Nanosized silicate-substituted hydroxyapatites, characterized by the general formula Ca9.8-x-nSrnZnx(PO4)6-y(SiO4)y(OH)2 (where: n = 0.2 [mol%]; x = 0.5-3.5 [mol%]; y = 4-5 [mol%]), co-doped with Zn2+ and Sr2+ ions, were synthesized with the help of a microwave-assisted hydrothermal technique. The structural properties were determined using XRD (X-ray powder diffraction) and Fourier-transformed infrared spectroscopy (FT-IR). The morphology, size and shape of biomaterials were detected using scanning electron microscopy techniques (SEM). The reference strains of Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa were used to assess bacterial survivability and the impact on biofilm formation in the presence of nanosilicate-substituted strontium-hydroxyapatites. Safety evaluation was also performed using the standard cytotoxicity test (MTT) and hemolysis assay. Moreover, the mutagenic potential of the materials was assessed (Ames test). The obtained results suggest the dose-dependent antibacterial activity of nanomaterials, especially observed for samples doped with 3.5 mol% Zn2+ ions. Moreover, the modification with five SiO4 groups enhanced the antibacterial effect; however, a rise in the toxicity was observed as well. No harmful activity was detected in the hemolysis assay as well as in the mutagenic assay (Ames test).

This study reports an impact of structure (XRPD, FT-IR) and surface morphology (SEM-EDS) of imatinib-functionalized galactose hydrogels, loaded and unloaded with nHAp, on osteosarcoma cell (Saos-2 and U-2OS) viability, levels of free oxygen radicals, and nitric oxide, levels of BCL-2, p53, and caspase 3 and 9, as well as glycoprotein-P activity. It was investigated how the rough surface of the crystalline hydroxyapatite-modified hydrogel affected amorphous imatinib (IM) release. The imatinib drug effect on cell cultures has been demonstrated in different forms of administration-directly to the culture or the hydrogels. Administration of IM and hydrogel composites could be expected to reduce the risk of multidrug resistance development by inhibiting Pgp.

The aim of this work was to prepare a new hydrogel based on nanohydroxyapatite (nFAP, 10% w/w) and fluorides (4% w/w), both of which are used as sources of fluoride ions in the treatment of dentin hypersensitivity, and to characterize its physicochemical properties. The release of fluoride ions from 3 gels (G-F, G-F-nFAP, and G-nFAP gel) was controlled in Fusayama-Meyer artificial saliva at pH 4.5, 6.6, and 8.0. The properties of the formulations were determined by an analysis of viscosity, a shear rate test, a swelling study, and gel aging. Various methods, i.e., FT-IR spectroscopy, UV-VIS spectroscopy, and thermogravimetric, electrochemical, and rheological analysis, were used for the experiment. The profiles of fluoride release indicate that the amount of fluoride ions released increases with a decrease in the pH value. The low pH value facilitated water absorption by the hydrogel, which was also confirmed by the swelling test, and it promoted the exchange of ions with the surrounding environment. Under conditions similar to physiological conditions (at pH 6.6), the amounts of fluorides released into artificial saliva were approximately 250 µg/cm2 and 300 µg/cm2 for the G-F-nFAP hydrogel and G-F hydrogel, respectively. The aging study and properties of the gels showed a loosening of the gel network structure. The Casson rheological model was used to assess the rheological properties of the non-Newtonian fluids. Hydrogels consisting of nanohydroxyapatite and sodium fluoride are promising biomaterials in the prevention and management of the dentin hypersensitivity.

Osteoporosis results in a severe decrease in the life quality of many people worldwide. The latest data shows that the number of osteoporotic fractures is becoming an increasing international health service problem. Therefore, a new kind of controllable treatment methods for osteoporotic fractures is extensively desired. For that reason, we have manufactured and evaluated nanohydroxyapatite (nHAp)-based composite co-doped with iron oxide (IO) nanoparticles. The biomaterial was used as a matrix for the controlled delivery of miR-21-5p and miR-124-3p, which have a proven impact on bone cell metabolism.

