mPEG-CHO (MW 1000) is involved in the creation of three-dimensional porous scaffolds and acts as a carrier for active substances. The -CHO functional group interacts with the -NH2 functional group on chitosan chains to form a glutaraldehyde-like adduct, thereby functionalizing mPEG. This functionalization and cross-linking influence the rigidity of the delivery system, enabling the cross-linked conjugated system to possess slow-release capabilities.