EX-5.1

Exhibit 5.1

LOGO

John T. McKenna

+1 650 843 5059

jmckenna@cooley.com

March 29, 2022

Surrozen, Inc.

171 Oyster Point Blvd, Suite 400

South San Francisco, CA 94080

Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection with the issuance and sale by Surrozen, Inc., a Delaware corporation (the “Company”) of 100,000 shares (the “Commitment Shares”) of the Company’s common stock, par value $0.0001 per share (“Common Stock”), and additional shares of Common Stock having aggregate sales proceeds of up to $50,000,000 (the “Purchase Shares” and, together with the Commitment Shares, the “Shares”) pursuant to a Registration Statement on Form S-1 (the “Registration Statement”) filed with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Act”), the related prospectus included in the Registration Statement (the “Base Prospectus”), and the prospectus supplement filed with the Commission pursuant to Rule 424(b) of the Rules and Regulations of the Act (together with the Base Prospectus, the “Prospectus”). The Commitment Shares have been issued and the Purchase Shares are to be issued and sold by the Company pursuant to that certain Purchase Agreement, dated as of February 18, 2022 (the “Purchase Agreement”), by and between the Company and Lincoln Park Capital Fund, LLC.

In connection with this opinion, we have examined and relied upon (a) the Registration Statement, the Prospectus, and the Purchase Agreement, (b) the Company’s Certificate of Incorporation and Bylaws, each as currently in effect, and (c) originals or copies certified to our satisfaction, of such records, documents, certificates, opinions, memoranda and other instruments as in our judgment are necessary or appropriate to enable us to render the opinion expressed below. We have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to originals of all documents submitted to us as copies; the accuracy, completeness and authenticity of certificates of public officials and the due authorization, execution and delivery of all documents by all persons other than the Company where due execution and delivery are a prerequisite to the effectiveness thereof. As to certain factual matters, we have relied upon a certificate of an officer of the Company and have not independently verified such matters.

We have assumed (i) that each sale of the Purchase Shares will be duly authorized by the Board of Directors of the Company, a duly authorized committee thereof or a person or body pursuant to an authorization granted in accordance with Section 152 of the General Corporation Law of the State of Delaware (the “DGCL”) and (ii) that no more than 6,903,383 Purchase Shares will be sold. We express no opinion to the extent that future issuances of securities of the Company and/or anti-dilution adjustments to outstanding securities of the Company cause the number of shares of Common Stock outstanding or issuable upon conversion or exercise of outstanding securities of the Company to exceed the number of Purchase Shares then issuable under the Purchase Agreement.

We note that the Company was initially incorporated under the laws of the Cayman Islands and was domesticated as a corporation in the State of Delaware (the “Domestication”) in accordance with Section 388 of the DGCL. We have assumed all matters determinable under the laws of the Cayman Islands in connection with the Domestication.

Cooley LLP 3175 Hanover Street, Palo Alto, CA 94304-1130

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