Viability and secretory activity of beneficial bacteria within hydrogel-based patches of tunable mechanical properties

Details

Supervisors

Glinel, Karine ; Jonas, Alain M.

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil biomédical, à finalité spécialisée

Abstract

enMany skin diseases associated with dysbiosis are currently only symptomatically treated. An innovative alternative would be to use the therapeutic properties of commensal bacteria. In this context, this study focuses on the fabrication and optimization of a therapeutic patch entrapping commensal bacteria that are beneficial for the skin. The device consists of a polydimethylsiloxane structure sealed with a polycarbonate membrane, containing a mixture of agarose and genetically modified Lactobacillus plantarum engineered to secrete elafin, an anti-inflammatory protein. Three encapsulation conditions were compared: a liquid medium, an agarose gel prepared with the same medium at a concentration of 0.5 wt%, and an agarose gel at 2 wt%. Bacterial leakage, cell viability, and elafin secretion were monitored over several days. The results show that gel stiffness influences the morphology of bacterial colonies, without affecting their viability or elafin secretion rate. In a second phase, the effect of storage at 4°C for up to 7 days was assessed for patches containing a 2 wt% agarose matrix prepared with medium. Elafin secretion remained stable, and the morphology of bacterial colonies showed little variation. Bacterial viability remained high overall, although a slight decrease was observed after 7 days of storage. Our study thus demonstrates the possibility to fabricate patches maintaining the viability and secretory activity of bacteria over long periods of time, and thereby offer interesting prospects for therapeutic topical applications.