Polymer brushes are macromolecular structures with polymer chains tethered to a surface resembling a brush. They have shown variety of uses in biological applications. Because of the nature of crafted polymers, the functionalized surfaces exhibit unique functions such as low friction, altered adhesion, protein binding and selective adsorption. Functionalization can be controlled by changing parameters such as grafting densities, chemical configurations, shapes and thickness. In this review, a particular emphasis has been provided for studies related to biological applications of polymer brushes based on their ultra-low friction, hydrophilic elongated surfaces, and binding properties. It provides useful information for researches and labs working on finding better solutions for drug delivery, arthritis, artificial joints, antibiofouling coatings and protein immobilization and purification.