Biodegradable microspheres containing a colchicine analogue inhibit DNA synthesis in vascular smooth muscle cells.

Smooth muscle cell proliferation plays a major role in the genesis of restenosis after angioplasty or vascular injury. Local application of agents capable of modulating vascular responses, including smooth muscle cell proliferation, has been achieved, but difficulty in maintaining active levels locally has been a factor limiting the efficacy of such approaches. One strategy to maintain adequate levels is the local delivery of microspheres that release active agents over sustained time periods.