“…Natural polymers that are extensively used in nanoparticle synthesis include chitosan, dextran, albumin, heparin, gelatin, and collagen ( 42 , 43 ). Chitosan-coated PLGA nanoparticles ( 44 , 45 ) and chitosan nanoparticles ( 46 – 49 ) can carry and deliver proteins in an active form and transport them to specific organs. Synthetic polymers, such as PEGylated PLA nanoparticles and PLA-PEG-PLA nanoparticles ( 50 – 54 ), poly-PLGA nanoparticles ( 55 ), monomethoxypolyethylene glycol-block-polycaprolactone nanoparticles ( 56 ), and N-(2-hydroxypropyl)-methacrylamide copolymers ( 57 ), assist in the transport of proteins within the drug capsules.…”