Hydrogel nanoparticles in drug delivery
Mehrdad Hamidi a ,b ,?,Amir Azadi a ,Pedram Ra ?ei a
a Faculty of Pharmacy,Shiraz University of Medical Sciences,P.O.Box 71345-1583,Shiraz,Iran
b
School of Pharmacy,Zanjan University of Medical Sciences,P.O.Box 45195-1338,Postal Code 45139-56184,Zanjan,Iran
a b s t r a c t
a r t i c l e i n f o Article history:
Received 7July 2008Accepted 8August 2008
Available online 20September 2008Keywords:Hydrogel
Nanoparticles
Hydrogel nanoparticles Nanogels
Hydrogel nanoparticles have gained considerable attention in recent years as one of the most promising nanoparticulate drug delivery systems owing to their unique potentials via combining the characteristics of a hydrogel system (e.g.,hydrophilicity and extremely high water content)with a nanoparticle (e.g.,very small size).Several polymeric hydrogel nanoparticulate systems have been prepared and characterized in recent years,based on both natural and synthetic polymers,each with its own advantages and drawbacks.Among the natural polymers,chitosan and alginate have been studied extensively for preparation of hydrogel nanoparticles and from synthetic group,hydrogel nanoparticles based on poly (vinyl alcohol),poly (ethylene oxide),poly (ethyleneimine),poly (vinyl pyrrolidone),and poly-N -isopropylacrylamide have been reported with different characteristics and features with respect to drug delivery.Regardless of the type of polymer used,the release mechanism of the loaded agent from hydrogel nanoparticles is complex,while resulting from three main vectors,i.e.,drug diffusion,hydrogel matrix swelling,and chemical reactivity of the drug/matrix.Several crosslinking methods have been used in the way to form the hydrogel matix structures,which can be classi ?ed in two major groups of chemically-and physically-induced crosslinking.
©2008Elsevier B.V.All rights reserved.
Contents 1.Introduction:Nanoparticles in drug delivery ..............................................16392.
Hydrogels:A brief overview......................................................16392.1.Hydrogel classi ?cations.....................................................16392.2.Release mechanism from hydrogel matrices ...........................................16402.3.Controlled-release hydrogel systems ...............................................16412.4.Hydrogels for pharmaceutical applications.............................................16413.Hydrogel nanoparticles (Nanogels ?)..............................
.....................16413.1.Chitosan-based hydrogel nanoparticles .........................
.....................
16413.1.1.Chitosan-based nanoparticles with covalent crosslinks ..................................16423.1.2.Chitosan-based nanoparticles with ionic crosslinks....................................16423.1.3.Chitosan-based nanoparticles prepared by desolvation method ..............................16423.1.4.Chitosan-based nanoparticles prepared by emulsion-droplet coalescence method .....................16423.1.5.Chitosan-based nanoparticles prepared by reverse micellar method............................16433.1.6.Chitosan-based nanoparticles prepared by self-assembly via chemical modi ?cation
....................16433.2.Alginate-based hydrogel nanoparticles .............................................16433.3.Poly (vinyl alcohol)-based hydrogel nanoparticles ........................................16443.4.Poly (ethylene oxide)and poly (ethyleneimine)-based hydrogel nanoparticles ...........................16443.5.Poly (vinyl pyrrolidone)-based hydrogel nanoparticles ......................................16443.6.Poly-N -isopropylacrylamide-based hydrogel nanoparticles ....................................16443.7.Hydrogel nanoparticles of other origins .............................................1645References ............................................
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Advanced Drug Delivery Reviews 60(2008)1638–1649
?Corresponding author.School of Pharmacy,Zanjan University of Medical Sciences,P.O.Box 45195-1338,Postal Code 45139-56184,Zanjan,Iran.Tel.:+982414273638;fax:+982414273639.
E-mail address:hamidim@sums.ac.ir (M.
Hamidi).0169-409X/$–see front matter ©2008Elsevier B.V.All rights reserved.doi:
10.1016/j.addr.2008.08.002
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