One-Pot Method for Preparation of Magnetic Multi-Core Nanocarriers for Drug Delivery

Biological macromolecule-based hydrogels with antibacterial and antioxidant activities for wound dressing: A review

Because of the complex symptoms resulting from metabolic dysfunction in the wound microenvironment during bacterial infections, along with the necessity to combat free radicals, achieving prompt and thorough wound healing remains a significant medical challenge that has yet to be fully addressed. Moreover, the misuse of common antibiotics has contributed to the emergence of drug-resistant bacteria, underscoring the need for enhancements in the practical and commonly utilized approach to wound treatment. In this context, hydrogel dressings based on biological macromolecules with antibacterial and antioxidant properties present a promising new avenue for skin wound treatment due to their multifunctional characteristics. Despite the considerable potential of this innovative approach to wound care, comprehensive research on these multifunctional dressings is still insufficient. Consequently, the development of advanced biological macromolecule-based hydrogels, such as chitosan, alginate, cellulose, hyaluronic acid, and others, has been the primary focus of this study. These materials have been enriched with various antibacterial and antioxidant agents to confer multifunctional attributes for wound healing purposes. This review article aims to offer a comprehensive overview of the latest progress in this field, providing a critical theoretical basis for future advancements in the utilization of these advanced biological macromolecule-based hydrogels for wound healing.

Iron oxide magnetic aggregates: Aspects of synthesis, computational approaches and applications

Superparamagnetic magnetite nanoparticles have been central to numerous investigations in the past few decades for their use in many applications, such as drug delivery, medical diagnostics, magnetic separation, and material science. However, the properties of single magnetic nanoparticles are sometimes not sufficient to accomplish tasks where a strong magnetic response is required. In light of this, aggregated magnetite nanoparticles have been proposed as an alternative advanced material, which may expand and combine some of the advantages of single magnetic nanoparticles, including superparamagnetism, with an enhanced magnetic moment and increased colloidal stability. This review comprehensively discusses the current literature on aggregates made of magnetic iron oxide nanoparticles. This review is divided into three sections. First, the current synthetic strategies for magnetite nanoparticle aggregates are discussed, together with the influence of different stabilizers on the primary crystals and the final aggregate size and morphology. The second section is dedicated to computational approaches, such as density functional methods (which permit accurate predictions of electronic and magnetic properties and shed light on the behavior of surfactant molecules on iron oxide surfaces) and molecular dynamics simulations (which provide additional insight into the influence of ligands on the surface chemistry of iron oxide nanocrystals). The last section discusses current and possible future applications of iron oxide magnetic aggregates, including wastewater treatment, water purification, medical applications, and magnetic aggregates for materials displaying structural colors.

Influence of Polymer Concentration on Drying of SPION Dispersions by Electrospinning

To improve the physical stability of nanoparticle dispersions, several methods for their transformation into stable and easily dispersible dry products have been investigated thus far. Recently, electrospinning was shown to be a novel nanoparticle dispersion drying method, which addresses the crucial challenges of the current drying methods. It is a relatively simple method, but it is affected by various ambient, process, and dispersion parameters, which impact the properties of the electrospun product. The aim of this study was, thus, to investigate the influence of the most important dispersion parameter, namely the total polymer concentration, on the drying method efficiency and the properties of the electrospun product. The formulation was based on a mixture of hydrophilic polymers poloxamer 188 and polyethylene oxide in the weight ratio of 1:1, which is acceptable for potential parenteral application. We showed that the total polymer concentration of prior-drying samples is closely related to their viscosity and conductivity, also affecting the morphology of the electrospun product. However, the change in morphology of the electrospun product does not affect the efficiency of SPION reconstitution from the electrospun product. Regardless of the morphology, the electrospun product is not in powder form and is therefore safer to handle compared to powder nanoformulations. The optimal total polymer concentration in the prior-drying SPION dispersion, which enables the formation of an easily dispersible electrospun product with high SPION-loading (65% (w/w)) and fibrillar morphology, was shown to be 4.2% (w/v).

Oleic Acid Protects Endothelial Cells from Silica-Coated Superparamagnetic Iron Oxide Nanoparticles (SPIONs)-Induced Oxidative Stress and Cell Death

Superparamagnetic iron oxide nanoparticles (SPIONs) have great potential for use in medicine, but they may cause side effects due to oxidative stress. In our study, we investigated the effects of silica-coated SPIONs on endothelial cells and whether oleic acid (OA) can protect the cells from their harmful effects. We used viability assays, flow cytometry, infrared spectroscopy, fluorescence microscopy, and transmission electron microscopy. Our results show that silica-coated SPIONs are internalized by endothelial cells, where they increase the amount of reactive oxygen species (ROS) and cause cell death. Exposure to silica-coated SPIONs induced accumulation of lipid droplets (LD) that was not dependent on diacylglycerol acyltransferase (DGAT)-mediated LD biogenesis, suggesting that silica-coated SPIONs suppress LD degradation. Addition of exogenous OA promoted LD biogenesis and reduced SPION-dependent increases in oxidative stress and cell death. However, exogenous OA protected cells from SPION-induced cell damage even in the presence of DGAT inhibitors, implying that LDs are not required for the protective effect of exogenous OA. The molecular phenotype of the cells determined by Fourier transform infrared spectroscopy confirmed the destructive effect of silica-coated SPIONs and the ameliorative role of OA in the case of oxidative stress. Thus, exogenous OA protects endothelial cells from SPION-induced oxidative stress and cell death independent of its incorporation into triglycerides.

Bioinspired Magnetic Nanochains for Medicine

Superparamagnetic iron oxide nanoparticles (SPIONs) have been widely used for medicine, both in therapy and diagnosis. Their guided assembly into anisotropic structures, such as nanochains, has recently opened new research avenues; for instance, targeted drug delivery. Interestingly, magnetic nanochains do occur in nature, and they are thought to be involved in the navigation and geographic orientation of a variety of animals and bacteria, although many open questions on their formation and functioning remain. In this review, we will analyze what is known about the natural formation of magnetic nanochains, as well as the synthetic protocols to produce them in the laboratory, to conclude with an overview of medical applications and an outlook on future opportunities in this exciting research field.

Comparison of Iron Oxide Nanoparticles in Photothermia and Magnetic Hyperthermia: Effects of Clustering and Silica Encapsulation on Nanoparticles’ Heating Yield

Photothermal therapy is gathering momentum. In order to assess the effects of the encapsulation of individual or clustered superparamagnetic iron oxide nanoparticles (SPIONs) on nanoparticle light-to-heat conversion, we designed and tested individual and clustered SPIONs encapsulated within a silica shell. Our study compared both photothermia and magnetic hyperthermia, and it involved individual SPIONs as well as silica-encapsulated individual and clustered SPIONs. While, as expected, SPION clustering reduced heat generation in magnetic hyperthermia, the silica shell improved SPION heating in photothermia.