Impact of static pressure on transmembrane fluid exchange in high molecular weight cut off microdialysis

• Published in: Biomedical microdevices Vol. 16; no. 2; pp. 301 - 310
• Main Authors: Chu, Jiangtao, Hjort, Klas, Larsson, Anders, Dahlin, Andreas P.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-04-2014; Springer Nature B.V
• Subjects: Biological and Medical Physics; Biomedical engineering; Biomedical Engineering and Bioengineering; Biophysics; Cerebrospinal Fluid - chemistry; Engineering; Engineering Fluid Dynamics; Engineering Science with specialization in Microsystems Technology; Female; Fluid mechanics; Humans; Male; Membranes; Microdialysis - methods; Models, Chemical; Nanotechnology; Pressure; Teknisk fysik med inriktning mot mikrosystemteknik; Colloid osmotic pressure; Microdialysis; Fluid recovery; Transmembrane pressure
• ISSN: 1387-2176; 1572-8781; 1572-8781
• DOI: 10.1007/s10544-013-9833-1

With the interest of studying larger biomolecules by microdialysis (MD), this sampling technique has reached into the ultrafiltration region of fluid exchange, where fluid recovery (FR) has a strong dependence on pressure. Hence in this study, we focus on the fluid exchange across the high molecular weight cut off MD membrane under the influence of the static pressure in the sampling environment. A theoretical model is presented for MD with such membranes, where FR has a linear dependence upon the static pressure of the sample. Transmembrane (TM) osmotic pressure difference and MD perfusion rate decide how fast FR increases with increased static pressure. A test chamber for
in vitro
MD under static pressure was constructed and validated. It can hold four MD probes under controlled pressurized conditions. Comparison showed good agreement between experiment and theory. Moreover, test results showed that the fluid recovery of the test chamber MD can be set accurately via the chamber pressure, which is controlled by sample injection into the chamber at precise rate. This
in vitro
system is designed for modelling
in vivo
MD in cerebrospinal fluid and studies with biological samples in this system may be good models for
in vivo
MD.