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                                 ACUSPHERE, INC.

                      2003 Stock Option and Incentive Plan

1.    Purpose and Eligibility

      The purpose of this 2003 Stock Option and Incentive Plan (the "Plan") of
Acusphere, Inc. (the "Company") is to provide stock options and other equity
interests in the Company (each an "Award") to employees, officers, directors,
consultants and advisors of the Company and its Subsidiaries, all of whom are
eligible to receive Awards under the Plan. Any person to whom an Award has been
granted under the Plan is called a "Participant." Additional definitions are
contained in Section 8.

2.    Administration

      a. Administration by Board of Directors. The Plan will be administered by
the Board of Directors of the Company (the "Board"). The Board, in its sole
discretion, shall have the authority to grant and amend Awards, to adopt, amend
and repeal rules relating to the Plan and to interpret and correct the
provisions of the Plan and any Award. All decisions by the Board shall be final
and binding on all interested persons. Neither the Company nor any member of the
Board shall be liable for any action or determination relating to the Plan.

      b. Appointment of Committees. To the extent permitted by applicable law,
the Board may delegate any or all of its powers under the Plan to one or more
committees or subcommittees of the Board (a "Committee"). All references in the
Plan to the "Board" shall mean such Committee or the Board.


      c. Delegation to Executive Officers. To the extent permitted by applicable
law, the Board may delegate to one or more executive officers of the Company the
power to grant Awards and exercise such other powers under the Plan as the Board
may determine, provided that the Board shall fix the maximum number of Awards to
be granted and the maximum number of shares issuable to any one Participant
pursuant to Awards granted by such executive officers.

3.    Stock Available for Awards

      a. Number of Shares. Subject to adjustment under Section 3(c), the
aggregate number of shares of Common Stock of the Company (the "Common Stock")
that may be issued pursuant to the Plan is fifteen million (15,000,000) shares.
If any Award expires, or is terminated, surrendered or forfeited, in whole or in
part, the unissued Common Stock covered by such Award shall again be available
for the grant of Awards under the Plan. If shares of Common Stock issued
pursuant to the Plan are repurchased by, or are surrendered or forfeited to, the
Company at no more than cost, such shares of Common Stock shall again be
available for the grant of Awards under the Plan; provided, however, that the
cumulative number of such shares that may be so reissued under the Plan will not
exceed fifteen million (15,000,000) shares.
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Shares issued under the Plan may consist in whole or in part of authorized but
unissued shares or treasury shares.

      b. Per-Participant Limit. Subject to adjustment under Section 3(c), no
Participant may be granted Awards during any one fiscal year to purchase more
than three million five hundred thousand (3,500,000) shares of Common Stock.


      c. Adjustment to Common Stock. In the event of any stock split, stock
dividend, extraordinary cash dividend, recapitalization, reorganization, merger,
consolidation, combination, exchange of shares, liquidation, spin-off, split-up,
or other similar change in capitalization or event, (i) the number and class of
securities available for Awards under the Plan and the per-Participant share
limit, (ii) the number and class of securities, vesting schedule and exercise
price per share subject to each outstanding Option, (iii) the repurchase price
per security subject to repurchase, and (iv) the terms of each other outstanding
stock-based Award shall be adjusted by the Company (or substituted Awards may be
made) to the extent the Board shall determine, in good faith, that such an
adjustment (or substitution) is appropriate. If Section 7(e)(i) applies for any
event, this Section 3(c) shall not be applicable.

4.    Stock Options

      a. General. The Board may grant options to purchase Common Stock (each, an
"Option") and determine the number of shares of Common Stock to be covered by
each Option, the exercise price of each Option and the conditions and
limitations applicable to the exercise of each Option and the Common Stock
issued upon the exercise of each Option, including vesting provisions,
repurchase provisions and restrictions relating to applicable federal or state
securities laws, as it considers advisable.

      b. Incentive Stock Options. An Option that the Board intends to be an
"incentive stock option" as defined in Section 422 of the Code (an "Incentive
Stock Option") shall be granted only to employees of the Company and shall be
subject to and shall be construed consistently with the requirements of Section
422 of the Code. The Board and the Company shall have no liability if an Option
or any part thereof that is intended to be an Incentive Stock Option does not
qualify as such. An Option or any part thereof that does not qualify as an
Incentive Stock Option is referred to herein as a "Nonstatutory Stock Option."

