Tailor made magnetic nanolights: fabrication to cancer theranostics applications

Fluorescent carbon dots in situ polymerized biodegradable semi-interpenetrating tough hydrogel films with antioxidant and antibacterial activity for applications in food industry

A flexible, antioxidant, biodegradable, and UV-resistant polymeric nanocomposite hydrogel with heteroatom-doped carbon dots (CDs) has been fabricated using a simple one-step in situ free radical gelation process. The hydrogel formation and their physico-mehcanical characteristics have been assessed by rheology, uniaxial tensile and compression testing. The water uptake behaviour of the hydrogels is controlled by the CDs by manipulating their internal morphology and porosity. The porous nature of the hydrogels has been found from their scanning electron microscopic images which are also supported by their anomalous diffusion-based transport mechanism. The rheological signatures of the hydrogels show delayed network rupturing due to the secondary physical crosslinking alleviated by CDs. Moreover, CDs are directly influencing the permeabilites (oxygen and moisture) by lowering the values compared to their neat hydrogel films which are essential for a packing material. The biodegradability of the hydrogel films showed gradual weight loss (<75 %) within 3 weeks. The hydrogel films also have been qualified to be acted as antibacterial and antioxidant material. The shelf-life and non-leaching of CDs from gel matrices are also performed which shows its excellent capability to be used as a potential antibacterial, biodegradable, antioxidant alternative packaging material in food sectors.

Identification of structural features of surface modifiers in engineered nanostructured metal oxides regarding cell uptake through ML-based classification

Nanoparticles (NPs) are considered as versatile tools in various fields including medicine, electronics, and environmental science. Understanding the structural aspects of surface modifiers in nanoparticles that govern their cellular uptake is crucial for optimizing their efficacy and minimizing potential cytotoxicity. The cellular uptake is influenced by multiple factors, namely, size, shape, and surface charge of NPs, as well as their surface functionalization. In the current study, classification-based ML models (i.e., Bayesian classification, random forest, support vector classifier, and linear discriminant analysis) have been developed to identify the features/fingerprints that significantly contribute to the cellular uptake of ENMOs in multiple cell types, including pancreatic cancer cells (PaCa2), human endothelial cells (HUVEC), and human macrophage cells (U937). The best models have been identified for each cell type and analyzed to detect the structural fingerprints/features governing the cellular uptake of ENMOs. The study will direct scientists in the design of ENMOs of higher cellular uptake efficiency for better therapeutic response.

Carbon dots as dual inhibitors of tau and amyloid-beta aggregation for the treatment of Alzheimer's disease

Alzheimer's disease (AD) is the most common form of senile dementia, presenting a significant challenge for the development of effective treatments. AD is characterized by extracellular amyloid plaques and intraneuronal neurofibrillary tangles. Therefore, targeting both hallmarks through inhibition of amyloid beta (Aβ) and tau aggregation presents a promising approach for drug development. Carbon dots (CD), with their high biocompatibility, minimal cytotoxicity, and blood-brain barrier (BBB) permeability, have emerged as promising drug nanocarriers. Congo red, an azo dye, has gathered significant attention for inhibiting amyloid-beta and tau aggregation. However, Congo red's inability to cross the BBB limits its potential to be used as a drug candidate for central nervous system (CNS) diseases. Furthermore, current studies only focus on using Congo red to target single disease hallmarks, without investigating dual inhibition capabilities. In this study, we synthesized Congo red-derived CD (CRCD) by using Congo red and citric acid as precursors, resulting in three variants, CRCD1, CRCD2 and CRCD3, based on different mass ratios of precursors. CRCD2 and CRCD3 exhibited sustained low cytotoxicity, and CRCD3 demonstrated the ability to traverse the BBB in a zebrafish model. Moreover, thioflavin T (ThT) aggregation assays and AFM imaging revealed CRCD as potent inhibitors against both tau and Aβ aggregation. Notably, CRCD1 emerged as the most robust inhibitor, displaying IC50 values of 0.2 ± 0.1 and 2.1 ± 0.5 µg/mL against tau and Aβ aggregation, respectively. Our findings underscore the dual inhibitory role of CRCD against tau and Aβ aggregation, showcasing effective BBB penetration and positioning CRCD as potential nanodrugs and nanocarriers for the CNS. Hence, CRCD-based compounds represent a promising candidate in the realm of multi-functional AD therapeutics, offering an innovative formulation component for future developments in this area. STATEMENT OF SIGNIFICANCE: This article reports Congo red-derived carbon dots (CRCD) as dual inhibitors of tau and amyloid-beta (Aβ) aggregation for the treatment of Alzheimer's disease (AD). The CRCD are biocompatible and show strong fluorescence, high stability, the ability to cross the blood-brain barrier, and the function of addressing two major pathological features of AD.

