Biomedical Engineering Reference
In-Depth Information
TABLE 11.5
Some.Cosmetic.Products.Containing.Liposomes
Manufacturer
Product
KeyIngredientsofLiposomes
Christian.Dior
Capture
Liposomes.in.gel.with.ingredients
L'Oréal
Efect.du.Soleil
Tanning.agents
Lancome.(L'Oréal)
Niosomes,.Nactosomes
Glyceropolyether.with.moisturizer
Payot.(Ferdinand.Muehlens)
Formule.Liposome.Gel
Thymoxin,.hyaluronic.acid
Estee.Lauder
Future.Perfect.Skin.Gel
TMF,.(Methyl.trimethicone).vitamins.E.and.A.
palmitate,.cerebroside.ceramide,.
phospholipids
advantage.over.conventional.liposomes;.they.are.stored.in.a.freeze-dried.form.(in.appro-
priate. conditions). until. use.. This. substantially. increases. the. shelf. life. of. the. liposomes.
from.1.week.to.several.months..DRVs.are.widely.used.in.liposomal.products.and.drugs.
such.as.Visudyne™.and.AmBisome
®
.
Another.study.involving.liposomes.attempted.to.develop.a.UV-responsive.drug.deliv-
ery.system.using.UV-sensitive.liposomes..UV.responsiveness.was.provided.by.Suprofen.
incorporated.into.the.liposomal.membrane.
68
.This.achieved.on-demand.delivery.of.a.par-
ticular. drug. in. a. site. of. the. body. accessible. to. electromagnetic. radiation.. Liposomes. are.
also. studied. as. both. drug. delivery. and. imaging. systems. to. track. their. route. inside. the.
tissue.and.for.detection.of.disease.sites.
69,70
11.2.2 Polymeric Nanoparticles as Drug Delivery Systems
11.2.2.1 Some Polymers Used in Nanoparticle Preparation
At. present,. the. use. of. polymeric. materials. in. dosage. forms. that. are. known. as. controlled.
release.systems.is.a.very.promising.area.of.biotechnology,.biomedical.devices,.and.pharma-
ceuticals.
71
.As.stated.earlier,.the.use.of.nanoscale.materials.has.signiicant.advantages,.such.
as.injectable.biocompatible.and.biodegradable.polymeric.particles,.reducing.the.inconve-
nience.of.surgical.insertion.of.larger.implants.and.also.avoiding.macrophages.when.intro-
duced.intravenously.and.accumulating.at.solid.tumor.sites.after.extravasation.
72
.Synthetic.
and.natural.polymers.have.been.investigated.extensively.in.the.last.few.decades.as.carriers.
for.controlled.drug.release.and.targeting..Among.the.natural.polymers.used.are.proteins.
like.human.serum.albumin.(HSA),.collagen,.gelatin,.and.hemoglobin,.all.of.which.are.both.
biodegradable.and.biocompatible..One.limitation.in.their.use.is.high.cost.and.impurities.that.
might.induce.undesirable.effects..Synthetic.polymers,.on.the.other.hand,.have.signiicant.
advantages.over.natural.ones,.such.as.high.purity,.ease.of.production.and.reproducibility,.
nontoxic.by-products,.and.controllable.biodegradability.and.biocompatibility.
72-74
.Synthetic.
polymers. such. as. poly(α-hydroxy. acids),. poly(β-hydroxy. acids),. poly(є-caprolactone),.
poly(amides),.poly(phosphazenes),.poly(orthoesters),.poly(anhydrides),.and.poly(phosphate.
esters).are.commonly.used.in.the.construction.of.controlled.release.systems.
75
.Among.them,.
poly(lactides).and.poly(hydroxyalkanoates).are.of.special.interest.
The.most.widely.studied.and.used.biodegradable.polymers.are.the.poly(α-esters),.such.as.
poly(lactic.acid).(PLA),.poly(glycolic.acid).(PGA),.and.their.copolymers.(Figure.11.2),.and.the.
poly(hydroxyalkanoates).(PHAs).(Fig.11.3),.such.as.poly(3-hydroxybutyrate).(P3HB),.poly(3-
hydroxyvalerate).(P3HV),.and.their.copolymers.(Figure 11.4)..They.have.a.range.of.pharma-
ceutical.and.biomedical.uses.as.a.result.of.these.characteristics.and.their.physicochemical.