In this study, solid-state solutions of yttrium orthovanadate-phosphate with varying concentrations of codopants (Eu3+, Bi3+) have been obtained via coprecipitation. An ionic radii mismatch between V5+ and P5+ substituents is manifested in broad XRD lines. The sharpening of the XRD lines is observed with increasing bismuth ions concentration in the Eu3+ codoped YV0.5P0.5O4 matrix. The difference in the number of the Stark components for the 5D0 → 7FJ transitions indicates changes in the lattice and a number of possible Eu3+ sites. A thorough, systematic spectroscopic analysis of YV0.5P0.5O4: x mol % Eu3+, y mol % Bi3+ was conducted at room temperature and 5 K. Metal-to-metal energy transfers occurring between Eu3+, V5+, and Bi3+ optically active ions have been investigated. Additionally, efficiency of the Bi3+-Eu3+ energy transfer (ET) was calculated.

Biomaterials are substances manufactured for medical purposes in direct contact with the tissues of organisms. Prior to their use, they are tested to determine their usefulness and safety of application. Hydroxyapatites are used in medicine as a bony complement because of their similarity to the natural apatite therein. Thanks to their bioactivity, biocompatibility, stability and non-toxicity hydroxyapatite are the most commonly used materials in osteoimplantology. The use of materials at the nanoscale in medicine or biology may carry the risk of undesirable effects. The aim of the study was to evaluate the cytotoxic effect of high-temperature annealed nanohydroxyapatites on the L929 murine fibroblasts. Nanohydroxyapatites in powder form were obtained by the wet chemistry method: in the temperature range of 800-1000 °C and used for the study. Based on performed studies evaluating the morphology and fibroblast viability, it was found that nanohydroxyapatites show no cytotoxic effects on the L929 cell line.

The research has been carried out with a focus on the assessment of the antimicrobial efficacy of pure nanohydroxyapatite, Cu2+-doped nanohydroxyapatite, ozonated olive oil-loaded nanohydroxyapatite, and Cu2+-doped nanohydroxyapatite, respectively. Their potential antimicrobial activity was investigated against Streptococcus mutans, Lactobacillus rhamnosus, and Candida albicans. Among all tested materials, the highest efficacy was observed in terms of ozonated olive oil. The studies were performed using an Ultraviolet-Visible spectrophotometry (UV-Vis), electron microscopy, and statistical methods, by determining the value of Colony-Forming Units (CFU/mL) and Minimal Inhibitory Concentration (MIC).

In the article has been presented an analysis of susceptibility of selected dental materials, made in the CAD/CAM technology. The morphology and structural properties of selected dental materials and their composites were determined by using XRPD (X-ray powder diffraction) techniques, as well as the IR (infrared) spectroscopy. Moreover, an adhesion as well as development of biofilm by oral microorganisms has been studied. It has been shown that a degree of the biofilm development on the tested dental materials depended on microorganism genus and species. Streptococcus mutans has demonstrated the best adhesion to the tested materials in comparison with Candida albicans and Lactobacillus rhamnosus. However, the sintered materials such as IPS e.max® and the polished IPS e.max® have showed the best "anti-adhesive properties" in relation to S. mutans and L. rhamnosus that have not formed the biofilm on the polished IPS e.max® sample. Furthermore, S. mutans have not formed the biofilm on both surfaces. On the contrary to S. mutans and L. rhamnosus, C. albicans has demonstrated the adhesive properties in relation to the above-mentioned surfaces. Moreover, in contrast to S. mutans and C. albicans, L. rhamnosus has not formed the biofilm on the polished IPS Empress material.

