UNLABELLED: In this work alpha tricalcium phosphate (α-TCP)/iron (Fe) composites were developed as a new family of biodegradable, load-bearing and cytocompatible materials. The composites with composition from pure ceramic to pure metallic samples were consolidated by pulsed electric current assisted sintering to minimise processing time and temperature while improving their mechanical performance. The mechanical strength of the composites was increased and controlled with the Fe content, passing from brittle to ductile failure. In particular, the addition of 25 vol% of Fe produced a ceramic matrix composite with elastic modulus much closer to cortical bone than that of titanium or biodegradable magnesium alloys and specific compressive strength above that of stainless steel, chromium-cobalt alloys and pure titanium, currently used in clinic for internal fracture fixation. All the composites studied exhibited higher degradation rate than their individual components, presenting values around 200 μm/year, but also their compressive strength did not show a significant reduction in the period required for bone fracture consolidation. Composites showed preferential degradation of α-TCP areas rather than β-TCP areas, suggesting that α-TCP can produce composites with higher degradation rate. The composites were cytocompatible both in indirect and direct contact with bone cells. Osteoblast-like cells attached and spread on the surface of the composites, presenting proliferation rate similar to cells on tissue culture-grade polystyrene and they showed alkaline phosphatase activity. Therefore, this new family of composites is a potential alternative to produce implants for temporal reduction of bone fractures. STATEMENT OF SIGNIFICANCE: Biodegradable alpha-tricalcium phosphate/iron (α-TCP/Fe) composites are promising candidates for the fabrication of temporal osteosynthesis devices. Similar to biodegradable metals, these composites can avoid implant removal after bone fracture healing, particularly in young patients. In this work, α-TCP/Fe composites are studied for the first time in a wide range of compositions, showing not only higher degradation rate in vitro than pure components, but also good cytocompatibility and mechanical properties controllable with the Fe content. Ceramic matrix composites show high specific strength and low elastic modulus, thus better fulfilling the requirements for bone fractures fixation. A significant advance over previous works on the topic is the use of pulsed electric current assisted sintering together with α-TCP, convenient to improve the mechanical performance and degradation rate, respectively.

• Klíčová slova
• Biodegradable metal, Degradation test, Mechanical properties, Spark plasma sintering, Tricalcium phosphate,
• MeSH
• fosforečnany vápenaté farmakologie   MeSH
• fraktury kostí farmakoterapie   metabolismus   patologie   MeSH
• keramika farmakologie   MeSH
• kostní náhrady farmakologie   MeSH
• lidé MeSH
• modul pružnosti MeSH
• nádorové buněčné linie MeSH
• osteoblasty metabolismus   patologie   MeSH
• testování materiálů MeSH
• železo farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alpha-tricalcium phosphate MeSH Prohlížeč
• beta-tricalcium phosphate MeSH Prohlížeč
• fosforečnany vápenaté MeSH
• kostní náhrady MeSH
• železo MeSH

The present work studies the microstructure and mechanical performance of tricalcium phosphate (TCP) based cermet toughened by iron particles. A novelty arises by the employment of spark plasma sintering for fabrication of the cermet. Results showed partial transformation of initial alpha TCP matrix to beta phase and the absence of oxidation of iron particles, as well as a lack of chemical reaction between TCP and iron components during sintering. The values of compressive and tensile strength of TCP/Fe cermet were 3.2 and 2.5 times, respectively, greater than those of monolithic TCP. Fracture analysis revealed the simultaneous action of crack-bridging and crack-deflection microstructural toughening mechanisms under compression. In contrast, under tension the reinforcing mechanism was only crack-bridging, being the reason for smaller increment of strength. Elastic properties of the cermet better matched values reported for human cortical bone. Thereby the new TCP/Fe cermet has potential for eventual use as a material for bone fractures fixation under load-bearing conditions.

• Klíčová slova
• Ceramic-matrix composite, Fractography, Microstructural toughening, Spark plasma sintering, Tricalcium phosphate,
• MeSH
• cementy Cermet chemie   MeSH
• fosforečnany vápenaté chemie   MeSH
• mechanické jevy * MeSH
• plazmové plyny chemie   MeSH
• testování materiálů MeSH
• tvrdost MeSH
• železo chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cementy Cermet MeSH
• fosforečnany vápenaté MeSH
• plazmové plyny MeSH
• tricalcium phosphate MeSH Prohlížeč
• železo MeSH

