. 2023 Apr 21;14:1135579. doi: 10.3389/fmicb.2023.1135579

Table 2.

Nanoparticles and their mechanism of action at the NP-bacterial membrane interface.

S. No.	Nanoparticle	Investigated bacteria	Interaction with/membrane target	Mechanism of nanoparticle action	Reference
1.	Ag NPs	E. coli	LPS and L- α -phosphatidyl-ethanolamine (PE)	NP interacted with O-antigen part of LPS via hydrogen bonding Ag NP broke phosphodiester bond of PE into phosphate monoesters to form highly disordered alkyl chain	Ansari et al. (2014a)
2.	Al₂O₃ NPs	E. coli	LPS and L- α -phosphatidyl-ethanolamine (PE)	LPS binding to Al₂O₃ NPs through hydrogen bonding and ligand exchange structural changes in phospholipids led to loss of amphiphilic properties	Ansari et al. (2014b)
3.	Au NPs functionalized with branched polyethylenimine	B. subtilis	Teichoic acid	Electrostatic interaction between NPs and teichoic acid No interaction with mutant having teichoic acid but lacking alanine	Caudill et al. (2020)
4.	Ampicillin- chitosan–polyanion nanoparticles	S. aureus strains (ATCC25923, ATCC29213 and ATCC43300)	Lipoteichoic acid (LTA)	Electrostatic interaction between chitosan and LTA leads to disturbance in membrane homeostasis MIC for free and NP-encapsulated Ampicillin was 0.26 μg/ml and 0.13 μg/ml respectively	Ciro et al. (2019)
5.	Curcumin-functionalized poly(lactic-co-glycolic acid)-dextran micelles	P. putida (PCL 1482) and P. fuorescens (PCL 1701) biofilms	Exopolysaccharide (EPS)	Micelle possibly altered surface hydrophobicity in bacteria Disruption of established biofilms induced electrostatic interaction between micelles and EPS to weaken overall architecture	Barros et al. (2021)
6.	CTAB-coated gold nanoshell	S. aureus, E. coli, S. enterica and P. aeruginosa	Cell wall	The aim was to use gold nanoshells as sensors for bacterial detection Both enzyme β-galactosidase and bacteria competed to interact with gold nanoshells Electrostatic interaction with LPS led to formation of gold nanoshell aggregates in cell wall causing cell death	Tanvir et al. (2017)
7.	Spherical and Rod-shaped Ag NPs	E. coli (ATCC25922) and S. aureus (ATCC25923). B. subtilis (AST5-2), P. aeruginosa (AL2-14B32) and K. pneumoniae (AWD5)	Cell wall	FESEM analysis suggested rupture of cell wall Rod-shaped Ag NPs showed enhanced antibacterial activity	Acharya et al. (2018)
8.	Curcumin loaded Solid Lipid Nanoparticles	E. coli (ATCC25922) S. aureus (ATCC25923)	Cell permeability	Combination of cholesterol-curcumin exhibited stronger antibacterial activity and led to enhanced cell membrane penetration and leakage	Jourghanian et al. (2016)
9.	Triclosan-loaded micellar nanocarriers	S. aureus (ATCC12600GFP) and bioluminescent S. aureus Xen36	Cell permeability	Enhanced biofilm penetration of micelle and accumulation due to electrostatic interaction with bacterial cell surface at acidic pH Triclosan release due to micelle degradation by bacterial lipase	Liu et al. (2016)
10.	Graphene oxide Ag Nanocomposite	Enterobacter cloacae Staphylococcus mutans	Cell leakage	Protein leakage was assessed and found to be significant in Gram – than in Gram + Gram + has thicker cell wall and posed barrier to nanocomposite penetration	Kulshrestha et al. (2017)
11.	Au NP capped with pyrimidine (Au-DAPT) 4,6-Diamino-2-pyrimidinethiol	MDR clinical isolates- E. coli and P. aeruginosa	Membrane Ions: Mg²⁺ and Ca²⁺ ion of outer membrane vesicle (OMV)	Sequestration or chelation of Mg²⁺ and Ca²⁺caused by Au-DAPT lead to the disruption of membrane integrity which lead to leakage of cellular components	Zhao et al. (2010)
12.	Poly(acrylic acid; PAA)-coated iron oxide (magnetite) nanoparticles (PAA-MNPs) and Rifampicin (TB drug)	Mycobacterium smegmatis	Efflux pump	Iron oxide NPs acted as efflux pump inhibitor which resulted in up to a 3-fold-increased accumulation of rifampicin inside Mycobacterium	Padwal et al. (2014)
13.	Cu NPs	Wild type- S. aureus and P. aeruginosa. MRSA and drug resistant mutant- S. aureus	Efflux pump	Exhibited remarkable efflux inhibition activity Reverse the MIC of the mutant S. aureus strain for ciprofloxacin by 4-fold	Christena et al. (2015)
14.	CuI NPs	B. subtilis (ATCC6633) and E. coli DHF 5α (ATCC10536), Shigella dysenteriae (ATCC12039)	ROS generation	Bactericidal activity due to ROS formation of the surface of CuI NP due to interaction with amine functional group of various biomolecules on cell membrane	Pramanik et al. (2012)
15.	TiO₂ NPs	MRSA, E. coli and P. aeruginosa	ROS generation	NP interaction with membrane protein and lipid leads to generation of ROS followed by cell death	Alhadrami and Shoudri (2020)
16.	ZnO NPs	Vibrio cholera	ROS generation and membrane disruption	NPs increased fluidity and depolarization of membrane, protein leakage leading to bacterial death	Sarwar et al. (2016)
17.	Chlorohexidine acetate nanoemulsion (CNE)	Skin burn wound MRSA infection	Ion leakage and membrane disruption	CNE treatment led to leakage of K⁺, Mg²⁺ Ions, DNA and protein Increase electrical conductivity and disruption of cell wall and cell membrane	Song et al. (2016)
18.	Hybrid Tellurium−Lignin Nanoparticles (TeLigNPs)	S. aureus (ATCC25923), E. coli (ATCC25922), and P. aeruginosa (ATCC10145),	ROS generation and membrane disruption	Strong antibacterial activity due to interaction of lignin with hydrophilic surface of Gram – bacteria as compared to Gram + Insertion of TeLig NPs into the outer membrane caused lipid peroxidation decomposing it into highly reactive short-chain aldehydes which further diffused into cytoplasm and oxidize thiol and amino groups of proteins leading to death	Morena et al. (2021)