Silk Hydrogel Electrostatically Functionalized with a Polycationic Antimicrobial Peptide: Molecular Interactions, Gel
San Seint Seint Aye1, Zhi-Hong Zhang2, Xin Yu1
1Institute for Frontier Materials, Deakin University, Geelong, Victoria 3217, Australia.
Langmuir : the ACS Journal of Surfaces and Colloids
|December 29, 2021
Summary
This study created antimicrobial silk hydrogels using electrostatic interactions with polymyxin B, an important antibiotic. The resulting hydrogels show effectiveness against Gram-negative bacteria, paving the way for new biomaterial applications.
Area of Science:
- Biomaterials Science
- Drug Delivery
- Microbiology
Background:
- Silk fibroin hydrogels are promising biomaterials but lack inherent antimicrobial properties.
- Functionalizing silk fibroin with antimicrobial agents is crucial for expanding its applications, especially in combating multidrug-resistant bacteria.
Purpose of the Study:
- To develop an antimicrobial silk fibroin hydrogel by incorporating the antimicrobial peptide (AMP) polymyxin B.
- To investigate the electrostatic interaction between silk fibroin and polymyxin B and characterize the resulting hydrogel properties.
- To evaluate the antimicrobial efficacy of the functionalized hydrogel against Gram-negative bacteria.
Main Methods:
- Electrostatic interaction was utilized to load polymyxin B into silk fibroin hydrogel.
- Characterization included analysis of nanofibril structure, gelation kinetics, ζ-potential, fluorescence emission, and rheological properties.
- Antimicrobial activity was tested against two Gram-negative bacterial strains.
Main Results:
- Strong electrostatic interactions were confirmed between the polycationic polymyxin B and negatively charged silk fibroin.
- The incorporation of polymyxin B altered the hydrogel's structural and physical properties.
- The silk-polymyxin B hydrogels exhibited significant antimicrobial activity against Gram-negative bacteria.
- The optimal molar ratio of polymyxin B to silk fibroin was determined to be 1:2.5.
Conclusions:
- A straightforward electrostatic approach successfully created antimicrobial silk fibroin hydrogels.
- This method is adaptable for functionalizing silk hydrogels with various cationic antimicrobial peptides.
- The developed antimicrobial hydrogels hold potential for applications requiring resistance to bacterial infections.