Chitosan-based nanosystems for cancer diagnosis and therapy: Stimuli-responsive, immune response, and clinical studies

Cancer, a global health challenge of utmost severity, necessitates innovative approaches beyond conventional treatments (e.g., surgery, chemotherapy, and radiation therapy). Unfortunately, these approaches frequently fail to achieve comprehensive cancer control, characterized by inefficacy, non-specific drug distribution, and the emergence of adverse side effects. Nanoscale systems based on natural polymers like chitosan have garnered significant attention as promising platforms for cancer diagnosis and therapy owing to chitosan's inherent biocompatibility, biodegradability, nontoxicity, and ease of functionalization. Herein, recent advancements pertaining to the applications of chitosan nanoparticles in cancer imaging and drug/gene delivery are deliberated. The readers are introduced to conventional non-stimuli-responsive and stimuli-responsive chitosan-based nanoplatforms. External triggers like light, heat, and ultrasound and internal stimuli such as pH and redox gradients are highlighted. The utilization of chitosan nanomaterials as contrast agents or scaffolds for multimodal imaging techniques e.g., magnetic resonance, fluorescence, and nuclear imaging is represented. Key applications in targeted chemotherapy, combination therapy, photothermal therapy, and nucleic acid delivery using chitosan nanoformulations are explored for cancer treatment. The immunomodulatory effects of chitosan and its role in impacting the tumor microenvironment are analyzed. Finally, challenges, prospects, and future outlooks regarding the use of chitosan-based nanosystems are discussed.

Carbon-Based Nanostructures as Emerging Materials for Gene Delivery Applications

Gene therapeutics are promising for treating diseases at the genetic level, with some already validated for clinical use. Recently, nanostructures have emerged for the targeted delivery of genetic material. Nanomaterials, exhibiting advantageous properties such as a high surface-to-volume ratio, biocompatibility, facile functionalization, substantial loading capacity, and tunable physicochemical characteristics, are recognized as non-viral vectors in gene therapy applications. Despite progress, current non-viral vectors exhibit notably low gene delivery efficiency. Progress in nanotechnology is essential to overcome extracellular and intracellular barriers in gene delivery. Specific nanostructures such as carbon nanotubes (CNTs), carbon quantum dots (CQDs), nanodiamonds (NDs), and similar carbon-based structures can accommodate diverse genetic materials such as plasmid DNA (pDNA), messenger RNA (mRNA), small interference RNA (siRNA), micro RNA (miRNA), and antisense oligonucleotides (AONs). To address challenges such as high toxicity and low transfection efficiency, advancements in the features of carbon-based nanostructures (CBNs) are imperative. This overview delves into three types of CBNs employed as vectors in drug/gene delivery systems, encompassing their synthesis methods, properties, and biomedical applications. Ultimately, we present insights into the opportunities and challenges within the captivating realm of gene delivery using CBNs.

Fabrication and Applications of Magnetic Polymer Composites for Soft Robotics

The emergence of magnetic polymer composites has had a transformative impact on the field of soft robotics. This overview will examine the various methods by which innovative materials can be synthesized and utilized. The advancement of soft robotic systems has been significantly enhanced by the utilization of magnetic polymer composites, which amalgamate the pliability of polymers with the reactivity of magnetic materials. This study extensively examines the production methodologies involved in dispersing magnetic particles within polymer matrices and controlling their spatial distribution. The objective is to gain insights into the strategies required to attain the desired mechanical and magnetic properties. Additionally, this study delves into the potential applications of these composites in the field of soft robotics, encompassing various devices such as soft actuators, grippers, and wearable gadgets. The study emphasizes the transformative capabilities of magnetic polymer composites, which offer a novel framework for the advancement of biocompatible, versatile soft robotic systems that utilize magnetic actuation.

Magnetite-based Janus nanoparticles, their synthesis and biomedical applications

The advent of Janus nanoparticles has been a great breakthrough in the emerging field of nanomaterials. Janus nanoparticles refer to a single structure with two distinct chemical functions on either side. Owing to their asymmetric structures, they can be utilized in a variety of applications where monomorphic particles are insufficient. In the last decade, a wide variety of materials have been employed to fabricate Janus nanoparticles, and due to the great advantages of magnetite (Iron-oxide) NPs, they have been considered as one of the best candidates. With the main benefit of magnetic controlling, magnetite Janus nanoparticles fulfill great promises, especially in biomedical areas such as bioimaging, cancer therapies, theranostics, and biosensing. The intrinsic characteristics of magnetite Janus nanoparticles (MJNPs) even hold great potential in magnetite Janus forms of micro-/nanomotors. Despite the great interest and potential in magnetic Janus NPs, the need for a comprehensive review on MJNPs with a concentration on magnetite NPs has been overlooked. Herein, we present recent advancements in the magnetite-based Janus nanoparticles in the flourishing field of biomedicine. First, the synthesis and fabrication methods of Janus nanoparticles are discussed. Then we will delve into their intriguing biomedical applications, with a separate section for magnetite Janus micro-/nanomotors in biomedicine. And finally, the challenges and future outlook are provided. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > Diagnostic Nanodevices Diagnostic Tools > In Vitro Nanoparticle-Based Sensing.

