Bioimaging Probes Based on Magneto-Fluorescent Nanoparticles

PET-Based Dual-Modal Probes for In Vivo Imaging

Molecular imaging has significantly advanced the detection and analysis of in vivo metabolic processes, while single-modal techniques remain limited. Dual-modal imaging, particularly positron emission tomography (PET)-based combinations has emerged as a powerful solution, offering enhanced capabilities through integration with magnetic resonance imaging (MRI) or near-infrared fluorescence (NIRF) imaging. This review highlights recent progress in PET-based dual-modal imaging, focusing on the development of various bimodal probes derived from antibodies, nanoparticles, and peptides, and key applications including image-guided surgery and disease assessment. PET-based dual-modal imaging holds substantial potential for advancing research and diagnostics by improving resolution and providing functional insights. By combining complementary modalities, these systems deliver a more comprehensive view of disease processes, leading to more accurate diagnoses and targeted treatments. Future research prioritizes optimizing probe design for enhanced biocompatibility and safety, facilitating clinical translation, and broadens applications beyond cancer. Through interdisciplinary collaboration, PET-based dual-modal probes are poised to play a pivotal role in improving patient outcomes, particularly in diagnosing and managing complex diseases.

Magnetic Polymeric Conduits in Biomedical Applications

Magnetic polymeric conduits are developing as revolutionary materials in regenerative medicine, providing exceptional benefits in directing tissue healing, improving targeted medication administration, and facilitating remote control via external magnetic fields. The present article offers a thorough examination of current progress in the design, construction, and functionalization of these hybrid systems. The integration of magnetic nanoparticles into polymeric matrices confers distinctive features, including regulated alignment, improved cellular motility, and targeted medicinal delivery, while preserving structural integrity. Moreover, the incorporation of multifunctional attributes, such as electrical conductivity for cerebral stimulation and optical characteristics for real-time imaging, expands their range of applications. Essential studies indicate that the dimensions, morphology, surface chemistry, and composition of magnetic nanoparticles significantly affect their biocompatibility, degrading characteristics, and overall efficacy. Notwithstanding considerable advancements, issues concerning long-term biocompatibility, biodegradability, and scalability persist, in addition to the must for uniform regulatory frameworks to facilitate clinical translation. Progress in additive manufacturing and nanotechnology is overcoming these obstacles, facilitating the creation of dynamic and adaptive conduit structures designed for particular biomedical requirements. Magnetic polymeric conduits, by integrating usefulness and safety, are set to transform regenerative therapies, presenting a new avenue for customized medicine and advanced healthcare solutions.

Construction of starch-based room temperature phosphorescence materials with wide color-tunable long afterglow and even persistent near-infrared luminescence via Förster resonance energy transfer

Environmentally friendly natural polymer-based room temperature phosphorescence (RTP) materials exhibit promising applications in anti-counterfeiting and information encryption. However, the construction of natural polymer-based RTP materials with multicolor long afterglow and even persistent near-infrared (NIR) luminescence remains a tough challenge. Here, starch (S)-based ultralong RTP materials with wide color-tunability, persistent NIR luminescence are conveniently prepared through Förster resonance energy transfer (FRET) strategies. The binary doping system S-4-carboxyphenylboric acid with an ultralong phosphorescence lifetime of up to 449 ms is used as energy donor, and commercial dyes fluorescein, rhodamine 6G and lissamine rhodamine B (LRB) are selected as energy acceptors. By adjusting the weight ratio of energy donor and acceptor, tunable multicolor long afterglow from blue to yellow-green, purple, red and even nearly white (0.32, 0.33) can be successfully achieved through the triplet-to-singlet FRET process. The quaternary doping system displays persistent NIR luminescence band from 650 to 800 nm along with the longest phosphorescence lifetime of up to 131 ms via the stepwise FRET process using LRB as the intermediate energy acceptor and NIR dye Nile blue A as the energy acceptor. Satisfactorily, the prepared S-based RTP materials with wide-range color-tunable long afterglow demonstrate potential applications in multimode information encryption and anti-counterfeiting.

