Regenerative medicine company Tengion Inc. priced its initial public offering below expectations, raising $30 million, the company's underwriter, Piper Jaffray, said Friday.

Tengion sold 6 million shares to initial investors for $5 apiece, according to Chad Burton, head of Piper's administration group. It had expected them to price from $8 to $10. The company boosted the number of shares sold from 4.4 million.

Current stockholders bought about $17.2 million in stock.

Tengion's technology uses a patient's own cells to create replacement organs and tissues. The company said in a regulatory filing that its auditors have raised doubt about its ability to continue as a going concern.

Tengion intends to use IPO proceeds for fund research, service its debt and maintain its manufacturing facility.

Shares are expected to trade under the symbol "TNGN" on the Nasdaq Friday.