Bioactividad y biocompatibilidad de compósitos de zirconia estabilizada con Y/ hidroxiapatita-Cu, Fosfato Tricálcico-Ag o Fosfato Tricálcico-Ga

The biological compatibility of bone and dental implants is limited, since it is placed until a long time after it has been implanted, due to its low resistance of infections attributed to a quick degradation of the implant which is present in the physiological fluids. Therefore, in this investigation, hydroxyapatite-zirconia (HA-ZrO2) composite materials were developed, where zirconia was stabilized with yttrium and hydroxyapatite was doped with silver, copper and gallium, in order to give biological properties to the composite that the zirconia does not present. Each component of the composite material has different characteristics; such as hydroxyapatite (HA) that provides it a bioactive behavior, On the other hand ZrO2 stabilized with yttrium gives it excellent resistance; otherwise, Ag, Ga and Cu provide antimicrobial properties. To obtain these systems, the materials were synthesized by the Pechini method and chemical precipitation. Afterward the compounds were obtained and tested by bioactivity tests, hemolysis, cell viability studies by the MTT method and osteoblast adhesion by staining, hence there were obtained bioactive, non-hemolytic, non-toxic materials with cell adhesion to the composite. and as a result of that, these awesome materials can be useful for dental implants

Magnetic Biochar Obtained by Chemical Coprecipitation and Pyrolysis of Corn Cob Residues: Characterization and Methylene Blue Adsorption

Biochar is a carbonaceous and porous material with limited adsorption capacity, which increases by modifying its surface. Many of the biochars modified with magnetic nanoparticles reported previously were obtained in two steps: first, the biomass was pyrolyzed, and then the modification was performed. In this research, a biochar with Fe3O4 particles was obtained during the pyrolysis process. Corn cob residues were used to obtain the biochar (i.e., BCM) and the magnetic one (i.e., BCMFe). The BCMFe biochar was synthesized by a chemical coprecipitation technique prior to the pyrolysis process. The biochars obtained were characterized to determine their physicochemical, surface, and structural properties. The characterization revealed a porous surface with a 1013.52 m2/g area for BCM and 903.67 m2/g for BCMFe. The pores were uniformly distributed, as observed in SEM images. BCMFe showed Fe3O4 particles on the surface with a spherical shape and a uniform distribution. According to FTIR analysis, the functional groups formed on the surface were aliphatic and carbonyl functional groups. Ash content in the biochar was 4.0% in BCM and 8.0% in BCMFe; the difference corresponded to the presence of inorganic elements. The TGA showed that BCM lost 93.8 wt% while BCMFe was more thermally stable due to the inorganic species on the biochar surface, with a weight loss of 78.6%. Both biochars were tested as adsorbent materials for methylene blue. BCM and BCMFe obtained a maximum adsorption capacity (qm) of 23.17 mg/g and 39.66 mg/g, respectively. The obtained biochars are promising materials for the efficient removal of organic pollutants