FAK, p-FAK, and p-AKT, along with a larger population of cells in the G2/M stage during cell cycle analysis, in contrast to cells on nRGD-PCL. These findings suggest that the movement of the RGD ligands may exert additional beneficial effects in promoting EC spreading and proliferation, beyond their essential adhesion and proliferation-promoting capabilities, possibly mediated by the RGD-integrin-FAK-AKT pathway. Moreover, in vitro vasculogenesis tests were conducted using two methods, revealing that ECs cultured on dRGD-PR exhibited much better vasculogenesis than nRGD-PCL in vitro. In vivo testing further demonstrated an increased presence of CD31-positive tissues on dRGD-PR. In conclusion, the enhanced EC spreading and proliferation resulting from the dynamic RGD ligands may contribute to improved in vitro vasculogenesis and in vivo vascularization.


Subject(s)
Cell Proliferation , Cyclodextrins , Oligopeptides , Humans , Cell Adhesion/drug effects , Cell Movement/drug effects , Cell Proliferation/drug effects , Cyclodextrins/chemistry , Cyclodextrins/pharmacology , Endothelial Cells/metabolism , Endothelial Cells/drug effects , Endothelial Cells/cytology , Human Umbilical Vein Endothelial Cells/metabolism , Human Umbilical Vein Endothelial Cells/drug effects , Ligands , Neovascularization, Physiologic/drug effects , Oligopeptides/pharmacology , Oligopeptides/chemistry , Poloxamer/chemistry , Poloxamer/pharmacology , Proto-Oncogene Proteins c-akt/metabolism , Rotaxanes
6.
Nature ; 628(8007): 320-325, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38600268

ABSTRACT

Force-controlled release of small molecules offers great promise for the delivery of drugs and the release of healing or reporting agents in a medical or materials context1-3. In polymer mechanochemistry, polymers are used as actuators to stretch mechanosensitive molecules (mechanophores)4. This technique has enabled the release of molecular cargo by rearrangement, as a direct5,6 or indirect7-10 consequence of bond scission in a mechanophore, or by dissociation of cage11, supramolecular12 or metal complexes13,14, and even by 'flex activation'15,16. However, the systems described so far are limited in the diversity and/or quantity of the molecules released per stretching event1,2. This is due to the difficulty in iteratively activating scissile mechanophores, as the actuating polymers will dissociate after the first activation. Physical encapsulation strategies can be used to deliver a larger cargo load, but these are often subject to non-specific (that is, non-mechanical) release3. Here we show that a rotaxane (an interlocked molecule in which a macrocycle is trapped on a stoppered axle) acts as an efficient actuator to trigger the release of cargo molecules appended to its axle. The release of up to five cargo molecules per rotaxane actuator was demonstrated in solution, by ultrasonication, and in bulk, by compression, achieving a release efficiency of up to 71% and 30%, respectively, which places this rotaxane device among the most efficient release systems achieved so far1. We also demonstrate the release of three representative functional molecules (a drug, a fluorescent tag and an organocatalyst), and we anticipate that a large variety of cargo molecules could be released with this device. This rotaxane actuator provides a versatile platform for various force-controlled release applications.


Subject(s)
Delayed-Action Preparations , Rotaxanes , Delayed-Action Preparations/chemical synthesis , Delayed-Action Preparations/chemistry , Polymers/chemistry , Rotaxanes/chemistry , Pharmaceutical Preparations/chemistry , Fluorescent Dyes/chemistry
7.
Int J Biol Macromol ; 265(Pt 1): 130680, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38462121

ABSTRACT

The catechol moiety found within mussel proteins plays a pivotal role in enhancing their adhesive properties. Nonetheless, catechol compounds, such as dopamine (DOP) derivatives, are susceptible to oxidation, leading to the formation of quinone. This oxidation process poses a significant challenge in the development of DOP-based hydrogels, hampering their adhesion capabilities and hindering polymerization. To protect DOP moieties from oxidation, DOP and N-(3-aminopropyl)methacrylamide (AMA) moieties were grafted onto the side groups of biocompatible poly(glutamic acid) (PGA). Subsequently, the DOP unit, serving as a second guest, would be captured by a polymerizable rotaxane of cucurbituril (CB[n]), in which the host molecule CB[8] complexed with the first guest, polymerizable methyl viologen (MV), forming a protective function and dynamic cross-linking. Upon exposure to light curing, a composite network emerged through the synergy of covalent cross-linking and supramolecular host-guest complexation of DOP with CB[8]. The generated complexation between DOP and CB[8] could protect the DOP moieties, resulting in photocured hydrogels with exceptional adhesive strength and remarkable tensile capabilities. Moreover, 3D printing technology was used to create various models with these DOP-based hydrogels, demonstrating their promising applications in future.


