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        <link:usedOn>link:calculationLink</link:usedOn>
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  <xsd:import namespace="http://www.xbrl.org/dtr/type/non-numeric" schemaLocation="http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2009/role/negated" schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" />
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  <xsd:element name="ClassOfWarrantOrRightWarrantsIssuedToUnderwriterForExerciseOfOverAllotmentOption" id="astm_ClassOfWarrantOrRightWarrantsIssuedToUnderwriterForExerciseOfOverAllotmentOption" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
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  <xsd:element name="WarrantsIssuedInDecember2010Member" id="astm_WarrantsIssuedInDecember2010Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
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  <xsd:element name="OrganizationalCostsActivity" id="astm_OrganizationalCostsActivity" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="BasisOfPresentationDisclosureAbstract" id="astm_BasisOfPresentationDisclosureAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="WarrantsAndRightsNoteDisclosureTextBlock" id="astm_WarrantsAndRightsNoteDisclosureTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfClassOfWarrantOrRightValuationAssumptionsTableTextBlock" id="astm_ScheduleOfClassOfWarrantOrRightValuationAssumptionsTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfChangeInEstimatedFairValueOfWarrantLiabilitiesTableTextBlock" id="astm_ScheduleOfChangeInEstimatedFairValueOfWarrantLiabilitiesTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="MinimumPeriodOfUncertaintyRegardingEntitysAbilityToMaintainLiquiditySufficientToOperateBusinessEffectively" id="astm_MinimumPeriodOfUncertaintyRegardingEntitysAbilityToMaintainLiquiditySufficientToOperateBusinessEffectively" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAbstract" id="astm_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" id="astm_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAggregateIntrinsicValueAbstract" id="astm_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAggregateIntrinsicValueAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="WarrantsAndRightsRollForward" id="astm_WarrantsAndRightsRollForward" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="StockIssuedDuringPeriodOfferingPricePerShare" id="astm_StockIssuedDuringPeriodOfferingPricePerShare" type="num:perShareItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="PreferredStockPeriodOfClosingOfOfferingAfterWhichSharesAreConvertible" id="astm_PreferredStockPeriodOfClosingOfOfferingAfterWhichSharesAreConvertible" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
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  <xsd:element name="PreferredStockCumulativeDividendRatePercentage" id="astm_PreferredStockCumulativeDividendRatePercentage" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="PreferredStockPeriodForAccrualOfDividend" id="astm_PreferredStockPeriodForAccrualOfDividend" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
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  <xsd:element name="SeriesIIIConvertiblePreferredStockMember" id="astm_SeriesIIIConvertiblePreferredStockMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="AdjustmentsToAdditionalPaidInCapitalPaymentReceivedUnderShareholderNoteReceivable" id="astm_AdjustmentsToAdditionalPaidInCapitalPaymentReceivedUnderShareholderNoteReceivable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="ExpectedProceedsFromIssuanceOrSaleOfEquity" id="astm_ExpectedProceedsFromIssuanceOrSaleOfEquity" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="PercentageOfGrossProceedsPayableAsCommission" id="astm_PercentageOfGrossProceedsPayableAsCommission" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="McNicollLewisAndVlakLLCMember" id="astm_McNicollLewisAndVlakLLCMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ClassOfWarrantOrRightAdditionalNumberOfRightsDistributedPerCommonShare" id="astm_ClassOfWarrantOrRightAdditionalNumberOfRightsDistributedPerCommonShare" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ClassOfWarrantOrRightConditionOnExerciseOfRightsPercentageOfCommonStockAcquired" id="astm_ClassOfWarrantOrRightConditionOnExerciseOfRightsPercentageOfCommonStockAcquired" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ClassOfWarrantOrRightConditionOnExerciseOfRightsPercentageOfCommonStockOwnedByPersonOrGroupCommencingTenderOffer" id="astm_ClassOfWarrantOrRightConditionOnExerciseOfRightsPercentageOfCommonStockOwnedByPersonOrGroupCommencingTenderOffer" type="num:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsCancelledInPeriod" id="astm_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsCancelledInPeriod" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsCancelledInPeriodWeightedAverageExercisePrice" id="astm_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsCancelledInPeriodWeightedAverageExercisePrice" type="num:perShareItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="DiversityOfCreditRiskPolicyTextBlock" id="astm_DiversityOfCreditRiskPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="WarrantsPolicyTextBlock" id="astm_WarrantsPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfAccruedEmployeeBenefitsTableTextBlock" id="astm_ScheduleOfAccruedEmployeeBenefitsTableTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="IncomeTaxReconciliationWarrants" id="astm_IncomeTaxReconciliationWarrants" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="IncomeTaxReconciliationNetOperatingLossBenefit" id="astm_IncomeTaxReconciliationNetOperatingLossBenefit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="IncomeTaxReconciliationNetOperatingLossExpirations" id="astm_IncomeTaxReconciliationNetOperatingLossExpirations" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
