Self-Adaptive Antibacterial Coating for Universal Polymeric Substrates Based on a Micrometer-Scale Hierarchical Polymer Brush System

Abstract

Surface-tethered hierarchical polymer brushes find wide applications in the development of antibacterial surfaces due to the well-defined spatial distribution and the separate but complementary properties of different blocks. Existing methods to achieve such polymer brushes mainly focused on inorganic material substrates, precluding their practical applications on common medical devices. In this work, a hierarchical polymer brush system is proposed and facilely constructed on polymeric substrates via light living graft polymerization. The polymer brush system with micrometer-scale thickness exhibits a unique hierarchical architecture consisting of a poly(hydroxyethyl methacrylate) (PHEMA) outer layer and an anionic inner layer loading with cationic antimicrobial peptide (AMP) via electrostatic attraction. The surface of this system inhibits the initial adhesion of bacteria by the PHEMA hydration outer layer under neutral pH conditions; when bacteria adhere and proliferate on this surface, the bacterially induced acidification triggers the cleavage of labile amide bonds within the inner layer to expose the positively charged amines and vigorously release melittin (MLT), allowing the surface to timely kill the adhering bacteria. The hierarchical surface employs multiple antibacterial mechanisms to combat bacterial infection and shows high sensitiveness and responsiveness to pathogens. A new paradigm is supplied by this modular hierarchical polymer brushes system for the progress of intelligent surfaces on universal polymer substrates, showing great potential to a promising strategy for preventing infection related to medical devices.

Host–Guest Interaction-Mediated Photo/Temperature Dual-Controlled Antibacterial Surfaces

“…Although “killing-releasing” surfaces can damage the attached bacteria and further release them to reset functions, challenges still remain because such surfaces are easily contaminated by bacteria due to the lack of antifouling property . Thus, the design of multifunctional antibacterial surface to realize long-term antifouling, highly efficient bacteria killing, and regeneration that can make the antibacterial surface more practical for real-world applications is highly desirable. , …”

“…27 Thus, the design of multifunctional antibacterial surface to realize long-term antifouling, highly efficient bacteria killing, and regeneration that can make the antibacterial surface more practical for real-world applications is highly desirable. 28,29 Aiming to develop multiresponsive and multifunctional antibacterial surface, this work designed and synthesized a photo and temperature dual-responsive P(NIPAM-co-AAAB)/ P(HEMA-co-GMA)@AgNP antibacterial surface, where temperature-responsive poly(N-isopropylacrylamide) (polyNI-PAM) was combined with poly(2-hydroxyethyl methacrylate) (polyHEMA) by Azo/CD host−guest interaction for achieving dual-responsive properties (e.g., chain conformation and dissociation of host−guest complex in response to temperature and UV 30 ) to individually or synergistically release attached bacteria, and three complementary antibacterial functions (antifouling property from hydrophilic polymer of polyHEMA, bacterial killing capability of Ag, and bacterial release function from temperature-responsive polyNIPAM and UV lightresponsive Azo/CD complex 31−35 ) were integrated for achieving "antifouling, killing, and releasing" trifunctions. 36 Such dual-responsive and trifunctional surfaces were prepared by the following methods: (1) poly(HEMA-co-GMA) brushes were first grafted on the target substrate, and then β-CD was introduced by the reaction between NH 2 -CD and epoxy group; 37−40 (2) poly(NIPAM-co-AAAB) with Azo group was prepared by radical polymerization and assembled onto polymer brushes by host−guest interaction; 33,41 (3) Ag nanoparticles were introduced by in situ reducing Ag + ions to offer bactericidal property.…”

Stimuli‐Responsive Antibacterial Materials: Molecular Structures, Design Principles, and Biomedical Applications

“…Once the bacteria‐infected, the acid microenvironment triggered the cleavage of labile amide bonds to release antimicrobial peptide allowing the surface to kill the adherent bacteria timely, and the bactericidal efficiency was more than 90% (Figure 10B ). [ 186 ] Stimuli‐responsive materials on medical device surfaces realize detection bacterial infection timely, and the bactericidal performance on demand with good biocompatibility and no biofilm formation.…”

Recent Progress on Bioinspired Antibacterial Surfaces for Biomedical Application

“…Taking QACs as an example, they have strong contact-killing activity against both Gram-positive bacteria and Gram-negative bacteria by destroying their membrane ( Figure 5 (Bi)). A QAC (s-poly (2,3-dimethylmaleic anhydride) (melittin)-b-poly (2-hydroxyethyl methacrylate) was modified on a surface as a multistage polymer brush to combat bacterial infection [ 106 ]. However, these QAC-based surfaces tended to induce irritation and inflammation, which hindered their practical application in the biomedical field [ 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 ].…”