Biomedical Engineering Reference
In-Depth Information
11
NanotechnologyinBiomaterials:
Nanoparti
culatesasDrugDeliverySystems
BirsenDemirbag,SinemKardesler,ArdaBuyuksungur,Aysu
Kucukturhan,GozdeEke,NesrinHasirci,andVasifHasirci
BIOMATEN,CenterofExcellenceinBiomaterialsandTissueEngineering,andDepartments
ofBiologicalSciencesandChemistryMiddleEastTechnicalUniversity,Ankara,Turkey
CONTENTS
11.1. Drug.Delivery.Systems.................................................................................................... 227
11.2. Nanoparticulates.for.Drug.Delivery.Systems.............................................................. 229
11.2.1. Liposomes.as.Drug.Delivery.Systems............................................................. 232
11.2.1.1. Methods.of.Liposome.Preparation.Based.on.Variations.
in.the.Replacement.of.Organic.Solvent(s).by.the.Aqueous.
Media...................................................................................................... 234
11.2.1.2. Applications.of.Liposomes............................................................... 234
11.2.2. Polymeric.Nanoparticles.as.Drug.Delivery.Systems.................................... 237
11.2.2.1. Some.Polymers.Used.in.Nanoparticle.Preparation...................... 237
11.2.2.2. Nanoparticles..................................................................................... 238
11.3. Conclusion......................................................................................................................... 243
Acknowledgments....................................................................................................................... 243
References..................................................................................................................................... 243
11.1 DrugDeliverySystems
A.drug.delivery.system.(DDS).can.be.deined.as.the.system.that.achieves.the.administra-
tion.of.a.therapeutic.agent.to.the.patient.and.improves.the.drug's.eficacy.and.safety.by.
controlling. the. concentration,. rate,. time,. and. place. of. release. of. drugs. in. the. body.
1
. The.
primary.purpose.of.drug.delivery.systems.is.to.deliver.the.drug.eficiently.and.precisely.
to.a.targeted.site.in.an.appropriate.period.of.time,.while.maintaining.a.high.concentration.
of.the.drug.in.the.diseased.site.and.as.low.as.possible.in.the.healthy.tissue.
2
In. conventional. systems. plasma. drug. levels. increase. after. administration. to. a. patient,.
and.then.decrease.to.an.ineffective.level;.however,.the.concentration.should.be.in.the.ther-
apeutic. window.. When. a. new. administration. is. made,. the. same. rise. and. fall. happens..
To.overcome.this.low.dose.problem,.higher.drug.concentrations.can.be.applied,.but.this.
increases.the.risk.of.toxic.effects.of.the.drug.and.the.treatment.cost..For.many.diseases,.the.
therapeutic.agent.should.reach.a.certain.concentration.and.remain.constant.at.the.site.of.
action..In.conventional.systems,.however,.the.plasma.drug.levels.do.not.remain.constant,.
227
