The use of knowledge from technetium radiochemistry (even from nuclear medicine applications) allows us to select an sorbent for 99mTc radionuclide sorption, which is hydroxyapatite. Using radioisotope indication, the 99mTcO4- sorption process on synthetic hydroxyapatite was studied by the batch method in the presence of SnCl2 and FeSO4 reducing agents. The complexing organic ligands' effect on the 99mTcO4- sorption under reducing conditions was investigated. In the presence of Sn2+ ions without the addition of organic ligand, the sorption percentage reached above 90% independently of the environment. In the presence of Fe2+ ions without the addition of organic ligand, the sorption of 99mTcO4- was significantly lower and was at approximately 6%, depending on the concentration of Fe2+ ions in solution. The effect of complexing organic ligands on the 99mTcO4- sorption on hydroxyapatite from the aqueous solution, acetate buffer and phosphate buffer decreases in the following order for Sn2+: oxalic acid > ethylenediaminetetraacetic acid > ascorbic acid. In the presence of Fe2+ ions without organic ligands, the sorption reached up to 15% depending on the composition of the solution. The addition of oxalic acid and ascorbic acid increased the sorption up to 80%. The ethylenediaminetetraacetic acid had no significant effect on the sorption of technetium on hydroxyapatite.
PURPOSE: Osteoporosis is a severe health problem with social and economic impacts on society. The standard treatment consists of the systemic administration of drugs such as bisphosphonates, with alendronate (ALN) being one of the most common. Nevertheless, complications of systemic administration occur with this drug. Therefore, it is necessary to develop new strategies, such as local administration. METHODS: In this study, emulsion/dispersion scaffolds based on W/O emulsion of PCL and PF68 with ALN, containing hydroxyapatite (HA) nanoparticles as the dispersion phase were prepared using electrospinning. Scaffolds with different release kinetics were tested in vitro on the co-cultures of osteoblasts and osteoclast-like cells, isolated from adult osteoporotic and control rats. Cell viability, proliferation, ALP, TRAP and CA II activity were examined. A scaffold with a gradual release of ALN was tested in vivo in the bone defects of osteoporotic and control rats. RESULTS: The release kinetics were dependent on the scaffold composition and the used system of the poloxamers. The ALN was released from the scaffolds for more than 22 days. The behavior of cells cultured in vitro on scaffolds with different release kinetics was comparable. The difference was evident between cell co-cultures isolated from osteoporotic and control animals. The PCL/HA scaffold show slow degradation in vivo and residual scaffold limited new bone formation inside the defects. Nevertheless, the released ALN supported bone formation in the areas surrounding the residual scaffold. Interestingly, a positive effect of systemic administration of ALN was not proved. CONCLUSION: The prepared scaffolds enabled tunable control release of ALN. The effect of ALN was proved in vitro and in in vivo study supported peri-implant bone formation.
- MeSH
- alendronát * farmakologie MeSH
- emulze farmakologie MeSH
- hydroxyapatit farmakologie MeSH
- inhibitory kostní resorpce * farmakologie MeSH
- krysa rodu rattus MeSH
- osteoblasty MeSH
- osteogeneze MeSH
- osteoklasty MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
This research work is focused on the investigation of newly developed titania sol-gel coatings containing silver, calcium and phosphate with appropriate abilities to be implanted into the human body. These abilities include adhesion, bioactivity, antibacterial property and cytocompatibility of prepared coatings. Four types of coatings were applied on a titanium substrate by dip-coating technique under different conditions (TCP1, TCP2, TCPA1 and TCPA2). Surfaces of coatings after the firing without silver featured different distribution of circular areas containing Ca. The coatings TCPA1 and TCPA2 were made up of unhomogeneously situated silver. Adhesion of the coatings to the substrates was measured by a tape test. All types of the coatings demonstrated very good adhesion. Isolated cracks that appeared during the firing did not have a negative influence on the adhesion properties. Bioactivity of the coatings was tested in vitro using a simulated body fluid. Three of the four types demonstrated bioactive properties (TCP1, TCP2 and TCPA2), that is, precipitation of crystalline hydroxyapatite as was confirmed by X-ray diffraction. The antibacterial effect (against Escherichia coli and Staphylococcus epidermidis) and cytotoxicity (toward L929 and U-2 OS cell lines, direct and indirect test) were then tested. All the coatings demonstrated very good antibacterial effect against both bacteria after 4- and 24-hr interaction. All the coating types were evaluated as cytocompatible in the indirect test. Cells were able to grow even directly on the coatings.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- biokompatibilní potahované materiály chemie farmakologie MeSH
