Polysaccharides constructed hydrogels as vehicles for proteins and peptides. A review

Macromolecular drugs, such as proteins and peptides, are lately readily available and used in the treatment of diseases including diabetes and cancer, as well as in therapies such as gene therapy, wound dressing, and tissue engineering. However, the bioavailability, the extent and the rate at which these drugs reach the target tissue are highly dependent on the carrier and on the route of administration. Among the multitude of biocompatible polymers used to design vehicles for macromolecular drugs, polysaccharides are preferred due to their mucoadhesive, antimicrobial, and anti-inflammatory properties. This review aims to give an overview on the evolution of polysaccharide-based vehicles recommended in the controlled delivery of proteins and peptides, mainly reported in the last five years. Both physically and chemically cross-linked drug delivery systems are presented such as: porous hydrogels, polyelectrolyte complexes and layer-by-layer thin films. Even if the pharmaceutical formulations for oral administration of proteins and peptides are preferred, other friendly routes are discussed in this review, such as transdermal delivery.