(K-401) Stimulation of Neurons Through a Chemomagnetic Approach Using the Neurotransmitter Capsaicin

Friday, October 13, 2023

9:30 AM – 10:30 AM PDT

Location: Exhibit Hall - Row K - Poster # 401

Presenting Author(s)

Athena B. Santi (she/her/hers)

Undergraduate Student
The University of Texas at San Antonio
San Antonio, Texas, United States

Primary Investigator(s)

GR

Gabriela Romero

Assistant Professor
University of Texas at San Antonio, United States

Introduction:: Neurodegenerative diseases, like Alzheimer’s and Parkinson’s disease, often result in loss of function in the neurons or neuron death. Current literature has cited capsaicin as a possible treatment to stimulate neurons that have been damaged due to neurodegenerative diseases. With the stimulation of these neurons, the debilitating effects of the damaged neurons may be mediated, and the quality of life may be improved for patients suffering from these diseases1. In this work, a chemomagnetic approach is used to stimulate neurons that have been damaged by neurodegenerative diseases by interrogation with the neurotransmitter capsaicin. Iron oxide magnetic nanoparticles (MNPs) coated with poly (oligo (ethylene glycol) methyl ether methacrylate) (POEGMA) brushes are used in tandem with alternating magnetic fields (AMFs) to locally release the neurotransmitter capsaicin from the MNPs onto hippocampal neurons2.

Materials and Methods:: Capsaicin is encapsulated inside a temperature-responsive polymer coating known as POEGMA that is functionally coated onto magnetic nanoparticles. The MNPs formulation is exposed to neurons by themselves and with AMFs. The purpose of using AMFs is to control the local release of the neurotransmitter onto hippocampal neurons through the magnetic heating of MNPs and the temperature response of the polymer coating. Four different groups are tested (neurons alone, AMFs alone, MNPs alone, and MNPs with AMFs) and analyzed to assess the chemomagnetic effects of the MNPs on hippocampal neurons. Cell viability assays and reactive oxygen species (ROS) tests have also been performed to evaluate the biological impact of the MNPs and the chemomagnetic stimulation.

Results, Conclusions, and Discussions:: In vitro experiments of hippocampal neuron stimulation show that the release of capsaicin from the MNPs is triggered via AMFs. The release of capsaicin is able to cause excitation and stimulation of hippocampal neurons. The live/dead assay shows no increase in deceased cells when the AMFs or MNPs are added, indicating that these methods of stimulation are non-toxic to the hippocampal cells.

Iron oxide magnetic nanoparticles were functionally coated with poly (oligo (ethylene glycol) methyl ether methacrylate) brushes that encapsulated the neurotransmitter capsaicin. These particles were used to evaluate the role of capsaicin in the stimulation of damaged neurons, both with and without the use of alternating magnetic fields. In vitro studies have shown that these functionally coated MNPs worked in tandem with AMFs to produce excitation in damaged hippocampal neurons. The toxicity of the MNPs was evaluated using live/dead assays and reactive oxygen species assays, and no toxic effects were observed.

Acknowledgements (Optional): :

References (Optional): :

1. Tyagi, S., Shekhar, N., & Thakur, A. K. (2022, February 12). Protective role of capsaicin in neurological disorders: An overview - neurochemical research. SpringerLink. https://link.springer.com/article/10.1007/s11064-022-03549-5#Sec2

2. Guntnur, R. T., Muzzio, N., Gomez, A., Macias, S., Galindo, A., Ponce, A., & Romero, G. (2022). On‐demand chemomagnetic modulation of striatal neurons facilitated by hybrid magnetic nanoparticles. Advanced Functional Materials, 32(35), 2204732. https://doi.org/10.1002/adfm.202204732