SpinaldorsalhornN-Methyl-D-asparticacidreceptor2B(NR2B)overexpressionplaysanimportantroleintheproductionandmaintenanceofneuropathicpain.BecausesmallinterferingRNA(siRNA)caninhibitNR2Bexpression,siRNAmayprovideanovelapproachtotreatneuropathicpainandpossiblynerveinjury.However,anefficientandsafevectorforNR2BsiRNAhasnotbeendiscov-ered.Thisstudyshowsthatawatersolublelipopolymer(WSLP)comprisedoflowmolecularweightpolyethyleneimine(PEI)andcholesterolcandeliversiRNAtargetingNR2Bforthetreatmentofneuropathicpain.ResultsshowthatintrathecalinjectionofWSLP/siRNAcomplexesfor3daysin-hibitNR2BgeneexpressionwithreductionsinmRNAandproteinlevelsby59%and54%,respec-tively,comparedwithcontrolrats(P<0.01).InjectionofWSLPcomplexedwithscrambledsiRNA,orPEIwithsiRNAdidnotshowthisinhibitoryeffect.Moreover,injectionofWSLP/siRNAcomplexessignificantlyrelievedneuropathicpainat3,7,12,and21days,whileinjectionofWSLPwithscrambledsiRNAorPEIwithsiRNAdidnot.TheseresultsdemonstratethatWSLPcanefficientlydeliversiRNAtargetingNR2Binvivoandrelieveneuropathicpain.