In response to the demand for new multifunctional materials characterized by high biocompatibility, hydrogel (HG) nanocomposites as a platform for bioactive compound delivery have been developed and fabricated. A specific crosslinking/copolymerization chemistry was used to construct hydrogels with a controlled network organization. The hydrogels were prepared using 3,6-anhydro-α-l-galacto-β-d-galactan (galactose hydrogel) together with resveratrol (trans-3,5,4'-trihydroxystilbene) and calcium hydroxyapatite nanoparticles. The resveratrol was introduced in three different concentrations of 0.1, 0.5, and 1 mM. Nanosized calcium hydroxyapatite was synthesized by a microwave-assisted hydrothermal technique, annealed at 500 °C for 3 h, and introduced at a concentration 10% (m/v). The morphology and structural properties of Ca10(PO₄)₆(OH)₂ and its composite were determined by using XRPD (X-ray powder diffraction) techniques, as well as the absorption and IR (infrared) spectroscopy. The average nanoparticle size was 35 nm. The water affinity, morphology, organic compound release profile, and cytocompatibility of the obtained materials were studied in detail. The designed hydrogels were shown to be materials of biological relevance and of great pharmacological potential as carriers for bioactive compound delivery. Their cytocompatibility was tested using a model of human multipotent stromal cells isolated from adipose tissue (hASCs). The biomaterials increased the proliferative activity and viability of hASCs, as well as reduced markers of oxidative stress. In light of the obtained results, it has been thought that the designed materials meet the requirements of the tissue engineering triad, and may find application in regenerative medicine, especially for personalized therapies.

Hydroxyapatite has been used in medicine for many years as a biomaterial or a cover for other biomaterials in orthopedics and dentistry. This study characterized the physicochemical properties (structure, particle size and morphology, surface properties) of Li+- and Li+/Eu3+-doped nanohydroxyapatite obtained using the wet chemistry method. The potential regenerative properties against neurite damage in cultures of neuron-like cells (SH-SY5Y and PC12 after differentiation) were also studied. The effect of nanohydroxyapatite (nHAp) on the induction of repair processes in cell cultures was assessed in tests of metabolic activity, the level of free oxygen radicals and nitric oxide, and the average length of neurites. The study showed that nanohydroxyapatite influences the increase in mitochondrial activity, which is correlated with the increase in the length of neurites. It has been shown that the doping of nanohydroxyapatite with Eu3+ ions enhances the antioxidant properties of the tested nanohydroxyapatite. These basic studies indicate its potential application in the treatment of neurite damage. These studies should be continued in primary neuronal cultures and then with in vivo models.

Eu3+-doped Sr10(PO4)6(OH)2-Sr3(PO4)2 (SrHAp-TSP) composites were obtained via the microwave-stimulated hydrothermal method and post-heat-treated from 750 to 950 °C. Concentration of the Eu3+ ions was set to be 0.5, 1, 2, 3, 5 mol% in a ratio of the strontium ions molar content. The structural and morphological properties were investigated by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FT-IR) techniques. The average particle size of the studied materials annealed at 750, 850 and 950 °C were counted about 100, 131 and 173 nm, respectively. The luminescence properties depending on the dopant ion concentration, heat-treatment temperature, excitation wavelength and temperature were investigated. In the emission spectra, a broad peak corresponding to the 4f65d1 → 4f7 (8S7/2) emission of Eu2+ ions as well as narrow 4f-4f transitions typical for Eu3+ ions can be observed. The luminescence intensity of the 1 mol% Eu3+:Sr10(PO4)6(OH)2-Sr3(PO4)2 was measured depending on the ambient temperature in the range of 80-550 K. The CIE 1931 (International Commission on Illumination) chromaticity diagram was determined from emission spectra measured in 80, 300 and 550 K. The reduction mechanism of the Eu3+ to the Eu2+ was explained by the charge compensation mechanism based on the Kröger-Vink-notation. The decay times were measured and the Judd-Ofelt (J-O) theory was applied to analyze the observed structural and spectroscopic features.

