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  <xsd:element name="DeferredFinancingCostAssets" id="pmn_DeferredFinancingCostAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="debit" />
  <xsd:element name="WarrantExercisePriceUsd0.0001Member" id="pmn_WarrantExercisePriceUsd0.0001Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="WarrantExercisePriceUsd315.00Member" id="pmn_WarrantExercisePriceUsd315.00Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="WarrantExercisePriceUsd240.00Member" id="pmn_WarrantExercisePriceUsd240.00Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="WarrantExercisePriceUsd50.50Member" id="pmn_WarrantExercisePriceUsd50.50Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="WarrantExercisePriceUsd187.50Member" id="pmn_WarrantExercisePriceUsd187.50Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="WarrantExercisePriceUsd152.50Member" id="pmn_WarrantExercisePriceUsd152.50Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="WarrantExercisePriceUsd43.75Member" id="pmn_WarrantExercisePriceUsd43.75Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="WarrantExercisePriceUsd62.50Member" id="pmn_WarrantExercisePriceUsd62.50Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="WarrantExercisePriceUsd31.25Member" id="pmn_WarrantExercisePriceUsd31.25Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="WarrantExercisePriceUsd14.40Member" id="pmn_WarrantExercisePriceUsd14.40Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="WarrantExercisePriceUsd0.25Member" id="pmn_WarrantExercisePriceUsd0.25Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="February2031Member" id="pmn_February2031Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="January2026PipeOfferingMember" id="pmn_January2026PipeOfferingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="CommonShareWarrantsIssuePriceOneMember" id="pmn_CommonShareWarrantsIssuePriceOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="CommonShareWarrantsIssuePriceTwoMember" id="pmn_CommonShareWarrantsIssuePriceTwoMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="CommonShareWarrantsIssuePriceThreeMember" id="pmn_CommonShareWarrantsIssuePriceThreeMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="DirectorsAndManagementMember" id="pmn_DirectorsAndManagementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="ThresholdDaysAfterCompletionOfMilestoneEventsConsideredForExpiryTerm" id="pmn_ThresholdDaysAfterCompletionOfMilestoneEventsConsideredForExpiryTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="January2026PipeOfferingIssuePriceOneMember" id="pmn_January2026PipeOfferingIssuePriceOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="January2026PipeOfferingIssuePriceTwoMember" id="pmn_January2026PipeOfferingIssuePriceTwoMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="January2026PipeOfferingIssuePriceThreeMember" id="pmn_January2026PipeOfferingIssuePriceThreeMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="AtMarketOffering2024Member" id="pmn_AtMarketOffering2024Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="DeferredFinancingCostsReclassifiedToAdditionalPaidInCapitalUponCompletionOfEquityFinancing" id="pmn_DeferredFinancingCostsReclassifiedToAdditionalPaidInCapitalUponCompletionOfEquityFinancing" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="credit" />
  <xsd:element name="InducementPlan2026Member" id="pmn_InducementPlan2026Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="UsDollarServiceBasedShareOptionsMember" id="pmn_UsDollarServiceBasedShareOptionsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="UsDollarPerformanceBasedShareOptionsMember" id="pmn_UsDollarPerformanceBasedShareOptionsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
</xsd:schema>
