Stimuli-Responsive Lysozyme Nanocapsule Engineered Microfiltration Membranes with a Dual-Function of Anti-Adhesion and Antibacteria for Biofouling Mitigation

Abstract

Biofouling remains as a persistent problem impeding the applications of membranes for water and wastewater treatment. Green anti-biofouling of membranes made of natural and environmentally friendly materials and methods is a promising strategy to tackle this problem. Herein, we have developed a functionalized PVDF membrane with stimuli-responsive lysozyme nanocapsules (NCP). These nanocapsules can responsively release lysozyme according to environmental stimuli (pH and redox) induced by bacteria. Results showed that (i) the surface of the functionalized membrane with NCP had enhanced hydrophilicity, reduced roughness, and negative charge, (ii) a remarkable reduction of adsorption of proteins, polysaccharides, and bacteria was achieved by the functionalized membrane, and (iii) the colony forming unit (CFU) of bacteria on a membrane surface was reduced more than 80% within 24 h of contact. In addition, the NCP membrane showed excellent anti-biofouling activity regarding the bacterial viability being 12.5 and 8.3% on the membrane after filtration with 108 CFU mL–1 Escherichia coli and Staphylococcus aureus solution as feed, respectively. The coating layer and assembled nanocapsules endowed the membrane with improved lysozyme stability, anti-adhesion performance, and antibacterial activity. Stimuli-responsive lysozyme nanocapsule engineered microfiltration membranes show great potential for anti-biofouling in future practical application.

Overlooked Spherical Nanoparticles Exist in Plant Extracts: From Mechanism to Therapeutic Applications

“…LYZ, also called muramidase, is an antimicrobial protein with antibacterial activity. It has played an important role in medicine, the food industry, protein studies, and enzymology . Gallic catechol could form uniform nanoparticles with LYZ, which were named TG-LYZ NPs.…”

“…It has played an important role in medicine, the food industry, protein studies, and enzymology. 39 Gallic catechol could form uniform nanoparticles with LYZ, which were named TG-LYZ NPs. To explore the antibacterial activities of TG-NPs and TG-LYZ NPs in vitro, antibacterial experiments were carried out with E. coli and S. aureus.…”

Advancing Strategies of Biofouling Control in Water-Treated Polymeric Membranes

“…Li et al developed a functionalized PVDF membrane with stimulus-responsive lysozyme nanocapsules (NCP). Coating and self-assembled nanocapsules were used to endow the membrane with improved lysozyme stability, anti-adhesion performance, and antibacterial activity [ 116 ]. As a result, the membrane showed excellent anti-biological contamination activity and the survival rate of bacteria was only 12.5%.…”

“…( h ) Chemical structure of tobramycin (TOB) and poly acrylic acid (PAA), charged sites are labeled and the schematic diagram of the membrane modification process ( i ) Normalized flux of the virgin membrane and 3 bilayer PAA/TOB-modified membrane as a function of fouling time in the presence of BSA foulant (BSA: 100 ppm, NaCl: 2000 mg/L and pH: 7.0 ± 0.2). ( j ) The mortality of E. coli and B. subtilis for the virgin membrane and 3 bilayer PAA/TOB-modified membrane with contact time (incubation level: 10 9 CFU/m 2 ) [ 114 , 116 ]. (Copyright (2021) with permission from American Chemical Society), (Copyright (2017) with permission from Elsevier Ltd.).…”

Single-Molecule Discrimination and the Specific Binding Properties of the Lipopolysaccharides with a Solid-State Nanopore sensor

“…Various affinity molecules such as protein [48][49][50][51] , peptide [52][53][54][55] (especially polymyxin B, PMB), and aptamer 4,13,56 have also been explored, as well as distinct nanomaterials systems including quantum dots 57 , nanoparticles [58][59][60][61][62][63] , MXenes 64 and hybrid system 65-68 for signal amplification. Silicon nanopore membrane was applied for filtering endotoxin decades ago 69 , and the single-cell level identification of bacteria was achieved with modified micropores or integrated with other techniques [70][71][72][73] . Though the aforementioned approaches, especially electrochemical technique demonstrated rather a low detection limit of LPS, the single-molecule identification of LPS structure and…”