Energy Conversion and Biocompatibility of Surface Functionalized Magnetite Nanoparticles with Phosphonic Moieties

Biofunctionalization of Magneto-Plasmonic Fe3O4@SiO2-NH2-Au Heterostructures with the Cellulase from Trichoderma reesei

The study focuses on the synthesis of Fe3O4@SiO2-NH2-Au heterostructures with magneto-plasmonic properties composed of well-defined cubic Fe3O4 cores (79 nm) covered with 10 nm silica shell and gold nanoparticles (8 nm) fabricated on silica shell. The surface-anchored MHDA (16-mercaptohexadecanoic acid) linker facilitated cellulase bioconjugation, which was confirmed through Raman spectroscopy. The presence of gold nanoparticle islands on the heterostructure enabled surface-enhanced Raman scattering (SERS), demonstrating the potential for bioactive substance identification. Immobilization of cellulase allowed for pH enhancement and enzyme thermal stability. The optimal pH shifted from 4.0 (free enzyme) to 6.0 while thermal stability increased by 20 °C. The immobilized cellulase kept its 49% activity after five hydrolysis cycles, compared to significantly lower activity for free cellulase. The proposed heterostructures for cellulase immobilization demonstrate potential for practical applications.

The Biological Impact of Some Phosphonic and Phosphinic Acid Derivatives on Human Osteosarcoma

Osteosarcoma malignancy currently represents a major health problem; therefore, the need for new therapy approaches is of great interest. In this regard, the current study aims to evaluate the anti-neoplastic potential of a newly developed phosphinic acid derivative (2-carboxyethylphenylphosphinic acid) and, subsequently, to outline its pharmaco-toxicological profile by employing two different in vitro human cell cultures (keratinocytes-HaCaT-and osteosarcoma SAOS-2 cells), employing different techniques (MTT assay, cell morphology assessment, LDH assay, Hoechst staining and RT-PCR). Additionally, the results obtained are compared with three commercially available phosphorus-containing compounds (P1, P2, P3). The results recorded for the newly developed compound (P4) revealed good biocompatibility (cell viability of 77%) when concentrations up to 5 mM were used on HaCaT cells for 24 h. Also, the HaCaT cultures showed no significant morphological alterations or gene modulation, thus achieving a biosafety profile even superior to some of the commercial products tested herein. Moreover, in terms of anti-osteosarcoma activity, 2-carboxyethylphenylphosphinic acid expressed promising activity on SAOS-2 monolayers, the cells showing viability of only 55%, as well as apoptosis features and important gene expression modulation, especially Bid downregulation. Therefore, the newly developed compound should be considered a promising candidate for further in vitro and in vivo research related to osteosarcoma therapy.

Polyrhodanine-based nanomaterials for biomedical applications: A review

Rhodanine is a heterocyclic organic compound that has been investigated for its potential biomedical applications, particularly in drug discovery. Rhodanine derivatives have been examined as the medication options for numerous illnesses, including cancer, inflammation, and infectious diseases. Some rhodanine derivatives have also shown promising activity against drug-resistant strains of bacteria and viruses. One of these derivatives is polyrhodanine (PR), a conducting polymer that has gained attention for its biomedical properties. This review article summarises the latest advancements in creating biomaterials based on PR for biosensing, antimicrobial treatments, and anticancer therapies. The distinctive characteristics of PR, such as biocompatibility, biodegradability, and good conductivity, render it an attractive candidate for these applications. The article also explores obstacles and potential future paths for advancing biomaterials made with PR, including synthesis modifications, characterisation techniques, and in vivo evaluation of biocompatibility and efficacy. Overall, as an emerging research topic, this review emphasises the potential of PR as a promising biomaterial for various biomedical applications and provides insights into the contemporary state of research and prospective directions for investigation.

Temperature effects induced by NIR photo-stimulation within Ist and IInd optical biological windows of seed-mediated multi-shell nanoferrites

Different types of ferrite core-shell structures, namely CoFe₂O₄@CoFe₂O₄, CoFe₂O₄@Fe₃O₄, CoFe₂O₄@MnFe₂O₄, and CoFe₂O₄@MnFe₂O₄@ZnFe₂O₄, were prepared by the seed-mediated approach. We show that this synthetic methodology offers great and important flexibility in the engineering of multi-shell ferrite nanoparticles which can be further used in various advanced applications. This impressive tool can be used for particle size tuning of homo- and heterostructures through convenient control of the concentration of metal acetylacetonates without the necessity of changing synthetic parameters, i.e., temperature, time, and solvent. The contactless conversion of laser light within I^st (808 nm) and II^nd (1122 nm) biological optical windows was studied on the fabricated ferrite core-shell materials which showed promising heating effects that can be a basis of their practical exploitation in the biomedical field.