3D-printed aerogels as theranostic implants monitored by fluorescence bioimaging

Aerogel scaffolds are nanostructured materials with beneficial properties for tissue engineering applications. The tracing of the state of the aerogels after their implantation is challenging due to their variable biodegradation rate and the lack of suitable strategies capable of in vivo monitoring the scaffolds. Upconversion nanoparticles (UCNPs) have emerged as advanced tools for in vitro bioimaging because of their fluorescence properties. In this work, highly fluorescent UCNPs were loaded into aerogels to obtain theranostic implants for tissue engineering and bioimaging applications. 3D-printed alginate-hydroxyapatite aerogels labeled with UCNPs were manufactured by 3D-printing and supercritical CO2 drying to generate personalize-to-patient aerogels. The physicochemical performance of the resulting structures was evaluated by printing fidelity measurements, nitrogen adsorption-desorption analysis, and different microscopies (confocal, transmission and scanning electron microscopies). Stability of the aerogels in terms of physicochemical properties was also tested after 3 years of storage. Biocompatibility was evaluated in vitro by different cell and hemocompatibility assays, in ovo and in vivo by safety and bioimaging studies using different murine models. Cytokines profile, tissue index and histological evaluations of the main organs unveiled an in vivo downregulation of the inflammation after implantation of the scaffolds. UCNPs-decorated aerogels were first-time manufactured and long-term traceable by fluorescence-based bioimaging until 3 weeks post-implantation, thereby endorsing their suitability as tissue engineering and theranostic nanodevices (i.e. bifunctional implants).

Magnetic engineering nanoparticles: Versatile tools revolutionizing biomedical applications

The use of nanoparticles has increased significantly over the past few years in a number of fields, including diagnostics, biomedicine, environmental remediation, and water treatment, generating public interest. Among various types of nanoparticles, magnetic nanoparticles (MNPs) have emerged as an essential tool for biomedical applications due to their distinct physicochemical properties compared to other nanoparticles. This review article focuses on the recent growth of MNPs and comprehensively reviews the advantages, multifunctional approaches, biomedical applications, and latest research on MNPs employed in various biomedical techniques. Biomedical applications of MNPs hold on to their ability to rapidly switch magnetic states under an external field at room temperature. Ideally, these MNPs should be highly susceptible to magnetization when the field is applied and then lose that magnetization just as quickly once the field is removed. This unique property allows MNPs to generate heat when exposed to high-frequency magnetic fields, making them valuable tools in developing treatments for hyperthermia and other heat-related illnesses. This review underscores the role of MNPs as tools that hold immense promise in transforming various aspects of healthcare, from diagnostics and imaging to therapeutic treatments, with discussion on a wide range of peer-reviewed articles published on the subject. At the conclusion of this work, challenges and potential future advances of MNPs in the biomedical field are highlighted.

Supramolecular Nano-Tracker for Real-Time Tracking of Drug Release and Efficient Combination Therapy

Real-time tracking of drug release from nanomedicine in vivo is crucial for optimizing its therapeutic efficacy in clinical settings, particularly in dosage control and determining the optimal therapeutic window. However, most current real-time tracking systems require a tedious synthesis and purification process. Herein, a supramolecular nano-tracker (SNT) capable of real-time tracking of drug release in vivo based on non-covalent host-guest interactions is presented. By integrating multiple cavities into a single nanoparticle, SNT achieves co-loading of drugs and probes while efficiently quenching the photophysical properties of the probe through host-guest complexation. Moreover, SNT is readily degraded under hypoxic tumor tissues, leading to the simultaneous release of drugs and probes and the fluorescence recovery of probes. With this spatial and temporal consistency in drug loading and fluorescence quenching, as well as drug release and fluorescence recovery, SNT successfully achieves real-time tracking of drug release in vivo (Pearson r = 0.9166, R2 = 0.8247). Furthermore, the released drugs can synergize effectively with fluorescent probes upon light irradiation, achieving potent chemo-photodynamic combination therapy in 4T1-bearing mice with a significantly improved survival rate (33%), providing a potential platform to significantly advance the development of nanomedicine and achieve optimal therapeutic effects in the clinic.

