PCL(2k)-PEG(5k)-BIO is a micelle-forming polymer with hydrophobic polycaprolactone (PCL) tethered to a hydrophilic PEG. The attached biotin is used for biotinylation due to its strong affinity with avidin or streptavidin. The PCL segment can be used to encapsulate hydrophobic drugs while the PEG can form a tight shell around the core to minimize drug degradation. Reagent grade, for research purpose.