Compositions comprising carboxypolysaccharides (CPS) including carboxymethylcellulose (CMC) and polyethylene glycols (PEGs) are provided where the PEG isa PEG-epoxide covalently linked to the CPS via an addition reaction In certainembodiments, the PEG attaches to only one CPS, forming a decorated CPS In otherembodiments, bi-functional PEG molecules are attached to adjacent CPSs, therebyforming a covalently cross-linked composition A PEG can be linked to the CPS byway of an ether linkage or by way of an ester linkage, and in still further embodiments,PEG molecule(s) can be attached to CPS molecule(s) by way of both ether and esterlinkages PEG/CMC compositions can include multi-branch and/or a multi-armPEG Compositions having desired viscoelastic properties can be used as space-fillingmaterials, load-bearing materials, anti-adhesion compositions for drug deliveryvehicles or for lubrication of tissues and medical instruments.
