Ruchi Agrawal

A series of highly crystalline and uniform-sized monodisperse Li+ codoped NaYF4:Ho3+, Yb3+ (YHYL) nanoparticles are successfully synthesized via a thermolysis approach by varying Li+ (0–15 at %) and Yb3+ (0–20 at %) concentrations. Li+ doping not only increases the crystallite size but also enhances the luminescence intensity by 60 times. Upon excitation with a 980 nm laser, it produces a super-bright green emission. Highly water-dispersible nanoparticles are obtained by a two-step ligand exchange method with five different capping agents, which have their own characteristic features in biomedical applications. HCl-washed NaYF4:2 at % Ho3+, 20 at % Yb3+, 10 at % Li+ (YHYL-10-HCl) nanoparticles exhibit high biocompatibility in the WI-26 normal human cell line and can therefore be utilized for ex vivo imaging, anticounterfeiting, and noncontact-based optical temperature sensors under NIR excitation. After chitosan coating, YHYL-10-chitosan nanoparticles demonstrate enhanced biocompatibility in the MCF-7 cancer cell line, as well as impressive hemocompatibility in human blood. Hence, chitosan-coated YHY, YHYL-2, and YHYL-10 nanoparticles are subsequently evaluated for multiphoton in vitro imaging, including Z-stack 3D imaging, suggesting internalization of chitosan-coated nanoparticles in MCF-7 and A549 cancer cell lines under 980 nm laser excitation.

The high incidence, aggressiveness, and chemo-refractory nature of cervical and triple-negative breast cancers (TNBC) warrant the development of targeted chemotherapy strategies for improving their therapeutic outcomes. The present study reports the design and preparation of highly monodispersed, biocompatible, and hemocompatible Ce–Tb-doped core@shell NaGdF4:20Ce@NaGdF4:5Tb (CS) nanorods prepared by a thermolysis process with an aim to enhance drug accumulation and site-specific chemotherapy in two aggressive drug-resistant human cancer cell lines, namely, cervical and TNBC. The nanorods were coated with silica to impart aqueous dispersibility, followed by covalent conjugation with folic acid, enabling their application in the site-specific delivery of anticancer drug, doxorubicin hydrochloride (DOX). MTT assay suggested a dose- and time-dependent enhancement in DOX-induced cytotoxicity of DOX-loaded CS (CS@Si-NH2–FA-DOX) in folate receptor overexpressing cervical (KB) and TNBC (MDA MB-231) cells in comparison to normal human mammary epithelial cells (MCF 10A) and human lung fibroblast cells (WI26VA4). IC50 values of CS@Si-NH2–FA-DOX were found to be ∼10–40-fold lower in KB and MDA MB-231 compared to normal cell lines, corroborating highly cancer-specific chemotherapeutic efficacy. The enhanced anticancer efficacy of CS@Si-NH2–FA-DOX was further supported by ∼3–5-fold higher intracellular uptake in both KB and MDA MB-231 cells in comparison to free DOX, as investigated by flow cytometry analysis. Pertinently, confocal studies validated that CS@Si-NH2–FA-DOX are able to deliver DOX to its intracellular target, i.e., nucleus, resulting in a significant enhancement of cytotoxicity as compared to free DOX. Furthermore, pretreatment of KB cells with pan caspase inhibitor, Z-VAD-fmk, showed significantly higher (∼2-fold) rescue after treatment with CS@Si-NH2–FA-DOX as compared to free DOX, suggesting a higher induction of apoptotic cell death by CS@Si-NH2–FA-DOX. Thus, CS@Si-NH2–FA-DOX nanorods are promising to be used as a nanodelivery vehicle for targeted chemotherapy and also for circumventing the chemo-resistance associated with cervical and TNBC cancers.

The utility of highly monodispersed magnetic and non-magnetic nanoparticles as a single entity for targeting, imaging and therapy of cancer.

Detailed insights into magnetic and optical properties of monodispersed γ-Fe ₂ O ₃ , γ-Fe _{2−2 x} Zn _{2 x} O ₃ (substitution) and γ-Fe ₂ O ₃ @ZnO (core@shell) nanostructures that can be used as nanocarriers in biomedical applications.

We have developed hybrid ⁻O–(PO₂)₃–O⁻⋯⁺NH₃–SiO⋯Fe₃O₄ magnetite particles for the removal of uranyl ions from water as well as blood serum. Pure Fe₃O₄ particles have absorption properties towards uranyl in water, but very negligible interaction properties in blood serum. However, our developed hybrid has strong absorption properties with uranyl ions in water as well as blood serum. The absorption percentages of uranyl over 10 mg of pure Fe₃O₄ and hybrid Fe₃O₄ are 2.06, and 66%, respectively in blood serum. The absorption properties of the hybrid are related to magnetic particles capped with NH₂ and ⁻O–(PO₂)₃–O⁻groups, as well as porous –SiO– over the magnetic particles. In blood serum, there are many components such as proteins and ions such as Na⁺, K⁺, Cl⁻, HPO₄ ²⁻, and HCO₃ ¹⁻, that can influence the absorption properties of magnetic particles towards uranyl, whereas these do not influence hybrid particles.

Deep eutectic solvents (DES) are considered a novel class of environmentally benign molecular solvents that are considered as potential solvents for nuclear fuel reprocessing, material recycling, and many other technological applications in both research and industry. However, there is a complete dearth of understanding pertaining to the behavior of metal ions in DES. Herein, we have investigated the speciation, complexation behavior, photochemistry, and redox properties and tried to obtain insight into the chemical aspects of the europium ion in DES (synthesized from heptyltriphenylphosphonium bromide and decanoic acid). The same has been probed using time-resolved photoluminescence (TRPL), cyclic voltammetry (CV), synchrotron-based extended X-ray absorption fine structure (EXAFS) spectroscopy, and density functional theory (DFT) calculations. TRPL indicated the stabilization of europium in the +3 oxidation state, favoring the potential of the Eu(III)–DES complex to emit red light under near UV excitation and the existence of inefficient energy transfer between DES and Eu³⁺. EXAFS analysis revealed the presence of Eu–O and Eu–Br, which represent the local surroundings of Eu³⁺ in the Eu(III)–DES complex. TRPL measurement has also suggested two distinct local environments of europium ions in the complex. DFT calculations supported the EXAFS findings, confirming that the Eu(III)–DES structure involves not only the oxygen atom of decanoic acid but also the oxygen atoms from the nitrate ions, contributing to the local coordination of Eu(III). Electrochemical studies demonstrated that the redox reaction of Eu(III)/Eu(II) in DES displays quasi-reversible behavior. The reaction rate was observed to increase with higher temperatures. The findings of this study can contribute to the understanding of the fundamental properties and potential applications of this luminescent and electrochemically active complex and pave the way for further studies and the development of novel materials with enhanced luminescent and electrochemical properties.