Subject(s)
Macrocyclic Compounds , Rotaxanes , Hydrogels , Dopamine , Adhesives
8.
Mol Pharm ; 21(3): 1501-1514, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38363209

ABSTRACT

Encapsulation of active pharmaceutical ingredients (APIs) in confined spaces has been extensively explored as it dramatically alters the molecular dynamics and physical properties of the API. Herein, we explored the effect of encapsulation on the molecular dynamics and physical stability of a guest drug, salicylic acid (SA), confined in the intermolecular spaces of γ-cyclodextrin (γ-CD) and poly(ethylene glycol) (PEG)-based polypseudorotaxane (PPRX) structure. The sublimation tendency of SA encapsulated in three polymorphic forms of the γ-CD/PEG-based PPRX complex, monoclinic columnar (MC), hexagonal columnar (HC), and tetragonal columnar (TC), was investigated. The SA sublimation rate was decreased by 3.0-6.6-fold and varied in the order of MC form > HC form > TC form complex. The 13C and 1H magic-angle spinning (MAS) solid-state nuclear magnetic resonance (NMR) spectra and 13C spin-lattice relaxation time (T1) indicated that the encapsulated SA molecules existed as the monomeric form, and its molecular mobility increased in the order of MC form > HC form > TC form complex. In the complexes, a rapid chemical exchange between two dynamic states of SA (free and bound) was suggested, with varying adsorption/desorption rates accounting for its distinct molecular mobility. This adsorption/desorption process was influenced by proton exchange at the interaction site and interaction strength of SA in the complexes, as evidenced by 1H MAS spectra and temperature dependency of the 13C carbonyl chemical shift. A positive correlation between the molecular mobility of SA and its sublimation rate was established. Moreover, the molecular mobility of γ-CD and PEG in the complexes coincided with that of SA, which can be explained by fast guest-driven dynamics. This is the first report on the stability improvement of an API through complexation in polymorphic supramolecular host structures. The relationship between the molecular dynamics and physical properties of encapsulated API will aid in the rational design of drug delivery systems.


Subject(s)
Cyclodextrins , Molecular Dynamics Simulation , Poloxamer , Rotaxanes , Pharmaceutical Preparations , Cyclodextrins/chemistry , Magnetic Resonance Spectroscopy , Salicylic Acid/chemistry
9.
Nanoscale ; 16(8): 4317-4324, 2024 Feb 22.
Article in English | MEDLINE | ID: mdl-38353661

ABSTRACT

A DNA rotaxane, with its unique mechanically interlocked architecture consisting of a circular DNA molecule threaded onto a linear DNA axle, holds promise as a fundamental component for nanoscale functional devices. Nevertheless, its structural and dynamic behaviors, essential for advancing molecular machinery, remain largely unexplored. Using extensive all-atom molecular dynamics simulations, we investigated the behaviors of double-stranded DNA (dsDNA) rotaxanes, concentrating on the effects of shape distortion induced by torsional stress in small circular dsDNA containing 70-90 base pairs. We analyzed structural characteristics, including shape, intermolecular distances, and tilt angles, while also exploring dynamic properties such as translational diffusion and toroidal rotation. Our results indicate that shape distortion brings the circular and linear dsDNA components into closer proximity and causes a slight increase in translational diffusion yet a minor decrease in toroidal rotation. Nevertheless, there is no apparent evidence of coupling between translation and rotation. Overall, the insights from this study indicate that such shape distortion does not significantly alter their structure and dynamics. This finding provides flexibility for the design of DNA rotaxanes in nanoscale applications.