In the present study, a nanoapatite-mediated delivery system for imatinib has been proposed. Nanohydroxyapatite (nHAp) was obtained by co-precipitation method, and its physicochemical properties in combination with imatinib (IM) were studied by means of XRPD (X-ray Powder Diffraction), SEM-EDS (Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy), FT-IR (Fourier-Transform Infrared Spectroscopy), absorption spectroscopy as well as DLS (Dynamic Light Scattering) techniques. The obtained hydroxyapatite was defined as nanosized rod-shaped particles with high crystallinity. The amorphous imatinib was obtained by conversion of its crystalline form. The beneficial effects of amorphous pharmaceutical agents have been manifested in the higher dissolution rate in body fluids improving their bioavailability. Imatinib-to-hydroxyapatite interactions on the surface were confirmed by SEM images as well as absorption and FT-IR spectroscopy. The cytotoxicity of the system was tested on NI-1, L929, and D17 cell lines. The effectiveness of imatinib was not affected by nHAp modification. The calculated IC50 values for drug-modified nHAp were similar to those for the drug itself. However, higher cytotoxicity was observed at higher concentrations of imatinib, in comparison with the drug alone.

A new combination of Toceranib (Toc; 5-[(5Z)-(5-Fluoro-2-oxo-1,2-dihydro-3H-indol-3-ylidene)methyl]-2,4-dimethyl-N-[2-(pyrrolidin-1-yl)ethyl]-1H-pyrrole-3-carboxamide) with nanohydroxyapatite (nHAp) was proposed as an antineoplastic drug delivery system. Its physicochemical properties were determined as crystallinity, grain size, morphology, zeta potential and hydrodynamic diameter as well as Toceranib release. The crystalline nanorods of nHAp were synthesised by the co-precipitation method, while the amorphous Toceranib was obtained by its conversion from the crystalline form during nHAp-Toc preparation. The surface interaction between both compounds was confirmed using Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-Vis) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS). The nHAp-Toc showed a slower and prolonged release of Toceranib. The release behaviour was affected by hydrodynamic size, surface interaction and the medium used (pH). The effectiveness of the proposed platform was tested by comparing the cytotoxicity of the drug combined with nHAp against the drug itself. The compounds were tested on NI-1 mastocytoma cells using the Alamar blue colorimetric technique. The obtained results suggest that the proposed platform shows high efficiency (the calculated IC50 is 4.29 nM), while maintaining the specificity of the drug alone. Performed analyses confirmed that nanohydroxyapatite is a prospective drug carrier and, when Toceranib-loaded, may be an idea worth developing with further research into therapeutic application in the treatment of canine mast cell tumour.

(1) Background: Different compositions of biodegradable materials are being investigated to successfully replace non-resorbable ones in bone tissue regeneration in dental surgery. The systematic review tried to address the question, "Can biodegradable polymers act as a replacement for conventional materials in dental surgery procedures?" (2) Methods: An electronic search of the PubMed and Scopus databases was conducted in October 2022. The following keywords were used: (lactide polymers) and (hydroxyapatite or fluorapatite) and (dentistry) and (regeneration). Initially, 59 studies were found. Forty-one studies met the inclusion criteria and were included in the review. (3) Results: These usually improved the properties and induced osteogenesis, tissue mineralisation and bone regeneration by inducing osteoblast proliferation. Five studies showed higher induction of osteogenesis in the case of biomaterials, UV-HAp/PLLA, ALBO-OS, bioresorbable raw particulate hydroxyapatite/poly-L-lactide and PLGA/Hap, compared to conventional materials such as titanium. Four studies confirmed improvement in tissue mineralisation with the usage of biomaterials: hydroxyapatite/polylactic acid (HA/PLA) loaded with dog's dental pulp stem cells (DPSCs), Coll/HAp/PLCL, PDLLA/VACNT-O:nHAp, incorporation of hydroxyapatite and simvastatin. Three studies showed an acceleration in proliferation of osteoblasts for the use of biomaterials with additional factors such as collagen and UV light. (4) Conclusions: Lactide polymers present higher osteointegration and cell proliferation rate than the materials compared. They are superior to non-biodegradable materials in terms of the biocompability, bone remodelling and healing time tests. Moreover, because there is no need of reoperation, as the material automatically degrades, the chance of scars and skin sclerosis is lower. However, more studies involving greater numbers of biomaterial types and mixes need to be performed in order to find a perfect biodegradable material.

