Festschrift remark-It was an honor to be invited to honor Allan Hoffman on the occasion of his 60th birthday. It seems like yesterday that Allan and I shared an office in old Building 12 on the M.I.T. campus. At that time Allan had lost a bout with a snow covered mountain while on skis, and consequently moved about awkwardly in our already small room on crutches with a heavy cast. Despite these impediments, he carried on his classroom activities with typical energy. It was even earlier that at M.I.T., under the supervision of Ed Gilliland and myself, he carried out his doctoral research on the radiation grafting of styrene to polyethylene. Both he and I have dabbled in radiation chemistry on and off since then-he far more than I. Neither of us at that epoch had much idea about biomaterials or medical applications of materials-at least I did not-perhaps Allan had it in the back of his mind. The University of Washington, Seattle, is recognized as one of the great centers of biomedical engineering in the world, both in scope and in depth, and Allan has played a stellar role in the evolution of Seattle's reputation. He has also developed a reputation for outstanding work in biomaterials and is one of the most visible and internationally recognized leaders in the field.