Review: Remotely controlled magneto-regulation of therapeutics from magnetoelastic gel matrices

Fabrication and optimization of chitosan-g-m-PEG-NH2 copolymer for advanced glioblastoma therapy using surface engineered lentinan loaded nanovesicles for nasal delivery

Glioblastoma multiforme (GBM) exhibits a high mortality with an incidence rate of 3-5 per 100,000 each year, which demands existence of newer approach for its treatment. The current study focuses on synthesis of novel lipidic nanovesicles (LNs) loaded with highly potent macromolecule Lentinan (LNT) and surface modified with methoxy poly (ethylene glycol; PEG) amine (m-PEG-NH2)-grafted-chitosan (CS) for intranasal delivery. The grafting procedure was optimized using Box Behnken design (BBD) to limit the use of organic solvents. The fabricated polymer showed enhanced aqueous solubility, biodegradability and mucoadhesion, resulting in higher nasal mucosa permeation (z = 53.52 μm). The presence of PEG enabled the sustained release of LNT till 48 h and assisted in achieving higher accumulation of LNT in CSF (41.7 ± 3.1 μg/mL) and a higher brain targeting potential of 96.3 ± 2.31 % (p < 0.05). In-vitro cellular studies showed the enhanced anti-GBM effect of LNT on U87 MG cells by reducing the cell viability (~2 times reduction in IC50 value) accompanied with large number of cells undergoing late apoptosis and death (p < 0.05) because of the higher cellular uptake (63.22 ± 3.01 ng/100 cells) of novel formulation. The copolymer comprising LNs were biocompatible, stable and can be used as an effective tool in the management of GBM.

Aerosolization of poly(sulfobetaine) microparticles that encapsulate therapeutic antibodies

Pulmonary delivery of protein therapeutics poses significant challenges that have not been well addressed in the research literature or practice. In fact, there is currently only one commercial protein therapeutic that is delivered through aerosolization and inhalation. In this study, we propose a drug delivery strategy that enables a high-concentration dosage for the pulmonary delivery of antibodies as an aerosolizable solid powder with desired stability. We utilized zwitterionic polymers for their promising properties as drug delivery vehicles and synthesized swellable, biodegradable poly(sulfo-betaine) (pSB) microparticles. The microparticles were loaded with Immunoglobulin G (IgG) as a model antibody. We quantified the microparticle size and morphology, and the particles were found to have an average diameter of 1.6 μm, falling within the optimal range (~1-5 μm) for pulmonary drug delivery. In addition, we quantified the impact of the crosslinker to monomer ratio on particle morphology and drug loading capacity. The results showed that there is a trade-off between desired morphology and drug loading capacity as the crosslinker density increases. In addition, the particles were aerosolized, and our data indicated that the particles remained intact and retained their initial morphology and size after aerosolization. The combination of morphology, particle size, antibody loading capacity, low cytotoxicity, and ease of aerosolization support the potential use of these particles for pulmonary delivery of protein therapeutics.

Amine functionalised graphene embedded polyvinyl alcohol (PVA) and PVA-chitosan hydrogel composites

A novel amine-functionalized graphene oxide (AFG) doped polyvinyl alcohol (PVA)/chitosan (PVA-Ch) composite film was developed using an eco-synthesis approach, eliminating the need for halogenated compounds. The resulting AFG-doped PVA/Chitosan (PVA-Ch/AFG) polymer film exhibited promising properties for controlled delivery and biosensing applications. The investigation included assessing the swelling behaviour, dissolution percent, gel fraction, and mechanical properties of the polymer film. The swelling characteristics of PVA-Ch and PVA-Ch/AFG were found to be pH and temperature-dependent across various pH ranges (3, 5, 7, and 9). Interestingly, PVA-Ch/AFG demonstrated a stable swelling pattern at pH 5 and 7, unaffected by changes in chitosan concentration, indicating enhanced stability compared to PVA-Ch. The study also explored the use of PVA-Ch/AFG in a drug delivery system, revealing controlled release of the model antibiotic amphicillin, emphasizing its potential in medical applications. Furthermore, the eco-friendly synthesis route underscored the safety of PVA-Ch/AFG for use in food and medical applications. Biocompatibility assessments, including biodegradability studies and cytotoxicity tests on fibroblasts (3T3 cells), confirmed the safety profile of PVA-Ch/AFG. In conclusion, the study suggests that PVA-Ch/AFG holds promise for bio-sensing applications, offering a flexible and colorimetric platform capable of encapsulating, adsorbing, and desorbing biomolecules such as drugs and sensing compounds.

