Genetically engineered silk fibroin with antibacterial and antioxidant properties

Area of Science:

• Biomaterials Science
• Molecular Biology
• Biochemistry

Background:

• Bombyx mori silk fibroin and cecropin B are promising biomolecules for biomedical use.
• Their unique properties suggest potential for synergistic applications in medicine.

Purpose of the Study:

• To express recombinant silk fibroin (R. fib) and a fusion protein (R. fib-cec) in Pichia pastoris.
• To characterize the recombinant proteins and evaluate their antimicrobial and cytoprotective properties.

Main Methods:

• Recombinant protein expression in Pichia pastoris.
• Protein characterization using SDS-PAGE, Western blotting, and MALDI-TOF.
• Assessment of antibacterial activity against E. coli and S. aureus.
• Evaluation of protective effects against H2O2 and UVB-induced oxidative damage in fibroblast cells.

Main Results:

• Successful expression of R. fib (6 mg/L) and R. fib-cec (1.3 mg/L) with confirmed purity.
• R. fib-cec demonstrated potent broad-spectrum antibacterial activity.
• Both R. fib and R. fib-cec significantly protected human dermal fibroblast cells from oxidative stress, improving viability and reducing cell damage markers.

Conclusions:

• R. fib and R. fib-cec exhibit significant antimicrobial and antioxidant properties.
• The silk-cecropin B fusion protein is a multifunctional biomaterial with potential for biomedical applications.
• These findings support the use of R. fib-cec in antimicrobial therapies, skin protection, and wound healing.