The emergence of rapid clinical testing for cerebrospinal fluid (CSF) leaks after experiencing surgery, trauma, tumors and other defects are considered to be crucial. This is because these leaks can result in life-threatening conditions, like intracranial and meningitis infection.
Cerebrospinal fluid detection in action showing inserted sensor strip and 4-digit readout. Image Credit: Minghan Xian, Chan-Wen Chiu, Patrick Carey, Chaker Fares, Liya Chen, Rena Wu, Fan Ren, Cheng-Tse Tsai, Siang-Sin Shan, Yu-Te Liao, Josephine F Esquivel-Upshaw, Stephen J. Pearton.
For such leaks to be detected with the help of primary conventional methods, like immunofixation electrophoresis (IFE) and enzyme-linked immunosorbent assay (ELISA), it takes hours or days to get the results. Secondary methods like optical techniques depend on MRI, frequently fail to determine the specific leak site.
In the Journal of Vacuum Science & Technology B by AIP Publishing, scientists from the University of Florida and Yang Ming-Chiao Tung University have come up with a single-use sensor strip that can be utilized with a circuit board, similar to a hand-held glucometer, for the detection of cerebrospinal fluid leaks.
The presence of cerebrospinal fluid in the brain and spinal cord offers crucial physiological functions, like waste removal and shock absorption. CSF directly connects extracranial space to subarachnoid space, a compartment inside which is the existence of major cerebral blood vessels.
Besides surgery, trauma and congenital defects, CSF leaks probably take place due to obstructive sleep apnea, obesity and high intracranial pressure. Discharge of cerebrospinal fluid occurs via the ears or the nose.
We were surprised to find out that our detection method could not only provide the result within one second, but our detection limit was also a lot more sensitive for a very diluted concentration than existing detection methods.
Minghan Xian, Study Co-Author, University of Florida
The scientists gathered nine human clinical samples from a Florida hospital and introduced the test fluid into a small liquid channel on the tip of the sensor strips. The liquid channel kept electrodes, containing antibodies on the surface specific to proteins found only in the cerebrospinal fluid of humans.
As soon as the test fluid was inserted into the liquid channel, some short electrode pulses were sent via the electrodes. Then, the circuit board examined the signal and generated a four-digit number that associates with the concentration of the protein, known as beta-2-transferrin, found in CSF.
The scientists were capable of detecting beta-2-transferrin in the fluid sample even when other salts and proteins were present and from samples across different patients.
The scientists utilized similar technology to detect proteins in SARS-CoV2. This is the virus that is responsible for causing COVID-19. Their next phase of the study will concentrate on detecting heart disease biomarkers and numerous cancers.
Journal Reference:
Xian, M., et al. (2022) Digital biosensor for human cerebrospinal fluid detection with single-use sensing strips. Journal of Vacuum Science & Technology B. doi.org/10.1116/6.0001576