Viscosan™ is technically speaking a homogenously (randomly) deacetylated chitin, a polysaccharide built up by N-acetyl-glucosamine and glucosamine units. By keeping a strict control of the deacetylation pattern and degree of deacetylation a number of useful properties can be tailored. Examples of such properties are: biodegradation rate, inflammatory responce, solubility and viscosity. Viscosan™ is manufactured to give products in a typical range from 40% to 70% degree of deacetylation and in different viscosities, see catalogue.

Chitosan is also derived from chitin but has generally a higher degree of deacetylation (80-95%) and a different distribution pattern of its remaing acetyl groups, in litterature often refered to as having a “blockwise” deacetylation pattern. Technically speaking chitosan is a heterogeneously deacetylated chitin.

Important differences between Viscosan™ and traditional Chitosan

Both polymers are biodegradable, antimicrobial and mucoadhesive. However, there are differences unique for Viscosan™ and makes it favourable in many applications. In contrast to traditional chitosans, which are practically insoluble at neutral pH and degrade slowly when used in vivo, Viscosan™ is soluble at physiological pH, degrades faster in vivo, and is less inflammatory.

The cartoon above illustrates the structural differences between chitin, Viscosanand Chitosan. The blue line is representing the long polysaccharide, built up by glucosamine, and the black bars are representing acetyl groups.
1. Sannan et. al., Makromol.Chem.177, 3589-3600 (1976)
2. M. Vårum et. al., Carbohydrate Polymers, 25, 65-70, (1994)
3. Tomihata and Y. Ikada, Biomaterials, 18, 567-575 (1997)
4. D. Fang et al., Biomaterials 129, 127-138 (2017)