Searching for biocompatible materials with proper luminescent properties is of fundamental importance, as they can be applied in fluorescent labeling and regenerative medicine. In this study, we obtained new phosphate-vanadate hydroxyapatites (abbr. HVps) co-doped with Sr2+ and Tb3+ ions via the hydrothermal method. We focused on examining the effect of various annealing temperatures (500, 600 and 700 °C) on the spectroscopic properties and morphology of the obtained HVps. To characterize their morphology, XRPD (X-ray powder diffraction), SEM-EDS (scanning electron microscopy-energy-dispersive spectrometry), FT-IR (Fourier transform infrared) spectroscopy and ICP-OES (inductively coupled plasma-optical emission spectrometry) techniques were used. A further study of luminescent properties and cytocompatibility showed that the obtained HVps co-doped with Sr2+ and Tb3+ ions are highly biocompatible and able to enhance the proliferation process and can therefore be potentially used as fluorescent probes or in regenerative medicine.

The aim of the presented systematic review is to update the state of knowledge and relate the properties and composition of fluoride gels to their potential application. This article aims to explore the effect of fluoride gel application on changes in the properties of dental biomaterials and tooth tissues. The review includes articles assessing studies on the effects of fluoride gel on dental tissues and materials. Employing the PRISMA protocol, a meticulous search was conducted across the PubMed, Scopus, and Web of Science databases, utilizing keywords such as fluoride, gel, and properties. The publications were selected without limitation by the year of publication, and then Cohen's κ test was used to assess the agreement of the respondents. Exclusion criteria included non-English studies, opinion pieces, editorial papers, letters to the editor, review articles and meta-analyses, clinical reports, studies lacking full-text accessibility, and duplicates. The quality of the chosen papers was assessed by two independent reviewers. A total of 2385 were located in databases, of which only 17 met the inclusion criteria. All publications showed increased surface mineralization, and seven studies showed the effect of fluoride gel on the surface of dental tissues. Three articles stated a negative effect of fluoride gels on titanium and stainless steel alloys and glass ionomer fillings. The effects on shear bond strength and plaque deposition require further investigation because the study results are contradictory.

This study aims to evaluate the influence of a nanohydroxyapatite layer applied to the surface of titanium or titanium alloy implants on the intricate process of osseointegration and its effect on osteoblast cell lines, compared to uncoated implants. Additionally, the investigation scrutinizes various modifications of the coating and their consequential effects on bone and cell line biocompatibility. On the specific date of November 2023, an exhaustive electronic search was conducted in esteemed databases such as PubMed, Web of Science, and Scopus, utilizing the meticulously chosen keywords ((titanium) AND ((osteoblasts) and hydroxyapatite)). Methodologically, the systematic review meticulously adhered to the PRISMA protocol. Initially, a total of 1739 studies underwent scrutiny, with the elimination of 741 duplicate records. A further 972 articles were excluded on account of their incongruence with the predefined subjects. The ultimate compilation embraced 26 studies, with a predominant focus on the effects of nanohydroxyapatite coating in isolation. However, a subset of nine papers delved into the nuanced realm of its modifiers, encompassing materials such as chitosan, collagen, silver particles, or gelatine. Across many of the selected studies, the application of nanohydroxyapatite coating exhibited a proclivity to enhance the osseointegration process. The modifications thereof showcased a positive influence on cell lines, manifesting in increased cellular spread or the attenuation of bacterial activity. In clinical applications, this augmentation potentially translates into heightened implant stability, thereby amplifying the overall procedural success rate. This, in turn, renders nanohydroxyapatite-coated implants a viable and potentially advantageous option in clinical scenarios where non-modified implants may not suffice.