Synergic Temperature Effect of Star-like Monodisperse Iron Oxide Nanoparticles and Their Related Responses in Normal and Cancer Cells

Magnetic nanoparticle (MNP) anisotropy has been tailored by the preparation of MNPs having different shapes (star-like, cubic, and polyhedral) using a self-modified rapid hot-injection process. The surface modification of MNPs was performed through etidronic ligand grafting with a strong binding affinity to mixed metal oxides, ensuring sufficient colloidal stability, surface protection, and minimized aggregation and interparticle interactions. The heating effect was induced by contactless external stimulation through the action of an alternating magnetic field and NIR laser radiation (808 nm). The efficacy of the energy conversion was evaluated as a function of the particle shape, concentration, and external stimuli parameters. In turn, the most efficient star-like particles have been selected to study their response in contact with normal and cancer cells. It was found that the star-like MNPs (Fe₃O₄ SL-NPs) at 2 mg/mL concentration induce necrosis and significantly alter cell cycle progression, while 0.5 mg/mL can stimulate the antioxidative and anti-inflammatory response in normal cells. A biologically relevant heating effect leading to heat-mediated cell death was achieved at a 2 mg/mL concentration of star-like particles and was enhanced by the addition of ascorbic acid (AA). AA-mediated photomagnetic hyperthermia can lead to the modulation of the heat-shock response in cancer cells that depends on the genotypic and phenotypic variations of cell lines.

Alternating magnetic field and NIR energy conversion on magneto-plasmonic Fe3O4@APTES–Ag heterostructures with SERS detection capability and antimicrobial activity

Fe3O4@APTES–Ag is a potential multipurpose platform for biological applications such as photomagnetic therapies, analytic probes exploiting the SERS effect and antibacterial activity.

Multifunctional Properties of Binary Polyrhodanine Manganese Ferrite Nanohybrids-From the Energy Converters to Biological Activity

The PRHD@MnFe₂O₄ binary hybrids have shown a potential for applications in the biomedical field. The polymer cover/shell provides sufficient surface protection of magnetic nanoparticles against adverse effects on the biological systems, e.g., it protects against Fenton’s reactions and the generation of highly toxic radicals. The heating ability of the PRHD@MnFe₂O₄ was measured as a laser optical density (LOD) dependence either for powders as well as nanohybrid dispersions. Dry hybrids exposed to the action of NIR radiation (808 nm) can effectively convert energy into heat that led to the enormous temperature increase ΔT 170 °C (>190 °C). High concentrated colloidal suspensions (5 mg/mL) can generate ΔT of 42 °C (65 °C). Further optimization of the nanohybrids amount and laser parameters provides the possibility of temperature control within a biologically relevant range. Biological interactions of PRHD@MnFe₂O₄ hybrids were tested using three specific cell lines: macrophages (RAW 264.7), osteosarcoma cells line (UMR-106), and stromal progenitor cells of adipose tissue (ASCs). It was shown that the cell response was strongly dependent on hybrid concentration. Antimicrobial activity of the proposed composites against Escherichia coli and Staphylococcus aureus was confirmed, showing potential in the exploitation of the fabricated materials in this field.

Efficient non-contact heat generation on flexible, ternary hydroxyapatite/curdlan/nanomagnetite hybrids for temperature controlled processes

The ternary HAp/curdlan/nanomagnetite hybrids with ceramic and polymer phase incorporation of magnetite nanoparticles (MNPs) were fabricated to study their heating ability under action of the alternating magnetic field (AMF), 808 nm near infrared laser radiation (NIR) and their synergic stimulation. The energy conversion was evaluated in terms of the specific absorption rate (SAR) as a function of the MNPs concentration in composites and to estimate their potential in temperature-controlled regenerative processes and hyperthermia. Measurements were carried out on dry and Ringer's solution soaked composite materials in order to mimic in situ conditions. It was found that the MNPs release during prolonged experiment is limited and has no significant effect on energy conversion emphasizing stability of the hybrids. Incorporation of the MNPs in polymer phase of the hybrid can additionally limit particle leaking as well as plays a role as insulating layer for the heat dissipation lowering the risk of sample overheating. In general, it was shown that maximum temperature of hybrid can be achieved in a relatively short time of exposure to stimulating factors whereas its control can be done through optimization of experiment conditions. MNPs incorporation into the curdlan (polymer phase) lead to strengthening of the mechanical properties of the whole network.