Chitosan Amphiphilic Derivatives. Chemistry and Applications

Abstract

Chitosan is a natural polymer composed of randomly distributed-(1-4)-linked D-glucosamine (deacetylated unit) and Nacetyl-D-glucosamine (acetylated unit). It has been described as a non-toxic, biodegradable and biocompatible polymer with very interesting biological properties, such as permeation-enhancing and mucoadhesive properties, anticoagulant and antimicrobial activity and so on. Chitosan has been used in several areas such as biomedical, pharmaceutical and biotechnological fields as well as in the food industry. Recently, there has been a growing interest in the modification of chitosan to improve its solubility in physiological conditions, to introduce new applications or to improve chitosan biological properties. Research and development on a variety of amphiphilic copolymers containing hydrophobic and hydrophilic segments, have been very active due to their spontaneous self-assembly behaviour in aqueous media These smart transitions often lead to diverse functional compartment structures like micelles, vesicles and gels, which represent promising applications in the field of biotechnology and pharmaceutics. The aim of the present paper is to review the latest advances in the synthesis of chitosan amphiphilic derivatives with a special emphasis in their applications.

Friction behaviour of hydrophilic lubricious coatings for medical device applications

“…To improve the physical and biological properties, as well as widen the range of potential applications, versatile chitosan derivatives have been synthesised [22]. Amphiphilic derivatives are especially interesting, due to the presence of a hydrophobic molecules in the chitosan structure, which can modify the rheological behaviour, resulting in self-assembly ability [23][24][25]. There are also studies that show improvements in blood compatibility and antimicrobial activity [26].…”

Biomedical Activity of Chitin/Chitosan Based Materials—Influence of Physicochemical Properties Apart from Molecular Weight and Degree of N-Acetylation

“…Being a highly insoluble and chemically rather unreactive material, chitin has a much lower applicability than chitosan. Recently, there has been growing interest in the chemical modification of chitosan and chitin (e.g., [32][33][34][35]) in order to improve their solubility and extend their applications (e.g., [7,19,36,37]). …”

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“…During specific modifications without too many difficulties at C-2 position specific groups can be introduced to design polymers for selected applications. The main reaction easily performed involving the C-2 position is the quarterisation of the amino group or a reaction in which an aldehydic function reacts with -NH 2 by reductive amination 30 .…”