      c. Exercise Price. The Board shall establish the exercise price (or
determine the method by which the exercise price shall be determined) at the
time each Option is granted and specify it in the applicable option agreement.


      d. Duration of Options. Each Option shall be exercisable at such times and
subject to such terms and conditions as the Board may specify in the applicable
option agreement.


      e. Exercise of Option. Options may be exercised only by delivery to the
Company of a written notice of exercise signed by the proper person together
with payment in full as specified in Section 4(f) for the number of shares for
which the Option is exercised.
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      f. Payment Upon Exercise. Common Stock purchased upon the exercise of an
Option shall be paid for by one or any combination of the following forms of
payment:


            (i) by check payable to the order of the Company;

            (ii) except as otherwise explicitly provided in the applicable
option agreement, and only if the Common Stock is then publicly traded, delivery
of an irrevocable and unconditional undertaking by a creditworthy broker to
deliver promptly to the Company sufficient funds to pay the exercise price, or
delivery by the Participant to the Company of a copy of irrevocable and
unconditional instructions to a creditworthy broker to deliver promptly to the
Company cash or a check sufficient to pay the exercise price; or

            (iii) to the extent explicitly provided in the applicable option
agreement, by (x) delivery of shares of Common Stock owned by the Participant
valued at fair market value (as determined by the Board or as determined
pursuant to the applicable option agreement), (y) delivery of a promissory note
of the Participant to the Company (and delivery to the Company by the
Participant of a check in an amount equal to the par value of the shares
purchased), or (z) payment of such other lawful consideration as the Board may
determine.

5.    Restricted Stock

      a. Grants. The Board may grant Awards entitling recipients to acquire
shares of Common Stock, subject to (i) delivery to the Company by the
Participant of cash or other lawful consideration in an amount at least equal to
the par value of the shares purchased, and (ii) the right of the Company to
repurchase all or part of such shares at their issue price or other stated or
formula price from the Participant in the event that conditions specified by the
Board in the applicable Award are not satisfied prior to the end of the
applicable restriction period or periods established by the Board for such Award
(each, a "Restricted Stock Award").

      b. Terms and Conditions. The Board shall determine the terms and
conditions of any such Restricted Stock Award. Any stock certificates issued in
respect of a Restricted Stock Award shall be registered in the name of the
Participant and, unless otherwise determined by the Board, deposited by the
Participant, together with a stock power endorsed in blank, with the Company (or
its designee). After the expiration of the applicable restriction periods, the
Company (or such designee) shall deliver the certificates no longer subject to
such restrictions to the Participant or, if the Participant has died, to the
beneficiary designated by a Participant, in a manner determined by the Board, to
receive amounts due or exercise rights of the Participant in the event of the
Participant's death (the "Designated Beneficiary"). In the absence of an
effective designation by a Participant, Designated Beneficiary shall mean the
Participant's estate.

6.    Other Stock-Based Awards

      The Board shall have the right to grant other Awards based upon the Common
Stock having such terms and conditions as the Board may determine, including,
without limitation, the
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grant of shares based upon certain conditions, the grant of securities
convertible into Common Stock and the grant of stock appreciation rights,
phantom stock awards or stock units.

7.    General Provisions Applicable to Awards

      a. Transferability of Awards. Except as the Board may otherwise determine
or provide in an Award, Awards shall not be sold, assigned, transferred, pledged
or otherwise encumbered by the person to whom they are granted, either
voluntarily or by operation of law, except by will or the laws of descent and
distribution, and, during the life of the Participant, shall be exercisable only
by the Participant. References to a Participant, to the extent relevant in the
context, shall include references to authorized transferees.

      b. Documentation. Each Award under the Plan shall be evidenced by a
written instrument in such form as the Board shall determine or as executed by
an officer of the Company pursuant to authority delegated by the Board. Each
Award may contain terms and conditions in addition to those set forth in the
Plan provided that such terms and conditions do not contravene the provisions of
the Plan.

      c. Board Discretion. The terms of each type of Award need not be
identical, and the Board need not treat Participants uniformly.