Subject(s)
Rotaxanes , Rotaxanes/chemistry , DNA/chemistry , DNA, Circular , Molecular Dynamics Simulation
10.
Biomater Adv ; 159: 213814, 2024 May.
Article in English | MEDLINE | ID: mdl-38417206

ABSTRACT

Controllable preparation of materials with new structure has always been the top priority of polymer materials science research. Here, the supramolecular binding strategy is adopted to develop covalent organic frameworks (COFs) with novel structures and functions. Based on this, a two-dimensional crown-ether ring threaded covalent organic framework (COF), denoted as Crown-COPF with intrinsic photothermal (PTT) and photodynamic (PDT) therapeutic capacity, was facilely developed using crown-ether threaded rotaxane and porphyrin as building blocks. Crown-COPF with discrete mechanically interlocked blocks in the open pore could be used as a molecular machine, in which crown-ether served as the wheel sliding along the axle under the laser stimulation. As a result, Crown-COPF combining with the bactericidal power of crown ether displayed a significant photothermal and photodynamic antibacterial activity towards both the Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus), far exceeding the traditional Crown-free COF. Noteworthily, the bactericidal performance could be further enhanced via impregnation of Zn2+ ions (Crown-COPF-Zn) flexible coordinated with the multiple coordination sites (crown-ether, bipyridine, and porphyrin), which not only endow the positive charge with the skeleton, enhancing its ability to bind to the bacterial membrane, but also introduce the bactericidal ability of zinc ions. Notably, in vivo experiments on mice with back infections indicates Crown-COPF-Zn with self-adaptive multinuclear zinc center, could effectively promote the repairing of wounds. This study paves a new avenue for the effectively preparation of porous polymers with brand new structure, which provides opportunities for COF and mechanically interlocked polymers (MIPs) research and applications.


Subject(s)
Crown Ethers , Cyclodextrins , Metal-Organic Frameworks , Poloxamer , Porphyrins , Rotaxanes , Animals , Mice , Metal-Organic Frameworks/pharmacology , Rotaxanes/pharmacology , Crown Ethers/pharmacology , Polymers/pharmacology , Anti-Bacterial Agents/pharmacology , Escherichia coli , Ions , Zinc/pharmacology , Wound Healing
11.
Biomolecules ; 14(2)2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38397461

ABSTRACT

We previously reported that acid-degradable methylated ß-cyclodextrins (Me-ß-CDs)-threaded polyrotaxanes (Me-PRXs) can induce autophagic cell death through endoplasmic reticulum (ER) stress-related autophagy, even in apoptosis-resistant cells. Hence, Me-PRXs show great potential as anticancer therapeutics. In this study, peptide-supermolecule conjugates were designed to achieve the targeted delivery of Me-PRX to malignant tumors. Arg-Gly-Asp peptides are well-known binding motifs of integrin αvß3, which is overexpressed on angiogenic sites and many malignant tumors. The tumor-targeted cyclic Arg-Gly-Asp (cRGD) peptide was orthogonally post-modified to Me-PRX via click chemistry. Surface plasmon resonance (SPR) results indicated that cRGD-Me-PRX strongly binds to integrin αvß3, whereas non-targeted cyclic Arg-Ala-Glu (cRGE) peptide conjugated to Me-PRX (cRGE-Me-PRX) failed to interact with integrins αvß3. In vitro, cRGD-Me-PRX demonstrated enhanced cellular internalization and antitumor activity in 4T1 cells than that of unmodified Me-PRX and non-targeted cRGE-Me-PRX, due to its ability to recognize integrin αvß3. Furthermore, cRGD-Me-PRX accumulated effectively in tumors, leading to antitumor effects, and exhibited excellent biocompatibility and safety in vivo. Therefore, cRGD conjugation to enhance selectivity for integrin αvß3-positive cancer cells is a promising design strategy for Me-PRXs in antitumor therapy.


