Abstract: Using renewable natural polymer resources to develop functional therapeutics and nanomedicine is a sustainable research area at the interface of multidisciplinary subjects such as green chemistry, polymer science and technology, nanobiomaterial and clinical medicine. It is disclosed that natural polysaccharides and their derivatives exhibited good biocompatibility, promising drug/gene delivery efficiency and immunomodulation capability, which have attracted tremendous attention in recent decades. This article reviewed up to date progresses of various natural polysaccharides and their derivatives as immunomodulators. The impact of molecular factors on immunomodulation-related features were stated, moreover, possible future outlooks on the natural polysaccharide-based immunomodulators were also discussed.

Key words: natural polysaccharides, immune modulation, structural factors, perspective