title: 3D lithographically fabricated nanoliter containers for drug delivery.
abstract: Lithographic patterning offers the possibility for precise structuring of drug delivery devices. The fabrication process can also facilitate the incorporation of advanced functionality for imaging, sensing, telemetry and actuation. However, a major limitation of present day lithographic fabrication is the inherent two-dimensionality of the patterning process. We review a new approach to construct three dimensional (3D) patterned containers by lithographically patterning two dimensional (2D) templates with liquefiable hinges that spontaneously fold upon heating into hollow polyhedral containers. The containers have finite encapsulation volumes, can be made small enough to pass through a hypodermic needle, and the 3D profile of the containers facilitates enhanced diffusion with the surrounding medium as compared to reservoir systems fabricated in planar substrates. We compare the features of the containers to those of present day drug delivery systems. These features include ease of manufacture, versatility in size and shape, monodisperse porosity, ability for spatial manipulation and remote triggering to release drugs on-demand, the incorporation of electronic modules, cell encapsulation, biocompatibility and stability. We also review possible applications in drug delivery and cell encapsulation therapy (CET). The results summarized in this review suggest a new strategy to enable construction of "smart", three dimensional drug delivery systems using lithography.
authors.affiliation: Department of Biomedical Engineering, Johns Hopkins University, 720 Rutland Avenue, Baltimore MD 21205, USA.
authors.forename: Christina L
authors.initials: CL
authors.lastname: Randall
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Leong
authors.forename: Noy
authors.initials: N
authors.lastname: Bassik
authors.forename: David H
authors.initials: DH
authors.lastname: Gracias
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D002460:Cell Line; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems / Q000379:methods*; D004355:Drug Stability; D004582:Electronics, Medical; D036103:Nanotechnology / Q000379:methods*; D016062:Porosity; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations