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Updated: Sep 24, 2025
Manganese Oxide Nanoparticle Synthesis by Thermal Decomposition of ManganeseII Acetylacetonate
Published on: June 18, 2020
Cytocompatible manganese dioxide-based hydrogel nanoreactors for MRI imaging
Soraia V Lopes1, Piotr Walczak2, Miroslaw Janowski3
13B's Research Group, Research Institute on Biomaterials, Biodegradables and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga, Guimarães, Portugal.
Manganese dioxide nanoparticles in hydrogels show potential for manganese-enhanced MRI (MEMRI) and reactive oxygen species scavenging. Commercial type 1 nanoparticles were less toxic than synthesized ones, with lower hyaluronic acid content improving cell viability.
Area of Science:
- Biomaterials Science
- Nanotechnology
- Medical Imaging
Background:
- Nanoparticles enhance magnetic resonance imaging (MRI) contrast and specificity.
- Manganese (Mn2+)-based nanoparticles are investigated for manganese-enhanced MRI (MEMRI).
- Mn2+ can scavenge reactive oxygen species (ROS), relevant for neurodegenerative diseases.
Purpose of the Study:
- To develop nanoreactors for combined MEMRI contrast enhancement and ROS scavenging.
- To create nanoreactors using methacrylated gellan gum (GG-MA) and hyaluronic acid (HA) hydrogels embedded with manganese dioxide (MnO2) nanoparticles.
- To characterize the physico-chemical properties and in vitro cytotoxicity of these nanoreactors.
Main Methods:
- Fabrication of GG-MA/HA hydrogels with different MnO2 nanoparticle types (synthesized, commercial types 1 and 2).
- Physico-chemical characterization: dynamic light scattering, scanning electron microscopy, water uptake, degradation studies.
- In vitro cytotoxicity assessment using L929 fibroblast cell line over 72 hours.
Main Results:
- Nanoreactors synthesized with an average size of 70 nm and round morphology.
- Hydrogel stability was unaffected by nanoparticle concentration or HA ratio.
- Synthesized MnO2 nanoparticles reduced cytocompatibility; commercial type 1 showed lower toxicity.
- Lower HA content enhanced cell proliferation and viability.
- Higher concentrations of synthesized and commercial type 1 MnO2 nanoparticles did not impair cell viability, unlike commercial type 2.
Conclusions:
- GG-MA/HA hydrogels embedded with MnO2 nanoparticles show promise as nanoreactors for MEMRI and ROS scavenging.
- Commercial type 1 MnO2 nanoparticles demonstrated better cytocompatibility compared to synthesized ones.
- Optimizing HA content and selecting appropriate MnO2 types are crucial for developing effective and safe nanoreactors for biomedical applications.