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  <xsd:element name="NetOperatingLossCarryforwardsAndTaxCreditCarryforwardsLineItems" id="astm_NetOperatingLossCarryforwardsAndTaxCreditCarryforwardsLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OperatingLeaseAreaLeased" id="astm_OperatingLeaseAreaLeased" type="num:areaItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OperatingLeaseTerm" id="astm_OperatingLeaseTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OperatingLeaseNumberOfFiveYearMarketValueRenewals" id="astm_OperatingLeaseNumberOfFiveYearMarketValueRenewals" type="xbrli:integerItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OperatingLeasePeriodOfMarketValueRenewals" id="astm_OperatingLeasePeriodOfMarketValueRenewals" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OperatingLeaseRatingClassOfModularManufacturingCleanRoomLaboratoriesAndOfficeSpaceLeased" id="astm_OperatingLeaseRatingClassOfModularManufacturingCleanRoomLaboratoriesAndOfficeSpaceLeased" type="xbrli:integerItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ClassOfWarrantOrRightNumberOfRightsPerCommonStockShare" id="astm_ClassOfWarrantOrRightNumberOfRightsPerCommonStockShare" type="xbrli:integerItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ClassOfRightConditionOnExerciseOfRightsNumberOfMultiplesOfExercisePriceHolderCanReceiveInCommonStockValue" id="astm_ClassOfRightConditionOnExerciseOfRightsNumberOfMultiplesOfExercisePriceHolderCanReceiveInCommonStockValue" type="xbrli:pureItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ClassOfRightConditionOnExerciseOfRightsNumberOfMultiplesOfExercisePriceHolderCanReceiveInCommonStockValueInEventOfMerger" id="astm_ClassOfRightConditionOnExerciseOfRightsNumberOfMultiplesOfExercisePriceHolderCanReceiveInCommonStockValueInEventOfMerger" type="xbrli:pureItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="MinimumCumulativePercentageChangeOfOwnershipOverWhichChangeInControlIsConsidered" id="astm_MinimumCumulativePercentageChangeOfOwnershipOverWhichChangeInControlIsConsidered" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="PeriodOverWhichCumulativeChangeOfOwnershipRequiredForChangeInControl" id="astm_PeriodOverWhichCumulativeChangeOfOwnershipRequiredForChangeInControl" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="IncomeTaxExpenseBenefitReductionResultingFromGrossUnrecognizedTaxBenefitsRecognizedDueToValuationAllowance" id="astm_IncomeTaxExpenseBenefitReductionResultingFromGrossUnrecognizedTaxBenefitsRecognizedDueToValuationAllowance" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="CollaborativeArrangementRoyaltyRevenueAsPercentageOfNetSalesOfProducts" id="astm_CollaborativeArrangementRoyaltyRevenueAsPercentageOfNetSalesOfProducts" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="MaximumPeriodBeforeCashAndCashEquivalentsAreFullyDepleted" id="astm_MaximumPeriodBeforeCashAndCashEquivalentsAreFullyDepleted" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OmnibusIncentivePlan2009Member" id="astm_OmnibusIncentivePlan2009Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="PriorPlansMember" id="astm_PriorPlansMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ProceedsFromIssuanceOfConvertibleSecuritiesDependingUponWhichWarrantsContainAntidilutionProvisions" id="astm_ProceedsFromIssuanceOfConvertibleSecuritiesDependingUponWhichWarrantsContainAntidilutionProvisions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
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  <xsd:element name="SublicenseAgreementMember" id="astm_SublicenseAgreementMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
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  <xsd:element name="NetProceedsFromIssuanceOrSaleOfEquity" id="astm_NetProceedsFromIssuanceOrSaleOfEquity" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
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  <xsd:element name="CorrectionOfErrorMember" id="astm_CorrectionOfErrorMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="AccumulatedUndeclaredDividends" id="astm_AccumulatedUndeclaredDividends" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element