Press Release February 24, 2005

Acusphere Announces Closing of Public Offering of Preferred Stock

BOSTON, Feb. 24, 2005 – Acusphere, Inc. (NASDAQ: ACUS), today announced that it closed its public offering of 6.5% convertible exchangeable preferred stock for estimated net proceeds of approximately $41.5 million, after deducting underwriting discounts and commissions and estimated offering expenses. Acusphere is a specialty pharmaceutical company that develops new drugs and improved formulations of existing drugs using its proprietary microparticle technology.

The partner from Goodwin Procter who represented Acusphere in this matter is Lawrence Wittenberg.