Salvia officinalis-Hydroxyapatite Nanocomposites with Antibacterial Properties

In the present study, sage-coated zinc-doped hydroxyapatite was incorporated into a dextran matrix (7ZnHAp-SD), and its physico-chemical and antimicrobial activities were investigated. A 7ZnHAp-SD nanocomposite suspension was obtained using the co-precipitation method. The stability of the nanocomposite suspension was evaluated using ultrasound measurements. The stability parameter calculated relative to double-distilled water as a reference fluid highlights the very good stability of the 7ZnHAp-SD suspension. X-ray diffraction (XRD) experiments were performed to evaluate the characteristic diffraction peak of the hydroxyapatite phase. Valuable information regarding the morphology and chemical composition of 7ZnHAp-SD was obtained via scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) studies. Fourier-transform infrared spectroscopy (FTIR) measurements were performed on the 7ZnHAp-SD suspensions in order to evaluate the functional groups present in the sample. Preliminary studies on the antimicrobial activity of 7ZnHAp-SD suspensions against the standard strains of Staphylococcus aureus 25923 ATCC, Enterococcus faecalis 29212 ATCC, Escherichia coli 25922 ATCC, and Pseudomonas aeruginosa 27853 ATCC were conducted. More than that, preliminary studies on the biocompatibility of 7ZnHAp-SD were conducted using human cervical adenocarcinoma (HeLa) cells, and their results emphasized that the 7ZnHAp-SD sample did not exhibit a toxic effect and did not induce any noticeable changes in the morphological characteristics of HeLa cells. These preliminary results showed that these nanoparticles could be possible candidates for biomedical/antimicrobial applications.

Surface characteristics of titanium dental implants with improved microdesigns: An in vivo study of their osseointegration performance in goat mandible

Current trends in endosseous implant research are focused on the modification of microdesign of implants to achieve early and strong osseointegration. This study compares the influence of zinc doped hydroxyapatite (ZnHAp) coated, hydrothermally treated (HT) and machined Ti6Al4V (control) implants on osseointegration. The surface characterisation and microbial affinity test for implants were performed. Twenty seven (27) cylinders (3 types in each animal) were placed in the mandible of 9 black Bengal goats. Bone-implant interface was examined with histological, radiological parameters and scanning electron microscopy at 6, 12, and 24 weeks post-implantation. Surface roughness alterations of bone-separated implants were analysed by non-contact profilometer with time. The ZnHAp coated implants revealed direct and early bone-implant contact but high bacterial adherence and coating cracks. Low bacterial affinity and early strong bony integration was observed with HT implants. Poor bacterial affinity and delayed but strong fixation was evident with control implants. Based on the results of laboratory and animal experiments, we conclude that the hydrothermal modification of titanium implant is the more suitable way to achieve safe and effective osseointegration than the other two implant types for endosseous application.