EXHIBIT 4.10

THIS CONVERTIBLE SUBORDINATED PROMISSORY NOTE HAS NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT") OR THE SECURITIES,
BLUE SKY OR OTHER APPLICABLE LAWS OF ANY STATE, OR ANY OTHER RELEVANT
JURISDICTION, AND MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED, PLEDGED OR
HYPOTHECATED UNLESS IT IS (A) REGISTERED AND/OR QUALIFIED PURSUANT TO THE
RELEVANT PROVISIONS OF U.S. FEDERAL SECURITIES LAWS, THE SECURITIES, BLUE SKY,
OR OTHER APPLICABLE LAWS OF ANY STATE, OR OTHER RELEVANT JURISDICTION OR (B)
EXEMPT FROM SUCH REGISTRATION OR QUALIFICATION. THEREFORE, NO SALE, PLEDGE OR
OTHER TRANSFER OF THIS SECURITY SHALL BE MADE, NO ATTEMPTED SALE, PLEDGE OR
OTHER TRANSFER SHALL BE VALID, AND THE ISSUER SHALL NOT BE REQUIRED TO GIVE ANY
EFFECT TO ANY SUCH TRANSACTION UNLESS (A) SUCH TRANSACTION SHALL HAVE BEEN DULY
REGISTERED UNDER THE SECURITIES ACT AND QUALIFIED OR APPROVED UNDER THE
SECURITIES, BLUE SKY, OR OTHER APPLICABLE LAWS OF ANY STATE, OR OTHER RELEVANT
JURISDICTION, OR (B) THE OBLIGOR SHALL HAVE BEEN SATISFIED THAT SUCH
REGISTRATION, QUALIFICATION OR APPROVAL IS NOT REQUIRED.


                    CONVERTIBLE SUBORDINATED PROMISSORY NOTE


$50,000 - Principal Amount                       Issue Date - September 2, 2003

      FOR VALUE RECEIVED, Crdentia Corp, a Delaware corporation ("Obligor"),
hereby promises to pay to the order of The DeLuca Trust, Joseph M. DeLuca,
Trustee, dated 1/7/2000 or its assigns ("Holder"), in lawful money of the United
States at the address of Holder set forth below, the principal sum of Fifty
Thousand dollars ($50,000), together with interest thereon from the date of this
Promissory Note (the "Note") on the unpaid principal balance. Interest shall
accrue at a rate of ten percent (10%) per annum, simple interest, and shall be
payable quarterly. Subject to the conversion provisions set forth herein, unpaid
principal together with all accrued and unpaid interest shall be due and payable
in full on September 2, 2004 (the "Due Date"). This Note may be prepaid, in
whole or in part, at any time without premium or penalty.

      This Note is being issued as one of a series of convertible subordinated
promissory notes (collectively, the "Notes") issued by the Obligor on or about
the date hereof pursuant to certain Subscription Agreements among the Obligor
and the holders of the Notes. Any of the terms of this Note may be waived or
modified only in writing, signed by the Obligor and the holders of sixty six and
two-thirds percent (66 2/3%) of the aggregate principal amount of all then
outstanding notes issued by the Obligor pursuant to the Subscription Agreements.

      The outstanding principal balance plus accrued and unpaid interest on this
Note shall be converted at Holder's option and in Holder's sole discretion prior
to the Due Date into shares of the Obligor's Common Stock (the "Common Stock").
The number of shares of Common Stock shall be equal to the quotient obtained by
dividing (a) the aggregate outstanding principal due, plus accrued and unpaid
interest on this Note on the date of conversion by (b) the Conversion Price. For
purposes of this Note, the "Conversion Price" shall mean the lesser of (x) one
<PAGE>

dollar and fifty cents ($1.50) or (y) the per share price of the Obligor's
equity securities issued upon the closing of the Obligor's next private equity
financing (the "New Financing"). If Obligor shall issue after the Issue Date any
Additional Stock for a consideration per share less than the Conversion Price in
effect immediately prior to the issuance of such Additional Stock, the
Conversion Price in effect immediately prior to such issuance shall be forthwith
adjusted to the price paid per share for such Additional Stock. For purposes of
this Note, Additional Stock shall mean any shares of Common Stock issued by
Obligor after the Issue Date other than: (a) Common Stock issued pursuant to the
conversion of the Notes or the conversion of exercise of any convertible or
exercisable instrument outstanding prior to the Issue Date, (b) Common Stock
issuable or issued to employees, consultants, directors or vendors of Obligor
pursuant to a stock plan or restricted stock plan, (c) Common Stock issued or
issuable in a public offering, (d) Common Stock issued in connection with the
acquisition of another corporation or entity by Obligor and (e) Common Stock
issued in connection with strategic alliances or to strategic corporate partners
or to parties that are providing Obligor with equipment loans, real property
leases, loans, credit lines, guarantees of indebtedness, licensing agreements,
consulting agreements, cash price reductions or similar transactions.

