title: The hydrogel template method for fabrication of homogeneous nano/microparticles.
abstract: Nano/microparticles have been used widely in drug delivery applications. The majority of the particles are prepared by the conventional emulsion methods, which tend to result in particles with heterogeneous size distribution with sub-optimal drug loading and release properties. Recently, microfabrication methods have been used to make nano/microparticles with a monodisperse size distribution. The existing methods utilize solid templates for making particles, and the collection of individual particles after preparation has not been easy. The new hydrogel template approach was developed to make the particle preparation process simple and fast. The hydrogel template approach is based on the unique properties of physical gels that can undergo sol-gel phase transition upon changes in environmental conditions. The phase reversible hydrogels, however, are in general mechanically too weak to be treated as a solid material. It was unexpectedly found that gelatin hydrogels could be made to possess various properties necessary for microfabrication of nano/microparticles in large quantities. The size of the particles can be adjusted from 200 nm to >50 microm, providing flexibility in controlling the size in drug delivery formulations. The simplicity in processing makes the hydrogel template method useful for scale-up manufacturing of particles. The drug loading capacity is 50% or higher, and yet the initial burst release is minimal. The hydrogel template approach presents a new strategy of preparing nano/microparticles of predefined size and shape with homogeneous size distribution for drug delivery applications.
authors.affiliation: Departments of Biomedical Engineering and Pharmaceutics, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Ghanashyam
authors.initials: G
authors.lastname: Acharya
authors.forename: Crystal S
authors.initials: CS
authors.lastname: Shin
authors.forename: Matthew
authors.initials: M
authors.lastname: McDermott
authors.forename: Himanshu
authors.initials: H
authors.lastname: Mishra
authors.forename: Haesun
authors.initials: H
authors.lastname: Park
authors.forename: Ick Chan
authors.initials: IC
authors.lastname: Kwon
authors.forename: Kinam
authors.initials: K
authors.lastname: Park
mesh_terms: D000818:Animals; D016503:Drug Delivery Systems; D005780:Gelatin / Q000737:chemistry; D020100:Hydrogels; D019344:Lactic Acid / Q000737:chemistry; D008422:Materials Testing; D055616:Microtechnology / Q000379:methods*; D008970:Molecular Weight; D053758:Nanoparticles; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D044367:Phase Transition; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry; D012825:Silicon / Q000737:chemistry; D013552:Swine
chemical_list: D020100:Hydrogels; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D005780:Gelatin; D012825:Silicon