An overview of polymer surface coated synthetic quantum dots as therapeutics and sensors applications

Quantum dots (QDs) are a class of remarkable materials that have garnered significant attention since their initial discovery. It is noteworthy to mention that it took approximately a decade for these materials to be successfully implemented in practical applications. While QDs have demonstrated notable optical properties, it is important to note that these attributes alone have not rendered them a feasible substitute for traditional organic dyes. Furthermore, it is worth noting that the substance under investigation exhibited inherent toxicity and instability in its initial state, primarily due to the presence of a heavy metal core. In the initial stages of research, it was observed that the integration of nanocomposites had a positive impact on the properties of QDs. The discovery of these nanocomposites was motivated by the remarkable properties exhibited by biocomposites found in nature. Recent discoveries have shed light on the potential utilization of QDs as a viable strategy for drug delivery, offering a promising avenue to enhance the efficacy of current pharmaceuticals and pave the way for the creation of innovative therapeutic approaches. The primary objective of this review was to elucidate the distinctive characteristics that render QDs highly suitable for utilization as nanocarriers. In this study, we will delve into the multifaceted applications of QDs as sensing nanoprobes and their utilization in diverse drug delivery systems. The focus of our investigation was directed toward the utilization of QD/polymer composites in sensing applications, with particular emphasis on their potential as chemical sensors, biosensors, and physical sensors.

Crystal structure and peculiarities of microwave parameters of Co1-xNixFe2O4 nano spinel ferrites

Nanosized spinel ferrites Co1-xNixFe2O4 (where x = 0.0-1.0) or CNFO have been produced using a chemical method. The crystal structure's characteristics have been determined through the utilization of X-ray diffraction (XRD). It has been demonstrated that all samples have a single phase with cubic syngony (space group Fd3̄m). The lattice parameter and unit cell volume behavior correlate well with the average ionic radii of Co2+ and Ni2+ ions and their coordination numbers. Thus, an increase in the Ni2+ content from x = 0.0 to x = 1.0 leads to a decrease in the lattice parameter (from 8.3805 to 8.3316 Å) and unit cell volume (from 58.86 to 57.83 Å3). Elastic properties have been investigated using Fourier transform infrared (FTIR) analysis. The peculiarities of the microwave properties have been analyzed by the measured S-parameters in the range of 8-18 GHz. It was assumed that the energy losses due to reflection are a combination of electrical and magnetic losses due to polarization processes (dipole polarization) and magnetization reversal processes in the region of inter-resonant processes. A significant attenuation of the reflected wave energy (-10 … -21.8 dB) opens broad prospects for practical applications.

A Green Synthesis Route to Derive Carbon Quantum Dots for Bioimaging Cancer Cells

Carbon quantum dots (CQDs) are known for their biocompatibility and versatile applications in the biomedical sector. These CQDs retain high solubility, robust chemical inertness, facile modification, and good resistance to photobleaching, which makes them ideal for cell bioimaging. Many fabrication processes produce CQDs, but most require expensive equipment, toxic chemicals, and a long processing time. This study developed a facile and rapid toasting method to prepare CQDs using various slices of bread as precursors without any additional chemicals. This fast and cost-effective toasting method could produce CQDs within 2 h, compared with the 10 h process in the commonly used hydrothermal method. The CQDs derived from the toasting method could be used to bioimage two types of colon cancer cells, namely, CT-26 and HT-29, derived from mice and humans, respectively. Significantly, these CQDs from the rapid toasting method produced equally bright images as CQDs derived from the hydrothermal method.

A Paper-Based Biomimetic Sensing Device for the Discrimination of Original and Fraudulent Cigarette Brands Using Mixtures of MoS2 Quantum Dots and Organic Dyes

In this study, we investigated the combined effects of MoS₂ QDs' catalytic properties and the colorimetric responses of organic reagents to create a sniffing device based on the sensor array concept of the mammalian olfactory system. The aim was to differentiate the volatile organic compounds (VOCs) present in cigarette smoke. The designed optical nose device was utilized for the classification of various cigarette VOCs. Unsupervised Principal Component Analysis (PCA) and supervised Linear Discriminant Analysis (LDA) methods were employed for data analysis. The LDA analysis showed promising results, with 100% accuracy in both training and cross-validation. To validate the sensor's performance, we assessed its ability to discriminate between five cigarette brands, achieving 100% accuracy in the training set and 82% in the cross-validation set. Additionally, we focused on studying four popular Iranian cigarette brands (Bahman Kootah, Omega, Montana Gold, and Williams), including fraudulent samples. Impressively, the developed sensor array achieved a perfect 100% accuracy in distinguishing these brands and detecting fraud. We further analyzed a total of 126 cigarette samples, including both original and fraudulent ones, using LDA with a matrix size of (126 × 27). The resulting LDA model demonstrated an accuracy of 98%. Our proposed analytical procedure is characterized by its efficiency, affordability, user-friendliness, and reliability. The selectivity exhibited by the developed sensor array positions it as a valuable tool for differentiating between original and counterfeit cigarettes, thus aiding in border control efforts worldwide.

Waste-Derived Sustainable Fluorescent Nanocarbon-Coated Breathable Functional Fabric for Antioxidant and Antimicrobial Applications

Hospital-acquired (nosocomial) infections account for the majority of adverse health effects during care delivery, placing an immense financial strain on healthcare systems around the world. For the first time, the present article provides evidence of a straightforward pollution-free technique to fabricate a heteroatom-doped carbon dot immobilized fluorescent biopolymer composite for the development of functional textiles with antioxidant and antimicrobial properties. A simple, facile, and eco-friendly approach was devised to prepare heteroatom-doped carbon dots from waste green tea and a biopolymer. The carbon dots showed an excitation-dependent emission behavior, and the XPS data unveiled that they are co-doped with nitrogen and sulfur. A facile physical compounding strategy was adopted to fabricate a carbon dot reinforced biopolymeric composite followed by immobilization onto the textile. The composite textiles revealed excellent antioxidant activity, determined by 1,1-diphenyl-2-picrylhydrazyl (>80%) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid assays (>90%). The results of the disc diffusion assay indicated that the composite textiles substantially inhibited the growth of both tested bacteria Escherichia coli and Bacillus subtilis with increasing coating cycles. The time-dependent antibacterial experiments revealed that the nanocomposite can inhibit significant bacterial growth within a few hours. The present study could open up the possibility for the commercialization of inexpensive smart textile substrates for the prevention of microbial contamination used for the medical and healthcare field.

