<PAGE>

                                                                    EXHIBIT 10.1

THIS PROMISSORY NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933,
AS AMENDED, OR QUALIFIED UNDER ANY STATE SECURITIES LAWS. THIS PROMISSORY NOTE
HAS BEEN ACQUIRED FOR INVESTMENT PURPOSES ONLY, AND NOT WITH A VIEW TO, OR IN
CONNECTION WITH, THE SALE OR DISTRIBUTION THEREOF. NO SUCH SALE OR DISTRIBUTION
MAY BE EFFECTED UNLESS PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT RELATED
THERETO, OR AN EXEMPTION FROM SUCH REGISTRATION STATEMENT REQUIREMENTS.

                             SECURED PROMISSORY NOTE

Principal Amount:  $250,000.00                         San Francisco, California
Interest Rate:  5.00% per annum                                    March 1, 2005


                  FOR VALUE RECEIVED, the undersigned, Crdentia Corp., a
Delaware corporation ("Crdentia"), Baker Anderson Christie, Inc., a California
corporation, Nurses Network, Inc., a California corporation, New Age Staffing,
Inc., a Delaware corporation, PSR Nurses, Ltd., a Texas limited partnership, PSR
Nurse Recruiting, Inc., a Texas corporation, PSR Nurses Holdings Corp., a Texas
corporation, CRDE Corp., a Delaware corporation, Arizona Home Health
Care/Private Duty, Inc., an Arizona corporation, and Care Pros Staffing, Inc, a
Texas corporation (each individually and referred to collectively as "Issuer"),
jointly and severally promise to pay to MedCap Partners L.P., or any assignees
of the Note ("Holder"), by wire transfer to such account as Holder may from time
to time designate in writing, the principal amount of Two Hundred Fifty Thousand
Dollars ($250,000.00) (the "Principal Amount") payable at such times as
specified in paragraph 1 below. Issuer also promises to pay interest on the
unpaid principal amount from the date of this Note until this Note is paid in
full, at the rate of five percent (5.00%) per annum, at such times as specified
in this Agreement. This Note is executed and delivered pursuant to, and in
recognition of, a loan of $250,000 made by Holder to Issuer on the date hereof.

                  1. PRINCIPAL PAYMENT. The Principal Amount shall be payable to
Holder on the earlier of (i) two business days (as defined below) following the
date of Crdentia's receipt of written demand by Holder requesting such payment
or (ii) the date on which Crdentia completes a private offering or offerings of
its equity securities (whether such offering or offerings consist of one or more
transactions) in an amount of not less than $5.0 million (the "Maturity Date").
All payments shall be made in immediately available funds in lawful currency of
the United States of America, without offset, deduction or counterclaim of any
kind. A "business day" shall mean any day except Saturday, Sunday or any day
that is a legal holiday in the State of California. Holder may make written
demand by facsimile, email or other usual means of communication between Holder
and Crdentia.

                                      -1-
<PAGE>

                  2. INTEREST. Prior to the Maturity Date or the occurrence of
an Event of Default (as defined in paragraph 3 below), the unpaid Principal
Amount periodically outstanding under this Note shall bear simple interest at
the rate of five percent (5.00%) per annum, calculated on the basis of a 365-day
year, based on the actual number of days elapsed (including the first day, but
excluding the last day). All accrued and unpaid interest on this Note shall be
due and payable on the Maturity Date. After the Maturity Date or upon the
occurrence and during the continuation of any Event of Default, any unpaid
Principal Amount or accrued interest shall bear interest at the rate of ten
percent (10%) per annum until paid in full.

                  3. EVENTS OF DEFAULT. The occurrence of any of the following
events shall constitute an event of default under this Note: (a) Issuer's
failure to pay the Principal Amount when due and payable; (b) any Issuer making
an assignment for the benefit of its creditors; (c) any Issuer filing (or
consenting to the filing of) any petition or complaint pursuant to federal or
state bankruptcy or insolvency laws, seeking the appointment of a receiver or
trustee for any of its assets, seeking the adjudication of such Issuer as
bankrupt or insolvent, seeking an "order for relief" under such statutes, or
seeking a reorganization of or a plan of arrangement for Issuer; or (d) any
default or breach by any Issuer of or under any agreement for borrowed money,
including loan agreements, or breach under any capital equipment lease
agreement, by which such Issuer is bound or obligated following the expiration
of any applicable grace period. Upon the occurrence of an Event of Default, the
entire Principal Amount then outstanding, together with accrued and unpaid
interest, shall become immediately due and payable.