State-of-the-art of lignin-derived carbon nanodots: Preparation, properties, and applications

Lignin-derived carbon nanodots (LCNs) are nanometer-scale carbon spheres fabricated from naturally abundant lignin. Owing to rich and highly heritable graphene like π-π conjugated structure of lignin, to fabricate LCNs from it not only endows LCNs with on-demand tunable size and optical features, but also further broadens the green and chemical engineering of carbon nanodots. Recently, they have become increasingly popular in sensing, bioimaging, catalysis, anti-counterfeiting, energy storage/conversion, and others. Despite the enormous research efforts put into the ongoing development of lignin value-added utilization, few commercial LCNs are available. To have a deeper understanding of this issue, critical impacts on the preparation, properties, and applications of state-of-the-art LCNs are carefully reviewed and discussed. A concise analysis of their unique advantages, limitations for specific applications, and current challenges and outlook is conducted. We hope that this review will stimulate further advances in the functional material-oriented production of lignin.

Magnetic Silica-Coated Fluorescent Microspheres (MagSiGlow) for Simultaneous Detection of Tumor-Associated Proteins

Multiplexed bead assays for solution-phase biosensing often encounter cross-over reactions during signal amplification steps, leading to unwanted false positive and high background signals. Current solutions involve complex custom-designed and costly equipment, limiting their application in simple laboratory setup. In this study, we introduce a straightforward protocol to adapt a multiplexed single-bead assay to standard fluorescence imaging plates, enabling the simultaneous analysis of thousands of reactions per plate. This approach focuses on the design and synthesis of bright fluorescent and magnetic microspheres (MagSiGlow) with multiple fluorescent wavelengths serving as unique detection markers. The imaging-based, single-bead assay, combined with a scripted algorithm, allows the detection, segmentation, and co-localization on average of 7500 microspheres per field of view across five imaging channels in less than one second. We demonstrate the effectiveness of this method with remarkable sensitivity at low protein detection limits (100 pg/mL). This technique showed over 85 % reduction in signal cross-over to the solution-based method after the concurrent detection of tumor-associated protein biomarkers. This approach holds the promise of substantially enhancing high throughput biosensing for multiple targets, seamlessly integrating with rapid image analysis algorithms.

Inorganic nanoparticle-cored dendrimers for biomedical applications: A review

Hybrid nanostructures exhibit a synergistic combination of features derived from their individual components, showcasing novel characteristics resulting from their distinctive structure and chemical/physical properties. Surface modifiers play a pivotal role in shaping INPs' primary attributes, influencing their physicochemical properties, stability, and functional applications. Among these modifiers, dendrimers have gained attention as highly effective multifunctional agents for INPs, owing to their unique structural qualities, dendritic effects, and physicochemical properties. Dendrimers can be seamlessly integrated with diverse inorganic nanostructures, including metal NPs, carbon nanostructures, silica NPs, and QDs. Two viable approaches to achieving this integration involve either growing or grafting dendrimers, resulting in inorganic nanostructure-cored dendrimers. The initial step involves functionalizing the nanostructures' surface, followed by the generation of dendrimers through stepwise growth or attachment of pre-synthesized dendrimer branches. This hybridization imparts superior qualities to the resulting structure, including biocompatibility, solubility, high cargo loading capacity, and substantial functionalization potential. Combining the unique properties of dendrimers with those of the inorganic nanostructure cores creates a multifunctional system suitable for diverse applications such as theranostics, bio-sensing, component isolation, chemotherapy, and cargo-carrying applications. This review summarizes the recent developments, with a specific focus on the last five years, within the realm of dendrimers. It delves into their role as modifiers of INPs and explores the potential applications of INP-cored dendrimers in the biomedical applications.