Revolutionizing Food Safety with Quantum Dot-Polymer Nanocomposites: From Monitoring to Sensing Applications

The present review article investigates the prospective utilisation of quantum dot-polymer nanocomposites in the context of ensuring food safety. The text pertains to the advancement of nanocomposites, encompassing their distinctive optical and electrical characteristics, and their prospective to transform the detection and perception of food safety risks. The article explores diverse methodologies for producing nanocomposites and underscores their potential utility in identifying impurities, microorganisms, and harmful substances in food. The article provides an overview of the challenges and limitations associated with the utilisation of nanocomposites in food safety applications, encompassing concerns regarding toxicity and the necessity for standardised protocols. The review article presents a comprehensive examination of the present research status in this area and underscores the potential of quantum dots-polymer nanocomposites in transforming food safety monitoring and sensing.

Proteinoid Polymers and Nanocapsules for Cancer Diagnostics, Therapy and Theranostics: In Vitro and In Vivo Studies

Proteinoids-simple polymers composed of amino acids-were suggested decades ago by Fox and coworkers to form spontaneously by heat. These special polymers may self-assemble in micrometer structures called proteinoid microspheres, presented as the protocells of life on earth. Interest in proteinoids increased in recent years, in particular for nano-biomedicine. They were produced by stepwise polymerization of 3-4 amino acids. Proteinoids based on the RGD motif were prepared for targeting tumors. Nanocapsules form by heating proteinoids in an aqueous solution and slowly cooling to room temperature. Proteinoid polymers and nanocapsules suit many biomedical applications owing to their non-toxicity, biocompatibility and immune safety. Drugs and/or imaging reagents for cancer diagnostic, therapeutic and theranostic applications were encapsulated by dissolving them in aqueous proteinoid solutions. Here, recent in vitro and in vivo studies are reviewed.

Understanding the aggregation of excitation wavelength independent emission of amphiphilic carbon dots for bioimaging and organic acid sensing

Herein, excitation wavelength-independent, tunable emissive and amphiphilic CDs with high quantum yield were synthesized by a low-temperature oxidation method employing banana peel waste as a carbon source. These CDs showed longer wavelength emissions (green to yellow) independent of the excitation wavelength when dispersed in different polar to non-polar solvents. The quantum yields of the same CDs were 9-32% in different solvent polarities for different emissions. On the other hand, a large stokes-shifted emission (∼9606 cm^-1) was observed for CDs in the non-polar and weak polar solvents. The particle size of CDs increases from a hydrophobic to a hydrophilic environment with the change in emission colour from yellow to green. A polar and a non-polar host matrix were used to overcome the limitation of aggregation-caused quenching of CDs in the solid state to obtain bright emissions. These CDs were potentially used for naked-eye detection of trifluoroacetic acid (TFA) by changing the emission colour from yellow to orange under UV 365 nm. Sensing of TFA was also shown reversibly switch emission colour and average lifetime for multiple cycles. Additionally, the highly emissive CDs show negligible cytotoxicity in 3T3 fibroblast cells, indicating possible bioimaging applications in 3T3 cells.

Doped Carbon Quantum Dots Reinforced Hydrogels for Sustained Delivery of Molecular Cargo

Hydrogels have emerged as important soft materials with numerous applications in fields including biomedicine, biomimetic smart materials, and electrochemistry. Because of their outstanding photo-physical properties and prolonged colloidal stability, the serendipitous findings of carbon quantum dots (CQDs) have introduced a new topic of investigation for materials scientists. CQDs confined polymeric hydrogel nanocomposites have emerged as novel materials with integrated properties of the individual constituents, resulting in vital uses in the realm of soft nanomaterials. Immobilizing CQDs within hydrogels has been shown to be a smart tactic for preventing the aggregation-caused quenching effect and also for manipulating the characteristics of hydrogels and introducing new properties. The combination of these two very different types of materials results in not only structural diversity but also significant improvements in many property aspects, leading to novel multifunctional materials. This review covers the synthesis of doped CQDs, different fabrication techniques for nanostructured materials made of CQDs and polymers, as well as their applications in sustained drug delivery. Finally, a brief overview of the present market and future perspectives are discussed.

Bioimaging Probes Based on Magneto-Fluorescent Nanoparticles

Novel nanomaterials are of interest in biology, medicine, and imaging applications. Multimodal fluorescent-magnetic nanoparticles demand special attention because they have the potential to be employed as diagnostic and medication-delivery tools, which, in turn, might make it easier to diagnose and treat cancer, as well as a wide variety of other disorders. The most recent advancements in the development of magneto-fluorescent nanocomposites and their applications in the biomedical field are the primary focus of this review. We describe the most current developments in synthetic methodologies and methods for the fabrication of magneto-fluorescent nanocomposites. The primary applications of multimodal magneto-fluorescent nanoparticles in biomedicine, including biological imaging, cancer treatment, and drug administration, are covered in this article, and an overview of the future possibilities for these technologies is provided.

