On Complex Formation between 5-Fluorouracil and β-Cyclodextrin in Solution and in the Solid State: IR Markers and Detection of Short-Lived Complexes by Diffusion NMR

Beta cyclodextrin conjugated AuFe3O4 Janus nanoparticles with enhanced chemo-photothermal therapy performance

The strategic integration of multi-functionalities within a singular nanoplatform has received growing attention for enhancing treatment efficacy, particularly in chemo-photothermal therapy. This study introduces a comprehensive concept of Janus nanoparticles (JNPs) composed of Au and Fe3O4 nanostructures intricately bonded with β-cyclodextrins (β-CD) to encapsulate 5-Fluorouracil (5-FU) and Ibuprofen (IBU). This strategic structure is engineered to exploit the synergistic effects of chemo-photothermal therapy, underscored by their exceptional biocompatibility and photothermal conversion efficiency (∼32.88 %). Furthermore, these β-CD-conjugated JNPs enhance photodynamic therapy by generating singlet oxygen (1O2) species, offering a multi-modality approach to cancer eradication. Computer simulation results were in good agreement with in vitro and in vivo assays. Through these studies, we were able to prove the improved tumor ablation ability of the drug-loaded β-CD-conjugated JNPs, without inducing adverse effects in tumor-bearing nude mice. The findings underscore a formidable tumor ablation potency of β-CD-conjugated Au-Fe3O4 JNPs, heralding a new era in achieving nuanced, highly effective, and side-effect-free cancer treatment modalities. STATEMENT OF SIGNIFICANCE: The emergence of multifunctional nanoparticles marks a pivotal stride in cancer therapy research. This investigation unveils Janus nanoparticles (JNPs) amalgamating gold (Au), iron oxide (Fe3O4), and β-cyclodextrins (β-CD), encapsulating 5-Fluorouracil (5-FU) and Ibuprofen (IBU) for synergistic chemo-photothermal therapy. Demonstrating both biocompatibility and potent photothermal properties (∼32.88 %), these JNPs present a promising avenue for cancer treatment. Noteworthy is their heightened photodynamic efficiency and remarkable tumor ablation capabilities observed in vitro and in vivo, devoid of adverse effects. Furthermore, computational simulations validate their interactions with cancer cells, bolstering their utility as an emerging therapeutic modality. This endeavor pioneers a secure and efficacious strategy for cancer therapy, underscoring the significance of β-CD-conjugated Au-Fe3O4 JNPs as innovative nanoplatforms with profound implications for the advancement of cancer therapy.

Different Drug Mobilities in Hydrophobic Cavities of Host-Guest Complexes between β-Cyclodextrin and 5-Fluorouracil at Different Stoichiometries: A Molecular Dynamics Study in Water

Cyclodextrins (CDs) are cyclic oligosaccharides able to form noncovalent water-soluble complexes useful in many different applications for the solubilization, delivery, and greater bioavailability of hydrophobic drugs. The complexation of 5-fluorouracil (5-FU) with natural or synthetic cyclodextrins permits the solubilization of this poorly soluble anticancer drug. In this theoretical work, the complexes between β-CD and 5-FU are investigated using molecular mechanics (MM) and molecular dynamics (MD) simulations in water. The inclusion complexes are formed thanks to the favorable intermolecular interactions between β-CD and 5-FU. Both 1:1 and 1:2 β-CD/5-FU stoichiometries are investigated, providing insight into their interaction geometries and stability over time in water. In the 1:2 β-CD/5-FU complexes, the intermolecular interactions affect the drug's mobility, suggesting a two-step release mechanism: a fast release for the more exposed and hydrated drug molecule, with greater freedom of movement near the β-CD rims, and a slow one for the less-hydrated and well-encapsulated and confined drug. MD simulations study the intermolecular interactions between drugs and specific carriers at the atomistic level, suggesting a possible release mechanism and highlighting the role of the impact of the drug concentration on the kinetics process in water. A comparison with experimental data in the literature provides further insights.

Uracil-water interaction revisited - in search of single H-bonded secondary minima

Monohydrated uracil (UW) complexes are stabilized by both O⋯HO and NH⋯O hydrogen bonds (H-bonds), simultaneously participating in forming three stable cyclic structures. The role and contribution of these individual H-bonds (O⋯HO and NH⋯O) to the stability of the three UW complexes are still not understood, because of the technical problems in obtaining their optimized structures by standard geometry optimization. The present study explores a non-standard approach to identify three single H-bonded local minima structures without imaginary frequency using DFT (M06-2X, B3LYP and B3LYP-D3), MP2 and CCSD(T) theories and Dunning's correlation-consistent aug-cc-pVTZ basis set, in both vacuum and aqueous media (CPCM method). The results reveal that these new structures are very shallow secondary minima between two deep wells or next to a deep well of primary minima (double H-bonded structures) in the potential energy surface. The H-bond energy of these single H-bonded complexes is found to be less sensitive to a wide range (about 15-20 degrees) of O⋯HO and NH⋯O angles, and the linearity is preferred in the stable three single H-bonded structures. The technical method used to locate such a shallow minimum is described in detail and may be useful for identifying local minima in other cases where consecutive multiple H-bonded structures are global minima. Energy decomposition (using symmetry adapted perturbation theory (SAPT)) of interaction energy, electron redistribution, and relevant vibrational modes are discussed.

