Pharmaceutics (Nov 2024)

Improving the Theranostic Potential of Magnetic Nanoparticles by Coating with Natural Rubber Latex for Ultrasound, Photoacoustic Imaging, and Magnetic Hyperthermia: An In Vitro Study

  • Thiago T. Vicente,
  • Saeideh Arsalani,
  • Mateus S. Quiel,
  • Guilherme S. P. Fernandes,
  • Keteryne R. da Silva,
  • Sandra Y. Fukada,
  • Alexandre J. Gualdi,
  • Éder J. Guidelli,
  • Oswaldo Baffa,
  • Antônio A. O. Carneiro,
  • Ana Paula Ramos,
  • Theo Z. Pavan

DOI
https://doi.org/10.3390/pharmaceutics16111474
Journal volume & issue
Vol. 16, no. 11
p. 1474

Abstract

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Background/Objectives: Magnetic nanoparticles (MNPs) have gained attention in theranostics for their ability to combine diagnostic imaging and therapeutic capabilities in a single platform, enhancing targeted treatment and monitoring. Surface coatings are essential for stabilizing MNPs, improving biocompatibility, and preventing oxidation that could compromise their functionality. Natural rubber latex (NRL) offers a promising coating alternative due to its biocompatibility and stability-enhancing properties. While NRL-coated MNPs have shown potential in applications such as magnetic resonance imaging, their effectiveness in theranostics, particularly magnetic hyperthermia (MH) and photoacoustic imaging (PAI), remains underexplored. Methods: In this study, iron oxide nanoparticles were synthesized via coprecipitation, using NRL as the coating agent. The samples were labeled by NRL amount used during synthesis: NRL-100 for 100 μL and NRL-400 for 400 μL. Results: Characterization results showed that NRL-100 and NRL-400 samples exhibited improved stability with zeta potentials of −27 mV and −30 mV, respectively and higher saturation magnetization values of 79 emu/g and 88 emu/g of Fe3O4. Building on these findings, we evaluated the performance of these nanoparticles in biomedical applications, including magnetomotive ultrasound (MMUS), PAI, and MH. NRL-100 and NRL-400 samples showed greater displacements and higher contrast in MMUS than uncoated samples (5, 8, and 9 µm) at 0.5 wt%. In addition, NRL-coated samples demonstrated an improved signal-to-noise ratio (SNR) in PAI. SNR values were 24.72 (0.51), 31.44 (0.44), and 33.81 (0.46) dB for the phantoms containing uncoated MNPs, NRL-100, and NRL-400, respectively. Calorimetric measurements for MH confirmed the potential of NRL-coated MNPs as efficient heat-generating agents, showing values of 43 and 40 W/g for NRL-100 and NRL-400, respectively. Conclusions: Overall, NRL-coated MNPs showed great promise as contrast agents in MMUS and PAI imaging, as well as in MH applications.

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