@article {20042,
	title = {Development of GG-MA:MnO2 nanoreactors for MRI Imaging},
	journal = {First Achilles Conference - "Molecular and Biological Mechanisms of Tendon Homeostasis and Repair"},
	year = {2019},
	month = {2019-07-08 00:00:00},
	address = {Porto, Portugal},
	abstract = {<p>Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease which is not fully understood. Previous studies have shown evidences that oxidative stress can be involved in motor neuron degeneration in ALS, having the possibility of becoming a therapeutic target [1,4]. Manganese Enhanced Magnetic Resonance Imaging (MEMRI) has been used to study functionality, anatomy and neural connection within the nervous system and it can also be used to guide intrathecal drug/cell delivery [1]. Manganese ions (Mn<sup>2+</sup>) are important for brain health, can enter excitable cells and be transported along axons and across synapses. Additionally, they can be used as contrast agent for long-term T1-weighted imaging [1]. Studies have shown that manganese dioxide (MnO<sub>2</sub>) nanoparticles are able to scavenge Reactive Oxygen Species (ROS), via decomposition of hydrogen peroxide in water, oxygen and Mn<sup>2+ </sup>[2]. Thus, we intend to develop MnO<sub>2</sub> nano/microreactors that can be delivered and guided by MRI, thus regulating cell death apoptotic mechanisms and modulating inflammation in tissues. These MnO<sub>2</sub> nanoparticles are toxic at high dosages and induce adverse effects in cells [2]. Thus, the nanoparticles will be blended with a methacrylated gellan-gum (GG-MA) based matrix. GG-MA is an anionic microbial polysaccharide that was chosen due to its biocompatibility, biodegradability, easy functionalization and similarity with the extracellular matrix, as well as due to its high affinity with Mn<sup>2+</sup> ions [3]. GG-MA was obtained as previously described [3], and chemically characterized by FTIR and <sup>1</sup>H-NMR. As a source of Mn<sup>2+</sup>, we intend to compare the activity of MnO<sub>2</sub> nanoparticles synthetized according to a previously published protocol and commercially available ones. Rheology, stability, permeability and morphology were evaluated and further studies considering cell viability and ROS scavenging ability will be pursued.</p>},
	keywords = {GG-MA, MnO2 nanoreactors, MRI imaging, ROS scavenging},
	author = {Lopes, S. V. and Oliveira, E. P. and Reis, R. L. and Silva-Correia, J. and Oliveira, J. M.}
}