Polycarboxylate functionalized magnetic nanoparticles Fe3O4@SiO2@CS-COOH: Preparation, characterization, and immobilization of bovine serum albumin

Magnetic nanoparticles with increasing superparamagnetism and magnetic targeting have found widespread application in fields such as food and medicine. In this study, polycarboxylated magnetic nanoparticles (Fe3O4@SiO2@CS-COOH) were prepared by surface functionalizing iron tetraoxide (Fe3O4) nanoparticles with ethylenediaminetetraacetic acid (EDTA) as a modifier. The appropriate degree of functionalization modification was obtained by adjusting the EDTA concentration and the ratio of cross-linking agents. The prepared magnetic nanoparticles were analyzed with structural and property characterization. The results showed that the Fe3O4@SiO2@CS-COOH magnetic nanoparticles prepared with 4 % EDTA and cross-linking agents at a molar ratio of 3:4 were uniform in particle size, with an average size of roughly 7 nm, and possessed an abundant carboxylate content (310.8064 μmol/g) and a high magnetization intensity (35.05 emu/g). As a model protein, bovine serum albumin (BSA) was immobilized on the surface of magnetic particles. The largest amount of immobilized protein was 500.4376 mg BSA/g at pH 4.0 and no extra salt ions. According to molecular docking simulations, its immobilization was due to the interaction of amino and carboxyl groups at the Fe3O4@SiO2@CS-COOH/BSA interface. Fe3O4@SiO2@CS-COOH possesses a large number of carboxyl groups, strong protein immobilization, and magnetic responsiveness, which may have potential applications in biomedical and food fields.

Emerging Applications of Nanotechnology in Healthcare and Medicine

Knowing the beneficial aspects of nanomedicine, scientists are trying to harness the applications of nanotechnology in diagnosis, treatment, and prevention of diseases. There are also potential uses in designing medical tools and processes for the new generation of medical scientists. The main objective for conducting this research review is to gather the widespread aspects of nanomedicine under one heading and to highlight standard research practices in the medical field. Comprehensive research has been conducted to incorporate the latest data related to nanotechnology in medicine and therapeutics derived from acknowledged scientific platforms. Nanotechnology is used to conduct sensitive medical procedures. Nanotechnology is showing successful and beneficial uses in the fields of diagnostics, disease treatment, regenerative medicine, gene therapy, dentistry, oncology, aesthetics industry, drug delivery, and therapeutics. A thorough association of and cooperation between physicians, clinicians, researchers, and technologies will bring forward a future where there is a more calculated, outlined, and technically programed field of nanomedicine. Advances are being made to overcome challenges associated with the application of nanotechnology in the medical field due to the pathophysiological basis of diseases. This review highlights the multipronged aspects of nanomedicine and how nanotechnology is proving beneficial for the health industry. There is a need to minimize the health, environmental, and ethical concerns linked to nanotechnology.

Fluorescent-Nanoparticle-Impregnated Nanocomposite Polymeric Gels for Biosensing and Drug Delivery Applications

Nanocomposite polymeric gels infused with fluorescent nanoparticles have surfaced as a propitious category of substances for biomedical purposes owing to their exceptional characteristics. The aforementioned materials possess a blend of desirable characteristics, including biocompatibility, biodegradability, drug encapsulation, controlled release capabilities, and optical properties that are conducive to imaging and tracking. This paper presents a comprehensive analysis of the synthesis and characterization of fluorescent-nanoparticle-impregnated nanocomposite polymeric gels, as well as their biomedical applications, such as drug delivery, imaging, and tissue engineering. In this discourse, we deliberate upon the merits and obstacles linked to these substances, encompassing biocompatibility, drug encapsulation, optical characteristics, and scalability. The present study aims to provide an overall evaluation of the potential of fluorescent-nanoparticle-impregnated nanocomposite polymeric gels for biomedical applications. Additionally, emerging trends and future directions for research in this area are highlighted.

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.

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.