Curtis, 31, suffered “a broken back, a broken neck, and a dislocated spine,” according to fighter Leah McCourt.
Since 2015, Curtis has competed professionally, appearing on Bellator and Cage Warriors shows.
“Sending my support and well wishes” to the Dublin warrior, McGregor wrote on social media.
Curtis and his family have also benefited from donations made by Belfast boxer Michael Conlan, MMA competitors Molly McCann and Dillon Danis, and coach John Kavanagh.
Belfast’s McCourt stated on Instagram that “there is no exact end date as to when his treatment will be complete”.
Ryan will never be able to pursue his passion for fighting and training mixed martial arts. a sport he has committed his entire life to since.
