Summary
UCLA researchers in the Department of Bioengineering have developed gelatin methacryloyl microneedles (GelMA MN) for minimally invasive, sustained transdermal drug delivery.
Background
Microneedle technology is promising for transdermal delivery of therapeutic drugs since it enables drugs to pass through the stratum corneum via microchannels in a minimally invasive manner. Due to their microscale dimensions microneedles (MNs) can puncture the skin seamlessly and deliver a range of therapeutic molecules with a wide range of molecular weights, such as small molecules, biomacromolecules, and even nanoparticles. MNs used in drug delivery applications are typically composed of water-soluble materials that dissolve upon contact with the skin. However, the dissolution rate of most of these materials is quite fast resulting in an initial burst release at toxic levels. Moreover, dissolvable MNs can overcome limitations of drug loading capacity compared to coated MNs and have demonstrated sustained drug delivery capabilities. However, dissolving MNs require additional fabrication step, which complicate their translation to the clinic.
Innovation
UCLA researchers have developed gelatin methacryloyl microneedles (GelMA MNs) for minimally invasive, sustained transdermal drug delivery. GelMA MNs possess high biocompatibility and tunable biodegradability and mechanical properties. More specifically, the mechanical and material characteristics of GelMA MNs can be easily modulated by controlling their crosslinking degrees. Anticancer drugs are easily loaded into the MNs by a simple mixing procedure, and the drug can be released over a period of days, weeks, or even longer by tuning the crosslinking degree. Moreover, the MNs retain their mechanical toughness with swelling, and can therefore be removed from the skin in an intact manner. The drug’s therapeutic activity is also preserved after release, and 100% penetration efficiency of the MNs was demonstrated in a mouse cadaver skin model. Overall, these GelMA MNs are easy to fabricate, biocompatible, and have readily tunable properties, making them excellent candidates for transdermal drug delivery.
Applications
▶ Transdermal drug delivery (drug patches)
▶ Drug delivery with other mammalian tissues (i.e., cardiovascular tissues)
Advantages
▶ Biocompatible
▶ Tunable biodegradability and mechanical properties
▶ Retain their mechanical toughness with swelling
▶ Therapeutic drug activity preserved
▶ Easy to fabricate
▶ MN has 100% penetration efficiency