Spinal cord repair with PHPMA hydrogel containing RGD peptides (NeuroGel (TM))

A biocompatible hydrogel of poly[N-(2-hydroxypropyl)methacrylamide] (PHPMA) which includes the cell-adhesive region of fibronectin Arg-Gly-Asp was syn thesized and its structure, theological and dielectric properties were char acterized. The ability of a PHPMA-RGD hydrogel to promote tissue regenerati on and support axonal outgrowth in the injured adult and developing rat spi nal cord was evaluated. The structure of the PHPMA-RGD hydrogel displayed a n interconnected porous structure, with viscoelastic properties similar to those of the neural tissue, and conductivity properties due to a peptide gr oup. The polymer hydrogel provided a structural, three-dimensional continui ty across the defect, facilitating the migration and reorganization of loca l wound-repair cells, as well as tissue development within the lesion. Angi ogenesis and axonal growth also occurred within the microstructure of the t issue network, and supraspinal axons migrated into the reconstructed cord s egment. In addition, the hydrogel induced a reduction of necrosis and cavit ation in the adjacent white and gray matter. These polymer hydrogel matrice s therefore display the potential to repair. tissue defects in the central nervous system by enhancing the development of a tissue equivalent as well as axonal growth across the reconstructed lesion. (C) 2001 Elsevier Science Ltd. All rights reserved.