Controlling the Growth of Staphylococcus epidermidis by Layer-By-Layer Encapsulation

Area of Science:

• Biotechnology
• Materials Science
• Microbiology

Background:

• Commensal skin bacteria, like Staphylococcus epidermidis, show potential for skincare applications.
• Controlling bacterial proliferation is essential to mitigate adverse effects in topical formulations.

Purpose of the Study:

• To develop a method for encapsulating Staphylococcus epidermidis to control its proliferation while maintaining viability.
• To investigate the impact of shell properties on bacterial growth and viability for skincare applications.

Main Methods:

• Layer-by-layer assembly was used to create polyelectrolyte shells of varying thickness around S. epidermidis.
• Shell composition (synthetic polyelectrolytes or polysaccharides), thickness, and outer layer charge were systematically varied.
• A scalable process for producing non-aggregated bacteria was developed and utilized.

Main Results:

• Bacterial growth delay was dependent on shell thickness and the charge of the outermost layer, not mechanical properties.
• The bacteriostatic effect is attributed to the diffusion of unpaired amine sites through the polyelectrolyte complex shell.
• Achieved lag times in bacterial growth are sufficient to prevent proliferation during daily topical use.

Conclusions:

• Polyelectrolyte encapsulation effectively controls S. epidermidis proliferation for safe use in skincare.
• The study provides a viable strategy for incorporating beneficial bacteria into cosmetic and dermatological products.