Synthesis, physical properties, and biomedical applications of magnetic nanoparticles: a review

Gold/cobalt ferrite nanocomposite as a potential agent for photothermal therapy

The study encompasses an investigation of optical, photothermal and biocompatibility properties of a composite consisting of golden cores surrounded by superparamagnetic CoFe2O4 nanoparticles. Accompanied with the experiment, the computational modeling reveals that each adjusted magnetic nanoparticle redshifts the plasmon resonance frequency in gold and nonlinearly increases the extinction cross-section at ~800 nm. The concentration dependent photothermal study demonstrates a temperature increase of 8.2 K and the photothermal conversion efficiency of 51% for the 100 μg/mL aqueous solution of the composite nanoparticles, when subjected to a laser power of 0.5 W at 815 nm. During an in vitro photothermal therapy, a portion of the composite nanoparticles, initially seeded at this concentration, remained associated with the cells after washing. These retained nanoparticles effectively heated the cell culture medium, resulting in a 22% reduction in cell viability after 15 min of the treatment. The composite features a potential in multimodal magneto-plasmonic therapies.

Biocompatible gelatin-coated ferrite nanoparticles: A magnetic approach to advanced drug delivery

Nanotechnology has transformed drug delivery, offering opportunities to enhance treatment outcomes while minimizing adverse effects. This study focuses on gelatin-coated cobalt and manganese ferrite nanoparticles for potential drug delivery applications. The synthesis involved a co-precipitation method, and the nanoparticles were characterized using various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and vibrating sample magnetometer (VSM). Results revealed stable structures, distinct chemical features introduced by gelatin coating, and unique magnetic properties. The hemolysis assay demonstrated reduced hemolytic activity with gelatin coating, enhancing biocompatibility. Drug release studies indicated differential release profiles, with gelatin-coated cobalt ferrite exhibiting higher drug release compared to gelatin-coated manganese ferrite. The Higuchi model supported diffusion-controlled drug release for gelatin-coated cobalt ferrite. These findings suggest the potential of gelatin-coated ferrite nanoparticles for controlled and targeted drug delivery, highlighting their significance in advancing nanomedicine.

Investigation on the structural, magnetic, magnetocaloric and magnetotransport behaviour of La0.7Sr0.3MnO3 manganites synthesised by different routes

In the present investigation, we present the comparison of the structural, magnetic, magnetocaloric and magnetoresistance behavior of solid state and sol-gel derived La0.7Sr0.3MnO3. X-ray diffraction together with Rietveld refinement confirms the rhombohedral structure of the synthesised samples with the R3̄c space group. The ferromagnetic-to-paramagnetic transition temperature decreases from 360 K to 346 K for the nanocrystalline sample. The XPS measurements confirm the presence of Mn3+ in the synthesised samples. Furthermore, the polycrystalline sample exhibits a considerable -ΔSM of 4.68 J kg-1 K-1 at 360 K for a field change of 50 kOe and a relative cooling power (RCP) of 205 J kg-1. A -ΔSM of 1.14 J kg-1 K-1 was obtained for the nanocrystalline sample at 346 K with an RCP of 83 J kg-1. Critical exponent analysis has also been performed on both samples to establish the universality class. Both samples exhibit a distinct metal-to-insulator transition, which increases with grain size from 187 K to 334 K as a result of grain growth and decreased grain boundary. As the grain size increases, the resistivity decreases and shifts towards high temperatures with increasing magnetic fields. The itinerant electron model (IEO) which is based on the hopping of O 2p itinerant electrons has been used to explain the resistivity behaviour of the samples. It is found that the negative magnetoresistance also increases with a decrease in grain size where the highest %MR of 26% can be observed for the nanocrystalline sample. These results make La0.7Sr0.3MnO3 a suitable candidate for multifunctional applications.

A review of recent advances in the use of complex metal nanostructures for biomedical applications from diagnosis to treatment

Complex metal nanostructures represent an exceptional category of materials characterized by distinct morphologies and physicochemical properties. Nanostructures with shape anisotropies, such as nanorods, nanostars, nanocages, and nanoprisms, are particularly appealing due to their tunable surface plasmon resonances, controllable surface chemistries, and effective targeting capabilities. These complex nanostructures can absorb light in the near-infrared, enabling noteworthy applications in nanomedicine, molecular imaging, and biology. The engineering of targeting abilities through surface modifications involving ligands, antibodies, peptides, and other agents potentiates their effects. Recent years have witnessed the development of innovative structures with diverse compositions, expanding their applications in biomedicine. These applications encompass targeted imaging, surface-enhanced Raman spectroscopy, near-infrared II imaging, catalytic therapy, photothermal therapy, and cancer treatment. This review seeks to provide the nanomedicine community with a thorough and informative overview of the evolving landscape of complex metal nanoparticle research, with a specific emphasis on their roles in imaging, cancer therapy, infectious diseases, and biofilm treatment. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Diagnostic Tools > Diagnostic Nanodevices.

