Chitin- and chitosan-based strategies in wound healing

Nowadays, chronic wounds are still a huge health problem with a high impact on the patients’ quality of life. In this way, the development of an ideal wound dressing is of utmost importance. To accomplish that, researchers have been using natural polymers to produce new types of dressings, that can activate/direct specific cellular responses, leading to an improved healing process. Among the natural polymers, chitin presents notable antibacterial and antiinflammatory properties that are crucial for enhancing the wound healing process. Moreover, chitosan, a deacetylated form of chitin, has been one of the most used biopolymers due to its straightforward processability into different forms, antimicrobial activity, and capacity to promote/accelerate the healing process. This chapter provides an overview of the properties exhibited by chitin and chitosan as well as examples of their application in the development of dressings aimed to improve the healing process.This work was financed by the Foundation for Science and Technology (FCT)/MCTES, through funds from the State Budget, and by the European Regional Development Fund (ERDF), under the Portugal 2020 Program, through the Regional Operational Program of the Center (Centro2020), through the Projects with the reference UIDB/00709/2020 and UIDP/00709/2020. The funding from CENTRO-01-0145-FEDER-028989 and POCI-01-0145-FEDER-031462 is also acknowledged. Duarte de Melo-Diogo acknowledges CENTRO-01- 0145-FEDER-028989 for the funding given on the form of a research contract. Catia S.D. Cabral acknowl- ´ edges his PhD fellowship from FCT (UI/BD/151024/2021). Mariana F.P. Grac¸a acknowledges funding from the grant UBI-Santander/Totta.