Encapsulation of ultra-hydrophobic sex hormones with Pluronics for medical applications

U-RHYTHM, www.u-rhythm.co.uk, is a groundbreaking wearable diagnostic clinical research device at the Bristol Medical School that uses micro-dialysis to sample hormones directly from human interstitial fluid at closely-space intervals throughout the day and night, monitoring the dynamics of hundreds of metabolites and advancing the field of endocrinology. However, ultra-hydrophobic sex hormones currently cannot be detected due to their low concentrations and their adsorption to the device tubing. Our trial experiments show that pre-coating the tubing with FDA-approved Pluronics F127 (a PEO-PPO-PEO copolymer) led to significant reduction in hormone adsorption, attributed to cooperative action of encapsulation of ultra-hydrophobic sex hormones by F127 micelles and formation of F127 surface layer on the tubing. Here, we propose a first comprehensive SANS study of self-assembly and encapsulation of the hormones with Pluronics in this context, varying hormone molecular architecture, concentration, and solution temperature, to provide critical complementary nano-structural evidence underpinning F127-sex hormone interaction, ultimately achieving enhanced clinical capacity of the U-RHYTHM technology.