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.

Biomedical Applications of Deformable Hydrogel Microrobots

Hydrogel, a material with outstanding biocompatibility and shape deformation ability, has recently become a hot topic for researchers studying innovative functional materials due to the growth of new biomedicine. Due to their stimulus responsiveness to external environments, hydrogels have progressively evolved into "smart" responsive (such as to pH, light, electricity, magnetism, temperature, and humidity) materials in recent years. The physical and chemical properties of hydrogels have been used to construct hydrogel micro-nano robots which have demonstrated significant promise for biomedical applications. The different responsive deformation mechanisms in hydrogels are initially discussed in this study; after which, a number of preparation techniques and a variety of structural designs are introduced. This study also highlights the most recent developments in hydrogel micro-nano robots' biological applications, such as drug delivery, stem cell treatment, and cargo manipulation. On the basis of the hydrogel micro-nano robots' current state of development, current difficulties and potential future growth paths are identified.

Curing spurious magneto-mechanical coupling in soft non-magnetic materials

The present work is concerned with the issue of spurious coupling effects that are pervasive in fully coupled magneto-mechanical finite element simulations involving very soft non-magnetic or air-like media. We first address the characterization of the spurious magneto-mechanical effects and their intuitive interpretation based on energy considerations. Then, as main contribution, we propose two new cures for the issue under consideration that completely prune the undesired spurious magneto-mechanical coupling in non-magnetic media. The proposed methods are compared with established methods in the context of magnetic bodies embedded in (i) air or vacuum and (ii) very soft elastic non-magnetic media. The comparison shows that the proposed approaches are accurate and effective. They, furthermore, allow for a consistent linearization of the coupled boundary value problems, which is crucial for the simulation of compliant structures. For reproducibility and accessibility of the proposed methods, we provide our implementations with Netgen/NGSolve as well as all codes necessary for the reproduction of our results as supplementary material.

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.

Electrochemical Reconstruction of NiFe/NiFeOOH Superparamagnetic Core/Catalytic Shell Heterostructure for Magnetic Heating Enhancement of Oxygen Evolution Reaction

Although (oxy)hydroxides generated by electrochemical reconstruction (EC-reconstruction) of transition-metal catalysts exhibit highly catalytic activities, the amorphous nature fundamentally impedes the electrochemical kinetics due to its poor electrical conductivity. Here, EC-reconstructed NiFe/NiFeOOH core/shell nanoparticles in highly conductive carbon matrix based on the pulsed laser deposition prepared NiFe nanoparticles is successfully confined. Electrochemical characterizations and first-principles calculations demonstrate that the reconstructed NiFe/NiFeOOH core/shell nanoparticles exhibit high oxygen evolution reaction (OER) electrocatalytic activity (a low overpotential of 342.2 mV for 10 mA cm^-2 ) and remarkable durability due to the efficient charge transfer in the highly conductive confined heterostructure. More importantly, benefit from the superparamagnetic nature of the reconstructed NiFe/NiFeOOH core/shell nanoparticles, a large OER improvement is achieved (an ultralow overpotential of 209.2 mV for 10 mA cm^-2 ) with an alternating magnetic field stimulation. Such OER improvement can be attributed to the Néel relaxation related magnetic heating effect functionalized superparamagnetic NiFe cores, which are generally underutilized in reconstructed core/shell nanoparticles. This work demonstrates that the designed superparamagnetic core/shell nanoparticles, combined with the large improvement by magnetic heating effect, are expected to be highly efficient OER catalysts along with the confined structure guaranteed high conductivity and catalytic stability.

Delivering on the promise of recombinant silk-inspired proteins for drug delivery

Effective drug delivery is essential for the success of a medical treatment. Polymeric drug delivery systems (DDSs) are preferred over systemic administration of drugs due to their protection capacity, directed release, and reduced side effects. Among the numerous polymer sources, silks and recombinant silks have drawn significant attention over the past decade as DDSs. Native silk is produced from a variety of organisms, which are then used as sources or guides of genetic material for heterologous expression or engineered designs. Recombinant silks bear the outstanding properties of natural silk, such as processability in aqueous solution, self-assembly, drug loading capacity, drug stabilization/protection, and degradability, while incorporating specific properties beneficial for their success as DDS, such as monodispersity and tailored physicochemical properties. Moreover, the on-demand inclusion of sequences that customize the DDS for the specific application enhances efficiency. Often, inclusion of a drug into a DDS is achieved by simple mixing or diffusion and stabilized by non-specific molecular interactions; however, these interactions can be improved by the incorporation of drug-binding peptide sequences. In this review we provide an overview of native sources for silks and silk sequences, as well as the design and formulation of recombinant silk biomaterials as drug delivery systems in a variety of formats, such as films, hydrogels, porous sponges, or particles.