      d. Termination of Status. The Board shall determine the effect on an Award
of the disability, death, retirement, authorized leave of absence or other
change in the employment or other status of a Participant and the extent to
which, and the period during which, the Participant, or the Participant's legal
representative, conservator, guardian or Designated Beneficiary, may exercise
rights under the Award.

      e. Acquisition of the Company

            (i) Consequences of an Acquisition. Upon the consummation of an
Acquisition, the Board or the board of directors of the surviving or acquiring
entity (as used in this Section 7(e)(i), also the "Board"), shall, as to
outstanding Awards (on the same basis or on different bases as the Board shall
specify), make appropriate provision for the continuation of such Awards by the
Company or the assumption of such Awards by the surviving or acquiring entity
and by substituting on an equitable basis for the shares then subject to such
Awards either (a) the consideration payable with respect to the outstanding
shares of Common Stock in connection with the Acquisition, (b) shares of stock
of the surviving or acquiring corporation or (c) such other securities or other
consideration as the Board deems appropriate, the fair market value of which (as
determined by the Board in its sole discretion) shall not materially differ from
the fair market value of the shares of Common Stock subject to such Awards
immediately preceding the Acquisition. In addition to or in lieu of the
foregoing, with respect to outstanding Options, the Board may, on the same basis
or on different bases as the Board shall specify, upon written notice to the
affected optionees, provide that one or more Options then outstanding must be
exercised, in whole or in part, within a specified number of days of the date of
such notice, at the end of which period such Options shall terminate, or provide
that one or more Options then
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outstanding, in whole or in part, shall be terminated in exchange for a cash
payment equal to the excess of the fair market value (as determined by the Board
in its sole discretion) for the shares subject to such Options over the exercise
price thereof; provided, however, that before terminating any portion of an
Option that is not vested or exercisable (other than in exchange for a cash
payment), the Board must first accelerate in full the exercisability of the
portion that is to be terminated. Unless otherwise determined by the Board (on
the same basis or on different bases as the Board shall specify), any repurchase
rights or other rights of the Company that relate to an Option or other Award
shall continue to apply to consideration, including cash, that has been
substituted, assumed or amended for an Option or other Award pursuant to this
paragraph. The Company may hold in escrow all or any portion of any such
consideration in order to effectuate any continuing restrictions.

            (ii) Acquisition Defined. An "Acquisition" shall mean: (x) the sale
of the Company by merger in which the shareholders of the Company in their
capacity as such no longer own a majority of the outstanding equity securities
of the Company (or its successor); or (y) any sale of all or substantially all
of the assets or capital stock of the Company (other than in a spin-off or
similar transaction) or (z) any other acquisition of the business of the
Company, as determined by the Board.

            (iii) Assumption of Options Upon Certain Events. In connection with
a merger or consolidation of an entity with the Company or the acquisition by
the Company of property or stock of an entity, the Board may grant Awards under
the Plan in substitution for stock and stock-based awards issued by such entity
or an affiliate thereof. The substitute Awards shall be granted on such terms
and conditions as the Board considers appropriate in the circumstances.

            (iv) Parachute Awards. If, in connection with an Acquisition
described therein, a tax under Section 4999 of the Code would be imposed on the
Participant (after taking into account the exceptions set forth in Sections
280G(b)(4) and 280G(b)(5) of the Code), then the number of Awards which shall
become exercisable, realizable or vested shall be reduced (or delayed), to the
minimum extent necessary, so that no such tax would be imposed on the
Participant (the Awards not becoming so accelerated, realizable or vested, the
"Parachute Awards"); provided, however, that if the "aggregate present value" of
the Parachute Awards would exceed the tax that, but for this sentence, would be
imposed on the Participant under Section 4999 of the Code in connection with the
Acquisition, then the Awards shall become immediately exercisable, realizable
and vested without regard to the provisions of this sentence. For purposes of
the preceding sentence, the "aggregate present value" of an Award shall be
calculated on an after-tax basis (other than taxes imposed by Section 4999 of
the Code) and shall be based on economic principles rather than the principles
set forth under Section 280G of the Code and the regulations promulgated
thereunder. All determinations required to be made under this Section 7(e)(iv)
shall be made by the Company.

