Two-photon polymerization of microneedles for transdermal drug delivery.
BACKGROUND
Microneedles are small-scale devices that are finding use for transdermal delivery of protein-based pharmacologic agents and nucleic acid-based pharmacologic agents; however, microneedles prepared using conventional microelectronics-based technologies have several shortcomings, which have limited translation of these devices into widespread clinical use.


METHODS
Two-photon polymerization is a laser-based rapid prototyping technique that has been used recently for direct fabrication of hollow microneedles with a wide variety of geometries. In addition, an indirect rapid prototyping method that involves two-photon polymerization and polydimethyl siloxane micromolding has been used for fabrication of solid microneedles with exceptional mechanical properties.


RESULTS
In this review, the use of two-photon polymerization for fabricating in-plane and out-of-plane hollow microneedle arrays is described. The use of two-photon polymerization-micromolding for fabrication of solid microneedles is also reviewed. In addition, fabrication of microneedles with antimicrobial properties is discussed; antimicrobial microneedles may reduce the risk of infection associated with the formation of channels through the stratum corneum.


CONCLUSIONS
It is anticipated that the use of two-photon polymerization as well as two-photon polymerization-micromolding for fabrication of microneedles and other microstructured drug delivery devices will increase over the coming years.
Gittard
Shaun D
SD
University of North Carolina Chapel Hill and North Carolina State University, Joint Department of Biomedical Engineering, CB 7115, 2147 Burlington Labs, Raleigh, NC 27695, USA.
Ovsianikov
Aleksandr
A
Chichkov
Boris N
BN
Doraiswamy
Anand
A
Narayan
Roger J
RJ
D000279:Administration, Cutaneous; D001672:Biocompatible Materials; D016503:Drug Delivery Systems / Q000295:instrumentation*; D006801:Humans; D055616:Microtechnology / Q000379:methods*; D009339:Needles; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*
D001672:Biocompatible Materials; D004364:Pharmaceutical Preparations