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.

Magnetic Nanoparticles: Current Advances in Nanomedicine, Drug Delivery and MRI

Magnetic nanoparticles (MNPs) have evolved tremendously during recent years, in part due to the rapid expansion of nanotechnology and to their active magnetic core with a high surface-to-volume ratio, while their surface functionalization opened the door to a plethora of drug, gene and bioactive molecule immobilization. Taming the high reactivity of the magnetic core was achieved by various functionalization techniques, producing MNPs tailored for the diagnosis and treatment of cardiovascular or neurological disease, tumors and cancer. Superparamagnetic iron oxide nanoparticles (SPIONs) are established at the core of drug-delivery systems and could act as efficient agents for MFH (magnetic fluid hyperthermia). Depending on the functionalization molecule and intrinsic morphological features, MNPs now cover a broad scope which the current review aims to overview. Considering the exponential expansion of the field, the current review will be limited to roughly the past three years.

Effect of Ti Atoms on Néel Relaxation Mechanism at Magnetic Heating Performance of Iron Oxide Nanoparticles

The study was based on understanding the relationship between titanium (Ti) doping amount and magnetic heating performance of magnetite (Fe3O4). Superparamagnetic nanosized Ti-doped magnetite ((Fe1−x,Tix)3O4; x = 0.02, 0.03 and 0.05) particles were synthesized by sol-gel technique. In addition to (Fe1−x,Tix)3O4 nanoparticles, SiO2 coated (Fe1−x,Tix)3O4 nanoparticles were produced as core-shell structures to understand the effects of silica coating on the magnetic properties of nanoparticles. Moreover, the magnetic properties were associated with the Néel relaxation mechanism due to the magnetic heating ability of single-domain state nanoparticles. In terms of results, it was observed that the induced RF magnetic field for SiO2 coated (Fe0.97,Ti0.03)3O4 nanoparticles caused an increase in temperature difference (ΔT), which reached up to 22 °C in 10 min. The ΔT values of SiO2 coated (Fe0.97,Ti0.03)3O4 nanoparticles were very close to the values of uncoated Fe3O4 nanoparticles.

Magnetic Field Effects Induced in Electrical Devices Based on Cotton Fiber Composites, Carbonyl Iron Microparticles and Barium Titanate Nanoparticles

This work consists in the process of preparing magnetic active composite materials based on cotton fibers, iron carbonyl microparticles and barium titanate nanoparticles, and the electrical devices manufactured with them. For different compositions of the aforementioned ingredients, three such composites are manufactured and compacted at constant pressure between two electrodes. In the absence and in the presence of a magnetic field, using an RLC bridge, magnetocapacitive, magnetoresistive and magnetopiezoelectric effects are highlighted in the custom fabricated devices. It is shown that these effects are significantly influenced by the composition of the materials. Based on the model elaborated in this paper, the mechanisms that contribute to the observed effects are described and the theoretical predictions are shown to agree with the experimental data. The obtained results can be used in the assembly of hybrid magnetic active composites, which are low cost, ecological and have other useful physical characteristics for applications.

Polymeric Composite of Magnetite Iron Oxide Nanoparticles and Their Application in Biomedicine: A Review

A broad spectrum of nanomaterials has been investigated for multiple purposes in recent years. Some of these studied materials are magnetics nanoparticles (MNPs). Iron oxide nanoparticles (IONPs) and superparamagnetic iron oxide nanoparticles (SPIONs) are MNPs that have received extensive attention because of their physicochemical and magnetic properties and their ease of combination with organic or inorganic compounds. Furthermore, the arresting of these MNPs into a cross-linked matrix known as hydrogel has attracted significant interest in the biomedical field. Commonly, MNPs act as a reinforcing material for the polymer matrix. In the present review, several methods, such as co-precipitation, polyol, hydrothermal, microemulsion, and sol-gel methods, are reported to synthesize magnetite nanoparticles with controllable physical and chemical properties that suit the required application. Due to the potential of magnetite-based nanocomposites, specifically in hydrogels, processing methods, including physical blending, in situ precipitation, and grafting methods, are introduced. Moreover, the most common characterization techniques employed to study MNPs and magnetic gel are discussed.

