A green chemistry approach to synthesize biocompatible selenium nanoparticles is proposed in this work, using hydrogen selenite (NaHSeO3) as selenium precursor and lactose as reducing agent. The formation of nanoparticles was confirmed by dynamic light Scattering, revealing a gaussian size distribution, the maximum percentage being in the range of 20-40 nm. Zeta potential measurement indicates a negative charge -38.2 mV, the stability of selenium colloidal sol being also confirmed by UV-visible spectroscopy. TEM and AFM revealed the homogeneous, spherical shape, confirming the size of nanoparticles in the range of 20-40 nm. Structural investigations of powder selenium nanoparticles by FTIR spectroscopy and XRD patterns emphasise the presence of stretching and bending vibrations of Se-O bonds, respectively the amorphous structure of the synthesized selenium. The proposed method is suitable for biological applications such drug release, functional food or nutritional supplements.

A novel strategy to improve the success of soft and hard tissue integration of titanium implants is the use of nanoparticles coatings made from basically any type of biocompatible substance, which can advantageously enhance the properties of the material, as compared to its similar bulk material. So, most of the physical methods approaches involve the compaction of nanoparticles versus micron-level particles to yield surfaces with nanoscale grain boundaries, simultaneously preserving the chemistry of the surface among different topographies. At the same time, nanoparticles have been known as one of the most effective antibacterial agents and can be used as effective growth inhibitors of various microorganisms as an alternative to antibiotics. In this paper, based on literature research, we present a comprehensive review of the mechanical, physical, and chemical methods for creating nano-structured titanium surfaces along with the main nanoparticles used for the surface modification of titanium implants, the fabrication methods, their main features, and the purpose of use. We also present two patented solutions which involve nanoparticles to be used in cranioplasty, i.e., a cranial endoprosthesis with a sliding system to repair the traumatic defects of the skull, and a cranial implant based on titanium mesh with osteointegrating structures and functional nanoparticles. The main outcomes of the patented solutions are: (a) a novel geometry of the implant that allow both flexible adaptation of the implant to the specific anatomy of the patient and the promotion of regeneration of the bone tissue; (b) porous structure and favorable geometry for the absorption of impregnated active substances and cells proliferation; (c) the new implant model fit 100% on the structure of the cranial defect without inducing mechanical stress; (d) allows all kinds of radiological examinations and rapid osteointegration, along with the patient recover in a shorter time.

The surgical meshes selection, according to the structure and porosity of the biomaterial type and meshes design, is directly dependent on the surgical procedure used and interaction between biomaterial type and abdominal viscera. Surgical mesh must provide sufficient biomechanical strength in order to assure the physiological requirements in order to protect the soft tissue defects. The large variety of biomaterials used in abdominal surgery and the multitude of surgical fixation procedures show that we are still far from the ideal prosthesis. The main objective of this paper is to determine the effect of the sterilization procedures of some surgical meshes, with different design and made of different materials, on their structure and properties of interest. Experimental research was conducted on three types of surgical meshes, different from material and design point of view. Fourier Transform Infrared (FTIR) Spectroscopy was used to evaluate the structural characteristics of the samples. In the evaluation of the surface properties, scanning electron microscopy (SEM) was used for the qualitative assessment of surface morphology and contact angle determinations (CA) to determine the wettability properties. The sterilization process used was chemical sterilization with ethylene oxide, a procedure used by surgeons in clinical practice. According to the experimental research, the negative effects of the sterilization process on surgical meshes used in abdominal surgery are accentuated for the samples sterilized with ethylene oxide for three times, while their sterilization only one cycle does not significantly affect the surface properties and tensile strength of surgical meshes, regardless of the design and material of which they are composed.

This study examined and compared surface of human dentine after acidic etching with hydrogen peroxide, phosphoric acid liquid and gel. Surface demineralization of dentin is necessary for a strong bond of adhesive at dental surface. Split human teeth were used. After application of mentioned substances at dentin level measures of the contact angle and surface morphology were employed. Surface morphology was analyzed with the help of scanning electron microscopy and atomic force microscopy. Liquid phosphoric acid yielded highest demineralization showing better hydrophobicity than the rest, thus having more contact surface. Surface roughness are less evident and formed surface micropores of 4 �m remained open after wash and air dry providing better adhesive canalicular penetration and subsequent bond.

No abstract