Multifunctional and Stimuli‐Responsive Polydopamine Nanoparticle‐Based Platform for Targeted Antimicrobial Applications

Abstract

The rising threat of antimicrobial resistance is a crisis of a global scale. If not addressed, it can lead to health care system problems worldwide. This warrants alternative therapeutic approaches whose mechanism of action starkly differs from conventional antibiotic-based therapies. Here, a multifunctional and stimuli-responsive (NIR laser-activated) antimicrobial platform is engineered by combining the intrinsic photothermal capability and excellent biocompatibility of polydopamine nanoparticles (PdNPs), with the membrane targeting and lytic activities of an antimicrobial peptide (AMP). The resulting PdNP-AMP nanosystem can specifically target and destabilize the mechanical integrity of the outer membrane of Escherichia coli, as measured using the atomic force microscope. Furthermore, the laser-induced nano-localized heating of PdNP-in close proximity to the already compromised bacterial envelope-induces further membrane damage. This results in a more efficient, laser-activated, bacterial killing action of PdNP-AMP. The antimicrobial platform developed in this work is shown to be effective against a drug-resistant E. coli. Overall, this work highlights the advantage and strength of combining multiple and coordinated biocidal mechanisms, into one nanomaterial-based system and its promise in treating drug-resistant pathogens.

Immobilization of Polyethyleneimine (PEI) on Flat Surfaces and Nanoparticles Affects Its Ability to Disrupt Bacterial Membranes

“…Figure 1 A shows an AFM topography image of E. coli immobilized on PC-PEI, where the bacteria retained its overall shape and size, with relatively smooth surface features (see Figure S1 for additional images). This is consistent with our previous work, as well as with prior reports on AFM imaging of bacteria immobilized on PEI-coated substrates [ 16 , 17 , 25 ]. Furthermore, the overall structure and surface features of PEI-immobilized E. coli are very similar to the structural features of E. coli embedded within its biofilm matrix, also grown on the surface of PC membrane [ 26 ].…”

“…Hertz fitting was done on the extended part of the force curve using a parabolic model for the tip with a radius of 2 nm, the nominal radius of SNL cantilevers. AFM data were analyzed using a software that was previously developed in the lab, where we use a selection tool to specifically define areas within the QI map to more accurately extract Young’s modulus values, i.e., only the top middle portion of the bacteria were included in the analysis [ 25 , 26 ].…”

Polydopamine/poly(sulfobetaine methacrylate) Co-deposition coatings triggered by CuSO4/H2O2 on implants for improved surface hemocompatibility and antibacterial activity

“…Therefore, to prevent the occurrence of device-associated infection, more effective method is to modify the bactericidal chemicals on the surface of the material [ 26 ]. Currently, the commonly used antibacterial agents are metal nanoparticles [ 27 ], metal ions [ 28 , 29 ], quaternary ammonium salts [ 30 ], antimicrobial peptides and polymer [ 31 ], etc. As an essential trace element in the human body, copper is one of the earliest inorganic antibacterial agents used by human.…”

Thermally and light‐triggered reconfigurable shape memory polydopamine/epoxy composite with self‐healing and recyclable ability

“…In order to achieve effective temperature control of light‐responsive polymer composites, fillers with high absorbance and high‐conversion efficiency 24–25 has been incorporated into the self‐healing matrix, such as carbon materials, 26–27 plasmonic nanoparticles, 28–29 dye compounds 12,30 . Polydopamine (PDA) is a dye compound with excellent photothermal effect and strong adhesion performance, and can almost any polymers surface modification 31–33 . It is introduced into the self‐healing polymer matrix and can be activated by near‐infrared light (NIR) to perform accurate and efficient photothermal self‐healing properties on the local damaged area.…”

“…12,30 Polydopamine (PDA) is a dye compound with excellent photothermal effect and strong adhesion performance, and can almost any polymers surface modification. [31][32][33] It is introduced into the self-healing polymer matrix and can be activated by near-infrared light (NIR) to perform accurate and efficient photothermal self-healing properties on the local damaged area.…”