Biomedical Engineering Reference
In-Depth Information
Hollow microneedles offer the possibility of delivering therapeutic
materials through their hollow structure, either by diffusion or under the
influence of positive pressure (McAllister et al., 2003; Prausnitz, 2004). A
range of hollow microneedles are shown in Figure 19. Nickel-coated
polymeric microneedles of hollow structures comprising an array of 16
needles having 500 nm length and 75 nm tip diameter have been fabricated for
delivery of insulin using a rat model (Davis et al., 2005). In a recent study,
hollow microneedles were used along with a vibratory inserter to open a pore
through the stratum corneum, resulting in successful delivery of the model
antigen protein ovalbumin (Daugimont et al., 2010).
(Source: McAllister et al., 2003).
Figure 19. Microscopy pictures of hollow microneedles having different shapes and
made from different materials and using different fabrication techniques. (A) Straight-
walled metal microneedles. (B) Tapered glass microneedle. (C and D) Tapered metal
microneedles.
