Les microaiguilles

Cet article présente les différents aspects de la recherche dans le domaine des microaiguilles. Les différents types de microaiguilles sont abordés ainsi que leurs méthodes de fabrication. Les travaux dans les domaines connexes que sont la mécanique de la rupture et celle de la pénétration dans la peau seront abordés. Enfin les rares applications industrielles sont présentées

Fabrication et caractérisation d'une peau humaine artificielle vascularisée

La déontologie interdisant des essais de prélèvement directs sur les nouveaux nés, le but de notre travail est de réaliser de la peau artificielle vascularisée et d'en étudier les propriétés mécaniques. Cette peau artificielle représente les différentes strates de la peau humaine et son réseau sanguin le plus superficiel grâce à l'utilisation de polymères, combinée à des procédés de micro-fabrication. L'aspect transparent de ce fantôme de peau permettra à postériori l'observation de différentes techniques de prélèvement sanguin au talon du bébé

A microfluidic distribution system for an array of hollow microneedles

9 pagesInternational audienceWe report a microfluidic device able to control the ejection of fluid through a matrix of out-of-plane microneedles. The device comprises a matrix of open dispensing units connected to needles and filled by a common filling system. A deformable membrane (e.g. in PDMS) is brought into contact with the dispensing units. Pressure exerted on the deformable membrane closes (and thus individualizes) each dispensing unit and provokes the ejection of the dispensing unit content through the outlets. Sufficient pressure over the deformable membrane ensures that all dispensing units deliver a fixed volume (their content) irrespective of the hydrodynamic pressure outside the dispensing unit outlet. The size of the ensemble matrix of dispensing units, the number of liquid reservoirs, as well as the material can vary depending on the considered application of the device or on the conditions of use. In the present paper, the liquid reservoirs are geometrically identical. The geometrical parameters of the device are optimized to avoid as much dead volume as possible, as it was to handle plasmid DNA solutions which are very expensive. The conception, the fabrication and the experimental results are described in this paper. Our prototype is conceived to inject in a uniform way 10 µl of drug through 100 microneedles distributed over 1 cm2

Etude de l'inhomogénéité de pénétration de matrices de microaiguilles dans la peau

Les progrès de la miniaturisation en micromécanique permettent aujourd'hui de produire des microsystèmes offrant des perspectives d'injection intradermique de médicaments sans douleur. Nos travaux portent sur l'élaboration de matrices de microaiguilles. La méthode de fabrication utilisée est issue des microtechnologies : les matrices de microaiguilles sont élaborées par étapes successives de gravure sèche et humide. En premier lieu, nous présentons leur tenue mécanique lors de la pénétration par résolution analytique. Puis, après fabrication des matrices de microaiguilles, nous avons réalisé des tests de pénétration sur un fantôme de peau afin d'évaluer leur mode de pénétration. Sous différentes charges, les essais présentent des phénomènes de bord que nous avons reproduits numériquement. Enfin, nous proposons une géométrie qui minimise ces effets

Electropermeabilization of endocytotic vesicles in B16 F1 mouse melanoma cells

It has been reported previously that electric pulses of sufficiently high voltage and short duration can permeabilize the membranes of various organelles inside living cells. In this article, we describe electropermeabilization of endocytotic vesicles in B16 F1 mouse melanoma cells. The cells were exposed to short, high-voltage electric pulses (from 1 to 20 pulses, 60 ns, 50 kV/cm, repetition frequency 1 kHz). We observed that 10 and 20 such pulses induced permeabilization of membranes of endocytotic vesicles, detected by release of lucifer yellow from the vesicles into the cytosol. Simultaneously, we detected uptake of propidium iodide through plasma membrane in the same cells. With higher number of pulses permeabilization of the membranes of endocytotic vesicles by pulses of given parameters is accompanied by permeabilization of plasma membrane. However, with lower number of pulses only permeabilization of the plasma membrane was detected

An overview on drug delivery through microneedles.

International audienc

Arrayed Micro Needles for Mechanical Gene Insertion

Times Cited: 3 Cabodevila, G Lepioufle, B Fujita, H International Symposium on Smart Materials, Nano-, and Micro-Smart Systems Dec 16-18, 2002 Melbourne, australia SPIE, Univ Arkansas, Natl Inst Adv Ind Sci & Technol, Cooperat Res Ctr Microtechnol, Dept Def, Australia, Swinburne Univ Technol, Adelaide Univ, Japanese Soc Electr Packaging, New Energy & Ind Technol Dev OrgA novel approach to realize arrays of out of plane micro needles is given. The exterior shape of the micro needles is realized by dry etching using a RIE. The exterior shape is realized in silicon by dry etching using a SF6 and Argon plasma that achieve the progressive etching of the mask composed by silicon nitride and photoresist. The needles realized present an outer diameter of 900 nm for a height of about 7 microns. The needle is then realized by wet oxidation using a thin film of silicon nitride to perform a LOCOS at the end of the needle. The last step consists in selectively etch the Si3N4 and the silicon inside the needle by xenon difluoride

Investigations of development process of high hollow beveled microneedles using a combination of ICP RIE and dicing saw

International audienceMicromachined needles provide a promising technology for painless delivery of molecules or foreign substance into a living cell. Over the recent years, a variety of different microneedle shapes and materials have been studied and have shown their facility to disrupt stratum corneum layer to increase the skin permeability. In this paper, we described an alternative process to fabricate high and beveled hollow out-of-plane microneedles. Silicon microneedles dimensions are 40–60 lm in inner diameter, 150–200 lm in outer diameter and over 700 lm in height. Tip angles reached are from 30 to 45