Veronica Montgomery

BME PhD Defense Presentation

Date: 2023-07-20
Time: 12:00 pm - 2:00 pm
Location / Meeting Link: EBB CHOA Seminar Room / Zoom: https://gatech.zoom.us/j/95058277535

Committee Members:
Mark Prausnitz (Advisor); Mark Styczynski; Neha Garg; James Dahlman; Krishnendu Roy


Title: Engineering the Skin Microbiome for Drug Delivery

Abstract:
Topical drug delivery is convenient for patients because the skin is a highly accessible tissue that allows simple self-application of therapies. However, topical drug delivery formulations are limited in their ability to deliver drugs for long periods of time, which constrains their suitability for chronic conditions. The skin microbiome, which consists of many commensal species of bacteria that can colonize the skin for days to months or years at a time, could be used to address these limitations if commensal bacteria were engineered to act as drug delivery platforms for the skin. The objective of this thesis was to evaluate a bacteria-based drug delivery platform for topical therapy using Bacillus subtilis, a genetically tractable organism that is found in the skin microbiome. The feasibility of using B. subtilis as a topical drug delivery platform was first assessed using a combination of computational and experimental skin models, with green fluorescent protein (GFP) serving as a model heterologous protein drug. We found that B. subtilis appeared safe for use on skin and was able to survive while producing GFP for at least 1 day across multiple skin models. We next explored two therapeutically relevant applications for engineered B. subtilis on the skin as an antifungal treatment and mosquito repellant. We identified challenges in the specific use of B. subtilis as a drug delivery platform as well as more broad challenges for the field of using engineered bacteria for skin treatments.