      In the event that Obligor completes a New Financing prior to the Due Date,
the outstanding principal balance plus accrued and unpaid interest on this Note
shall be converted at Holder's option and in Holder's sole discretion into the
equity securities issued in the New Financing. The number of shares of equity
securities shall be equal to the quotient obtained by dividing (a) the aggregate
outstanding principal due, plus accrued and unpaid interest on this Note on the
date of such conversion by (b) the per share price of such equity securities
issued in the New Financing.

      No fractional shares will be issued upon conversion of this Note. In lieu
of any fractional share to which Holder would otherwise be entitled, Obligor
will pay to Holder in cash that amount of the unconverted principal and interest
balance of this Note. Upon conversion of this Note into such equity securities,
Holder shall surrender this Note, duly endorsed, at the principal offices of the
Obligor or any transfer agent for the Obligor. At its expense, Obligor will, as
soon as practicable thereafter, issue and deliver to Holder a certificate for
the number of shares of equity securities to which Holder is entitled upon such
conversion, together with any other securities and property to which Holder is
entitled upon such conversion under the terms of this Note, including a check
payable to Holder for any cash amounts payable as described above. Upon
conversion of this Note into such equity securities, Obligor will be forever
released from all its obligations and liabilities under this Note, including
without limitation the obligation to pay the principal and interest amounts.

      If any payment of principal or interest on this Note shall become due on a
Saturday, Sunday, or a public holiday under the laws of the State of California,
such payment shall be made on the next succeeding business day and such
extension of time shall be included in computing interest in connection with
such payment.

      The indebtedness evidenced by this Note is hereby expressly subordinated,
to the extent and in the manner hereinafter set forth, in right of payment to
the prior payment in full of all the Obligor's Senior Debt. For purposes of this
Note, "Senior Debt" shall mean the principal of (and premium, if any) and unpaid

                                       2
<PAGE>

interest on, or other payment obligation with respect to (a) all indebtedness of
the Obligor to commercial banks, equipment lessors and other traditional lending
institutions for money borrowed by the Obligor whether or not secured, and (b)
any such indebtedness to commercial banks or any debentures, notes or other
evidence of indebtedness issued in exchange for such indebtedness.
Notwithstanding anything herein to the contrary, no payment of principal or
interest shall be made on this Note if, but only as long as, there exists any
default, or the existence of any event which, with the giving of notice, would
constitute a default, in the payment of Senior Debt, as determined by the terms
of any such Senior Debt. Holder shall execute, at or following the date hereof,
as the case may be, all subordination documents required by the holders of
Senior Debt necessary to effectuate the terms of the foregoing.

      In the event that Obligor (a) fails to make payment on any date for
payment herein above specified of all principal and interest due hereunder on
such date, (b) admits in writing its inability to pay its debts as they become
due, or makes a general assignment for the benefit of creditors or files any
petition or action for relief under any bankruptcy, reorganization, insolvency
or moratorium law, or any other law or laws for the relief of, or relating to,
debtors or (c) an involuntary petition is filed against Obligor under any
bankruptcy, reorganization, insolvency or moratorium law, or any other law or
laws for the relief of, or relating to, debtors unless such petition shall be
dismissed or vacated within sixty (60) days of the date thereof, Obligor shall
be deemed to be in default hereunder. In the event of such default, Holder may,
at Holder's option and in Holder's sole discretion, five (5) days after giving
notice of default to Obligor, accelerate the maturity of all amounts due under
this Note by giving notice of such acceleration.

      The acceptance by Holder of any payment hereunder which is less than the
payment in full of all amounts due and payable at the time of such payment shall
not constitute a waiver of the right to accelerate at that time or any
subsequent time or nullify any prior acceleration without the express consent of
Holder except as and to the extent otherwise provided by law.

      Obligor waives presentment, demand for performance, notice of
nonperformance, protest, notice of protest, and notice of dishonor (but not
notice of default). No delay on the part of Holder in exercising any right
hereunder shall operate as a waiver of such right under this Note. This Note is
being delivered in and shall be construed in accordance with the laws of the
State of California as applied to contracts entered into by California residents
within the State of California, which contracts are to be performed entirely
within the State of California.

