OFM uses probes with macroscopic openings to exchange substances in a liquid pathway that is based on convection rather than diffusion so that the exchange can occur non-selectively in either direction.
The direct liquid pathway between the probe’s perfusate and the surrounding interstitial fluid (ISF) provides a diluted but otherwise unchanged ISF sample, since no dialysis or filtering occurs. OFM provides unfiltered, merely diluted interstitial fluid from the investigated target tissues (skin, adipose, brain tissue). Endogenous and exogenous substances present in the interstitial fluid of targeted tissues can thus be quantified without the risk of investigating an altered sample.
Dermal OFM (dOFM) measures PK/PD of drugs in the dermis after topical or systemic application.
e.g. antibodies, protein-bound drugs.
Cerebral OFM (cOFM) monitors BBB function and drug transport across the intact blood-brain-barrier (BBB).
e. g. nanoformulations, antibodies.
Adipose OFM (aOFM) assesses transport routes, drug dispersion and drug effects in adipose tissue,
e.g. insulins, GLP-1 receptor agonists.