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.

Modelling of Dynamic Behaviour in Magnetic Nanoparticles

The efficient development and utilisation of magnetic nanoparticles (MNPs) for applications in enhanced biosensing relies on the use of magnetisation dynamics, which are primarily governed by the time-dependent motion of the magnetisation due to externally applied magnetic fields. An accurate description of the physics involved is complex and not yet fully understood, especially in the frequency range where Néel and Brownian relaxation processes compete. However, even though it is well known that non-zero, non-static local fields significantly influence these magnetisation dynamics, the modelling of magnetic dynamics for MNPs often uses zero-field dynamics or a static Langevin approach. In this paper, we developed an approximation to model and evaluate its performance for MNPs exposed to a magnetic field with varying amplitude and frequency. This model was initially developed to predict superparamagnetic nanoparticle behaviour in differential magnetometry applications but it can also be applied to similar techniques such as magnetic particle imaging and frequency mixing. Our model was based upon the Fokker-Planck equations for the two relaxation mechanisms. The equations were solved through numerical approximation and they were then combined, while taking into account the particle size distribution and the respective anisotropy distribution. Our model was evaluated for Synomag®-D70, Synomag®-D50 and SHP-15, which resulted in an overall good agreement between measurement and simulation.

Iron-Loaded Carbon Aerogels Derived from Bamboo Cellulose Fibers as Efficient Adsorbents for Cr(VI) Removal

A unique iron/carbon aerogel (Fe/CA) was prepared via pyrolysis using ferric nitrate and bamboo cellulose fibers as the precursors, which could be used for high-efficiency removal of toxic Cr(VI) from wastewaters. Its composition and crystalline structures were characterized by FTIR, XPS, and XRD. In SEM images, the aerogel was highly porous with abundant interconnected pores, and its carbon-fiber skeleton was evenly covered by iron particles. Such structures greatly promoted both adsorption and redox reaction of Cr(VI) and endowed Fe/CA with a superb adsorption capacity of Cr(VI) (182 mg/g) with a fast adsorption rate (only 8 min to reach adsorption equilibrium), which outperformed many other adsorbents. Furthermore, the adsorption kinetics and isotherms were also investigated. The experiment data could be much better fitted by the pseudo-second-order kinetics model with a high correlating coefficient, suggesting that the Cr(VI) adsorption of Fe/CA was a chemical adsorption process. Meanwhile, the Langmuir model was found to better describe the isotherm curves, which implied the possible monolayer adsorption mechanism. It is noteworthy that the aerogel adsorbent as a bulk material could be easily separated from the water after adsorption, showing high potential in real-world water treatment.

Tailor made magnetic nanolights: fabrication to cancer theranostics applications

Nanoparticles having magnetic and fluorescent properties could be considered as a gift to materials scientists due to their unique magneto-optical qualities. Multiple component particles can overcome challenges related with a single component and unveil bifunctional/multifunctional features that can enlarge their applications in diagnostic imaging agents and therapeutic delivery vehicles. Bifunctional nanoparticles that have both luminescent and magnetic features are termed as magnetic nanolights. Herein, we present recent progress of magneto-fluorescent nanoparticles (quantum dots based magnetic nanoparticles, Janus particles, and heterocrystalline fluorescent magnetic materials), comprehensively describing fabrication strategies, types, and biomedical applications. In this review, our aim is not only to encompass the preparation strategies of these special types of magneto-fluorescent nanomaterials but also their extensive applications in bioimaging techniques, cancer therapy (targeted and hyperthermic), and sustained release of active agents (drugs, proteins, antibodies, hormones, enzymes, growth factors).

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.