Subject(s)
Neoplasms , Peptides, Cyclic , Rotaxanes , beta-Cyclodextrins , Humans , Rotaxanes/pharmacology , Rotaxanes/chemistry , Rotaxanes/metabolism , beta-Cyclodextrins/chemistry , Oligopeptides/chemistry , Neoplasms/drug therapy , Integrins
12.
Biomacromolecules ; 25(2): 1144-1152, 2024 Feb 12.
Article in English | MEDLINE | ID: mdl-38166194

ABSTRACT

Hyaline cartilage, a soft tissue enriched with a dynamic extracellular matrix, manifests as a supramolecular system within load-bearing joints. At the same time, the challenge of cartilage repair through tissue engineering lies in replicating intricate cellular-matrix interactions. This study attempts to investigate chondrocyte responses within double-network supramolecular hybrid hydrogels tailored to mimic the dynamic molecular nature of hyaline cartilage. To this end, we infused noncovalent host-guest polyrotaxanes, by blending α-cyclodextrins as host molecules and polyethylene glycol as guests, into a gelatin-based covalent matrix, thereby enhancing its dynamic characteristics. Subsequently, chondrocytes were seeded into these hydrogels to systematically probe the effects of two concentrations of the introduced polyrotaxanes (instilling different levels of supramolecular dynamism in the hydrogel systems) on the cellular responsiveness. Our findings unveiled an augmented level of cellular mechanosensitivity for supramolecular hydrogels compared to pure covalent-based systems. This is demonstrated by an increased mRNA expression of ion channels (TREK1, TRPV4, and PIEZO1), signaling molecules (SOX9) and matrix-remodeling enzymes (LOXL2). Such outcomes were further elevated upon external application of biomimetic thermomechanical loading, which brought a stark increase in the accumulation of sulfated glycosaminoglycans and collagen. Overall, we found that matrix adaptability plays a pivotal role in modulating chondrocyte responses within double-network supramolecular hydrogels. These findings hold the potential for advancing cartilage engineering within load-bearing joints.


Subject(s)
Chondrocytes , Rotaxanes , Chondrocytes/metabolism , Rotaxanes/pharmacology , Hydrogels/pharmacology , Hydrogels/metabolism , Molecular Dynamics Simulation , Cartilage/metabolism , Tissue Engineering , Cells, Cultured
13.
Drug Deliv Transl Res ; 14(1): 103-115, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37555906

ABSTRACT

This study aims to investigate the effect of the preparation of solid dispersions using supercritical CO2 (scCO2) on the physicochemical properties and the performance of supramolecular gels based on polymer-cyclodextrin (CD) interactions (named poly(pseudo)rotaxanes, PPR) envisaging a transdermal administration. Solid dispersions containing Soluplus®, the antihypertensive drug carvedilol (CAR), and CD (αCD or HPßCD) were prepared and characterized by HPLC, XRPD, FTIR, and DSC. PPRs prepared from solid dispersions (SCF gels) and the corresponding physical mixtures (PM gels) were analyzed regarding rheology, morphology, in vitro drug diffusion, and ex vivo drug skin permeation. The application of scCO2 led to the loss of the crystalline lattice of CAR while preserving its chemical identity. On the contrary, αCD crystals were still present in the SCF solid dispersions. SCF gels were more uniform than their corresponding PM, and the supercritical treatment resulted in changes in the rheological behavior, reducing the viscosity. CAR in vitro diffusion was significantly higher (p < 0.05) for the αCD-based SCF gel than its corresponding PM gel. Drug skin permeation showed a significant increase in drug flux from CD-based SCF gels (containing αCD or HPßCD) compared to corresponding PM gels. Additionally, the pretreatment of the skin with αCD exhibited increased CAR permeation, suggesting an interaction between αCD and the skin membrane. Results evidenced that SCF processing decisively modified the properties of the supramolecular gels, particularly those prepared with αCD.


Subject(s)
Cyclodextrins , Rotaxanes , Cyclodextrins/chemistry , Rotaxanes/chemistry , Administration, Cutaneous , 2-Hydroxypropyl-beta-cyclodextrin , Carvedilol , Gels/chemistry
14.
Adv Mater ; 36(7): e2310365, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38029425

ABSTRACT

Stroke is the primary cause of disability without effective rehabilitation methods. Emerging brain-machine interfaces offer promise for regulating brain neural circuits and promoting the recovery of brain function disorders. Implantable probes play key roles in brain-machine interfaces, which are subject to two irreconcilable tradeoffs between conductivity and modulus match/transparency. In this work, mechanically interlocked polyrotaxane is incorporated into topological hydrogels to solve the two tradeoffs at the molecular level through the pulley effect of polyrotaxane. The unique performance of the topological hydrogels enables them to acquire brain neural information and conduct neuromodulation. The probe is capable of continuously recording local field potentials for eight weeks. Optogenetic neuromodulation in the primary motor cortex to regulate brain neural circuits and control limb behavior is realized using the probe. Most importantly, optogenetic neuromodulation is conducted using the probe, which effectively reduces the infarct regions of the brain tissue and promotes locomotor function recovery. This work exhibits a significant scientific advancement in the design concept of neural probes for developing brain-machine interfaces and seeking brain disease therapies.