Phytonano silver for cosmetic formulation- synthesis, characterization, and assessment of antimicrobial and antityrosinase potential

Novel formulations of silver nanoparticles remain exciting if it is applicable for cosmetic purposes. This study proposes a value-added brand-new nanomaterial for improving skin complexion by inhibiting melanin development. This work aims to develop cost effective, efficient, natural silver nanoparticles phytomediated by aqueous extract of leaf sheath scales of Cocos nucifera (Cn-AgNPs) having potential as tyrosinase inhibitors hindering melanin synthesis. The formation of Cn-AgNPs was assessed spectrophotometrically and confirmed by the sharp SPR spectrum at 425 nm. The chemical composition profiling was characterized by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy. The morphology was confirmed by Field Emission Scanning Electron Microscopy (FESEM) and the thermal stability was assessed by Thermogravimetric analysis (TGA). Pharmacological application studies supported the materialization of Cn-AgNPs with significant antityrosinase potential and considerably improved antibacterial and antioxidant properties. Cn-AgNPs showed potential antibacterial effects against gram-positive and negative strains, including prominent infectious agents of the skin. Antioxidant capacity was confirmed with an IC50 of 57.8 μg/mL by DPPH radical scavenging assay. Furthermore, in vitro melanin content determination was performed using SK-MEL cells. Cell line studies proved that Cn-AgNPs decrease the melanin content of cells. The IC50 value obtained was 84.82 μg/mL. Hence Cn-AgNPs is proposed to be acting as a whitening agent through lessening cellular melanin content and as a significant inhibitor of tyrosinase activity. The antioxidant properties and antibacterial effects can contribute to skin rejuvenation and can prevent skin infections as well. This evidence proposes the development of a new nanostructured pharmaceutical and cosmetic formulation from Cocos nucifera leaf sheath scales.

Magnetic two-dimensional nanocomposites for multimodal antitumor therapy: a recent review

Magnetic two-dimensional nanocomposites (M2D NCs) that synergistically combine magnetic nanomedicine and 2D nanomaterials have emerged in multimodal antitumor therapy, attracting great interest in materials science and biomedical engineering. This review provides a summary of the recent advances of M2D NCs and their multimodal antitumor applications. We first introduce the design and fabrication of M2D NCs, followed by discussing new types of M2D NCs that have been recently reported. Then, a detailed analysis and discussions about the different types of M2D NCs are presented based on the structural categories of 2D NMs, including 2D graphene, transition metal dichalcogenides (TMDs), transition metal carbides/nitrides/carbonitrides (MXenes), black phosphorus (BP), layered double hydroxides (LDHs), metal organic frameworks (MOFs), covalent organic frameworks (COFs) and other 2D nanomaterials. In particular, we focus on the synthesis strategies, magnetic or optical responsive performance, and the versatile antitumor applications, which include magnetic hyperthermia therapy (MHT), photothermal therapy (PTT), photodynamic therapy (PDT), drug delivery, immunotherapy and multimodal imaging. We conclude the review by proposing future developments with an emphasis on the mass production and biodegradation mechanism of the M2D NCs. This work is expected to provide a comprehensive overview to researchers and engineers who are interested in such a research field and promote the clinical translation of M2D NCs in practical applications.

Harnessing Hyperthermia: Molecular, Cellular, and Immunological Insights for Enhanced Anticancer Therapies

Hyperthermia, the raising of tumor temperature (≥39°C), holds great promise as an adjuvant treatment for cancer therapy. This review focuses on 2 key aspects of hyperthermia: its molecular and cellular effects and its impact on the immune system. Hyperthermia has profound effects on critical biological processes. Increased temperatures inhibit DNA repair enzymes, making cancer cells more sensitive to chemotherapy and radiation. Elevated temperatures also induce cell cycle arrest and trigger apoptotic pathways. Furthermore, hyperthermia modifies the expression of heat shock proteins, which play vital roles in cancer therapy, including enhancing immune responses. Hyperthermic treatments also have a significant impact on the body's immune response against tumors, potentially improving the efficacy of immune checkpoint inhibitors. Mild systemic hyperthermia (39°C-41°C) mimics fever, activating immune cells and raising metabolic rates. Intense heat above 50°C can release tumor antigens, enhancing immune reactions. Using photothermal nanoparticles for targeted heating and drug delivery can also modulate the immune response. Hyperthermia emerges as a cost-effective and well-tolerated adjuvant therapy when integrated with immunotherapy. This comprehensive review serves as a valuable resource for the selection of patient-specific treatments and the guidance of future experimental studies.

Anticancer potential of biologically synthesized silver nanoparticles using Lantana camara leaf extract

A Lantana camara leaf (LC) extract was used as a mild reducing agent to produce silver metal nanoparticles (LC-AgNPs) efficiently. The size, shape, and morphology of synthesized silver nanoparticles were verified. LC-AgNPs were found in LC extract by XRD. The optimal concentrations of silver nitrate and LC extract necessary for the production of stable silver nanoparticles were determined. The LC-AgNPs were found spherical in form and monodispersed. Under optimal conditions, the round LC-AgNPs of 50-90 nm were utilized to cure lung cancer (A549 cell line) and breast cancer (MCF7) cell lines. Finally, the produced LC-AgNPs enhanced anti-cancer efficacy against A549 cells, with an IC50 = 49.52 g/mL. Similarly, the effect of LC-AgNPs on MCF7 cell line was assessed using an MTT test and inhibitory concentration (IC50) was determined found that 46.67 g/mL.