Iron Oxide Nanoparticles in Regenerative Medicine and Tissue Engineering

In recent years, many promising nanotechnological approaches to biomedical research have been developed in order to increase implementation of regenerative medicine and tissue engineering in clinical practice. In the meantime, the use of nanomaterials for the regeneration of diseased or injured tissues is considered advantageous in most areas of medicine. In particular, for the treatment of cardiovascular, osteochondral and neurological defects, but also for the recovery of functions of other organs such as kidney, liver, pancreas, bladder, urethra and for wound healing, nanomaterials are increasingly being developed that serve as scaffolds, mimic the extracellular matrix and promote adhesion or differentiation of cells. This review focuses on the latest developments in regenerative medicine, in which iron oxide nanoparticles (IONPs) play a crucial role for tissue engineering and cell therapy. IONPs are not only enabling the use of non-invasive observation methods to monitor the therapy, but can also accelerate and enhance regeneration, either thanks to their inherent magnetic properties or by functionalization with bioactive or therapeutic compounds, such as drugs, enzymes and growth factors. In addition, the presence of magnetic fields can direct IONP-labeled cells specifically to the site of action or induce cell differentiation into a specific cell type through mechanotransduction.

Magnetic microgels and nanogels: Physical mechanisms and biomedical applications

Soft micro- and nanostructures have been extensively developed for biomedical applications. The main focus has been on multifunctional composite materials that combine the advantages of hydrogels and colloidal particles. Magnetic microgels and nanogels can be realized by hybridizing stimuli-sensitive gels and magnetic nanoparticles. They are of particular interest since they can be controlled in a wide range of biological environments by using magnetic fields. In this review, we elucidate physical principles underlying the design of magnetic microgels and nanogels for biomedical applications. Particularly, this article provides a comprehensive and conceptual overview on the correlative structural design and physical functionality of the magnetic gel systems under the concept of colloidal biodevices. To this end, we begin with an overview of physicochemical mechanisms related to stimuli-responsive hydrogels and transport phenomena and summarize the magnetic properties of inorganic nanoparticles. On the basis of the engineering principles, we categorize and summarize recent advances in magnetic hybrid microgels and nanogels, with emphasis on the biomedical applications of these materials. Potential applications of these hybrid microgels and nanogels in anticancer treatment, protein therapeutics, gene therapy, bioseparation, biocatalysis, and regenerative medicine are highlighted. Finally, current challenges and future opportunities in the design of smart colloidal biodevices are discussed.

Microwave-Synthesized Polysaccharide-Derived Carbon Dots as Therapeutic Cargoes and Toughening Agents for Elastomeric Gels

Fluorescent carbon dots (CDs) play a versatile role in materials science. Herein, we have developed alginate-derived nitrogen-doped CDs as a drug carrier and a toughening agent for hydrogels by a microwave-assisted method. In the first phase of work, we carried out covalent conjugation of the drug onto the CD surface for controlled delivery of drug molecules, and in the second phase of work, we demonstrated how CDs could act as a toughening agent as well as a viscosity modifier for poly(acrylic acid-co-methacrylamide) copolymer hydrogels. The hydrogels were evaluated by Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, and solid-state nuclear magnetic resonance. The hybrid hydrogels have been tested to be mechanically robust with extraordinary stretchability (∼1200% elongation at break), recoverable to the original position (low permanent set), tunable water uptake, and thixotropic character in dynamic stress. The crosslinked structure has been evaluated through void calculation revealing gradual densification of the network with increasing CD content. Exceptional gel strength (ratio of elastic modulus to loss modulus; G'/G″) has been achieved from analogous crosslinking made by CDs. The delayed network rupturing and superstretchability could make this material a good choice for soft biomaterials and soft robotics.

From Single-Core Nanoparticles in Ferrofluids to Multi-Core Magnetic Nanocomposites: Assembly Strategies, Structure, and Magnetic Behavior

Iron oxide nanoparticles are the basic components of the most promising magnetoresponsive nanoparticle systems for medical (diagnosis and therapy) and bio-related applications. Multi-core iron oxide nanoparticles with a high magnetic moment and well-defined size, shape, and functional coating are designed to fulfill the specific requirements of various biomedical applications, such as contrast agents, heating mediators, drug targeting, or magnetic bioseparation. This review article summarizes recent results in manufacturing multi-core magnetic nanoparticle (MNP) systems emphasizing the synthesis procedures, starting from ferrofluids (with single-core MNPs) as primary materials in various assembly methods to obtain multi-core magnetic particles. The synthesis and functionalization will be followed by the results of advanced physicochemical, structural, and magnetic characterization of multi-core particles, as well as single- and multi-core particle size distribution, morphology, internal structure, agglomerate formation processes, and constant and variable field magnetic properties. The review provides a comprehensive insight into the controlled synthesis and advanced structural and magnetic characterization of multi-core magnetic composites envisaged for nanomedicine and biotechnology.