Progression of Quantum Dots Confined Polymeric Systems for Sensorics

The substantial fluorescence (FL) capabilities, exceptional photophysical qualities, and long-term colloidal stability of quantum dots (QDs) have aroused a lot of interest in recent years. QDs have strong and wide optical absorption, good chemical stability, quick transfer characteristics, and facile customization. Adding polymeric materials to QDs improves their effectiveness. QDs/polymer hybrids have implications in sensors, photonics, transistors, pharmaceutical transport, and other domains. There are a great number of review articles available online discussing the creation of CDs and their many uses. There are certain review papers that can be found online that describe the creation of composites as well as their many different uses. For QDs/polymer hybrids, the emission spectra were nearly equal to those of QDs, indicating that the optical characteristics of QDs were substantially preserved. They performed well as biochemical and biophysical detectors/sensors for a variety of targets because of their FL quenching efficacy. This article concludes by discussing the difficulties that still need to be overcome as well as the outlook for the future of QDs/polymer hybrids.

Surface decorated quantum dots: Synthesis, properties and role in herbal therapy

Quantum dots are the serendipitous outcome of materials research. It is the tiny carbonaceous nanoparticles with diameters ranging from 1 to 10 nm. This review is a brief discussion of the synthesis, properties, and biomedical applicability of quantum dots, especially in herbal therapy. As quantum dots are highly polar, they can be surface decorated with several kinds of polar functionalities, such as polymeric molecules, small functional molecules, and so on. The review also consists of the basic physical and optical properties of quantum dots and their excitation-dependent properties in the application section. We focus on therapeutics, where quantum dots are used as drugs or imaging probes. Nanoprobes for several diagnostics are quite new in the biomedical research domain. Quantum dot-based nanoprobes are in high demand due to their excellent fluorescence, non-bleaching nature, biocompatibility, anchoring feasibility for several analytes, and fast point-of-care sensibility. Lastly, we also included a discussion on quantum dot-based drug delivery as phytomedicine.

Naturally Derived Carbon Dots In Situ Confined Self-Healing and Breathable Hydrogel Monolith for Anomalous Diffusion-Driven Phytomedicine Release

Fluorescent nanocarbons are well-proficient nanomaterials because of their optical properties and surface engineering. Herein, Apium graveolens-derived carbon dots (ACDs) have been synthesized by a one-step hydrothermal process without using any surplus vigorous chemicals or ligands. ACDs were captured via an in situ gelation reaction to form a semi-interpenetrating polymer network system showing mechanical robustness, fluorescent behavior, and natural adhesivity. ACDs-reinforced hydrogels were tested against robust uniaxial stress, repeated mechanical stretching, thixotropy, low creep, and fast strain recovery, confirming their elastomeric sustainability. Moreover, the room-temperature self-healing behavior was observed for the ACDs-reinforced hydrogels, with a healing efficacy of more than 45%. Water imbibition through hydrogel surfaces was digitally monitored via "breathing" and "accelerated breathing" behaviors. The phytomedicine release from the hydrogels was tuned by the ACDs' microstructure regulatory activity, resulting in better control of the diffusion rate compared to conventional chemical hydrogels. Finally, the phytomedicine-loaded hydrogels were found to be excellent bactericidal materials eradicating more than 85% of Gram-positive and -negative bacteria. The delayed network rupturing, superstretchability, fluorescent self-healing, controlled release, and antibacterial behavior could make this material an excellent alternative to soft biomaterials and soft robotics.

Alginate-Derivative Encapsulated Carbon Coated Manganese-Ferrite Nanodots for Multimodal Medical Imaging

Carbon-decorated ferrite nanodots (MNF@Cs) have been enhanced with superparamagnetism and higher fluorescence quantum yield by encapsulation with an alginate derivative to create a cost-effective and less toxic multimodal contrast agent for replacing the conventional heavy metal Gd-containing contrast agent used in MR imaging. The novel surface-engineered particles (MNF@C-OSAs), devoid of labels, can simultaneously provide both longitudinal and transverse relaxation-based magnetic resonance imaging (MRI) and fluorescence emission. According to the findings of in vitro studies, the calculated molar relaxivities and the molar radiant efficiencies are indicative of the multimodal efficacy of MNF@C-OSA as compared with MNF@C particles and conventional contrast agents used in medical imaging. MNF@C-OSAs were shown to be significantly biocompatible and negligibly toxic when assessed against A549 cells and zebrafish embryos, indicating their potential for use as theranostic agents.