Due to unique osteogenic properties, tricalcium phosphate (TCP) has gained relevance in the field of bone repair. The development of novel and rapid sintering routes is of particular interest since TCP undergoes to high-temperature phase transitions and is widely employed in osteoconductive coatings on thermally-sensitive metal substrates. In the present work, TCP bioceramics was innovatively obtained by Ultrafast High-temperature Sintering (UHS). Ca-deficient hydroxyapatite nano-powder produced by mechanochemical synthesis of mussel shell-derived calcium carbonate was used to prepare the green samples by uniaxial pressing. These were introduced within a graphite felt which was rapidly heated by an electrical current flow, reaching heating rates exceeding 1200 °C min-1. Dense (> 93%) ceramics were manufactured in less than 3 min using currents between 25 and 30 A. Both β and α-TCP were detected in the sintered components with proportions depending on the applied current. Preliminary tests confirmed that the artifacts do not possess cytotoxic effects and possess mechanical properties similar to conventionally sintered materials. The overall results prove the applicability of UHS to bioceramics paving the way to new rapid processing routes for biomedical components.

• Klíčová slova
• Bioceramics, Mechanochemical synthesis, TCP, UHS, Ultra-high temperature sintering,
• MeSH
• biokompatibilní materiály * MeSH
• fosforečnany vápenaté * MeSH
• keramika MeSH
• teplota MeSH
• testování materiálů MeSH
• vysoká teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biokompatibilní materiály * MeSH
• fosforečnany vápenaté * MeSH
• tricalcium phosphate MeSH Prohlížeč

This report describes the histological characteristics of large human bone defects that were implanted with β-tricalcium phosphate (β-TCP). Samples were obtained longer after the primary operation than in the earlier studies. We assessed a total of nine biopsies taken 33-208 weeks after implantation. The tissue sections were stained with hematoxylin-eosin for general observation, with Gomori stain to visualize the reticulin fibers, and with an antibody against tartrate-resistant alkaline phosphatase (TRAP) to characterize the cells. Ongoing bone remodeling was observed even 208 weeks after implantation as determined by the presence of osteoclasts and active osteoblasts and new woven and lamellar bone. We observed multinuclear giant cells phagocytosing the biomaterial and the attachment of osteoclasts to the β-TCP. The osteoclasts showed intense TRAP positivity, while the giant cells showed variable TRAP positivity. There was a zonal pattern in the original defects: The central regions showed granules and fibrous septa, while peripheral areas showed a layer of new bone formation. These data demonstrate ongoing bone remodeling long after implantation in the peripheral regions of the original defects as well as fibrous changes in the central regions and phagocytosis of biomaterial by multinuclear giant cells.

• MeSH
• biopsie MeSH
• dítě MeSH
• dospělí MeSH
• fosforečnany vápenaté terapeutické užití   MeSH
• kosti a kostní tkáň patologie   MeSH
• kostní náhrady terapeutické užití   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nemoci kostí patologie   terapie   MeSH
• osteoblasty patologie   MeSH
• osteoklasty patologie   MeSH
• remodelace kosti MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• beta-tricalcium phosphate MeSH Prohlížeč
• fosforečnany vápenaté MeSH
• kostní náhrady MeSH

PURPOSE: To compare the efficacy of 2 common materials in sinus augmentation surgery and to assess their contribution when enriched with autogenous bone. MATERIALS AND METHODS: The prospective human study was performed in 48 sinus grafting operations using beta-tricalcium phosphate or deproteinized bovine bone (pure or mixed with 10% to 20% autogenous bone) or autogenous bone. Biopsy specimens were taken after 9 months. Statistical evaluation was done with a 2-sample t test (P < .05). RESULTS: When autogenous bone was used, 49.2% +/- 3.1% of new bone was found, which is significantly higher than in all the other groups. A higher proportion (34.2% +/- 13.1%) of the new vital bone was found in the deproteinized bovine bone group, in comparison with the beta-tricalcium phosphate group (21.4% +/- 8.1%) and the beta-tricalcium phosphate composite graft group (24.0% +/- 6.6%; P < .05). No significant differences between single-component grafts and corresponding composite grafts were established. CONCLUSIONS: Sinus augmentation with the aforementioned augmentation materials is a well-accepted procedure. However, autogenous bone alone was the best material. More new bone was found using deproteinized bovine bone than beta-tricalcium phosphate. The addition of 10% to 20% autogenous bone to the bone substitute did not significantly influence the new bone formation.