      The right to plead any and all statutes of limitations as a defense to any
demand on this Note, or any guaranty hereof, or any agreement to the same, or
any instrument securing this Note, or any and all obligations or liabilities
arising out of or in connection with this Note, is expressly waived by Obligor
and each and every endorser or guarantor if any, to the fullest extent permitted
by law.

      Notwithstanding anything to the contrary contained herein, the total
liability for payments hereunder in the nature of interest shall not exceed the
limits imposed by applicable interest rate limitation laws.

                                       3
<PAGE>

      The provisions of this Note are intended by Obligor to be severable and
divisible and the invalidity or unenforceability of a provision or term herein
shall not invalidate or render unenforceable the remainder of this Note or any
part thereof.

      If the indebtedness represented by this Note or any part thereof is
collected at law or in equity or in bankruptcy, receivership or other judicial
proceedings or if this Note is placed in the hands of attorneys for collection
after default, Obligor agrees to pay, in addition to the principal and interest
payable hereon, reasonable attorneys' fees and costs incurred by Holder.

      Any notice or other communication (except payment) required or permitted
hereunder shall be in writing and shall be deemed to have been given upon
delivery if personally delivered or one day after deposit if deposited in the
United States mail for mailing by certified mail, postage prepaid, and addressed
as follows:

         If to Holder:              Joseph M. DeLuca
                                    1221 Grand Street
                                    Alameda, CA 94501

         If to Obligor:             Crdentia Corp.
                                    Attention: James D. Durham
                                    455 Market Street, Suite 1220
                                    San Francisco, California 94105


         with a copy to:            Steven G. Rowles, Esq.
                                    Morrison & Foerster LLP
                                    3811 Valley Centre Drive, Suite 500
                                    San Diego, CA 92130

Any payment shall be deemed made upon receipt by Holder. Holder or Obligor may
change their address for purposes of this paragraph by giving to the other party
notice in conformance with this paragraph of such new address.

OBLIGOR:                               CRDENTIA CORP.,
                                       a Delaware corporation



                                       By: /s/ James D. Durham
                                          --------------------------------------
                                          Name: James D. Durham
                                          Title:  Chief Executive Officer


                                       4
<PAGE>

                                 CRDENTIA CORP.

              AMENDMENT TO CONVERTIBLE SUBORDINATED PROMISSORY NOTE

      This Amendment to Convertible Subordinated Promissory Note (this
"Amendment") is made effective as of September 2, 2004 by and among Crdentia
Corp., a Delaware corporation (the "Company") and The DeLuca Trust, Joseph M.
DeLuca Trustee, dated 1/7/2000 (the "Noteholder").


                                    RECITALS

      A. On or about September 2, 2003, the Company issued to the Noteholder a
certain Convertible Subordinated Promissory Note in the original principal
amount of $50,000 (the "Note").

      B. The Company and the Noteholder desire to amend certain terms of the
Note.

      In consideration of the foregoing and the promises and covenants contained
herein and other good and valuable consideration the receipt of which is hereby
acknowledged, the parties hereto agree as follows. Any capitalized terms not
otherwise defined herein shall have the meanings given such terms in the Note:

      1. Amendment to First Paragraph of the Note.

      The first paragraph of the Note shall be amended and restated to read as
follows:

                  FOR VALUE RECEIVED, Crdentia Corp, a Delaware corporation
         ("Obligor"), hereby promises to pay to the order of The DeLuca Trust,
         Joseph M. DeLuca, Trustee, dated 1/7/2000 or its assigns ("Holder"), in
         lawful money of the United States at the address of Holder set forth
         below, the principal sum of Fifty Thousand dollars ($50,000), together
         with interest thereon from the date of this Promissory Note (the
         "Note") on the unpaid principal balance. Interest shall accrue at a
         rate of ten percent (10%) per annum, simple interest, and shall be
         payable quarterly. Subject to the conversion provisions set forth
         herein, unpaid principal together with all accrued and unpaid interest
         shall be due and payable in full on March 2, 2005 (the "Due Date").
         This Note may be prepaid, in whole or in part, at any time without
         premium or penalty.

      2. Effect of Amendment. Except as expressly amended, restated or consented
to in this Amendment, the Note shall continue in full force and effect. In the
event of any conflict between the terms of this Amendment and the Note, the
terms of this Amendment shall govern and control.

      3. Governing Law. This Amendment shall be governed by and construed under
the laws of the State of California as applied to agreements among California
residents entered into and to be performed entirely within California.

                                       5
<PAGE>

      4. Counterparts. This Amendment may be executed in any number of
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

      5. Severability. If one or more provisions of this Amendment are held to
be unenforceable under applicable law, such provision shall be excluded from
this Amendment and the balance of the Amendment shall be interpreted as if such
provision were so excluded and shall be enforceable in accordance with its
terms.

