Lecture2PreclinicalStudies[h??m?l?ɡ?s]（singledose)（repeateddose)homologoustetratogenicityreproducibilityinvitromaximumtolerateddoseinvivogenotoxicitymodelchimeratoxicokineticsmodelefficacyadverseeventscandidatevalidationpharmacokineticscharacterizationstringentgeneralsafetyPreclinicalstudyPharmacological/toxicologicalstudyPharmaceuticalstudypharmacodynamicstudypharmacokineticstudyacutetoxicitystudychronictoxicitystudyspecialtoxicitystudystructurevalidationAPImanufacturingAPIspecificationsstabilitystudyofAPImanufacturingofdrugproductdrugproductspecificationsstabilitystudyofdrugproduct1.Whataretheprosandconsofanimaltesting?Pleasegivesupportingdetails.ProsEthicalconsiderationsContributiontothedevelopmentoflife-savingmedicationsandvaccinesSimilaritiestohumansEasiergeneticmodificationEnactmentoflawstoprotectanimalsfrommistreatment…ConsCrueltyDifferencesbetweenspeciesAvailabilityofalternativetestingmethodsAnimalabuseisstillexistingMisleadresearchersintoignoringpotentialcuresandtreatments…1.Whyarealotofmedicalresearchesespeciallypreclinicalstudiesconductedinrodents?----Theyaresmall,easytobreedandrelativelycheaptocareforinlargenumbers;----Theyhavealotofsimilaritieswithhumans,includinggenetics,behaviorandbiology;----Largenumbersofratscanhavealmostidenticalgenomes,allowingformoreuniformandreliableresults;----Theycanbegeneticallymanipulated.2.Whatarethesafetymeasuresresearchersbuildintominimizetheriskofadversereactionsinhumantrialfollowinganimalstudies?----Tograduallydialupthedosageatthebeginningofthefist-in-humantrial;----Tohavecleardefinitionof“working”or“beingeffective”;----Setguidelinesforadverseeventoutcomes;----Takingmoretimebetweendosingeachparticipanttoseeifsomethingbadhappens;----Totakeadvantagesofnewertechnologiestopredictdrugperformance;----Tomakebetterprotocolsforworkingwithanimals.1.Whydidtheresearchersdomostoftheanalysisinthetailregionofzebrafish?Theanimalisverythin,whichisniceforconfocalanalysis.Therearealsoalotofmacrophageslocatedinthetailregion.Thevasculatureinthisregionisverydefined.Allvenousvasculatureexpressscavengerreceptorstabilin-2.2.Howdidtheresearchersvalidatetheirzebrafishmodelintermsofmacrophageuptakeandhepaticclearance?ValidationofmacrophageuptakeItisreportedinliteraturethatincreasedPEGmolecularweightdeceasestherecognitionofparticlesbymacrophages;LiposomescontainingthesameamountofPEGbutwithincreasingPEGmolecularweightareinjectedintozebrafishmodel;ThehigherthePEGmolecularweight,thelowertherecognitionoftheparticleandthelowerco-localizationofnanoparticles;ThedecreasedcolocalizationofPEGmoleculeswithincreasedmolecularweightsindicatesthattheanimalmodelcanworkasexpected.ValidationofhepaticclearanceAsetofliposomeswhichhasbeendescribedinaveryearlyliposomepublicationwereused;Inthepublication,liposomescontainingDOPCorDMPCwereprovedlong-circulatingandliposomescontainingDPPC,DSPCorDAPCwereprovedshort-circulating;Liposomescontainingthesedifferentlipidsareinjectedintothezebrafishmodel;Theresultsshowthat1hourafterinjectionlong-circulatingliposomesarestillincirculationwhileshort-circulatingliposomesareboundbythevenouspartofthevasculaturebecausetheyarescavengedbysabilin-2receptor.3.Whatarethemajorfindingsofthestudy?Azebrafishmodelformacrophageclearanceregardingpegy