• MeSH
• dospělí MeSH
• fosforečnany vápenaté MeSH
• kostní náhrady * MeSH
• lidé středního věku MeSH
• lidé MeSH
• minerály MeSH
• průřezové studie MeSH
• regenerace kostí MeSH
• senioři MeSH
• sinus maxillaris chirurgie   MeSH
• skot MeSH
• stomatochirurgické předprotetické výkony metody   MeSH
• transplantace kostí * MeSH
• zvířata MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky kontrolované MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• beta-tricalcium phosphate MeSH Prohlížeč
• Bio-Oss MeSH Prohlížeč
• fosforečnany vápenaté MeSH
• kostní náhrady * MeSH
• minerály MeSH

A natural polymer of carboxymethyl starch (CMS) was used in combination with the inorganic mineral of β-Tricalcium Phosphate (β-TCP) and Poly l-lactide (PLLA) to prepare composite nanofibers with the potential to be used as a biomedical membrane. β-TCP contents varied in the range of 0.25% to 1% in the composition of PLLA and CMS. A mixed composition of these organic and inorganic materials was electro-spun to produce composite nanofibers. Morphological investigation indicated that smooth and uniform nanofibers could be produced via this technique. The average of the nanofiber diameters was slightly increased from 190 to 265 nm with the β-TCP content but some agglomeration of particles began to impede in the fiber at a higher content of β-TCP. It was observed that the fibers were damaged at a higher content of β-TCP nanoparticles. With the presence of higher β-TCP, the wettability of the PLLA was also improved, as indicated by the water contact angle measurement from 127.3° to 118°. The crystallization in the composite decreased, as shown in the changes in glass transition (Tg) and melting temperature (Tm) by differential scanning calorimeter (DSC) and X-ray diffraction analysis. Increases in β-TCP contributed to weaker mechanical strength, from 8.5 to 5.7 MPa, due to imperfect fiber structure.

• Klíčová slova
• carboxymethyl starch (CMS), electrospinning, nanofibers, poly l-lactide (PLLA), β-tricalcium phosphate (β-TCP),
• Publikační typ
• časopisecké články MeSH

This prospective study sought to evaluate the healing quality of implanted ultraporous β-tricalcium phosphate sown with expanded autologous mesenchymal stromal cells (MSCs) into femoral defects during revision hip arthroplasty. A total of 37 osseous defects in 37 patients were treated and evaluated concerning bone regeneration. Nineteen subjects received β-tricalcium phosphate graft material serving as a carrier of expanded autologous MSCs (the trial group A), nine subjects received β-tricalcium phosphate graft material only (the study group B) and nine subjects received cancellous allografts only (the control group C). Clinical and radiographic evaluations were scheduled at 6 weeks, 3, 6, and 12 months post-operatively, and performed at the most recent visit as well. All observed complications were recorded during follow-up to assess the use of an ultraporous β-tricalcium phosphate synthetic graft material combined with expanded MSCs in bone defect repair. The resulting data from participants with accomplished follow-up were processed and statistically evaluated with a Freeman-Halton modification of the Fischer's exact test, a P < 0.05 value was considered to be significant. Whereas no significant difference was observed between the trial group A with β-tricalcium phosphate synthetic graft material serving as a carrier of expanded autologous MSCs and control group C with cancellous impaction allografting in terms of the bone defect healing, significant differences were documented between the study group B with β-tricalcium phosphate graft material only and control group C. Regarding adverse effects, six serious events were recorded during the clinical trial with no causal relationship to the cell product. β-tricalcium phosphate synthetic graft material serving as a carrier of expanded autologous MSCs appears safe and promotes the healing of bone defects in a jeopardized and/or impaired microenvironment. This clinical trial was registered at the EU Clinical Trials Register before patient recruitment (Registration number: EudraCT number 2012-005599-33; Date of registration: 2013-02-04).

• Klíčová slova
• bone defect, cell therapy, mesenchymal stromal cells, scaffold,
• MeSH
• dospělí MeSH
• femur cytologie   zranění   fyziologie   chirurgie   MeSH
• fosforečnany vápenaté chemie   terapeutické užití   MeSH
• kostní náhrady chemie   terapeutické užití   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mezenchymální kmenové buňky cytologie   MeSH
• regenerace kostí * MeSH
• senioři MeSH
• tkáňové podpůrné struktury chemie   MeSH
• transplantace mezenchymálních kmenových buněk metody   MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky, fáze II MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• beta-tricalcium phosphate MeSH Prohlížeč
• fosforečnany vápenaté MeSH
• kostní náhrady MeSH

Alloplastic bone graft materials are widely been used in combination with barrier membranes to achieve guided tissue regeneration in the treatment of periodontal intrabony defects. This study was designed to evaluate the clinical outcome of a composite material, beta tricalcium phosphate in combination with calcium sulphate in the treatment of periodontal intrabony defects. The combination of these materials is believed to aid in guided tissue regeneration owing to their properties. Thirty nine intrabony defects in 21 patients were treated with Fortoss Vital (Biocomposites, Staffordshire, UK). Clinical parameters were evaluated including changes in probing depth, clinical attachment level/loss and gingival recession at baseline and one year postoperatively. The mean differences in measurements between the baseline and one year postoperatively are a reduction of 1.98 +/- 1.16 mm (p = 0.000) in case of probing depth and a gain of 1.68 +/- 1.12 mm (p = 0.000) in clinical attachment level and an increase of 0.31 +/- 0.67 mm (p = 0.009) in gingival recession measurements. The study results show that the treatment with a combination of beta tricalcium phosphate and calcium sulphate led to a significantly favorable clinical improvement in periodontal intrabony defects one year postoperatively.