- Escherichia coli MeSH
- hydroxyapatit farmakologie MeSH
- lidé MeSH
- stříbro * farmakologie MeSH
- titan * chemie farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Collagen I-based foams were modified with calcined or noncalcined hydroxyapatite or calcium phosphates with various particle sizes and pores to monitor their effect on cell interactions. The resulting scaffolds thus differed in grain size, changing from nanoscale to microscopic, and possessed diverse morphological characteristics and resorbability. The materials' biological action was shown on human bone marrow MSCs. Scaffold morphology was identified by SEM. Using viability test, qPCR, and immunohistochemical staining, we evaluated the biological activity of all of the materials. This study revealed that the most suitable scaffold composition for osteogenesis induction is collagen I foam with calcined hydroxyapatite with a pore size of 360 ± 130 μm and mean particle size of 0.130 μm. The expression of osteogenic markers RunX2 and ColI mRNA was promoted, and a strong synthesis of extracellular protein osteocalcin was observed. ColI/calcined HAP scaffold showed significant osteogenic potential, and can be easily manipulated and tailored to the defect size, which gives it great potential for bone tissue engineering applications.
Streptococcus mutans is one of the bacteria that initiates the colonization of the pellicle at the tooth surface. It forms a plaque, together with other bacteria, which gradually dissolves the pellicle and leaves the tooth surface unprotected against the acidic oral environment. Calcium phosphate ceramics are excellent synthetic materials for the study of biofilm formation in dentistry because they are comparable to teeth in chemical composition and structure. Calcium phosphates can be processed to achieve a variety of crystalline compounds with biologically relevant ionic substitutions and structures that allow study of the effect of the surface chemistry and the topography independently. In this article, we describe the preparation and characterization of three types of calcium phosphate-based materials as a suitable surface for the formation of the S. mutans biofilm: beta-tricalcium phosphate (β-TCP); sintered hydroxyapatite (SHA); and calcium-deficient hydroxyapatite (CDHA). The densest biofilms were formed on the surfaces of SHA and CDHA, with no significant differences due to the stoichiometry or microstructure. In contrast, β-TCP showed a lower susceptibility to S. mutans biofilm formation, suggesting that the crystalline structure is the controlling parameter. Subsequently, SHA was selected to develop a dental biofilm model that allowed study of S. mutans biofilm susceptibility to chlorhexidine and ethanol.
PURPOSE: To evaluate 5-year voice outcomes of vocal fold augmentation (VFA) using autologous fat (AF) injection via direct microlaryngoscopy versus office-based calcium hydroxylapatite (CaHA) injection. METHODS: Retrospective study of patients who underwent VFA between 2012 and 2015, with a 5-year follow-up. Patients with a glottic gap of ≤ 3 mm caused by unilateral vocal fold paralysis or vocal fold atrophy were included in the study. VFA was performed using AF injection via direct microlaryngoscopy in 17 patients, and using office-based CaHA injection in 19 patients. Subjective satisfaction with voice, voice handicap index (VHI), and maximal phonation time (MPT) were analyzed pre-injection, and at 12 and 60 months post-VFA. RESULTS: Altogether 36 patients underwent VFA between 2012 and 2015, of whom 5 were excluded within 1 year post-VFA, and 2 were excluded between 1 and 5 years post-VFA. Of the remaining 29 patients, 3 (10.3%) underwent re-intervention at between 1 and 3 years post-VFA. Thus, the 5-year follow-up included 26 patients (72.2%; 11 males and 15 females). At 5 years after surgery, 73.1% of the patients were satisfied with their voice, with no significant between-group difference (P = 0.307). The mean improvement of VHI was 28.8 ± 17.82 in the autologous fat group versus 33 ± 26.24 in the CaHA group (P = 0.458). MPT improvement was also similar between the two groups: 6.2 ± 4.26 for the autologous fat group versus 6.3 ± 4.34 for the CaHA group (P = 0.667). CONCLUSIONS: Both AF injection via direct microlaryngoscopy and office-based CaHA injection yielded good and comparable 5-year results.
