The requirements on nanoparticles for cosmetic and medical applications are very different. While nanoparticles applied in sunscreens shall remain on the skin surface or in the upper cell layers of the stratum corneum, nanoparticles for medical drug delivery shall penetrate through the skin barrier to the target structures in the living cells.
Under the Collaborative Research Project 1112 various methods are used at the CCP to investigate the cutaneous penetration and storage of nanoparticles, hair follicles being in the focus of attention. Human hair follicles are ideal target structures for drug delivery. Hosting both the stem and dendritic cells, they are surrounded by a dense network of blood vessels. Investigating nanoparticles of different size and materials, particles of approximately 600 nm in diameter were found to penetrate best into the hair follicles, where they can be stored for maximally 10 days. Their retention time in the hair follicles exceeds that in the stratum corneum by almost one order of magnitude. Particles penetrate more efficiently into the hair follicles than non-particulate substances.
For particles from 40 nm-1 µm in diameter, however, no follicular penetration has been detectable if the skin barrier was intact. This is plausible as the hair follicle has its own barrier.
It will be demonstrated that the best way for drug delivery is the application of drug-loaded particulate carrier systems. In the hair follicles the particles may either dissolve and release the drug, or an external signal must trigger the drug release from the particle.
Jürgen M. Lademann, Heike Richter, Sora Jung, Martina C. Meinke, Eckart Rühl, Ulrike Alexiev, Marcelo Calderon, and Alexa Patzelt, "Topical application of nanoparticles: prospects and safety aspects
(Conference Presentation)," Proc. SPIE 9707, Dynamics and Fluctuations in Biomedical Photonics XIII, 97070I (Presented at SPIE BiOS: February 15, 2016; Published: 26 April 2016); https://doi.org/10.1117/12.2212109.4848677962001.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the proceedings. They include the speaker's narration with video of the slides and animations. Most include full-text papers. Interactive, searchable transcripts and closed captioning are now available for most presentations.
Search our growing collection of more than 22,000 conference presentations, including many plenaries and keynotes.