Background and objectivesA current public health issue is preventing post-surgical complications by designing antibacterial implants. To achieve this goal, in this study we evaluated the antibacterial activity of an animal-free chitosan grafted onto a titanium alloy.MethodsAnimal-free chitosan binding on the substrate was performed by covalent link via a two-step process using TriEthoxySilylPropyl Succinic Anhydride (TESPSA) as the coupling agent. All grafting steps were studied and validated by means of X-ray Photoelectron Spectroscopy (XPS), Time-of-Flight secondary ion mass spectrometry (ToF-SIMS) analyses and Dynamic-mode Secondary Ion Mass Spectrometry (DSIMS). The antibacterial activity against Escherichia coli and Staphylococcus aureus strains of the developed coating was assessed using the number of colony forming units (CFU).ResultsXPS showed a significant increase in the C and N atomic percentages assigned to the presence of chitosan. A thick layer of polymer deposit was detected by ToF-SIMS and the results obtained by DSIMS measurements are in agreement with ToF-SIMS and XPS analyses and confirms that the coating synthesis was a success. The developed coating was active against both gram negative and gram positive tested bacteria.ConclusionThe success of the chitosan immobilization was proven using the surface characterization techniques applied in this study. The coating was found to be effective against Escherichia coli and Staphylococcus aureus strains.

Antimicrobial textiles (65% cotton – 35% polyester) were functionalized using a patented technology that combines an antimicrobial molecule – polyhexamethylene biguanide (PHMB) and a precipitating agent – sodium laurylsulphate. Surface characterization was performed by x‐ray photoelectron spectroscopy and time‐of‐flight secondary ion mass spectrometry, and both techniques made clear signatures of PHMB at the top surface of treated textiles. Washing led to a strong decrease of PHMB concentration at the surface. Comparison of textile surface analysis and antimicrobial tests indicated that the amount of PHMB at its extreme surface of textiles after five or 10 industrial washings was sufficient to inhibit Listeria innocua but not Pseudomonas aeruginosa growth. The viability of L. innocua cells after contact with PHMB‐treated textile after one industrial washing was estimated using the Live/Dead BacLight kit (Molecular Probes, Eugene, OR): the combination of epifluorescence microscopy observations coupled with classic enumeration allowed detection of the presence of viable but nonculturable cells. PRACTICAL APPLICATIONS Protective clothing is required in the food‐processing industry to protect products from being contaminated by microorganisms carried by workers' clothes or filtration systems. Consequently, there is an increasing interest in the use of antimicrobial functionalized textiles in the food industry to avoid that textiles could be vectors for pathogenic or food spoilage microorganisms. In the present study, the correlation between PHMB (the antimicrobial agent) at the surface of textiles (monitored by surface analysis characterization methods) and their antibacterial activity was assessed. After contact with antimicrobial textiles, the enumeration of bacteria was performed either by plate counting or by direct observation by epifluorescence microscopy in the presence of fluorescent viability markers in order to determine whether viable but nonculturable bacterial cells were present.

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The integration and evolution of implantable medical devices made of bioresorbable polymers and used for temporary biomedical applications are crucial criteria in the success of a therapy and means of follow-up after implantation are needed. The objective of this work is to develop and evaluate a method based on microscopic Fourier Transform InfraRed spectroscopy (FTIR) mappings to monitor the degradation of such polymers on tissue explant sections, after implantation. This technique provided information on their location and on both their composition and crystallinity, which is directly linked to their state of degradation induced predominantly by chain scissions. An in vitro study was first performed on poly(L-lactic acid) (PLLA) meshes to validate the procedure and the assumption that changes observed on FTIR spectra are indeed a consequence of degradation. Then, mappings of in vivo degraded PLLA meshes were realized to follow up their degradation and to better visualize their degradation mechanisms. This work further warrants its translation to medical implants made of copolymers of lactic acid and to other polyesters.