RESUMO
Much Research has been going to find ideal system for drug delivey within body.It is great advantage to find drug delivery device that is capable of controlled or continous release of wide variety of drug.Microchip are provided, which control both the rate and the time release of molecule.This allows release of wide variety of molecule in either continous or pulsatile manner. The device consist of substrate containing multiple reservoir is capped with conductive membrane (gold) and wired with final circuitry controlled by microprocessor.Reservoir are etched into substrate using either chemical etching or ion beam etching techniques. Hundreds to thousands reservoirs can be fabricated on a single microchip using microfabrication.The molecule to be delivered are inserted into reservoir by injection. The reservoir can contain multiple drug or other molecule in variable dosages. The filled reservoirs can be capped with material that degrade or allow the molecule to diffuse out of reservoir over time or materials that oxidize and dissolve upon application of electric current.Release from an active device can be controlled by a preprogrammed microprocessor.It is used in diabetes, Parkinson’s disease, congestive heart failure, anti coagulation.
RESUMO
This paper presents a review of work on the fabrication and use of nanochannels in silicon and polymers for the control of molecular transport. The method of Sacrificial Layer Lithography is reviewed and demonstrated for silicon and polymers. A novel technique for the productions of conical nanopores through a polymer membrane is also reviewed. Nanochannels and nanopores have many potential applications for drug delivery, immunoprotection of cell implants, blocking of globular proteins from biosensor surfaces, and diagnostic devices. All of these applications benefit from the more direct interactions of devices with biomolecules.
El presente trabajo presenta una revisión literaria sobre los métodos de fabricación de nanocanales en silicio y diferentes materiales poliméricos; y su uso en control de transporte molecular. Se describe el método "Sacrificial Layer Lithography" para silicio y polímeros. Adicionalmente, una novedosa técnica para la producción de nanoporos cónicos a través de una membrana polimérica es descrita. Los nanocanales y los nanoporos poseen diversas aplicaciones potenciales en la liberación de drogas, en la inmunoprotección de implantes celulares, el bloqueo de proteínas globulares en la superficie de biosensores, y en dispositivos para diagnóstico. Todas estas aplicaciones se benefician de la interacción directa entre los dispositivos y las biomoléculas.
RESUMO
Enfermedades hormonales como la diabetes exigen el uso frecuente de procedimientos para muestreo de fluidos y suministro de medicamentos que ocasionan traumas en los tejidos epiteliales por la penetración de agujas convencionales. Este hecho motiva el desarrollo de tecnologías alternativas que disminuyan el daño tisular y contribuyan a mejorar la calidad de vida de los pacientes, tema que constituye un campo activo de investigación en compañías y universidades alrededor del mundo. Este artículo presenta los resultados preliminares de la fabricación de arreglos de microagujas en Colombia, empleando la técnica de fotolitografía en capas gruesas de SU-8 que ha sido utilizada por el grupo de Ciencia y Tecnología de Materiales de la Universidad Nacional de Colombia Sede Medellín. Se presentan las micrografías de agujas huecas y macizas obtenidas en diferentes tamaños y se discuten las cualidades y defectos del proceso de fabricación.
Hormonal illnesses like diabetes demand the frequent use of fluid sampling and drug delivery procedures, which produces traumas on skin tissues, as a result of conventional needles penetration. This fact motivates the development of alternative technologies that decrease tissue damage and contribute to improve the quality of life of the patients. This topic constitutes an active field of research in many companies and universities around the world. This paper presents preliminary results of the fabrication of microneedle arrays, using the technique of SU-8 thick film photolithography, previously standardized by the Group of Materials Science and Technology of the National University of Colombia in Medellín. Micrographs of the obtained hollowed and solid needles of different sizes are presented and goals and limitations of the proposed methodology are discussed.