日常生活类阅读(2012江苏)CMedicaldrugssometimescausemoredamagethantheycure
Onesolutiontothisproblemistoputthedrugsinsideacapsule,protectingthemfromthebody—andthebodyfromthem—untiltheycanbereleasedatjusttherightspot
Therearelotsofwaystotrigger(引发)thisrelease,includingchangingtemperature,acidity,andsoon
Buttriggerscancomewiththeirownrisks—burns,forexample
Now,researchersinCaliforniahavedesignedwhatcouldbeaharmlesstriggertodate:shiningnear-infraredlight(NIR,近红外线)onthedruginthecapsule
Theideaofusinglighttoliberatethedruginthecapsuleisn'tnew
Researchersaroundtheglobehavedevelopedpolymers(聚合物)andothermaterialsthatbegintobreakdownwhentheyabsorbcitherultraviolet(UV,紫外线)orvisiblelight
ButtissuesalsoreadilyabsorbUVandvisiblelight,whichmeansthedrugreleasecanbetriggeredonlyneartheskin,wherethelightcanreach