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Our study reports the fabrication and characterization (surface morphology, hydrophobicity/hydrophilicity, photocatalytic efficiency) of cotton fibers treated by various methods with graphene oxide decorated with Fe, N-doped TiO2 nanoparticles. Designed as prospective industrial self-cleaning, antimicrobial and biocompatible textiles, microbiological and cytotoxicity tests were performed on these particles-treated fibers to validate their qualities. The photocatalytic effect was dependent on chemicals used to disperse the nanoparticles, the parameters of the treatment, the fiber structure and composition of the material. The double and triple treatment of the textiles with the same particle dispersion resulted in a relatively uniform coverage of cotton fibers with relatively large amounts of particles. A larger amount of doped TiO2 particles demonstrated a better photocatalytic effect under visible light. The material's hydrophobicity increased with the number of treatments due to the deposition of successive layers of reduced graphene, ensuring self-cleaning properties. The photocatalyst-treated cotton fabrics exhibited an increased resistance to Enterococcus faecalis and Escherichia coli colonization, and also high biocompatibility, as they did not affect the cell viability, membrane integrity and morphology, nor induce inflammation. All these data confirm the improved properties of cotton fibers treated with graphene oxide decorated with Fe, N-doped TiO2 particles in order to be used as industrial self-cleaning and biocompatible textiles.

The aim of this study was to develop a nanostructured bioactive surface based on zinc oxide, sodium stearate (C18) and usnic acid (UA) exhibiting harmless effects with respect to the human cells, but with a significant antimicrobial effect, limiting the attachment and biofilm formation of food pathogens. ZnO nanoparticles were synthesized by sol–gel method and functionalized with C18 and UA. The coatings were fabricated by matrix assisted pulsed laser evaporation technique (MAPLE) and further characterized by TEM, SEM, SAED, XRD and IRM. The biological characterization of the prepared coatings consisted in cytotoxicity and antimicrobial assays. The cytotoxicity of ZnO@C18 and ZnO@C18-UA films was evaluated with respect to the human skin fibroblasts (CCD 1070SK cell line) by phase contrast microscopy, MTT assay and nitric oxide (NO) release. The covered surfaces exhibited a decreased cell attachment, effect which was more pronounced in the presence of UA as shown by purple formazan staining of adhered cells. The unattached fibroblasts remained viable after 24 h in the culture media as it was revealed by their morphology analysis and NO level which were similar to uncovered slides. The quantitative microbiological assays results have demonstrated that the bioactive coatings have significantly inhibited the adherence and biofilm formation of Salmonella enterica. The obtained results recommend these materials as efficient approaches in developing anti-adherent coatings for various industrial, medical and food processing applications.

In this study we aimed to obtain functionalized thin films based on hydroxyapatite/poly(lactic-co-glycolic acid) (HAp/PLGA) containing ceftriaxone/cefuroxime antibiotics (ATBs) deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The prepared thin films were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-Ray diffraction (XRD), selected area electron diffraction (SAED), and infra red (IR) analysis. HAp/PLGA/ATBs thin films sustained the growth of human osteoblasts, proving their good biocompatibility. The microscopic evaluation and the culture-based quantitative assay of the E. coli biofilm development showed that the thin films inhibited the initial step of microbial attachment as well as the subsequent colonization and biofilm development on the respective surfaces. This study demonstrates that MAPLE technique could represent an appealing technique for the fabrication of antibiotics-containing polymeric implant coatings. The bioevaluation results recommend this type of surfaces for the prevention of bone implant microbial contamination and for the enhanced stimulation of the implant osseointegration process.

Three novel hybrid materials, SBA-15-RuValen, SBA-15-RuValpnol, and SBA-15-RuValdiamci, were obtained by immobilization of new [Ru(L)(PPh3)Cl] complexes (H2L = H2Valen, H2Valpnol, H2Valdiamci, are Schiff base proligands obtained by condensation of o-vanillin with ethylenediamine, 1,3-diamino-2-propanol, and 1,2-diaminocyclohexane, respectively) inside the mesoporous channels of SBA-15. [Ru(Valen)(PPh3)Cl]·3H2O (RuValen), [Ru(Valpnol)(PPh3)Cl]·3H2O (RuValpnol), and [Ru(Valdiamci)(PPh3)Cl]·4H2O (RuValdiamci) complexes were characterized by microanalysis (C,H,N), IR and UV–Vis spectroscopy, magnetic measurements. The structure of RuValen was also confirmed by single crystal X-ray diffraction. The hybrid materials were thoroughly characterized in terms of structure, composition, morphology, and textural properties. The results indicate the uniform distribution of Ru(III) complexes on the internal surface of SBA-15, the immobilization process having no significant influence on the structure of the support. The novel hybrid materials demonstrated high antibacterial and anti-biofilm activity against Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. In vitro tests regarding the cytotoxic effect on adenocarcinoma (HeLa) cells showed that all three hybrid materials decreased the cell viability in a dose-dependent manner, being very promising for medical applications.

