▲(from the left) Professor Jun Ki Kim and Professor Sung Hoon Kim 

Intravital images are widely used in preclinical trials because living tissues and cells of small animals can be observed in real time. Various diagnoses and therapy evaluation could be brought to the next level if clearer images can be obtained. Asan Medical Center (AMC) team led by Professor Jun Ki Kim of the Department of Convergence Medicine and Professor Sung Hoon Kim of the Department of Anesthesiology and Pain Medicine recently succeeded in acquiring high-quality fluorescent intravital images with a intravital microscopy through minimized small animal movement after injecting a dexmedetomidine that has a sedative effect.

As breathing and pulmonary circulation continue in small animals even under anesthesia, involuntary movements are unavoidable within the target tissues for imaging. AMC team conducted the study after acquiring fluorescent intravital images of small animals using a two-photon fluorescence excitation microscope and dexmedetomidine. Two-photon fluorescence excitation microscope is one of the high-end intravital microscopy and has taken care of photobleaching and photodamaging effects that occur in existing intravital microscopy. Dexmedetomidine injection is less invasive than conventional methods and relatively simply reduces involuntary movements such as breathing in small animals. A comparison was made for in vivo two-photon fluorescence excitation microscopy measurements before and after injecting dexmedetomidine into small animals, and the results demonstrated the resolution of fluorescent images and videos improved after injecting the medication as breathing or heart movements of small animals stabilized. It was also observed that the effect of dexmedetomidine decreased the blood flow rate in tissue.

This research was conducted as an R&D project of the Ministry of Health and Welfare and support project of the Ministry of Science and ICT. Also, it was published in the ‘Microscopy and Microanalysis,’ a renowned academic journal in the field of microscopy. At the same time, a high-quality fluorescent intravital image acquired through dexmedtomidine made the cover of the journal.