Research On The Fabrication And Performance Of Bionic Mechano-Bactericidal Surfaces Inspired By The Nanostructures Of Cicada Wing

Bacterial contamination on various medical devices poses an imperative threat to global human health.The extensive utilization of various antibacterial agents,such as antibiotics,although effective in dealing with bacterial infections,but also bring many adverse effects,even trigger the emergence of antibiotic-resistant strains.The prevalence of antibiotic resistance has become one of the most intractable problem in routine treatments of bacterial infections to become increasingly difficult.Recently,some insect-wing-inspired surfaces with densely packed nanopillars exhibited rapid and efficient antibacterial actions by physically rupturing bacterial cell membranes,hence totally avoiding any antibiotic involvement for preventing antimicrobial resistance.Inspired by this,many bionic mechano-bactericidal surfaces were developed.However,they are prone to become contaminated with the killed bacterial debris,and the relative researches concerning mechano-bactericidal surface are still in the proofof-concept,lacking of practical experiences.In this paper,aiming at aforementioned problems,we proposed several strategies to improve the antibacterial efficiency and practical application potential of the bio-inspired mechano-bactericidal surface,and mainly as follows:1.The nanopattern of cicada-wings were served as bionic prototype,and the bioinspired nanostructured mechano-bactericidal surfaces were obtained by replicating porous anodized aluminum oxide(AAO)templates.Subsequently,salt-responsive polyzwitterionic brushes(poly(3-(dimethyl(4-vinylbenzyl)ammonio)propyl sulfonate),poly DVBAPS)were grafted from the substrate by surface-initiated photoinifertermediated polymerization(SI-PIMP).Benefiting from the salt-triggered configuration change of the grafted polymer brushes,this dual-functional surface shows high mechano-bactericidal efficiency in water(low ionic strength condition),while the dead bacterial residuals can be easily lifted by the extended polymer chains and removed from the surface in 1 M Na Cl solution(high ionic strength conditions).Notably,this dual-functional surface shows selective biocidal activity between bacterial cells and eukaryotic cells,showing excellent biocompatibility with red blood cells(RBCs)and mammalian cells.The prevention of perioperative contamination activity was verified by in vivo evaluation in a mouse subcutaneous implant model.This nanostructured surface with bacterial killing and releasing activities may open new avenues for designing bio-inspired mechano-bactericidal platforms with long-term efficacy,thus presenting a facile alternative in combating perioperative-related bacterial infection.2.A bio-inspired self-adaptive nanocomposite surface that can transform from non-antibiotic antibacterial actions to promotion of cell proliferation is developed by in situ assembly of bacteriostatic 3,3’-diaminodipropylamine(DADP)-doped zeolitic imidazolate framework-8(ZIF-8)on bio-inspired nanopillars nanostructures.Initially,the nanocomposite surface shows impressive antibacterial effects,even under severe bacterial infection,due to the combination of mechano-bactericidal activity from a nanopillar structure and bacteriostatic activity contributed by p H-responsive release of DADP.After the complete degradation of the ZIF-8 layer,the refurbished nanopillars not only can still physically rupture bacterial membrane but also facilitate mammalian cell proliferation,due to the obvious difference in cell size.Additionally,the surface exhibited excellent histocompatibility and lower inflammatory response properties as revealed by in vivo tests.This type of self-adaptive surface may provide a promising alternative for addressing the intractable implant-associated requirements,where antibiotic-free antibacterial activity and native tissue integration are both highly needed.3.Inspired by the “selective biocidal activity” of the nanostructures from cicada wings,a bionic Janus patch is developed to achieve efficient antibacterial,pro-healing and preventing visceral tissue adhesion property via AAO assisted thermal nanoimprinting lithography(TNIL)and surface-initiated photoiniferter-mediated polymerization(SI-PIMP).The cicada wings-liked top surface shows impressive mechano-bactericidal effects and can significantly improve L929 fibroblasts adhesion and tissue integration.And the grafted poly(sulfobetaine methacrylate)(PSBMA)of the bottom-surface exhibits robust adhesion resistance against microorganisms,proteins,fibroblasts and thrombus to do not trigger any visceral tissue adhesion.The practical application value of the novel bionic Janus patch was also demonstrated via a Sprague-Dawley(SD)rat abdominal wall defect model.More strikingly,compared to the commercial polypropylene(PP)mesh,the bionic Janus patch showed higher antibacterial efficiency,more remarkable repair abdominal wall defect and anti-adhesion properties in vivo.With facile preparation,low cost,and excellent performance,this bionic Janus patch shows great prospect in biomedical implantable patch.