In this era, there is a global concern in the use of bioactive molecules such as chitosan
in the field of antimicrobial and antioxidant benefits. Because of its biodegradability,
biological compatibility, antimicrobial, antioxidants activity, and high safety, chitosan
could be used in a large number of applications. It could exist in many forms, such
as fibers, gels, films, sponges, nanoparticles, and beads. The different biological
activities of chitosan and its products are extensively investigated to broaden the
application fields in several areas. Chitosan's natural properties depend strongly
on water and other solvent solubility. Consequently, the chitosan oligosaccharides
with a low polymerization degree are getting significant attention in the pharmaceutical
and medical applications because they have lower viscosity and higher water solubility
than chitosan. The objective of this review article is to put the antioxidant and
antimicrobial properties of chitosan and its derivatives under the spotlight. The
impacts of chitosan on physicochemical parameters like molecular weight and deacetylation
degree on its bioactivities are also identified. Additionally, other applications
of chitosan and its derivatives, including wound healing products, wastewater treatment,
and cosmetics, have also been highlighted.