      6. Entire Agreement. This Amendment, together with the Note and the
agreements executed pursuant hereto and thereto, constitutes the full and entire
understanding and agreement between the parties with regard to the subjects
hereof and thereof.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]


                                       6
<PAGE>

      IN WITNESS WHEREOF, the parties hereto have executed this Amendment as of
the date first above written.

COMPANY:

CRDENTIA CORP.


By: /s/ James D. Durham
    -------------------------
    James D. Durham
    Chief Executive Officer


NOTEHOLDER:

THE DELUCA TRUST, JOSEPH M. DELUCA TRUSTEE, DATED 1/7/2000


By: /s/ Joseph M. DeLuca
    -------------------------
    Joseph M. DeLuca
    Trustee


                                       7
<PAGE>

                                 CRDENTIA CORP.

          AMENDMENT NO. 2 TO CONVERTIBLE SUBORDINATED PROMISSORY NOTE

      This Amendment No. 2 to Convertible Subordinated Promissory Note (this
"Amendment") is made effective as of March 2, 2005 by and among Crdentia Corp.,
a Delaware corporation (the "Company") and The DeLuca Trust, Joseph M. DeLuca
Trustee, dated 1/7/2000 (the "Noteholder").


                                    RECITALS

      A. On or about September 2, 2003, the Company issued to the Noteholder a
certain Convertible Subordinated Promissory Note in the original principal
amount of $50,000 (the "Note").

      B. On or about September 2, 2004, the Company and the Noteholder entered
into an Amendment to the Note ("Amendment No. 1").

      B. The Company and the Noteholder desire to amend certain terms of the
Note, as previously amended by Amendment No. 1.

      In consideration of the foregoing and the promises and covenants contained
herein and other good and valuable consideration the receipt of which is hereby
acknowledged, the parties hereto agree as follows. Any capitalized terms not
otherwise defined herein shall have the meanings given such terms in the Note:

      7. Amendment to First Paragraph of the Note.

      The first paragraph of the Note, as previously amended by Amendment No. 1,
shall be amended and restated to read as follows:

                  FOR VALUE RECEIVED, Crdentia Corp, a Delaware corporation
         ("Obligor"), hereby promises to pay to the order of The DeLuca Trust,
         Joseph M. DeLuca, Trustee, dated 1/7/2000 or its assigns ("Holder"), in
         lawful money of the United States at the address of Holder set forth
         below, the principal sum of Fifty Thousand dollars ($50,000), together
         with interest thereon from the date of this Promissory Note (the
         "Note") on the unpaid principal balance. Simple interest shall accrue
         at a rate of ten percent (10%) per annum. Accrued and unpaid interest
         shall be payable, together with a pro rata portion of the unpaid
         principal balance hereunder, on each of June 2, 2005, September 2,
         2005, December 2, 2005 and March 2, 2006 (March 2, 2006 being sometimes
         referred to herein as the "Due Date"). This Note may be prepaid, in
         whole or in part, at any time without premium or penalty.

      8. Effect of Amendment. Except as expressly amended, restated or consented
to in this Amendment, the Note shall continue in full force and effect. In the
event of any conflict between the terms of this Amendment and the Note, the
terms of this Amendment shall govern and control.

                                       8
<PAGE>

      9. Governing Law. This Amendment shall be governed by and construed under
the laws of the State of California as applied to agreements among California
residents entered into and to be performed entirely within California.

      10. Counterparts. This Amendment may be executed in any number of
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

      11. Severability. If one or more provisions of this Amendment are held to
be unenforceable under applicable law, such provision shall be excluded from
this Amendment and the balance of the Amendment shall be interpreted as if such
provision were so excluded and shall be enforceable in accordance with its
terms.

      12. Entire Agreement. This Amendment, together with the Note and the
agreements executed pursuant hereto and thereto, constitutes the full and entire
understanding and agreement between the parties with regard to the subjects
hereof and thereof.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]


                                       9
<PAGE>

      IN WITNESS WHEREOF, the parties hereto have executed this Amendment as of
the date first above written.

COMPANY:

CRDENTIA CORP.


By: /s/ James D. Durham
    --------------------------
    James D. Durham
    Chief Executive Officer


NOTEHOLDER:

THE DELUCA TRUST, JOSEPH M. DELUCA TRUSTEE, DATED 1/7/2000


By: /s/ Joseph M. DeLuca
    --------------------------
    Joseph M. DeLuca
    Trustee

                                       10