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  <xs:element id="plyx_PercentageOfSublicenseesNetSales" name="PercentageOfSublicenseesNetSales" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xs:element id="plyx_PercentageRoyaltyOfNetSales" name="PercentageRoyaltyOfNetSales" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xs:element id="plyx_MstoneMember" name="MstoneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_RushMember" name="RushMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_ServiceAgreementMember" name="ServiceAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_StatementOfIncomeLocationBalancesAxis" name="StatementOfIncomeLocationBalancesAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_StatementOfIncomeLocationBalancesDomain" name="StatementOfIncomeLocationBalancesDomain" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_GeneralAndAdministrativeExpensesMember" name="GeneralAndAdministrativeExpensesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_ResearchAndDevelopmentExpensesMember" name="ResearchAndDevelopmentExpensesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_WorkingCapital" name="WorkingCapital" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xs:element id="plyx_RushUniversityMedicalCenterMember" name="RushUniversityMedicalCenterMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_AggregateConsideration" name="AggregateConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xs:element id="plyx_AggregateShares" name="AggregateShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xs:element id="plyx_CommonStockOutstandingPercentage" name="CommonStockOutstandingPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xs:element id="plyx_MstonePartnersHealthcareLimitedMember" name="MstonePartnersHealthcareLimitedMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_PurchasePricePerShare" name="PurchasePricePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xs:element id="plyx_IncrementalBonusShares" name="IncrementalBonusShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xs:element id="plyx_InvestorsMember" name="InvestorsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_TwoThousandTwentyTwoEquityIncentivePlanMember" name="TwoThousandTwentyTwoEquityIncentivePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_TwoThousandTwentyFiveEquityIncentivePlanMember" name="TwoThousandTwentyFiveEquityIncentivePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_StockSubjectTo2025PlanMember" name="StockSubjectTo2025PlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_PercentageOfCommonStockSharesAnnualIncrease" name="PercentageOfCommonStockSharesAnnualIncrease" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xs:element id="plyx_DenominatorForBasicNetLossPerShare" name="DenominatorForBasicNetLossPerShare" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xs:element id="plyx_DenominatorForDilutedNetLossPerShare" name="DenominatorForDilutedNetLossPerShare" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xs:element id="plyx_ScheduleOfBasicAndDilutedNetLossPerShareAbstract" name="ScheduleOfBasicAndDilutedNetLossPerShareAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_LicenseUpfrontFee" name="LicenseUpfrontFee" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xs:element id="plyx_MilestonesForANonOrphanIndication" name="MilestonesForANonOrphanIndication" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xs:element id="plyx_MilestonesForOrphanIndication" name="MilestonesForOrphanIndication" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xs:element id="plyx_PercentageOfNonRoyaltyConsideration" name="PercentageOfNonRoyaltyConsideration" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xs:element id="plyx_PercentageOfPatentNetSales" name="PercentageOfPatentNetSales" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xs:element id="plyx_CommitmentsAndContingenciesTable" name="CommitmentsAndContingenciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xs:element id="plyx_IncreaseDecreaseInAccruedLiabilitiesRelatedParty" name="IncreaseDecreaseInAccruedLiabilitiesRelatedParty" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xs:element id="plyx_DueToRelatedParty" name="DueToRelatedParty" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
</xs:schema>