Atherosclerosis is a multifactorial disease, for which the etiology is so complex that we are currently unable to prevent it and effectively lower the statistics on mortality from cardiovascular diseases. Parallel to modern analyses in molecular biology and biochemistry, we want to carry out analyses at the level of micro- and macroelements in order to discover the interdependencies between elements during atherogenesis. In this work, we used the Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) to determine the content of calcium, magnesium, iron, copper, chromium, zinc, manganese, cadmium, lead, and zinc in the aorta sections of people who died a sudden death. We also estimated the content of metalloenzymes MMP-9, NOS-3, and SOD-2 using the immunohistochemical method. It was observed that with the age of the patient, the calcium content of the artery increased, while the content of copper and iron decreased. Very high correlations (correlation coefficient above 0.8) were observed for pairs of parameters in women: Mn-Ca, Fe-Cu, and Ca-Cd, and in men: Mn-Zn. The degree of atherosclerosis negatively correlated with magnesium and with cadmium. Chromium inhibited absorption of essential trace elements such as Cu and Fe due to its content being above the quantification threshold only if Cu and Fe were lower. Moreover, we discussed how to design research for the future in order to learn more about the pathomechanism of atherosclerosis and the effect of taking dietary supplements on the prevalence of cardiovascular diseases.

Li+/Eu3+ dual-doped calcium apatite analogues were fabricated using a microwave stimulated hydrothermal technique. XRPD, FT-IR, micro-Raman spectroscopy, TEM and SAED measurements indicated that obtained apatites are single-phased, crystallize with a hexagonal structure, have similar morphology and nanometric size as well as show red luminescence. Lithium effectively modifies the local symmetry of optical active sites and, thus, affects the emission efficiency. Moreover, the hydrodynamic size and surface charge of the nanoparticles have been extensively studied. The protein adsorption (lysozyme, LSZ; bovine serum albumin, BSA) on the nanoparticle surface depended on the type of cationic dopant (Li+, Eu3+) and anionic group (OH-, Cl-, F-) of the apatite matrix. Interaction with LSZ resulted in a positive zeta potential, and the nanoparticles had the lowest hydrodynamic size in this protein medium. The cytotoxicity assessment was carried out on the human osteosarcoma cell line (U2OS), murine macrophages (J774.E), as well as human red blood cells (RBCs). The studied apatites were not cytotoxic to RBCs and J774.E cells; however, at higher concentrations of nanoparticles, cytotoxicity was observed against the U2OS cell line. No antimicrobial activity was detected against Gram-negative bacteria with one exception for P. aeruginosa treated with Li+-doped fluorapatite.

This research investigates hydrothermally synthesized hydroxyapatite nanoparticles doped with rubidium(I) and europium(III) ions. Investigation focused on establishing the influence of co-doped Eu3+ and Rb+ ions on hydroxyapatite lattice. Therefore, structural, and morphological properties were characterized via using X-ray powder diffraction (XRPD), infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM), as well as transmission electron microscopy (TEM) techniques. Furthermore, this investigation evaluates the impact of various Rb+ ion doping concentrations on the distinct red emission of co-doped Eu3+ ions. Hence, luminescence properties of the obtained materials were evaluated by measuring emission excitation, emission spectra, and luminescence decays. As established by numerous studies, synthetic hydroxyapatite has excellent application in biomedical field, as it is fully biocompatible. Its biocompatible makes it highly useful in the biomedical field as a bone fracture filler or hydroxyapatite coated dental implant. By the incorporation of Eu3+ ions and Rb+ ions we established the impact these co-doped ions have on the biocompatibility of hydroxyapatite powders. Therefore, biocompatibility toward a ram's red blood cells was evaluated to exclude potential cytotoxic features of the synthesized compounds. Additionally, experimental in vitro bioactive properties of hydroxyapatite nanoparticles doped with Rb+ and Eu3+ ions were established using a mouse osteoblast model. These properties are discussed in detail as they contribute to a novel method in regenerative medicine.