The Consequences of Water Interactions with Nitrogen-Containing Carbonaceous Quantum Dots-The Mechanistic Studies

Despite the importance of quantum dots in a wide range of biological, chemical, and physical processes, the structure of the molecular layers surrounding their surface in solution remains unknown. Thus, knowledge about the interaction mechanism of Nitrogen enriched Carbonaceous Quantum Dots' (N-CQDs) surface with water-their natural environment-is highly desirable. A diffusive and Stern layer over the N-CQDs, characterized in situ, reveals the presence of anionic water clusters [OH(H₂O)_n]^-. Their existence explains new observations: (i) the unexpectedly low adsorption enthalpy (ΔH_ads) in a pressure range below 0.1 p/p_s, and ΔH_ads being as high as 190 kJ/mol at 0.11 p/p_s; (ii) the presence of a "conductive window" isolating nature-at p/p_s below 0.45-connected to the formation of smaller clusters and increasing conductivity above 0.45 p/p_s, (iii) Stern layer stability; and (iv) superhydrophilic properties of the tested material. These observables are the consequences of H₂O dissociative adsorption on N-containing basic centers. The additional direct application of surfaces formed by N-CQDs spraying is the possibility of creating antistatic, antifogging, bio-friendly coatings.

DOTAREM (DOTA)-Gold-Nanoparticles: Design, Spectroscopic Evaluation to Build Hybrid Contrast Agents to Applications in Nanomedecine

Introduction

The realization of MRI contrast agents through chemical protocols of functionalization is a strong domain of research. In this work, we developed and formulated a novel hybrid gold nanoparticle system in which a gold salt (HAuCl₄) is combined with dotarem, an MRI contrast agent (DOTA) by chelation (Method IN) and stabilized by a lactose-modified chitosan polymer (CTL; Chitlac) to form DOTA IN-CTL AuNPs.

Result and Discussion

The authors demonstrate the biological efficiency of these nanoparticles in the case of three cell lines: Mia PaCa-2 (human pancreatic cancer cell line), TIB-75 (murine liver cell line) and KKU-M213 (cholangiocarcinoma cell line). DOTA IN-CTL AuNPs are stable under physiological conditions, are nontoxic, and are very efficient as PTT agents. The highlights, such as high stability and preliminary MRI in vitro and in vivo models, may be suitable for diagnosis and therapy.

Conclusion

We proved that DOTA IN-CTL AuNPs have several advantages: i) Biological efficacy on three cell lines: MIA PaCa-2 (human pancreatic cancer cell line), TIB-75 (murine liver cell line) and KKU-M213 (cholangiocarcinoma cell line); ii) high stability, and no-toxicity; iii) high efficiency as a PPT agent. The study conducted on MRI in vitro and in vivo models will be suitable for diagnosis and therapy.

Recent advancements on hyperthermia driven controlled drug delivery from nanotherapeutics

Previous reviews of the works on magnetic nanoparticles for hyperthermia induced treatment concentrated mostly on magnetic fluid hyperthermia (MFH) employing monometallic/metal oxide nanocomposites. In the literature, the word "hyperthermia" was also limited to the use of heat for medicinal purposes. A number of publications have recently been published demonstrating that magnetic nanoparticle-based hyperthermia may produce restricted high temperatures, resulting in the release of medicines that are either connected to the magnetic nanoparticles or encased in polymer matrices. In this debate, we propose broadening the concept of "hyperthermia" to encompass temperature-based treatment as well as magnetically controlled medication delivery. The review also addresses core-shell magnetic nanomaterials, particularly nanoshells made by stacked assembly, for the use of hyperthermia-based treatment and precise administration of drugs. The primary objective of this review article is to demonstrate how the combination of hyperthermia-induced therapy and 'on demand' drug release models may lead to effective applications in personalized medicine.

Fluorescence temperature sensing of NaYF4:Yb3+/Tm3+@NaGdF4:Nd3+/Yb3+ nanoparticles at low and high temperatures

NaYF₄:Yb³⁺/Tm³⁺@NaGdF₄:Nd³⁺/Yb³⁺upconversion nanoparticles were prepared using a solvothermal method, and the effects of key factors such as the content of sensitiser Nd³⁺and Yb³⁺on their luminescence properties were investigated. The nanoparticles are homogeneous in size and well dispersed. Under 808 nm excitation, it can produce strong upconversion fluorescence. At the same time, the nanoparticles have good temperature sensing properties at the thermally coupled energy levels of 700 and 646 nm for Tm³⁺. Using its fluorescence intensity ratio, accurate temperature measurements can be performed, and it has been found that it exhibits different temperature sensing properties in low and high-temperature regions. The maximum relative sensitivity was found to be 0.88% K^-1and 1.89% K^-1for the low-temperature region of 285-345 K and the high-temperature region of 345-495 K. The nanoparticles were applied to the internal temperature measurement of lithium batteries and the actual high-temperature environment, respectively, and were found to have good temperature measurement performance.

Microwave-Assisted Synthesis of Sulfur Quantum Dots for Detection of Alkaline Phosphatase Activity

Sulfur quantum dots (SQDs) are a kind of pure elemental quantum dots, which are considered as potential green nanomaterials because they do not contain heavy metal elements and are friendly to biology and environment. In this paper, SQDs with size around 2 nm were synthesized by a microwave-assisted method using sulfur powder as precursor. The SQDs had the highest emission under the excitation of 380 nm and emit blue fluorescence at 470 nm. In addition, the SQDs had good water solubility and stability. Based on the synthesized SQDs, a fluorescence assay for detection of alkaline phosphatase (ALP) was reported. The fluorescence of the SQDs was initially quenched by Cr (VI). In the presence of ALP, ALP-catalyzed hydrolysis of 2-phospho-L-ascorbic acid to generate ascorbic acid. The generated ascorbic acid can reduce Cr (VI) to Cr (III), thus the fluorescence intensity of SQDs was restored. The assay has good sensitivity and selectivity and was applied to the detection of ALP in serum samples. The interesting properties of SQDs can find a wide range of applications in different sensing and imaging areas.