Spherical noble metal-titanium dioxide nanoparticles (Pt/TiO2, Au/TiO2 and Ag/TiO2) were synthesized using laser pyrolysis (LP) followed by wet impregnation and reduction methods. Also, aerosol-assisted LP was used for direct Ag/TiO2 generation. Nanomaterial morpho-structural characteristics were evaluated using transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and UV–Vis diffuse reflectance spectroscopy (DRS). Titania based nanocomposites, with (0.01–0.28 at %) noble metal loading, exhibit band gap reduction (down to 2.77 eV) due to two cumulative factors: near atmospheric pressure LP synthesis and metal addition on TiO2 nanoparticle surface, via Surface Plasmon Resonance (SPR). Nanocomposites photocatalytic performance, in UV and Vis range, attests LP synthesized Ag-catalyst as the highly effective product in aqueous methyl orange (MO) total photodegradation (with rate constants of 28.74 × 10−3 min−1 for UV and 16.78 × 10−3 min−1 for Vis). Moreover, LP samples biocompatibility tests indicate good biocompatibility with human lung cells (MRC-5), their toxicity being diminished when compared with commercially P25 Degussa. This study reveals that LP technique generates lower band gap biocompatible titania photocatalysts. LP-titania noble metal decoration enhances UV and Vis pollutant photodegradation efficiencies, contributing to the development of a low risk environmentally-friendly method for water treatment.

The present paper is a hybrid approach, proposing the elaboration of a complex ceramic coating on Ti plates, containing TiO 2 nanotubes obtained by anodizing, multiwalled carbon nanotubes (MWCNTs) functionalized with –COOH groups and hydroxyapatite. The research led to a new hybrid material with improved characteristics that can be used in biomedical applications. For this purpose we proceeded to functionalize multiwalled carbon nanotubes with –COOH groups. Anodic procedure was used to obtain TiO 2 nanotubes. After anodizing, electrodeposition as a cheaper and faster procedure of hybrid material MWCNT-COOH/HA took place. The structure of the hybrid material was identified using infrared spectroscopy (FTIR analysis) and morphological features were studied by scanning electron microscopy (SEM). The wettability was evaluated by contact angle measurements and microhardness was determined by a mechanical resistance test. Hemolysis assays were performed and in vitro cell response was investigated. This ceramic coating has an optimal microstructure and morphology, as indicated by SEM, showing a proper surface for the osteoblast adhesion, viability and proliferation. The new ceramic coating has induced an increase of microhardness and of the hemolytic index, in the same time with a decrease of contact angle, but the values remained in the domains of hydrophilic character and of nonhemolytic materials. Therefore, based on osteoblast response as well, we propose a new complex ceramic coating which satisfies exigent requirements and signifies a progress in the field of the implant biomaterials.

Titania nanotubes (TNTs) were prepared by anodization on different substrates (titanium, Ti6Al4V and Ti6Al7Nb alloys) in ethylene glycol and glycerol. The influence of the applied potential and processing time on the nanotube diameter and length is analyzed. The as-formed nanotube layers are amorphous but they become crystalline when subjected to subsequent thermal treatment in air at 550°C; TNT layers grown on titanium and Ti6Al4V alloy substrates consist of anatase and rutile, while those grown on Ti6Al7Nb alloy consist only of anatase. The nanotube layers grown on Ti6Al7Nb alloy are less homogeneous, with supplementary islands of smaller diameter nanotubes, spread across the surface. Better adhesion and proliferation of osteoblasts was found for the nanotubes grown on all three substrates by comparison to an unprocessed titanium plate. The sensitivity towards bovine alkaline phosphatase was investigated mainly by electrochemical impedance spectroscopy in relation to the crystallinity, the diameter and the nature of the anodization electrolyte of the TNT/Ti samples. The measuring capacity of the annealed nanotubes of 50nm diameter grown in glycerol was demonstrated and the corresponding calibration curve was built for the concentration range of 0.005-0.1mg/mL.