Subject(s)
Brain-Computer Interfaces , Rotaxanes , Stroke , Humans , Hydrogels , Brain/physiology , Stroke/therapy
15.
J Am Chem Soc ; 145(37): 20451-20461, 2023 09 20.
Article in English | MEDLINE | ID: mdl-37694929

ABSTRACT

Integrating an NIR fluorescent probe with a magnetic resonance imaging (MRI) agent to harvest complementary imaging information is challenging. Here, we have designed water-soluble, biocompatible, noncytotoxic, bright-NIR-emitting, sugar-functionalized, mechanically interlocked molecules (MIMs)-capped superparamagnetic ultrasmall Fe3O4 NPs for targeted multimodal imaging. Dual-functional stoppers containing an unsymmetrical NIR squaraine dye interlocked within a macrocycle to construct multifunctional MIMs are developed with enhanced NIR fluorescence efficiency and durability. One of the stoppers of the axle is composed of a lipophilic cationic TPP+ functionality to target mitochondria, and the other stopper comprises a dopamine-containing catechol group to anchor at the surface of the synthesized Fe3O4 NPs. Fe3O4 NPs surface-coated with targeted NIR rotaxanes help to deliver ultrasmall magnetic NPs specifically inside the mitochondria. Two carbohydrate moieties are conjugated with the macrocycle of the rotaxane via click chemistry to improve the water solubility of MitoSQRot-(Carb-OH)2-DOPA-Fe3O4 NPs. Water-soluble, rotaxane-capped Fe3O4 NPs are used for live-cell mitochondria-targeted NIR fluorescence confocal imaging, 3D and multicolor imaging in combination with T2-weighted MRI on a 9.4 T MR scanner with a high relaxation rate (r2) of 180.7 mM-1 s-1. Biocompatible, noncytotoxic, ultrabright NIR rotaxane-capped superparamagnetic ultrasmall monodisperse Fe3O4 NPs could be a promising agent for targeted multimodal imaging applications.


Subject(s)
Nanoparticles , Rotaxanes , Magnetic Resonance Imaging , Optical Imaging , Magnetic Iron Oxide Nanoparticles
16.
Chem Commun (Camb) ; 59(53): 8266-8269, 2023 Jun 29.
Article in English | MEDLINE | ID: mdl-37314502

ABSTRACT

Water-soluble [3]pseudorotaxane with enhanced fluorescence emission was successfully constructed and applied in cell imaging and photodynamic cancer therapy.


Subject(s)
Neoplasms , Rotaxanes , Humans , Water , Fluorescence , Neoplasms/diagnostic imaging , Neoplasms/drug therapy
17.
Biomolecules ; 13(6)2023 05 29.
Article in English | MEDLINE | ID: mdl-37371483

ABSTRACT

Activation of autophagy represents a potential therapeutic strategy for the treatment of diseases that are caused by the accumulation of defective proteins and the formation of abnormal organelles. Methylated ß-cyclodextrins-threaded polyrotaxane (Me-PRX), a supramolecular structured polymer, induces autophagy by interacting with the endoplasmic reticulum. We previously reported on the successful activation of mitochondria-targeted autophagy by delivering Me-RRX to mitochondria using a MITO-Porter, a mitochondria-targeted nanocarrier. The same level of autophagy induction was achieved at one-twentieth the dosage for the MITO-Porter (Me-PRX) compared to the naked Me-PRX. We report herein on the quantitative evaluation of the intracellular organelle localization of both naked Me-PRX and the MITO-Porter (Me-PRX). Mitochondria, endoplasmic reticulum and lysosomes were selected as target organelles because they would be involved in autophagy induction. In addition, organelle injury and cell viability assays were performed. The results showed that the naked Me-PRX and the MITO-Porter (Me-PRX) were localized in different intracellular organelles, and organelle injury was different, depending on the route of administration, indicating that different organelles contribute to autophagy induction. These findings indicate that the organelle to which the autophagy-inducing molecules are delivered plays an important role in the level of induction of autophagy.


