A New Model of Salivary Pacemaker-A Proof of Concept and First Clinical Use.

Background and Objectives: Saliva is of utmost importance for maintaining oral health. Management of saliva flow rate deficiency recently includes salivary neuro-electrostimulation. The aim of this paper is to present a new model of salivary pacemaker-the MICROSAL device (MD), an intelligent, miniaturized, and implant-supported oral device used for salivary stimulation. Materials and Methods: This report presents the development, calibration, and first clinical tests which involved the MD. The novel features of this device are the pH sensor and the fact that it communicates with the patient's smartphone, where oral wetness and pH are graphically exposed. Saliva samples were taken before and after the MD was used on a 68-year-old patient suffering from post-irradiation xerostomia, and albumin and total protein were analyzed. Results: The device uses up to 3 V and time intervals of 2 s seconds for stimulation. The total volume of all saliva samples collected during the clinical trial was almost seven times higher after the device was used. Albumin decreased from a maximum of 0.15 g/dL to 0.04 g/dL, and total proteins from 0.65 g/dL to 0.21 g/dL, after salivary stimulation. Conclusions: The MD increased saliva secretion of the patient, and we are confident it will be a good solution for future management of salivary gland hypofunction.

TiO2 Nanotubes Functionalized with Icariin for an Attenuated In Vitro Immune Response and Improved In Vivo Osseointegration.

Due to their superior mechanical and chemical properties, titanium (Ti) and its alloys have been widely used as orthopedic implantable devices. However, their bioinertness represents a limitation, which can be overcome by employing various surface modifications, such as TiO2 nanotube (TNT) fabrication via electrochemical anodization. Anodic TNTs present tunable dimensions and unique structures, turning them into feasible drug delivery platforms. In the present work, TNTs were loaded with icariin (Ica) through an adhesive intermediate layer of polydopamine (DP), and their in vitro and in vivo biological performance was evaluated. The successful fabrication of the modified surfaces was verified by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), and contact angle measurements (CA), while the in vitro release of Ica was evaluated via UV-VIS spectrophotometry. In terms of in vitro behaviour, comparative studies on RAW 264.7 macrophages demonstrated that the TNT substrates, especially TNT-DP-Ica, elicited a lower inflammatory response compared to the Ti support. Moreover, the in vivo implantation studies evinced generation of a reduced fibrotic capsule around this implant and increased thickness of the newly formed bone tissue at 1 month and 3 months post-implantation, respectively. Overall, our results indicate that the controlled release of Ica from TNT surfaces could result in an improved osseointegration process.

Characterization and In Vitro and In Vivo Assessment of a Novel Cellulose Acetate-Coated Mg-Based Alloy for Orthopedic Applications.

Despite their good biocompatibility and adequate mechanical behavior, the main limitation of Mg alloys might be their high degradation rates in a physiological environment. In this study, a novel Mg-based alloy exhibiting an elastic modulus E = 42 GPa, Mg-1Ca-0.2Mn-0.6Zr, was synthesized and thermo-mechanically processed. In order to improve its performance as a temporary bone implant, a coating based on cellulose acetate (CA) was realized by using the dipping method. The formation of the polymer coating was demonstrated by FT-IR, XPS, SEM and corrosion behavior comparative analyses of both uncoated and CA-coated alloys. The potentiodynamic polarization test revealed that the CA coating significantly improved the corrosion resistance of the Mg alloy. Using a series of in vitro and in vivo experiments, the biocompatibility of both groups of biomaterials was assessed. In vitro experiments demonstrated that the media containing their extracts showed good cytocompatibility on MC3T3-E1 pre-osteoblasts in terms of cell adhesion and spreading, viability, proliferation and osteogenic differentiation. In vivo studies conducted in rats revealed that the intramedullary coated implant for fixation of femur fracture was more efficient in inducing bone regeneration than the uncoated one. In this manner, the present study suggests that the CA-coated Mg-based alloy holds promise for orthopedic aplications.