Living Materials Approach for In Situ Bio-Polymers Production Using Bacillus Paralicheniformis in Microneedles.

Area of Science:

• Biomaterials Science
• Synthetic Biology
• Dermatology

Background:

• Living biomaterials leverage live organisms for in situ synthesis of biomolecules.
• Production of high-molecular-weight biopolymers via living biomaterials is underexplored.
• Gamma-polyglutamic acid (γ-PGA) is a high-molecular-weight biopolymer with therapeutic potential.

Purpose of the Study:

• To develop a microneedle (MN) patch system for delivering Bacillus paralicheniformis to produce γ-PGA in the skin.
• To evaluate the efficacy, safety, and stability of the bacterial delivery system.
• To explore optimal conditions for bacterial growth and γ-PGA biosynthesis.

Main Methods:

• Encapsulation of Bacillus paralicheniformis in microneedles.
• Application of MN patches to mouse skin models.
• Analysis of bacterial colonization, γ-PGA production, and host response.
• Optimization of bacterial growth media (LB vs. E medium).

Main Results:

• The MN patch successfully delivered B. paralicheniformis to the dermis.
• Bacteria produced γ-PGA with molecular weights ranging from 64 to 563 kDa.
• B. paralicheniformis colonized mouse skin without toxicity or inflammation.
• E medium was found to enhance γ-PGA biosynthesis compared to LB medium.

Conclusions:

• A novel microneedle-based living biomaterial system for in situ γ-PGA production in the skin was developed.
• The system demonstrates potential for sustainable and symbiotic dermal therapies.
• This approach offers a promising platform for delivering therapeutic biopolymers directly to the skin.