Spectroscopic and Structural Properties of β-Tricalcium Phosphates Ca9RE(PO4)7 (RE = Nd, Gd, Dy)

Rare-earth-basedCa9RE(PO4)7 (RE = Nd, Gd, Dy) materials were synthesized by solid-state reaction at T = 1200 °C. The obtained tricalcium phosphate (TCP) materials are efficient light emitters due to the presence of RE3+ ions, although these ions are present at high concentrations. Moreover, in these host structures, these ions can be used as optical probes to study their local environments. Thus, photoluminescence (PL) emission spectra of the powder samples clearly indicated, for Dy3+ and Gd3+ ions, the presence of the RE3+ ion in low-symmetry sites with some local structural disorder, and the spectra show the presence of vibrational features (in the case of Gd3+). For the Nd3+ phase, emission bands are present around 900, 1050, and 1330 nm, originating from the 4F3/2 level. In general, these RE-TCP samples are interesting luminescent materials in the visible (Dy), UV (Gd), and NIR (Nd) regions, due to weak concentration quenching even for high concentrations of the emitting ion.

Conversion of Bivalve Shells to Monocalcium and Tricalcium Phosphates: An Approach to Recycle Seafood Wastes

The search for sustainable resources remains a subject of global interest and the conversion of the abundantly available bivalve shell wastes to advanced materials is an intriguing method. By grinding, calcium carbonate (CaCO3) powder was obtained from each shell of bivalves (cockle, mussel, and oyster) as revealed by FTIR and XRD results. Each individual shell powder was reacted with H3PO4 and H2O to prepare Ca(H2PO4)2·H2O giving an anorthic crystal structure. The calcination of the mixture of each shell powder and its produced Ca(H2PO4)2·H2O, at 900 °C for 3 h, resulted in rhombohedral crystal β-Ca3(PO4)2 powder. The FTIR and XRD data of the CaCO3, Ca(H2PO4)2·H2O, and Ca3(PO4)2 prepared from each shell powder are quite similar, showing no impurities. The thermal behaviors of CaCO3 and Ca(H2PO4)2·H2O produced from each shell were slightly different. However, particle sizes and morphologies of the same products obtained from different shells were slightly different—but those are significantly different for the kind of the obtained products. Overall, the products (CaCO3, Ca(H2PO4)2·H2O, and Ca3(PO4)2) were obtained from the bivalve shell wastes by a rapidly simple, environmentally benign, and low-cost approach, which shows huge potential in many industries providing both economic and ecological benefits.

Comparative Characteristics of Bone-Plastic Materials for Mastoidoplasty

The paper presents the results of the comparative characteristics of the use of various bone-plastic materials for mastoidoplasty. The study included 30 patients who underwent an open-type sanitizing operation with mastoidoplasty with osteoplastic materials. When comparing drugs, the following criteria were used: 1) convenience of modeling the material; 2) the course of the wound process; 3) osseointegration - the process of formation of "new bone tissue (CT of the temporal bones 6 and 12 months). As a result, it was confirmed that the samples of the main groups of bone replacements studied by us. preparations (biositalls, composite materials and β- tricalcium phosphates) can be successfully used in mastoidoplasty after open types of sanitizing operations on the middle ear.

Physicochemical and Biological Characterisation of Diclofenac Oligomeric Poly(3-hydroxyoctanoate) Hybrids as β-TCP Ceramics Modifiers for Bone Tissue Regeneration

Nowadays, regenerative medicine faces a major challenge in providing new, functional materials that will meet the characteristics desired to replenish and grow new tissue. Therefore, this study presents new ceramic-polymer composites in which the matrix consists of tricalcium phosphates covered with blends containing a chemically bounded diclofenac with the biocompatible polymer—poly(3-hydroxyoctanoate), P(3HO). Modification of P(3HO) oligomers was confirmed by NMR, IR and XPS. Moreover, obtained oligomers and their blends were subjected to an in-depth characterisation using GPC, TGA, DSC and AFM. Furthermore, we demonstrate that the hydrophobicity and surface free energy values of blends decreased with the amount of diclofenac modified oligomers. Subsequently, the designed composites were used as a substrate for growth of the pre-osteoblast cell line (MC3T3-E1). An in vitro biocompatibility study showed that the composite with the lowest concentration of the proposed drug is within the range assumed to be non-toxic (viability above 70%). Cell proliferation was visualised using the SEM method, whereas the observation of cell penetration into the scaffold was carried out by confocal microscopy. Thus, it can be an ideal new functional bone tissue substitute, allowing not only the regeneration and restoration of the defect but also inhibiting the development of chronic inflammation.

Phosphate Solubilization Potentials of Rhizosphere Fungi Isolated from Insecticide Treated Soil

Insecticides are used widely to control a variety of pests and often residues of these insecticides are left in soil which may have impact on the phosphate solubilization potentials of rhizosphere fungi. Rhizosphere soils were collected from carefully uprooted cowpea seedlings with hand trowel on 50, 70 and 90th days of germination containing the lambda-cyhalothrin and dimethoate insecticides. Fungi associated with the above samples were identified by standard microbiological techniques. Screening for phosphate solubilization potential of the isolates was done by spot inoculation on Pikovskaya agar by measuring the clear zones around the colonies supplemented with tricalcium phosphates [Ca3(PO4)2]. The phosphatase produced by the fungal species was optimized using parameters such as incubation time, pH, temperature, carbon source and nitrogen source in submerged fermentation. The isolated rhizosphere fungi were identified as Rhizopus stolonifer, Aspergillus niger, Aspergillus fumigatus, Aspergillus terreus, Trichoderma viride, Arthroderma fulvum and Fusarium oxysporum. Among the isolates, Trichoderma viride showed the best ability to solubilize phosphate with solubilization index of 2.82 with dimethoate of 12.5ml/L of water. The optimization study for the enzyme production showed that the best incubation time for phosphatase production was 72 hours by Trichoderma viride. It was observed that the optimum pH for production of phosphatase by Trichoderma viride was 6.5. This study suggests that all the isolated fungi especially Trichoderma viride can adapt to these insecticidal treatments, which make them useful as biofertilizers to increase uptake of phosphorous in plants.