RESUMEN
Heterogeneous metal implants have been applied in clinical treatments of skeletal wounds, but their low antibacterial properties and the possibility of a release of metal ions may have harmful influences on the human body. Therefore, a polymer implant with low cost, high safety, an elastic modulus similar to that of human bone, and a good antibacterial property must be produced for orthopedic treatments. In this study, the surface of a 3D-printed polyetheretherketone (PEEK) disk was grown with ZnO/TiO2 rodlike arrays using a chemical bath deposition. X-ray diffraction patterns and transmission electron microscopy images showed that TiO2/ZnO rodlike arrays were deposited onto the PEEK substrate. With the direct absorption of antibiotic agents onto the surface of TiO2/ZnO/PEEK samples, their antibacterial performances greater than the values of minimum inhibitory concentration required to inhibit the growth of 90% of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) remained for around 10 days. The concentration of Zn2+ ions in a buffer solution is reduced with the coating of a TiO2 layer on a ZnO rodlike array. The sample with absorption from a mixture containing ampicillin and vancomycin salts with a weight ratio of 1:1 had the best inhibitory effect on the growth of E. coli and S. aureus.
RESUMEN
In this study, zinc oxide (ZnO) nanorod arrays as antibiotic agent carriers were grown on polyetheretherketone (PEEK) substrates using a chemical synthesis method. With the concentration of ammonium hydroxide in the precursor solution kept at 4 M, ZnO nanorod arrays with diameters in the range of 100-400 nm and a loading density of 1.7 mg/cm2 were grown onto the PEEK substrates. Their drug release profiles and the antibacterial properties of the antibiotic agent/ZnO/PEEK samples in the buffer solution were investigated. The results showed that the concentrations of antibiotic agents (ampicillin or vancomycin) released from the samples into the buffer solution were higher than the value of minimum inhibitory concentration of 90% for Staphylococcus aureus within the 96 h test. The bioactivities of ampicillin and vancomycin on substrates also showed around 40% and 80% on the Staphylococcus aureus, respectively. In the antibacterial activity test, sample with the suitable loading amount of antibiotic agent had a good inhibitory effect on the growth of Staphylococcus aureus.
RESUMEN
Multicomponent metal sulfide (stannite Ag2ZnSnS4) samples were grown onto the conductive metal oxide-coated glass substrates by using the sulfurization of cosputtering silver-zinc-tin precursors. Several [Ag]/[Zn + Sn] and [Zn]/[Sn] ratios were set in the metal precursors to investigate their influences on the crystal phases, microstructures, and physical properties of the stannite Ag2ZnSnS4 samples. The results of the crystal phases and the compositions of the samples showed that the stannite Ag2ZnSnS4 phase can be obtained using the two-step sulfurization process, which maintained the silver-zinc-tin precursors at 160 °C for 1 h and then kept them at 450 °C for 30 min under a sulfur/nitrogen atmosphere. N-type stannite Ag2ZnSnS4 samples with the carrier concentrations of 5.54 × 1012 to 9.11 × 1012 cm-3 can be obtained. High resistivities of Ag2ZnSnS4 samples were observed because of the low values of carrier concentration. Increasing the silver content in the sample can improve its photoelectrochemical (PEC) performance because of the decrease in the sample resistivity. The ratio of [Ag]/[Zn + Sn] at 0.8 and the ratio of [Zn]/[Sn] set at 0.90 in the stannite Ag2ZnSnS4 sample had the highest PEC performance of 0.31 mA·cm-2, with the potential set at 1.23 V versus the relative hydrogen electrode applied on the sample because of it having the lowest charge-transfer resistance in the electrolyte.
RESUMEN
In this study, polylactic acid (PLA) disks with antibacterial performances were prepared using 3D printing technology combined with direct adsorption of the antibiotic agents in solution baths. The effects of the layer thicknesses for the building of the 3D printing PLA disks and the amounts of antibiotic agents absorbed onto the sample surfaces on their antibacterial activities were investigated. The antibiotic agent release profiles from the samples surface into the buffer solution show that the antibacterial performances of these samples can reach up to 28 days. With a decrease in the concentration of antibiotic agent in the solution bath, the amount of antibiotic agent adsorbed on the sample surfaces also decreases, but their antibacterial performances can still maintain at least 7 days. In the bioactivity tests of the various organisms, the release amount of antibiotic agent from the sample can inhibit E. coli and S. aureus for over 80% up to 28 days. In the antibacterial activity tests, a PLA disk with suitable antibiotic agents covering its surface has a good inhibitory effect on the growth ability of S. aureus of less than 50% in six hours.
