Tengion Inc., a Montgomery County biotechnology firm that is developing ways to generate new organs based on a patient's own cells, registered with the Securities and Exchange Commission to raise $42.25 million in an initial public offering.

The East Norriton company, founded in 2003, has spent $88.2 million on research and development but does not yet have any revenues.

In deals with venture capital firms, Tengion has previously raised $144 million from the sale of redeemable convertible preferred stock.

It's three biggest stockholders are Oak Investment Partners, HealthCap Venture Capital, and Johnson & Johnson Development Corp.    - Harold Brubaker