Preparation of nanoformulation of 5-fluorouracil to improve anticancer efficacy: integrated spectroscopic, docking, and MD simulation approaches

Nanoformulations (NFs) can be used as a novel drug delivery system to treat all cancer types. One of the major drawbacks of conventional anticancer drugs is that they have poor specificity and higher toxicity towards normal cells. 5-fluorouracil (5-FU) is a well-studied anticancer drug that has a significant role in various cancers, specifically colorectal cancer therapy. This study was performed to determine the functional groups, particle size, surface charge, heterogeneity, and stability of the NF. The NFs of 5-FU were prepared through the ultrasonication technique by increasing the surfactant (Tween-80) concentrations. Among all three NFs, nanoformulated 5-FU (n5-FU) showed the most effective particle size (10.72 nm) with a zeta potential of (-4.57 mV). The cytotoxicity and apoptosis profiles confirmed that n5-FU enhanced the anticancer effect of the pure drug in HCT-116 cells, as evident from MTT assay, fluorescence microscopy, and FACS analysis. In HCT-116 cells, the IC50 values of pure and n5-FU were obtained as 41.3 μM and 18.8 μM, respectively, indicating that n5-FU was more effective against the cancer cell line. The cellular uptake study was performed to check the intake of NF in cancer cells. However, the microtubule-affinity regulating kinase-4 (MARK-4), a cancer-target protein, was purified to study the inhibition and interaction studies. The inhibition assay confirmed the inhibitory potential of 5-FU against MARK-4 protein. the multi-spectroscopic, molecular docking and MD simulation studies were performed to analyse the conformational changes, binding studies, intermolecular interactions, and stability of MARK-4 protein upon binding 5-FU. This demonstrates that NF can enhance the effectiveness of anticancer drugs.Communicated by Ramaswamy H. Sarma.

Tumor tropic delivery of FU.FA@NSs using mesenchymal stem cells for synergistic chemo-photodynamic therapy of colorectal cancer

To overcome the limitations associated with the targeting abilities of nanotherapeutics and drug loading capacity of mesenchymal stem cells (MSCs), the present study relies on the combination of MSCs tumor tropism with the controlled release function of nano-based drug delivery platforms to achieve tumor-specific accumulation of chemotherapeutics with minimal off-target effects. 5-fluorouracil (5-FU)-containing ceria (CeNPs) coated calcium carbonate nanoparticles (CaNPs) were functionalized with folinic acid (FA) to develop drug-containing nanocomposites (Ca.FU.Ce.FA NCs). NCs were then conjugated with graphene oxide (GO) and decorated with silver nanoparticles (Ag°NPs) to form FU.FA@NS, a rationally designed drug delivery system with O₂ generation capacity that alleviates tumor hypoxia for improved photodynamic therapy. Engineering of MSCs with FU.FA@NSs provided successful loading and long-term retention of therapeutics on the surface membrane with minimal changes to the functional properties of MSCs. Co-culturing of FU.FA@NS.MSCs with CT26 cells upon UVA exposure revealed enhanced apoptosis in tumor cells through ROS-mediated mitochondrial pathway. FU.FA@NSs released from MSCs were effectively taken up by CT26 cells via a clathrin-mediated endocytosis pathway and distributed their drug depots in a pH, H₂O₂, and UVA-stimulated fashion. Therefore, the cell-based biomimetic drug delivery platform formulated in the current study could be considered a promising strategy for targeted chemo-photodynamic therapy of colorectal cancer.

Polyacrylic acid and β-cyclodextrin polymer cross-linking binders to enhance capacity performance of silicon/carbon composite electrodes in lithium-ion batteries

Binders play a key role in maintaining the integrity of high-capacity silicon anodes, which otherwise experience serious capacity decay during cycling caused by huge volume variation of the silicon. With an aim to developing a highly efficient polymeric binder to mitigate this capacity decay, we present a novel binder synthesized from polyacrylic acid (PAA) and polymerized β-cyclodextrin (β-CDp) for Si anodes for the lithium-ion batteries. This PAA-β-CDp binder has a 3D network structure, which provides strong adhesion between the active material and the current collector. PAA-β-CDp binder makes silicon anode achieve a specific capacity of 2326.4 mAhg^-1 at the current density of 0.2 A g^-1 with a capacity retention of 64.6% after 100 cycles. The experimental results show that the PAA-β-CDp binder can effectively mitigate the huge volume change and improve the capacity and cycling performance of Si anodes.