                  4. AMENDED AND RESTATED SECURITY AGREEMENT. This Note is
executed and delivered together with an Amended and Restated Security Agreement
(the "Security Agreement"), entered into as of November 29, 2004 and as amended
and restated on January 4, 2005, February 2, 2005 and March 1, 2005, between
Holder and Issuer (Issuer therein referred to as "Grantor") by which Grantor has
granted Holder a security interest in the right, title, and interest in and to
all of Grantor's Collateral (as defined in the Security Agreement), subject to
the liens and encumbrances on the Collateral existing as of the date hereof.

                  5. SUBORDINATION. The indebtedness evidenced by this Note is
expressly junior and subordinate in right of payment to the prior payment in
full of all of Issuer's indebtedness under (i) that certain Loan and Security
Agreement, dated as of June 16, 2004, by and among Crdentia and its
subsidiaries, on the one hand, and Bridge Healthcare Finance, LLC, on the other
hand (the "Revolving Loan Agreement"), and (ii) that certain Loan and Security
Agreement, dated as of August 31, 2004, by and among Crdentia and its
subsidiaries, on the one hand, and Bridge Opportunity Finance, LLC, on the other
hand (the "Term Loan Agreement" and, together with the Revolving Loan Agreement,
the "Loan Agreement"). Notwithstanding anything herein to the contrary, no
payment of principal or interest shall be made on this Note if there exists any
default, or the existence of any event which, with the giving of notice, would
constitute a default, in the payment of any indebtedness under the Loan
Agreement, as determined by the terms of the Loan Agreement. Holder agrees to
execute all subordination documents reasonably required by Bridge Healthcare
Finance, LLC and/or Bridge Opportunity Finance, LLC.

                                      -2-
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                  6. PREPAYMENT. This Note may be prepaid, at the option of
Issuer, in whole or in part, at any time or from time to time, without penalty
or premium; PROVIDED, HOWEVER, that any prepayment shall be applied first to the
Principal Amount then outstanding until paid in full and then to accrued and
unpaid interest as of the date of such prepayment. In the event that Issuer
sells any of the Collateral (as defined in the Security Agreement), the net
proceeds from such sale shall be applied as set forth in the Security Agreement
and, to the extent any proceeds are required to be applied to the payment of the
Principal Amount and interest hereunder, in accordance with the preceding
sentence.

                  7. MAXIMUM RATE OF INTEREST. In no event shall any interest
rate provided for hereunder exceed the maximum rate legally chargeable by Holder
under applicable law. If at any time such laws would render usurious any amount
due under this Note, then it is the express intention of Holder and Issuer that
Issuer not be required to pay interest on this Note at a rate in excess of the
maximum lawful rate, that the provisions of this paragraph 7 shall control over
all other provisions of this Note which may be in apparent conflict, that such
excess amount shall be immediately credited to the principal balance owing under
this Note (or, if this Note has been fully repaid, refunded by Holder to
Issuer), and the provisions hereof shall be immediately reformed and the amounts
thereafter decreased, so as to comply with the then applicable usury law, but so
as to permit the recovery of the fullest amount otherwise due under this Note.
Any credit or refund shall not cure or waive any default by Issuer under this
Note. For the purposes of this paragraph 7, the term "applicable law" means the
laws of the State of California, as such laws now exist or may be changed or
amended or come into effect in the future.

                  8. HOLDER REPRESENTATIONS.

                           (a) This Note is being acquired for Holder's own
account, not as a nominee or agent, and not with a view to the resale or
distribution of any part hereof in violation of the Securities Act of 1933, as
amended (the "1933 Act"), and Holder has no present intention of selling,
granting any participation in, or otherwise distributing this Note in violation
of the 1933 Act.

                           (b) Holder acknowledges that it can bear the economic
risk of complete loss of its investment in this Note and has such knowledge and
experience in financial or business matters that it is capable of evaluating the
merits and risks of the investment in this Note. Holder acknowledges that there
are substantial risks incident to the ownership of this Note, and such
investment is speculative and involves a high degree of risk of loss by Holder
of Holder's entire investment in the Issuer

                           (c) Holder has had an opportunity to receive all
information related to Issuer requested and to ask questions of and receive
answers from Issuer regarding Issuer and its business. Holder has reviewed the
reports and other documents filed by Issuer with the Securities and Exchange
Commission.

                           (d) Holder acknowledges and understands that this
Note is a "restricted security" under the 1933 Act.

                           (e) Holder is an "accredited investor" as defined by
Rule 501 or Regulation D promulgated under the 1933 Act.