name="StockIssuedDuringPeriodValuePreferredStockIssues" id="astm_StockIssuedDuringPeriodValuePreferredStockIssues" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="StockIssuedDuringPeriodSharesPreferredStockIssues" id="astm_StockIssuedDuringPeriodSharesPreferredStockIssues" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ClassOfWarrantOrRightsRedemptionPricePerRight" id="astm_ClassOfWarrantOrRightsRedemptionPricePerRight" type="num:perShareItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ConvertiblePreferredStock5.5Member" id="astm_ConvertiblePreferredStock5.5Member" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="LincolnParkCapitalFundLLCMember" id="astm_LincolnParkCapitalFundLLCMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ValueOfSharesOfCommonStockToBeSold" id="astm_ValueOfSharesOfCommonStockToBeSold" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="ValueOfSharesOfCommonStockToBePurchased" id="astm_ValueOfSharesOfCommonStockToBePurchased" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="PeriodOverWhichSharesOfCommonStockToBePurchased" id="astm_PeriodOverWhichSharesOfCommonStockToBePurchased" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="NumberOfSharesOfCommonStockToBePurchasedInRegularPurchases" id="astm_NumberOfSharesOfCommonStockToBePurchasedInRegularPurchases" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="NumberOfSharesOfCommonStockToBePurchasedBasedOnClosingSalePriceOfCommonStock" id="astm_NumberOfSharesOfCommonStockToBePurchasedBasedOnClosingSalePriceOfCommonStock" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ThresholdClosingSalePriceOfCommonStockOnDateOfRegularPurchaseToTriggerAcceleratedPurchasesOfAdditionalCommonStock" id="astm_ThresholdClosingSalePriceOfCommonStockOnDateOfRegularPurchaseToTriggerAcceleratedPurchasesOfAdditionalCommonStock" type="num:perShareItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xsd:element name="PeriodOfBusinessDaysOverWhichPurchasePriceOfSharesOfCommonStockWillBeDetermined" id="astm_PeriodOfBusinessDaysOverWhichPurchasePriceOfSharesOfCommonStockWillBeDetermined" type="xbrli:durationItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="FloorPriceForSaleOfSharesOfCommonStock" id="astm_FloorPriceForSaleOfSharesOfCommonStock" type="num:perShareItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xsd:element name="StockIssuedDuringPeriodValueReverseStockSplitInLieuOfFractionalShares" id="astm_StockIssuedDuringPeriodValueReverseStockSplitInLieuOfFractionalShares" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="StockIssuedDuringPeriodSharesReverseStockSplitInLieuOfFractionalShares" id="astm_StockIssuedDuringPeriodSharesReverseStockSplitInLieuOfFractionalShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="CumulativeProceedsFromIssuanceOfCommonStock" id="astm_CumulativeProceedsFromIssuanceOfCommonStock" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="ReverseStockSplitPolicyTextBlock" id="astm_ReverseStockSplitPolicyTextBlock" type="nonnum:textBlockItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ReverseStockSplitAbstract" id="astm_ReverseStockSplitAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OperatingLossCarryforwardsAmountUnderstated" id="astm_OperatingLossCarryforwardsAmountUnderstated" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="OperatingLossCarryforwardsValuationAllowanceAmountUnderstated" id="astm_OperatingLossCarryforwardsValuationAllowanceAmountUnderstated" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="ErrorInIncomeTaxDisclosureMember" id="astm_ErrorInIncomeTaxDisclosureMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="StockIssuedDuringPeriodValueCommonStockIssuesIPO" id="astm_StockIssuedDuringPeriodValueCommonStockIssuesIPO" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="StockIssuedDuringPeriodSharesCommonStockIssuesIPO" id="astm_StockIssuedDuringPeriodSharesCommonStockIssuesIPO" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="EasternCapitalLimitedAndAffiliatesMember" id="astm_EasternCapitalLimitedAndAffiliatesMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ClassOfWarrantOrRightPercentageOfCommonStockApprovedToBePurchased" id="astm_ClassOfWarrantOrRightPercentageOfCommonStockApprovedToBePurchased" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ClassOfWarrantOrRightNumberOfRightsDeemedToBeDeliveredPerCommonStockShareIssuedOrTransferred" id="astm_ClassOfWarrantOrRightNumberOfRightsDeemedToBeDeliveredPerCommonStockShareIssuedOrTransferred" type="xbrli:integerItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OperatingLossCarryforwardsAmountOverstated" id="astm_OperatingLossCarryforwardsAmountOverstated" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element name="StockIssuedDuringPeriodValueConversionOfTemporaryEquity" id="astm_StockIssuedDuringPeriodValueConversionOfTemporaryEquity" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="StockIssuedDuringPeriodSharesConversionOfTemporaryEquity" id="astm_StockIssuedDuringPeriodSharesConversionOfTemporaryEquity" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="NetIncomeLossAvailableToCommonStockholdersBasicBeforeDividends" id="astm_NetIncomeLossAvailableToCommonStockholdersBasicBeforeDividends" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="SanofiMember" id="astm_SanofiMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="NumberOfPatentsAndPatentApplicationsToBeAcquired" id="astm_NumberOfPatentsAndPatentApplicationsToBeAcquired" type="xbrli:integerItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xsd:element name="OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems" id="astm_OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ThresholdOnPercentageOfOutstandingSharesOfCommonStockThatCanBeBeneficiallyOwnedByCounterparty" id="astm_ThresholdOnPercentageOfOutstandingSharesOfCommonStockThatCanBeBeneficiallyOwnedByCounterparty" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ThresholdPercentageOfOutstandingEquitySecuritiesForPrepaymentOfPromissoryNoteDue" id="astm_ThresholdPercentageOfOutstandingEquitySecuritiesForPrepaymentOfPromissoryNoteDue" type="num:percentItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
</xsd:schema>