Subject(s)
Rotaxanes , beta-Cyclodextrins , beta-Cyclodextrins/pharmacology , Rotaxanes/metabolism , Rotaxanes/pharmacology , Mitochondria/metabolism , Lysosomes/metabolism , Biological Transport , Autophagy
18.
Chem Commun (Camb) ; 59(49): 7579-7582, 2023 Jun 15.
Article in English | MEDLINE | ID: mdl-37259944

ABSTRACT

The CuAAC active-template approach was exploited to construct rotaxanes incorporating cage-like silsesquioxane stoppers, namely, POSSaxanes. The compounds were characterized in the solution and solid state, providing the unprecedented molecular structures of POSS-incorporating rotaxanes.


Subject(s)
Rotaxanes , Rotaxanes/chemistry , Molecular Structure
19.
Angew Chem Int Ed Engl ; 62(26): e202305282, 2023 Jun 26.
Article in English | MEDLINE | ID: mdl-37186156

ABSTRACT

Tough and self-healable substrates can enable stretchable electronics long service life. However, for substrates, it still remains a challenge to achieve both high toughness and autonomous self-healing ability at room temperature. Herein, a strategy by using the combined effects between quadruple H-bonding and slidable cross-links is proposed to solve the above issues in the elastomer. The elastomer exhibits high toughness (77.3 MJ m-3 ), fracture energy (≈127.2 kJ m-2 ), and good healing efficiency (91 %) at room temperature. The superior performance is ascribed to the inter and intra crosslinking structures of quadruple H-bonding and polyrotaxanes in the dual crosslinking system. Strain-induced crystallization of PEG in polyrotaxanes also contributes to the high fracture energy of the elastomers. Furthermore, based on the dual cross-linked supramolecular elastomer, a highly stretchable and self-healable electrode containing liquid metal is also fabricated, retaining resistance stability (0.16-0.26 Ω) even at the strain of 1600 %.


Subject(s)
Rotaxanes , Crystallization , Elastomers , Electrodes , Electronics
20.
Biomacromolecules ; 24(5): 2327-2341, 2023 05 08.
Article in English | MEDLINE | ID: mdl-37036902

ABSTRACT

Acid-degradable polyrotaxanes (PRXs) containing threading ß-cyclodextrins (ß-CDs) are promising candidates for therapeutic applications of ß-CDs in metabolic diseases with cholesterol overload or imbalance. To improve cellular uptake specificity and efficiency of PRXs in hepatocytes, N-acetyl-d-galactosamine (GalNAc)-modified PRXs were developed to facilitate asialoglycoprotein receptor (ASGR)-mediated endocytosis. Binding affinity studies revealed that the dissociation constant (KD) values between recombinant ASGR and GalNAc-PRXs decreased with an increase in the number of modified GalNAc units. Additionally, the KD values for GalNAc-PRXs were smaller than those for GalNAc-modified ß-CD and amylose, suggesting that the PRX backbone structure improves the binding affinity with ASGR. However, the intracellular uptake levels of GalNAc-PRXs in HepG2 cells increased with a decrease in the number of modified GalNAc units, which was opposite to the trend observed in the binding affinity study. We found that GalNAc-PRXs had a large number of GalNAc units localized in recycling endosomes, resulting in the low intracellular uptake. The cholesterol-reducing abilities of GalNAc-PRXs were assessed using cholesterol-overloaded HepG2 cells. GalNAc-PRXs with a small number of GalNAc units were demonstrated to show superior cholesterol-reducing effects compared to previously designed acid-degradable PRX and clinically tested ß-CD derivatives. Thus, we conclude that GalNAc modification is a promising molecular design for the therapeutic application of ß-CD-threaded PRXs in various metabolic diseases with cholesterol overload or imbalance in the liver.


Subject(s)
Rotaxanes , beta-Cyclodextrins , Rotaxanes/chemistry , Acetylgalactosamine , Galactosamine , beta-Cyclodextrins/chemistry , Hepatocytes/metabolism , Liver/metabolism , Acids , Asialoglycoprotein Receptor , Cholesterol/metabolism
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