DextranastheDressingComponentofFASTCLOT®
TimothyFloyd,MDFACS
Dextranisabranched-chainpolysaccharidethathasbeenusedinmedicineformanydecades.
Itisavailableintwoforms,themorecommon“Dextran40,”commonly10%dextran,and
“Dextran70,”commonly6%and32%dextran.
MostofthemedicinalusesofdextraninvolveintravenousadministrationofDextran40.Dueto
itshighmolecularweightitisanexcellentosmoticagent.Therefore,itisadministered
intravenouslywhereitactsasavolumeexpanderduringhemorrhagicshock.Itisusedinthis
applicationforbothcivilianandcombattrauma.1,2Italsocanbeusedduringelectivesurgery
forvolumeexpansion.
IntravenousadministrationofDextran40exertsanantithromboticeffectonplatelets,
endotheliumandredbloodcellsbyreducingaggregationandadhesiveness.Intravascularclots
arelesslikelytoforminthepresenceofdextran.Thispropertyofdextranhasmadeitusefulas
aprophylacticagentfordeepvenousthrombosis(DVT)insurgicalpatients.Italsoisusedto
maintainpatencyofvesselsinproceduresthatrequiremicroanastomosis.
Typicalintravenousdosagesofdextranarealiterormoreonthefirstdayfollowedbyahalfa
literforseveraldays.
Inadditiontointravenousadministration,dextranhasbeenusedtopically.Gynecological
surgeonshaveusedDextran70asanagentofchoicewhendistendingtheabdomenandpelvis
duringlaparoscopicandhysteroscopicsurgery.Dextran70issuperiortobarrierssuchas
GelfoamandSurgicelforpreventingpost-surgicaladhesions.3Italsoappearstobesuperiorto
normalsaline.4,5
Generally,from250mlto1literofdextran70isusedforirrigationoftheabdomenandpelvis.
Theothercommontopicaluseofdextranisasacomponentofophthalmologicsolutions,
whereitactsasasoothingagentandlubricant.Dosagesaremeasuredindrops.
FASTCLOT®isahemostaticdressingprimarilycomposedofadrypowderoftheclotting
proteinsfibrinogenandthrombinembeddedwithinasoliddextrandressing.Thereareother
minorcomponentstothedressingthatactaspreservativesandstabilizers.
Dextranwaschosenforanumberofreasons.First,asamolecule,itisamenabletotheprocess
ofelectrospinning.Electrospinningcreatesdrynanofibersofdextranthatcanbeconfigured
intoanydesiredsizeorshape.Theresultingproduct,calleda“dextranmat,”ishighlyporous
onananoscale.Theporesofthemataresmallenoughtocontaintheproteinpowder,yet
largeenoughtoreadilyadmitwater.
Secondly,dextranishighlysolubleinwater,sowhenwater,orblood,contactsthematit
quicklydissolvesthematandliberatestheproteins.Thedryproteinpowdersolubilizesrapidly,
whichallowsthetwoclottingproteinstointeract,resultinginastable,tenaciousclot.The
processisveryrapid,andatthestageofclotformationthedextranhasbeenremovedfromthe
areaofapplication.6
Finally,dextranistheidealdressingmaterialforFASTCLOT®becauseofitssafetyprofile.The
dextrandosagesusedintheFASTCLOT®dressingsareafractionoftherecommended
intravenoususe,orthetopicalintra-abdominaluse.ThedoseofdextraninFASTCLOT®is
proprietary,butisseveralordersofmagnitudelessperdressingthanwhatisused
intravenouslyintreatmentofshock,DVTprophylaxis,orabdominalirrigation.
Insummary,electrospundextranistheidealdressingmaterialinFASTCLOT®becauseitissafe,
itdissolvesrapidly,anditdoesnotleaveatrace.
FASTCLOT®couldbecomeanidealplatformforthedeliveryofpharmaco-therapeuticagents.It
ispossibletoembeddryformsofdrugsintheFASTCLOT®dressing.Forexample,antibiotics
couldbeembeddedinthedressing,alongwithfibrinogenandthrombin.Theantibioticwould
thenbecomeembeddedintheclotandcouldeluteintothetissuesoveraperiodoftime,
deliveringantibioticsdirectlytoawound.Similarly,itispossiblethatsomechemotherapeutic
agentsusedincancertreatmentcouldalsobeembeddedinthedressingforlocaldeliveryof
higherconcentrationsthancouldbedeliveredbyintravenousorothermethods.
FASTCLOT®isaplatformnanotechnologythatwillhavemanyapplications,notonlyin
hemostasis,butasadeliverysystemforamyriadofmedications.
References
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destranprovidesoptimalinitialresuscitationafteruncontrolledhemorrhagicshock.JTrauma
andAcuteCareSurg61(1):75-81.
2.DubickM,AtkinsJL.2003.Small-volumefluidresuscitationforthefar-forwardcombat
environment:currentconcepts.JTraumaandAcuteCareSurg54(5):S43-45.
3.SoulesMR,DennisL,BosargeA,MooreDE.1982.Thepreventionofpostoperativepelvic
adhesions:ananimalstudycomparingbarriermethodswithdextran70.AJOG143(7):829-34.
4.NeuwirthRS,KhalafSH.1975.Effectofthirty-twopercentdextran70onperitonealadhesion
formation.AJOG121(3):420-22.
5.ButtramVC,MalinakR,ClearyR,etal.1983.Reductionofpostoperativepelvicadhesions
withintraperitoneal32%dextran70:aprospectiverandomizedclinicaltrial.Fertilityand
Sterility40(5):612-19.
6.Padua RA, Olson CE, Floyd CT. Resorption characteristics of a novel fibrin hemostatic
dressing. Orthopedic Research Society Annual Meeting, Orlando, 2016.