ABSTRACT
Nowadays, due to the increasing number of diseases and injuries related to bone tissue, there is an acute problem of creating a material that could be incorporated into the bone tissue structure and contribute to accelerated bone regeneration. Such materials can be represented by a polymeric matrix that holds the material in the bone and an inorganic component that can be incorporated into the bone structure and promote accelerated bone regeneration. Therefore, in this work we investigated polyvinyl alcohol-based composite cryogels containing an in situ deposited inorganic filler, hydroxyapatite. The freezing temperature was varied during the synthesis process. The composition of the components was determined by infrared spectroscopy and the phase composition by X-ray phase analysis, from which it was found that the main phase of the composite is hydroxyapatite and that the particle size decreases with increasing freezing temperature. The elemental composition of the surface is dominated by carbon, oxygen, phosphorus and calcium; no impurities of other elements not typical for polyvinyl alcohol/ hydroxyapatite cryogels were found. Higher mechanical properties and melting points were observed at -15 °C. Cryogenic treatment parameters did not affect cell viability; however, cell viability was above 80% in all samples.
ABSTRACT
At the moment, the field of biomedical materials science is actively developing, which aims at creating new functional materials. A developing direction in biomedical materials science is that towards the treatment of diseases associated with bone tissue disorders, using biodegradable composite materials based on polymer and calcium phosphate materials. We developed a material based on polyvinyl alcohol cryogel, mineralized with calcium phosphate. A material based on cryogel of polyvinyl alcohol mineralized with calcium phosphate was developed. The composites were obtained by the method of cyclic freezing-thawing, and the synthesis of calcium phosphates was carried out in situ with heating, stirring, and exposure to microwave radiation. The phase composition, as well as the composition of functional groups, was determined by IR spectroscopy and X-ray phase analysis. Monocytes isolated from human blood showed higher viability compared to the controls.
ABSTRACT
The primary purpose of the study, presented in this article, was to obtain a composite cement material intended for osteanagenesis. The ß-tricalcium phosphate powder (ß-TCP, ß-Ca3(PO4)2) was obtained by the liquid-phase method. Setting and hardening of the cement system were achieved by adding calcium sulfate hemihydrate (CSH, CaSO4·1/2H2O). An aqueous solution of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and a PVA/PVP mixture were used as a polymer component. The methods of capillary viscometry and Fourier-transform infrared spectroscopy (FTIR) revealed the formation of intermolecular hydrogen bonds between polymer components, which determines the good miscibility of polymers. The physicochemical properties of the synthesized materials were characterized by X-ray diffraction (XRD) and FTIR methods, and the added amount of polymers does not significantly influence the processes of phase formation and crystallization of the system. The size of crystallites CSD remained in the range of 32-36 nm, regardless of the ratio of polymer components. The influence of the composition of composites on their solubility was investigated. In view of the lower solubility of pure ß-TCP, as compared to calcium sulfate dihydrate (CSD, CaSO4·2H2O), the solubility of composite materials is determined to a greater degree by the CSD solubility. Complexometric titration showed that the interaction between PVA and PVP impeded the diffusion of calcium ions, and at a ratio of PVA to PVP of 1/1, the smallest exit of calcium ions from the system is observed. The cytotoxicity analysis results allowed us to establish the fact that the viability of human macrophages in the presence of the samples varied from 80% to 125% as compared to the control.
ABSTRACT
The application of various materials in biomedical procedures has recently experienced rapid growth. One of the areas is the treatment of many of different types of bone-related diseases and disorders by using biodegradable polymer-ceramic composites. We have developed a material based on cryogel polyvinyl alcohol, mineralized with calcium phosphate. Composites were obtained by cyclic freezing-thawing, the synthesis of calcium phosphates was carried out in situ under the influence of microwave radiation with heating and stirring. The components of the composites were determined using the methods of IR-spectroscopy and scanning electron microscopy and electron probe microanalyzer, as well as their morphology and surface properties. The biological compatibility of the material was investigated in vivo for a Wistar rat. The assessment of the quality of bone formation between the cryogel-based implant and the damaged bone was carried out by computed tomography. An improvement in the consolidation of the bone defect is observed in the bone with the composite in comparison with the control bone.
ABSTRACT
The intensive development of reconstructive surgery and traumatology provides a stable demand for new materials for implants. Of particular interest are materials based on hydroxyapatite, which are chemically close to the elemental composition and structure of bone and have similar bioactive properties. The aim of this work was to obtain porous composite materials based on hydroxyapatite and a copolymer of lactide and glycolide with properties suitable for use as a material for bone implants. The phase and elemental composition of composites was investigated by infrared spectroscopy, X-ray diffraction, and X-ray photoelectronic spectroscopy methods, and it was established how the production process affects the composition of materials. Regularities of the formation of porosity by the methods of low-temperature adsorption of nitrogen, immersion in a liquid (determination of the pore space volume), measurement of the diffusion coefficient through the material (Franz cell), and surface properties of composite materials by the Hammett indicator method, by the lying drop method were revealed. Regularities were established between the surface properties and the composition of materials and their biocompatibility determined using monocytes isolated from human peripheral blood.
ABSTRACT
Hydroxyapatites modified with metal ions are the main inorganic components of bone tissue and are approved for use as components for biocomposites and coatings for surgical implants. This study examined prototypes of functional materials for bone implants based on hydroxyapatite modified with zinc ions. Zinc-modified hydroxyapatite was composed and synthesized. Using the XRD method, the phase composition was established. Using SEM, EPMA, and low-temperature nitrogen adsorption (BET) methods, surface properties were investigated. Antibacterial activity and biocompatibility have been established. The studied materials have antimicrobial activity; the samples did not cause significant changes in either the internal organs or the general condition of laboratory animals during the entire experiment.
