-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 VKyhAMPyIgVsl9xToUYO05RMptcRg7LAkAoVQkQe1f2Xr7VZo73vcCJvXm0c4aDj
 o5ZvXcYIYGKtTkaRj6nLLg==

<SEC-DOCUMENT>0001179110-08-010714.txt : 20080528
<SEC-HEADER>0001179110-08-010714.hdr.sgml : 20080528
<ACCEPTANCE-DATETIME>20080528071355
ACCESSION NUMBER:		0001179110-08-010714
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080527
FILED AS OF DATE:		20080528
DATE AS OF CHANGE:		20080528

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OSIRIS THERAPEUTICS, INC.
		CENTRAL INDEX KEY:			0001360886
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				710881115
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		7015 ALBERT EINSTEIN DRIVE
		CITY:			COLUMBIA
		STATE:			MD
		ZIP:			21046
		BUSINESS PHONE:		443-545-1819

	MAIL ADDRESS:	
		STREET 1:		7015 ALBERT EINSTEIN DRIVE
		CITY:			COLUMBIA
		STATE:			MD
		ZIP:			21046

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VENTURETEC INC
		CENTRAL INDEX KEY:			0001134883

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32966
		FILM NUMBER:		08862327

	BUSINESS ADDRESS:	
		STREET 1:		FRIEDLI CORP FINANCE AG
		STREET 2:		PRAIGUTERRASSE 5
		CITY:			ZURICH SWITZERLAND
		STATE:			V8
		ZIP:			00000
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-05-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001360886</issuerCik>
        <issuerName>OSIRIS THERAPEUTICS, INC.</issuerName>
        <issuerTradingSymbol>OSIR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001134883</rptOwnerCik>
            <rptOwnerName>VENTURETEC INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O OSIRIS THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>7015 ALBERT EINSTEIN DRIVE</rptOwnerStreet2>
            <rptOwnerCity>COLUMBIA</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21046</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Convertible Promissory Note</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.18</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-05-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2500000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.18</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2008-05-29</value>
            </exerciseDate>
            <expirationDate>
                <value>2009-11-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>189681</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2500000</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Convertible promissory note pursuant to a private placement intended to qualify under Regulation S of the Securities Act of 1933, as amended.  The Note bears interest at a rate of 4% per annum payable at maturity on November 30, 2009. This Note may be converted into common stock at any time at the option of the Holder at the conversion price of $13.18 per share. The Note automatically converts into common staock at the same conversion price if for ten consecutive trading days on the NASDAQ Global Market, the closing price equals $20.00 per share or greater. The Note is redeemable at any time by the Company upon thirty(30) days written ntoice to the Holder.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Peter Friedli, President</signatureName>
        <signatureDate>2008-05-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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