**3.7 Medicine and biotechnology**

Smart polymeric materials may be chemically attached to bio-substances or physically combined with them to create a vast variety of polymeric materials and bio-molecular systems that really can adapt to physiological and chemical stimuli. Oligosaccharides, Polypeptides, glucose and polysaccharides, solitary as well as double-sided oligonucleotides, DNA plasmid, basic lipids and ligands, phospholipids, as well as synthesized medicine compounds are examples of bio-substances that can be polymer linked. Smart polymeric materials and sensitive surfaces that cope with environmental stimuli are made with these materials. Smart polymers with sizespecific switches for turning proteins on and off were also studied. When a sensible polymer chain is connected to a protein complex that is further away from active site, the expanded polymer chain shields the active-locations, preventing bigger molecules from attaching. These polymers operate as a molecular gatekeeper, limiting the types of molecules that really can attach to proteins depending on their size [85].