      f. Withholding. Each Participant shall pay to the Company, or make
provisions satisfactory to the Company for payment of, any taxes required by law
to be withheld in connection with Awards to such Participant no later than the
date of the event creating the tax
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liability. The Board may allow Participants to satisfy such tax obligations in
whole or in part by transferring shares of Common Stock, including shares
retained from the Award creating the tax obligation, valued at their fair market
value (as determined by the Board or as determined pursuant to the applicable
option agreement). The Company may, to the extent permitted by law, deduct any
such tax obligations from any payment of any kind otherwise due to a
Participant.

      g. Amendment of Awards. The Board may amend, modify or terminate any
outstanding Award including, but not limited to, substituting therefor another
Award of the same or a different type, changing the date of exercise or
realization, and converting an Incentive Stock Option to a Nonstatutory Stock
Option, provided that, the Participant's consent to such action shall be
required unless the Board determines that the action, taking into account any
related action, would not materially and adversely affect the Participant.

      h. Conditions on Delivery of Stock. The Company will not be obligated to
deliver any shares of Common Stock pursuant to the Plan or to remove
restrictions from shares previously delivered under the Plan until (i) all
conditions of the Award have been met or removed to the satisfaction of the
Company, (ii) in the opinion of the Company's counsel, all other legal matters
in connection with the issuance and delivery of such shares have been satisfied,
including any applicable securities laws and any applicable stock exchange or
stock market rules and regulations, and (iii) the Participant has executed and
delivered to the Company such representations or agreements as the Company may
consider appropriate to satisfy the requirements of any applicable laws, rules
or regulations, including any applicable withholding tax.

      i. Acceleration. The Board may at any time provide that any Options shall
become immediately exercisable in full or in part, that any Restricted Stock
Awards shall be free of some or all restrictions, or that any other stock-based
Awards may become exercisable in full or in part or free of some or all
restrictions or conditions, or otherwise realizable in full or in part, as the
case may be, despite the fact that the foregoing actions may (i) cause the
application of Sections 280G and 4999 of the Code if a change in control of the
Company occurs, or (ii) disqualify all or part of the Option as an Incentive
Stock Option.

8.    Miscellaneous

      a. Definitions.


            (i) "Company," for purposes of eligibility under the Plan, shall
include any present or future subsidiary corporations of Acusphere, Inc., as
defined in Section 424(f) of the Code (a "Subsidiary"), and any present or
future parent corporation of Acusphere, Inc., as defined in Section 424(e) of
the Code. For purposes of Awards other than Incentive Stock Options, the term
"Company" shall include any other business venture in which the Company has a
direct or indirect significant interest, as determined by the Board in its sole
discretion.

            (ii) "Code" means the Internal Revenue Code of 1986, as amended, and
any regulations promulgated thereunder.
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            (iii) "employee" for purposes of eligibility under the Plan (but not
for purposes of Section 4(b)) shall include a person to whom an offer of
employment has been extended by the Company.


      b. No Right To Employment or Other Status. No person shall have any claim
or right to be granted an Award, and the grant of an Award shall not be
construed as giving a Participant the right to continued employment or any other
relationship with the Company. The Company expressly reserves the right at any
time to dismiss or otherwise terminate its relationship with a Participant free
from any liability or claim under the Plan.

      c. No Rights As Stockholder. Subject to the provisions of the applicable
Award, no Participant or Designated Beneficiary shall have any rights as a
stockholder with respect to any shares of Common Stock to be distributed with
respect to an Award until becoming the record holder thereof.

      d. Effective Date and Term of Plan. The Plan shall become effective on the
date on which it is adopted by the Board. No Awards shall be granted under the
Plan after the completion of ten years from the date on which the Plan was
adopted by the Board, but Awards previously granted may extend beyond that date.

      e. Amendment of Plan. The Board may amend, suspend or terminate the Plan
or any portion thereof at any time.


      f. Governing Law. The provisions of the Plan and all Awards made hereunder
shall be governed by and interpreted in accordance with the laws of Delaware,
without regard to any applicable conflicts of law.


                                          Adopted by the Board of Directors on
                                          August 4, 2003

                                          Approved by the stockholders on
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