Trypsin inhibition, calcium and zinc ion binding of starch–g-poly(acrylic acid) copolymers and starch/poly(acrylic acid) mixtures for peroral peptide drug delivery

Enhanced pH-responsive carrier system based on alginate and chemically modified carboxymethyl chitosan for oral delivery of protein drugs: Preparation and in-vitro assessment

“…Also, some studies showed that polymers containing carboxylic groups have the ability to protect protein and peptide drugs from some protease enzymes such as trypsin and chymotrypsin. This enzyme inhibitory effect was mainly attributed to ability of these polymers to bind with extracellular divalent cations (calcium and zinc) (Ameye et al, 2001). The more reduction in concentration of extracellular divalent ion can also help in opening of tight junctions and consequently improves the paracellular transport of protein drugs across the intestinal epithelium (Luessen et al, 1995).…”

Oral insulin delivery – challenges and strategies

“…Efforts have been made by various researchers to protect polymeric delivery systems by the use of enzyme inhibitors. In an attempt to inhibit trypsin, starch-g-poly(acrylic acid) copolymers and starch/poly(acrylic acid) mixtures were evaluated using Carbopol ® 934P as the reference polymer for Ca 2+ and Zn 2+ binding and enzyme inhibition was observed [132]. Chitosans have also been chemically modifi ed to serve as enzyme inhibitors and have shown inhibitory effects against pancreatic serine proteases [133].…”

Temperature and pH sensitive star‐shaped material for the controlled release of coenzyme A

“…[6][7][8][9][10][11] However, biological applications need materials with good biocompatibility. 12,13 Poly(ethylene oxide) (PEO) is a biocompatible nonionic water-soluble polymer. Polymer including PEO received growing attention for applications in various technologies including medical applications such as wound dressing, controlled release drug systems, and others.…”