                                      -3-
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                  9. NO WAIVER. No extension of time for payment of any amount
owing hereunder shall affect the liability of Issuer or any person or entity,
now or at any time hereafter, liable for payment of the indebtedness evidenced
hereby. No delay by Holder in exercising any power or right hereunder shall
operate as a waiver of any power or right hereunder.

                  10. ATTORNEYS' FEES. If any action or proceeding is brought by
Holder to enforce payment of this Note, then the prevailing party shall be
entitled to recover its reasonable costs and expenses (including without
limitation attorneys' fees, experts fees, etc.) associated therewith. In
addition, upon the payment in full of the Principal Amount, Issuer agrees to pay
to Holder the reasonable legal fees, not to exceed $15,000, incurred by MedCap
Partners L.P. in connection with the review and preparation of this Note and the
Security Agreement and any related filings to protect Holder's security
interests.

                  11. WAIVER OF PRESENTMENT, ETC. Each Issuer, for itself and
its respective successors and assigns, hereby expressly waive presentment,
demand, protest, notice of protest, dishonor, notice of dishonor and any other
notice of any type or nature. No waiver or modification of the terms of this
Note shall be valid unless in writing and signed by the holder hereof.

                  12. SEVERABILITY. If any provision of this Note is held
invalid or unenforceable by any court of competent jurisdiction, the other
provisions of this Note shall remain in full force and effect. Any provision of
this Note held invalid or unenforceable only in part or degree shall remain in
full force and effect to the extent not held invalid or unenforceable.

                  13. TIME OF ESSENCE. Time is of the essence with regard to all
dates set forth in this Note.

                  14. ASSIGNMENT AND TRANSFER. No Issuer may assign or otherwise
transfer its rights or obligations under this Note without the prior written
consent of Holder. Any purported assignment or transfer in contravention of this
paragraph 14 shall be null and void. Subject to the foregoing, this Note shall
be binding upon the successors and assigns of Issuer, and shall inure to the
benefit of and be enforceable by the successors and assigns of Holder. Holder
agrees that it shall not transfer this Note (a) in violation of the 1933 Act or
any state securities laws and (b) unless pursuant to an effective registration
statement or an exemption from such registration statement requirements.

                  15. GOVERNING LAW. This Note shall be construed in accordance
with and governed by the laws of the State of California, without regard to
conflict of laws principles.

                            [signature pages follow]


                                      -4-
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                  IN WITNESS WHEREOF, the undersigned have executed this Note as
of the date first written above.

                                     CRDENTIA CORP.



                                     By: /S/ James D. Durham
                                         -------------------

                                     Name:___________________________

                                     Title:__________________________


                                     BAKER ANDERSON CHRISTIE, INC.



                                     By: /S/ JAMES D. DURHAM
                                         -------------------

                                     Name:_________________________________

                                     Title:________________________________


                                     NURSES NETWORK, INC.



                                     By: /S/ JAMES D. DURHAM
                                         -------------------

                                     Name:_________________________________

                                     Title:________________________________


                                      -5-
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                                     NEW AGE STAFFING, INC.



                                     By: /S/ JAMES D. DURHAM
                                         -------------------

                                     Name:_________________________________

                                     Title:________________________________


                                     PSR NURSES, LTD.



                                     By: PSR Nurse Recruiting, Inc.

                                     Its:  General Partner

                                     By: /S/ JAMES D. DURHAM
                                         -------------------

                                     Name:_________________________________

                                     Title:________________________________


                                     PSR NURSE RECRUITING, INC.



                                     By: /S/ JAMES D. DURHAM
                                         -------------------

                                     Name:_________________________________

                                     Title:________________________________


                                     PSR NURSES HOLDINGS CORP.



                                     By: /S/ JAMES D. DURHAM
                                         -------------------

                                     Name:_________________________________

                                     Title:________________________________

                                      -6-
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                                     CRDE CORP.



                                     By: /S/ JAMES D. DURHAM
                                         -------------------

                                     Name:_________________________________

                                     Title:________________________________


                                     ARIZONA HOME HEALTH CARE/PRIVATE DUTY, INC.



                                     By: /S/ JAMES D. DURHAM
                                         -------------------

                                     Name:_________________________________

                                     Title:________________________________


                                     CARE PROS STAFFING, INC.



                                     By: /S/ JAMES D. DURHAM
                                         -------------------

                                     Name:_________________________________

                                     Title:________________________________


                                      -7-
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Acknowledged and Agreed to:

MEDCAP PARTNERS L.P.

BY:     MEDCAP MANAGEMENT & RESEARCH LLC
ITS:    GENERAL PARTNER


By:     /s/ C. Fred Toney
        -----------------
        Name:  C. Fred Toney
        Title: Managing Member


                                      -8-