An osteoconductive collagen hyaluronate matrix for bone regeneration

A new type of collagen-hyaluronate (COL/HA) matrix was synthesized by cross -linking collagen fibers with modified hyaluronate polymers bearing active formyl groups. The resulting matrix is a three-dimensional scaffold consist ing of interconnected pores with an average size of 40 mu m and a high pore volume/surface area ratio. The covalent nature of the bond between the col lagen fibers and the modified hyaluronate was demonstrated by extended elut ion with phosphate buffered saline and by extraction in increasing ionic gr adients. The fraction of covalently bound hyaluronate in the matrix ranged from 5 to 25 w%. The total hyaluronate content of the COL/HA matrix affecte d both the in vitro non-enzymatic and enzymatic degradation as well as the in vivo turnover. When implanted in cranial defects in rats, the COL/HA mat rix demonstrated good biocompatibility and exhibited greater osteoconductiv e potential than matrices composed of either cross-linked collagen or cross -linked hyaluronate alone. (C) 1999 Elsevier Science Ltd. All rights reserv ed.