- MeSH
- hlasové řasy * chirurgie MeSH
- hydroxyapatit * MeSH
- lidé MeSH
- retrospektivní studie MeSH
- vápník MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Bone tissue engineering tries to simulate natural behavior of hard tissues. This study aimed to produce scaffolds based on polyvinyl alcohol (PVA) and hyaluronic acid (HA) with hydroxyapatite (HAp) incorporated in two different ways, by in situ synthesis and physical mixing of pre-prepared HAp. In situ synthesis resulted in calcium deficient form of HAp with lower crystallinity. The proliferation of human osteoblast-like cells MG-63 proved to be better in the scaffolds with in situ synthesized HAp compared to those with physically mixed pre-prepared HAp. For scaffolds with PVA/HA/HAp ratio 3:1:2, there was significantly higher initial adhesion (p = 0.0440), as well as the proliferation in the following days (p < 0.001). It seemed to be advantageous improve the properties of the scaffold by in situ synthesizing of HAp directly in the organic matrix.
- MeSH
- biokompatibilní materiály chemie MeSH
- buněčná adheze MeSH
- hemolýza MeSH
- hydrogely chemie MeSH
- hydroxyapatit chemie MeSH
- kyselina hyaluronová chemie MeSH
- lidé MeSH
- osteoblasty cytologie MeSH
- polyvinylalkohol chemie MeSH
- proliferace buněk MeSH
- testování materiálů MeSH
- tkáňové inženýrství MeSH
- tkáňové podpůrné struktury chemie MeSH
- viabilita buněk MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
This work studies the mechanical and biological properties of Baghdadite (BAG, Ca3ZrSi2O9) coating manufactured on Ti6Al4V substrates by hybrid water-stabilized plasma spray (WSP-H). Hydroxyapatite (HAp, Ca10(PO4)6(OH)2) coating was produced by gas-stabilized atmospheric plasma spray and used as a reference material. Upon spraying, the BAG coating exhibited lower crystallinity than the HAp coating. Mechanical testing demonstrated superior properties of the BAG coating: its higher hardness, elastic modulus as well as a better resistance to scratch and wear. In the cell viability study, the BAG coating presented better human osteoblast attachment and proliferation on the coating surface after three days and seven days compared to the HAp counterpart. Furthermore, the gene expression study of human osteoblasts indicated that the BAG coating surface showed higher expression levels of osteogenic genes than those on the HAp coating. Overall, this study indicates that enhanced mechanical and bioactive properties can be achieved for the BAG coating compared to the benchmark HAp coating. It is therefore concluded here that the BAG coating is a potential candidate for coating orthopedic implants.
- MeSH
- biokompatibilní potahované materiály farmakologie MeSH
- hydroxyapatit MeSH
- keramika * farmakologie MeSH
- lidé MeSH
- povrchové vlastnosti MeSH
- silikáty MeSH
- testování materiálů MeSH
- voda * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The international standard ISO 23317:2014 for the in vitro testing of inorganic biomaterials in simulated body fluid (SBF) uses TRIS buffer to maintain neutral pH. In our previous papers, we investigated the interaction of a glass-ceramic scaffold with TRIS and HEPES buffers. Both of them speeded up glass-ceramic dissolution and hydroxyapatite (HAp) precipitation, thereby demonstrating their unsuitability for the in vitro testing of highly reactive biomaterials. In this article, we tested MOPS buffer (3-[N-morpholino] propanesulfonic acid), another amino acid from the group of "Goods buffers". A highly reactive glass-ceramic scaffold (derived from Bioglass®) was exposed to SBF under static-dynamic conditions for 13/15 days. The kinetics and morphology of the newly precipitated HAp were studied using two different concentrations of (PO4 )3- ions in SBF. The pH value and the SiIV , Ca2+ , and (PO4 )3- concentrations in the SBF leachate samples were measured every day (AAS, spectrophotometry). The glass-ceramic scaffold was monitored by SEM/EDS, XRD, WD-XRF, and BET before and after 1, 3, 7, 11, and 13/15 days of exposure. As in the case of TRIS and HEPES, the preferential dissolution of the glass-ceramic crystalline phase (Combeite) was observed, but less intensively. The lower concentration of (PO4 )3- ions slowed down the kinetics of HAp precipitation, thereby causing the disintegration of the scaffold structure. This phenomenon shows that the HAp phase was predominately generated by the presence of (PO4 )3- ions in the SBF, not in the glass-ceramic material. Irrespective of this, MOPS buffer is not suitable for the maintenance of pH in SBF.