• MeSH
• biokompatibilní materiály aplikace a dávkování   MeSH
• fosforečnany vápenaté aplikace a dávkování   MeSH
• kostní náhrady aplikace a dávkování   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• nemoci parodontu diagnóza   terapie   MeSH
• resorpce alveolární kosti terapie   MeSH
• řízená tkáňová regenerace parodontu * MeSH
• síran vápenatý aplikace a dávkování   MeSH
• zubní materiály * MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• beta-tricalcium phosphate MeSH Prohlížeč
• biokompatibilní materiály MeSH
• fosforečnany vápenaté MeSH
• kostní náhrady MeSH
• síran vápenatý MeSH
• zubní materiály * MeSH

The study was designed to evaluate the clinical outcome of a composite material, beta-tricalcium phosphate in combination with calcium sulphate, in the treatment of periodontal intrabony defects. The combination of these materials is believed to aid in guided tissue regeneration owing to their properties. A total of 47 teeth with intrabony defects in 26 periodontitis patients were treated with Fortoss Vital (Biocomposites, Staffordshire, U.K.). Clinical parameters were evaluated which included changes in probing depth, clinical attachment level/loss and gingival recession at the baseline and 2 years postoperatively. The mean differences in measurements between the baseline and 2 years postoperatively were a reduction of 2.07 +/- 1.14 mm (p = 0.000) in case of probing depth and a gain of 1.93 +/- 1.36 mm (p = 0.000) in clinical attachment level; but an increase of 0.14 +/- 0.73 mm (p = 0.571) in gingival recession. The study results show that the treatment with a combination of beta tricalcium phosphate and calcium sulphate led to a significantly favorable clinical improvement in periodontal intrabony defects 2 years after the surgery.

• MeSH
• biokompatibilní materiály aplikace a dávkování   MeSH
• dospělí MeSH
• fosforečnany vápenaté aplikace a dávkování   MeSH
• kostní náhrady aplikace a dávkování   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• parodontitida komplikace   terapie   MeSH
• resorpce alveolární kosti komplikace   terapie   MeSH
• řízená tkáňová regenerace parodontu MeSH
• síran vápenatý aplikace a dávkování   MeSH
• zubní materiály terapeutické užití   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• beta-tricalcium phosphate MeSH Prohlížeč
• biokompatibilní materiály MeSH
• fosforečnany vápenaté MeSH
• kostní náhrady MeSH
• síran vápenatý MeSH
• zubní materiály MeSH

The purpose of this prospective controlled study was to compare healing quality following the implantation of ultraporous β-tricalcium phosphate, containing either expanded autologous mesenchymal stromal cells (trial group, 9 patients) or β-tricalcium phosphate alone (control group, 9 patients), into femoral defects during revision total hip arthroplasty. Both groups were assessed using the Harris Hip Score, radiography, and DEXA scanning at 6 weeks and 3, 6, and 12 months postoperatively. A significant difference in the bone defect healing was observed between both groups of patients (P < 0.05). In the trial group, trabecular remodeling was found in all nine patients and in the control group, in 1 patient only. Whereas, over the 12-month follow-up period, no significant difference was observed between both groups of patients in terms of the resorption of β-tricalcium phosphate, the significant differences were documented in the presence of radiolucency and bone trabeculation through the defect (P < 0.05). Using autologous mesenchymal stromal cells combined with a β-tricalcium phosphate scaffold is a feasible, safe, and effective approach for management of bone defects with compromised microenvironment. The clinical trial was registered at the EU Clinical Trials Register before patient recruitment has begun (EudraCT number 2012-005599-33).

• MeSH
• autologní transplantace * MeSH
• femur patofyziologie   chirurgie   MeSH
• fosforečnany vápenaté terapeutické užití   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mezenchymální kmenové buňky MeSH
• náhrada kyčelního kloubu * MeSH
• regenerace kostí fyziologie   MeSH
• remodelace kosti účinky léků   fyziologie   MeSH
• senioři MeSH
• tkáňové podpůrné struktury chemie   MeSH
• trabekulární kostní tkáň účinky léků   patofyziologie   chirurgie   MeSH
• transplantace mezenchymálních kmenových buněk metody   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky, fáze II MeSH
• Názvy látek
• beta-tricalcium phosphate MeSH Prohlížeč
• fosforečnany vápenaté MeSH