How Can We Deliver Life Enhancing Therapy to the Brain Via the Skin?
What are topical nootropics (brain enhancing drugs)? How does transdermal drug delivery work? What are common drugs delivered via the skin? How will this change in the future?
The skin is the largest organ in the body, and it accounts for approximately 10% of an individual's body mass. Its large surface area means that the skin is a feasible portal for delivering potent drugs for systemic effect.
According to an article by Prausnitz and Langer, “Transdermal delivery represents an attractive alternative to oral delivery of drugs and is poised to provide an alternative to hypodermic injection tool. For thousands of years, people have placed substances on the skin for therapeutic effects and, in the modern era, a variety of topical formulations have been developed to treat local indications. The first transdermal system for systemic delivery—a three-day patch that delivers scopolamine to treat motion sickness—was approved for use in the United States in 1979. A decade later, nicotine patches became the first transdermal blockbuster, raising the profile of transdermal delivery in medicine and for the public in general.” Today, there are dozens of transdermal delivery systems for such drugs as estradiol, fentanyl, lidocaine and testosterone; combination patches containing more than one drug for contraception and hormone replacement, and iontophoretic and ultrasonic delivery systems for analgesia; it is estimated more than one billion transdermal patches are currently manufactured each year for cosmetic, topical and transdermal delivery systems.
What about treating brain cancers that metastasize from the skin? Stem cells loaded with oncolytic viruses show promising results in preclinical models for targeting skin cancer metastases in the brain.
In a study at Brigham and Women's Hospital reported in PNAS, investigators have a potential solution for how to kill tumor cells that have metastasized to the brain. The team has developed cancer-killing viruses that can deliver stem cells via the carotid artery and applied them to metastatic tumors in the brain of clinically relevant mouse models. "Metastatic brain tumors -- often from lung, breast or skin cancers -- are the most commonly observed tumors within the brain and account for about 40 percent of advanced melanoma metastases. Current therapeutic options for such patients are limited, particularly when there are many metastases," says Khalid Shah, MS, PhD, director of the Center for Stem Cell Therapeutics and Imaging (CSTI) in the BWH Department of Neurosurgery, who led the study. "Our results are the first to provide insight into ways of targeting multiple brain metastatic deposits with stem-cell-loaded oncolytic viruses that specifically kill dividing tumor cells."
How can lasers be used on the skin for drug delivery? Using lasers can be an effective drug permeation-enhancement approach for facilitating drug delivery into or across the skin. The controlled disruption and ablation of the stratum corneum (SC), the predominant barrier for drug delivery, can be achieved by the use of lasers.
In an article by Lin et al, it was noted how using lasers can be an effective drug permeation-enhancement approach for facilitating drug delivery into or across the skin. The controlled disruption and ablation of the stratum corneum (SC), the predominant barrier for drug delivery, is achieved by the use of lasers. The authors note that “the possible mechanisms of laser-assisted drug permeation are the direct ablation of the skin barrier, optical breakdown by a photomechanical wave and a photothermal effect. It has been demonstrated that ablative approaches for enhancing drug transport provide some advantages, including increased bioavailability, fast treatment time, quick recovery of SC integrity and the fact that skin surface contact is not needed.”
Using transdermalstem cells, and laser techniques to treat the skin and brain have attracted increasing attention and will continue to grow over time.
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For more information, look at my YouTube series on the Brain-Skin Connections:
