Ann Arbor-based Arboretum Ventures, one of the top venture capital firms in the Midwest, has hired the former CEO of the Ann Arbor biotech firm Aastrom Biosciences.

George Dunbar, who stepped down as CEO of Aastrom last month, is joining Arboretum as a venture partner. That means he'll help Arboretum, which manages some $97 million in capital, identify potential investments.

George Dunbar

“We are very pleased to add such an experienced healthcare executive to our investment team,” Arboretum Managing Director Tim Petersen said in a statement. “George’s knowledge and nationwide contacts will help us uncover new investment opportunities, and he will be tremendously helpful in working with the leadership teams of our existing portfolio companies.”

Dunbar, who remains chairman of Aastrom, left the firm last month after asking Esperion Therapeutics veteran Timothy Mayleben to take over day-to-day leadership of the company.

The move reflects Arboretum's growing magnetism in Michigan's venture capital industry. The firm last fall reaped a windfall in profits when one of its investments, University of Michigan spinoff HandyLab, was acquired by Becton, Dickinson and Co. for $275 million.

Arboretum in early 2009 finished financing on a new $73 million investment fund - money the company will invest in health care technology companies in Michigan and throughout the nation.

Contact AnnArbor.com’s Nathan Bomey at (734) 623-2587 or nathanbomey@annarbor.com. You can also follow him on Twitter.