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Selective Capture, Separation, and Photothermal Inactivation of Methicillin-Resistant Staphylococcus aureus (MRSA)
Chengnan Li1, Zongshao Li1, Yingying Gan1
1School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen 518107, PR China.
Abstract:
Antibiotic-free antimicrobial strategies are urgently needed to address the rapid evolution of antimicrobial resistance and transmission of multidrug-resistance bacterial infections. Herein, we fabricated polydopamine-coated porous magnetic nanoparticles (pMNPs@PDA) for effective separation and photothermal killing of methicillin-resistant Staphylococcus aureus (MRSA). Taking advantage of the excellent bacteria-affinitive property of polydopamine, the nanoparticles were anchored on the surface of bacteria, permitting rapid and efficient MRSA capture and separation with over 99% removal via the application of a magnetic field in 30 min. It was found, for the first time, that polydopamine-coated magnetic nanoparticles displayed a selective capture of Gram-positive bacteria when compared with Gram-negative bacteria. The selectivity was attributed to the preferable binding capability of pMNPs@PDA to peptidoglycan (PGN) of Gram-positive bacteria, compared to the lipopolysaccharide (LPS) of Gram-negative bacteria. With the magnetic separation and photothermal properties, pMNPs@PDA exhibited efficient killing of the captured MRSA under the irradiation of near-infrared (NIR) light. Cell cytotoxicity testing demonstrated good biocompatibility of the nanoparticles. These antibiotic-free nanoparticles capable of fast capture, separation, and inactivation of MRSA may be potentially used for water disinfection, blood purification, and treatment of bacterial infections.
Insights
New magnetic nanoparticles offer an antibiotic-free method to capture and kill antibiotic-resistant bacteria like MRSA. These nanoparticles selectively target Gram-positive bacteria, showing promise for water disinfection and infection treatment.
Area of Science:
- Biomaterials Science
- Nanotechnology
- Infectious Diseases
Background:
- Antimicrobial resistance necessitates novel, antibiotic-free therapeutic strategies.
- Multidrug-resistant bacterial infections pose a significant global health threat.
- Developing efficient methods for bacterial capture and inactivation is crucial.
Purpose of the Study:
- To fabricate polydopamine-coated porous magnetic nanoparticles (pMNPs@PDA) for MRSA capture and killing.
- To investigate the selective binding of pMNPs@PDA to Gram-positive bacteria.
- To evaluate the efficacy and biocompatibility of pMNPs@PDA as an antimicrobial agent.
Main Methods:
- Fabrication of polydopamine-coated porous magnetic nanoparticles (pMNPs@PDA).
- Utilizing magnetic fields for rapid capture and separation of bacteria.
- Employing near-infrared (NIR) light for photothermal inactivation of captured bacteria.
- Assessing nanoparticle selectivity for Gram-positive versus Gram-negative bacteria.
- Conducting cell cytotoxicity tests to evaluate biocompatibility.
Main Results:
- pMNPs@PDA achieved over 99% removal of MRSA within 30 minutes via magnetic separation.
- Demonstrated selective capture of Gram-positive bacteria over Gram-negative bacteria.
- Efficient inactivation of captured MRSA using NIR light photothermal therapy.
- pMNPs@PDA exhibited good biocompatibility in cytotoxicity testing.
Conclusions:
- pMNPs@PDA effectively capture, separate, and inactivate MRSA using an antibiotic-free approach.
- The nanoparticles show selectivity for Gram-positive bacteria due to preferential binding to peptidoglycan.
- These findings suggest potential applications in water disinfection, blood purification, and treating bacterial infections.
