Antibacterial Coatings Of Chitosan-based Self-assembly Colloidal Particles

With the continuous development of modern medicine,orthopedic metal implants in medicine has been widely used,causing the wound around the wound infection,leading to a series of complications.The main reason is that the bacteria easily adhere to the wound near the surface of the implant and generate biofilm,making the wound infection.So to prevent the adhesion of bacteria on the surface of the implant,the prevention of biofilm formation is the focus of implant infection research.Chitosan is one of the most important and most widely studied natural polymers.Compared with other natural polymers,the cationic properties of chitosan make it more widely used in the field of biomedicine.In this paper,Chitosan-based composite colloidal particles were prepared by macromolecule self-assembly technique.Then,the colloidal particle dispersion liquid was used as the electrolyte,and the antimicrobial coating was prepared on the metal surface by cathodic electrodeposition.So that the surface of the metal implant has good antibacterial properties.Specific research includes the following parts: 1.Preparation antibacterial coatings by chitosan/tannic acid self-assembled composite colloidalChitosan(CS)and tannic acid(TA)were used as primers to prepare chitosan/tannic acid(CS/TA)composite colloidal particles by pH-induced assembly in aqueous solution.The size,morphology,and structure of the resulting nanoparticles were successfully studied.Multifunctional coating materials were then fabricated in situ on the surfaces of 316 L stainless steel by electrophoretic deposition of CS/TA nanoparticles.Scanning electron microscopy(SEM)images showed that the particles could be uniformly deposited on the surfaces of 316 L stainless steel,Fourier transform infrared spectroscopy(FTIR)confirmed the successful anchoring of CS/TA nanoparticles,and contact angle measurement indicated the surface hydrophilicity of the substrate were improved by coating materials.More importantly,these coatings effectively promoted L929 cell adhesion and proliferation on the sample surfaces as compared to bare 316 L stainless steel,and exhibited excellent antibacterial activity against E.coli and S.aureus in vitro environment.The above results suggested that our coatings,which effectively enhance the cytocompatibility and antimicrobial properties of 316 L stainless steel substrate,provide a simple and practical strategy to expedite clinical acceptance of biomedical metals.2.Preparation antibacterial coatings by quaternized chitosan/ZnO self-assembled hybrid colloidal particlesQuaternized chitosan(QAC)and L-cysteine were used as co-stabilizers to stabilize different contents of nano-ZnO(Zn O),the QAC/L/ZnO hybrid micelles were prepared by pH in aqueous solution.The structure of the hybrid micelles was characterized by Zeta potential and nano-particle size analyzer,ATR-FTIR,X-ray diffraction(XRD)and TEM.The nanocomposite coating was prepared by secondary assembly of the colloidal particles on the surface of 316 L stainless steel by electrophoretic deposition.The chemical composition,surface morphology and hydrophobicity of the coatings were studied by ATR-FTIR,SEM and contact angle test.The cell compatibility of the coatings were explored by in vitro cell experiments.The antimicrobial activity of the coatings against Staphylococcus aureus and Escherichia coli were tested.The results show that QAC and L-cysteine can coherent ZnO in the presence of pH,and the size of hybrid micelles is 200-400 nm.The nanoparticles can be formed on the surface of 316 L stainless steel by electro-induced colloidal particles.The layer have excellent cell compatibility and antibacterial activity.The antimicrobial activity of hybrid micelles against S.aureus and E.coli were tested.The results show that the prepared coatings have good antibacterial property,and the antibacterial property of the coatings increases with the increase of ZnO content.3.Preparation antibacterial coatings by colloidal particles self-assembled from cinnamoyl chloride modified quaternized chitosanQAC and cinnamoyl chloride(CNCL)in the methanesulfonic acid substitution reaction,can produce amphiphilic photosensitive grafting QAC-CNCL,QAC-CNCL can self-assemble to form micellar particles by hydrophobic interaction.The effects of UV light and salt concentration on micelle properties were studied by UV and Zeta potential nanoparticles.The morphology of micelles were characterized by TEM.The functional coatings were prepared by secondary assembly of colloidal particles on the surface of 316 L stainless steel by electrophoretic deposition.The chemical composition,surface morphology and the hydrophobicity of the coatings were tested by ATR-FTIR,SEM and water contact angle.The cell compatibility of the coatings were explored by in vitro cell experiments.The antimicrobial activity of the coatings against S.aureus and E.coli were tested by antibacterial test.The results show that with the increase of the degree of CNCL substitution,the particles size of the micelle increases,the charge of the micelle increases,the photodolymerization intensity increases,and the biocompatibility of the micellar solution decreases.After photocrosslinking,the coatings of the biocompatibility,while the coatings of antibacterial stronger.