Plant-based polyphenols are natural compounds, present in fruits and vegetables. During recent years, polyphenols have gained special attention due to their nutraceutical and pharmacological activities for the prevention and treatment of human diseases. Nevertheless, their photosensitivity and low bioavailability, rapid metabolism and short biological half-life represent the major limitations for their use, which could be overcome by polyphenols encapsulation (flavonoids and non-flavonoids) into chitosan (CS)-tripolyphosphate (TPP) based nanoparticles (NP). In this review, we particularly focused on the ionic gelation method for the NP design. This contribution exhaustively discusses and compares results of scientific reports published in the last decade referring to ionic gelation applied for the protection, controlled and site-directed delivery of polyphenols. As a consequence, CS-TPP NP would constitute true platforms to transport polyphenols, or a combination of them, to be used for the designing of a new generation of drugs or nutraceuticals.

Natural polymers, particularly polysaccharide, have been used as drug delivery systems for a variety of therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and non-parenteral administration. Chitosan, the second most abundant naturally occurring polysaccharide after cellulose, is a biocompatible and biodegradable mucoadhesive polymer that is extensively used in the preparation of nanoparticles (NPs). Chitosan NPs loaded with drugs were found to be stable, permeable and bioactive. In this review, the importance of chitosan and its derivatives in drug delivery is illustrated, different methods of preparation of chitosan and chitosan derivatives NPs and their physio- chemical properties are addressed. Moreover, the desirable characteristics of successful NPs based drug delivery systems, as well as the pharmaceutical applications of these NPs are also clearly explored.