A Novel Reversible Fluorescent Probe for Cu2+and S2-Ions and Imaging in Living Cells

A novel fluorescent probe TSOC (thiazole salicylaldehyde oxazole chlorinated) was synthesized based on benzothiazole conjugated olefinic bond with salicylicaldehyde unit as fluorophore and a phenyl oxazole unit as bonding unit. The probe could reversibly detect of Cu2+ and S2- over other common ions with longer emission and large stokes shift in an aqueous solution at pH 7.3 (DMSO-Hepes, v/v, 5:1, 10 mM). The bonding mechanism was supported through the titration experiment of fluorescence and absorption spectroscopy, 1H-NMR titration, HR-MS and DFT calculations. Moreover, the probe further exhibited good cell permeability and were successfully used to visualize Cu2+ and S2- in living cells.

Facile Synthesis of Green Fluorescent Carbon Dots and Their Application to Fe3+ Detection in Aqueous Solutions

Carbon dots (CDs), a class of fluorescent nanomaterials, have attracted widespread attention from researchers. Because of their unique chemical properties, these high-quality fluorescent probes are widely used for ion and molecule detection. Excess intake of many ions or molecules can cause harm to the human body. Although iron (in the form of Fe³⁺ ions) is essential for the human body, excess iron in the human body can cause many diseases, such as iron poisoning. In this study, we have synthesized fluorine and nitrogen co-doped carbon dots (FNCDs) by a hydrothermal method. These FNCDs exhibited good stability, selectivity, and anti-interference ability for Fe³⁺. Fe³⁺ could be detected in the range of 0.2–300 μM, and their detection limit is up to 0.08 μM. In addition, the recovery and relative standard deviation measured by the standard addition recovery method were not higher than 107.5% and 1.1%, respectively, indicating that FNCDs have good recovery and accuracy for Fe³⁺ detection.

A Fluorescent “Turn-On” Clutch Probe for Plasma Cell-Free DNA Identification from Lung Cancer Patients

Early diagnosis of cancer is of paramount significance for the therapeutic intervention of cancers. Although the detection of circulating cell-free DNA (cfDNA) has emerged as a promising, minimally invasive approach for early cancer diagnosis, there is an urgent need to develop a highly sensitive and rapid method to precisely identify plasma cfDNA from clinical samples. Herein, we report a robust fluorescent “turn-on” clutch probe based on non-emissive QDs-Ru complexes to rapidly recognize EGFR gene mutation in plasma cfDNA from lung cancer patients. In this system, the initially quenched emission of QDs is recovered while the red emission of Ru(II) complexes is switched on. This is because the Ru(II) complexes can specifically intercalate into the double-stranded DNA (dsDNA) to form Ru-dsDNA complexes and simultaneously liberate free QDs from the QDs-Ru complexes, which leads to the occurrence of an overlaid red fluorescence. In short, the fluorescent “turn-on” clutch probe offers a specific, rapid, and sensitive paradigm for the recognition of plasma cfDNA biomarkers from clinical samples, providing a convenient and low-cost approach for the early diagnosis of cancer and other gene-mutated diseases.

Smart MXene Quantum Dot-Based Nanosystems for Biomedical Applications

MXene quantum dots (QDs), with their unique structural, optical, magnetic, and electronic characteristics, are promising contenders for various pharmaceutical and biomedical appliances including biological sensing/imaging, cancer diagnosis/therapy, regenerative medicine, tissue engineering, delivery of drugs/genes, and analytical biochemistry. Although functionalized MXene QDs have demonstrated high biocompatibility, superb optical properties, and stability, several challenging issues pertaining to their long-term toxicity, histopathology, biodistribution, biodegradability, and photoluminescence properties are still awaiting systematic study (especially the move towards the practical and clinical phases from the pre-clinical/lab-scale discoveries). The up-scalable and optimized synthesis methods need to be developed not only for the MXene QD-based nanosystems but also for other smart platforms and hybrid nanocomposites encompassing MXenes with vast clinical and biomedical potentials. Enhancing the functionalization strategies, improvement of synthesis methods, cytotoxicity/biosafety evaluations, enriching the biomedical applications, and exploring additional MXene QDs are crucial aspects for developing the smart MXene QD-based nanosystems with improved features. Herein, recent developments concerning the biomedical applications of MXene QDs are underscored with emphasis on current trends and future prospects.

Mussel-Inspired Polynorepinephrine/MXene-Based Magnetic Nanohybrid for Electromagnetic Interference Shielding in X-Band and Strain-Sensing Performance

The current work delivers preparation of MXene-based magnetic nanohybrid coating for flexible electronic applications. Herein, we report carbon dot-triggered photopolymerized polynorepinepherene (PNE)-coated MXene and iron oxide hybrid deposited on the cellulose microporous membrane via a vacuum-assisted filtration strategy. The surface morphologies have been monitored by scanning electron microscopy analysis, and the coating thickness was evaluated by the gallium-ion-based focused ion beam method. Coated membranes have been tested against uniaxial tensile stretching and assessed by their fracture edges in order to assure flexibility and mechanical strength. Strain sensors and electromagnetic interference (EMI) shielding have both been tested on the material because of its electrical conductivity. The bending strain sensitivity has been stringent because of their fast 'rupture and reform' percolation network formation on the coated surface. Increased mechanical strength, solvent tolerance, cyclic deformation tolerance, and EMI shielding performance were achieved by decreasing interstitial membrane porosity. Considering a possible application, the membrane also has been tested against simulated static and dynamic water flow conditions that could infer its excellent robustness which also has been confirmed by elemental analysis via ICP-MS. Thus, as of nurturing the works of the literature, it could be believed that the developed material will be an ideal alternative of flexible lightweight cellulose for versatile electronic applications.

Preparation and Characterization of Photoluminescent Graphene Quantum Dots from Watermelon Rind Waste for the Detection of Ferric Ions and Cellular Bio-Imaging Applications

Graphene quantum dots (GQDs) were synthesized using watermelon rind waste as a photoluminescent (PL) agent for ferric ion (Fe3+) detection and in vitro cellular bio-imaging. A green and simple one-pot hydrothermal technique was employed to prepare the GQDs. Their crystalline structures corresponded to the lattice fringe of graphene, possessing amide, hydroxyl, and carboxyl functional groups. The GQDs exhibited a relatively high quantum yield of approximately 37%. Prominent blue emission under UV excitation and highly selective PL quenching for Fe3+ were observed. Furthermore, Fe3+ could be detected at concentrations as low as 0.28 μM (limit of detection), allowing for high sensitivity toward Fe3+ detection in tap and drinking water samples. In the bio-imaging experiment, the GQDs exhibited a low cytotoxicity for the HeLa cells, and they were clearly illuminated at an excitation wavelength of 405 nm. These results can serve as the basis for developing an environment-friendly, simple, and cost-effective approach of using food waste by converting them into photoluminescent nanomaterials for the detection of metal ions in field water samples and biological cellular studies.

A Fluorescent Nanosensor for Silver (Ag+) and Mercury (Hg2+) Ions Using Eu (III)-Doped Carbon Dots

Carbon dots doped with Eu³⁺ ions (Eu-Cdots) were prepared by a hydrothermal treatment, using citric acid and urea as precursors and Eu (NO₃)₃ as a europium source. The Eu³⁺ ions are strongly coordinated with the carboxylate groups at the surface of the Cdots and incorporated within the nanographene network in the carbon core. Vibrational spectroscopy provides evidence of such interaction with identification of bands assigned to the stretching of the Eu-O bond. Eu³⁺ doped Cdots have larger diameters then undoped Cdots, but they are divided into smaller domains of sp² carbon. The UV-vis excitation spectrum provides evidence of energy transfer from the Cdots to the Eu³⁺. The luminescence spectrum shows the characteristic sharp peaks of Eu³⁺ in the red part of the visible spectrum and a broad emission of Cdots centered at 450 nm. The luminescence of the Cdots is strongly quenched by Hg²⁺ and Ag⁺, but not by other cations. The quenching mechanism differs significantly depending on the nature of the ion. Both the blue emission of Cdots and the red emission of Eu³⁺ are quenched in the presence of Hg²⁺ while only the emission of the Cdots is affected by the presence of Ag⁺. A ratiometric sensor can be built using the ratio of luminescence intensities of the Cdots to the Eu³⁺ peaks.

A Review on Synthesis Methods of Phyllosilicate- and Graphene-Filled Composite Hydrogels

This review discusses, in brief, the various synthetic methods of two widely-used nanofillers; phyllosilicate and graphene. Both are 2D fillers introduced into hydrogel matrices to achieve mechanical robustness and water uptake behavior. Both the fillers are inserted by physical and chemical gelation methods where most of the chemical gelation, i.e., covalent approaches, results in better physical properties compared to their physical gels. Physical gels occur due to supramolecular assembly, van der Waals interactions, electrostatic interactions, hydrophobic associations, and H-bonding. For chemical gelation, in situ radical triggered gelation mostly occurs.

Design of Magnetic Hydrogels for Hyperthermia and Drug Delivery

Hydrogels are spatially organized hydrophilic polymeric systems that exhibit unique features in hydrated conditions. Among the hydrogel family, composite hydrogels are a special class that are defined as filler-containing systems with some tailor-made properties. The composite hydrogel family includes magnetic-nanoparticle-integrated hydrogels. Magnetic hydrogels (MHGs) show magneto-responsiveness, which is observed when they are placed in a magnetic field (static or oscillating). Because of their tunable porosity and internal morphology they can be used in several biomedical applications, especially diffusion-related smart devices. External stimuli may influence physical and chemical changes in these hydrogels, particularly in terms of volume and shape morphing. One of the most significant external stimuli for hydrogels is a magnetic field. This review embraces a brief overview of the fabrication of MHGs and two of their usages in the biomedical area: drug delivery and hyperthermia-based anti-cancer activity. As for the saturation magnetization imposed on composite MHGs, they are easily heated in the presence of an alternating magnetic field and the temperature increment is dependent on the magnetic nanoparticle concentration and exposure time. Herein, we also discuss the mode of different therapies based on non-contact hyperthermia heating.