Biological characteristic of Polish catches of the horse mackerel - Trachurus trachurus capensis Castelnau, 1861 in the region of the South-West African shelf

This paper contains a short estimate of catches with regard to the yield and specific composition shown against the background of occurring depths and water temperatures; it presents results of the analysis of length and age composition as well as those of growth and mortality of the horse mackerel. Further chapters contain the results of food analysis and the gonad′s state of this species

Characterization of the novel calcium phosphate/sulfate based bone cements

Calcium phosphate cements (CPCs) are a family of self-setting, bone repair materials. CPCs possess excellent biocompatibility, surgical handiness and adequate mechanical properties but reveal slow resorption in vivo. Currently, very interesting group of CPCs are biomaterials composed of a-tricalcium phosphate (a-TCP, a-Ca3(PO4)2) and calcium sulfate. Calcium sulfate hemihydrate (CSH, CaSO40.5 H2O) posses a long clinical history in different fields of medicine and is widely recognized as a safe, fast setting and resorbable implant material. The main goal of this study was to investigate how different factors influence the phase composition and physico-chemical properties of the new, cement-type material on the basis of a-TCP, CSH and anhydrous dicalcium phosphate (DCP, CaHPO4). In presented work two different powder phase compositions and three liquid phases were used to produce new bone substitutes. XRD results showed that obtained materials, after setting and hardening, consisted of α-TCP, DCP, DCPD (CaHPO42H2O), HA and bassanite phases. Initial (I) and final (F) setting times of the cement pastes were determined with Gillmore needles and differed in the range of 4-14 min (I) and 10-30 min (F). Increase in the amount of CSH in the powder component resulted in shortening of setting time. Microstructure of cements was evaluated on the fractured samples by scanning electron microscopy (SEM) and the porosity via mercury porosimetry. Open porosity of the final materials was similar for all investigated compositions. Compressive strength depended on the composition and increased steadily over a period of maturation. The results obtained suggest that calcium phosphate/sulfate bone cement has the potential to be applied for bone augmentation

The effect of biomaterials ion reactivity on cell viability in vitro

Powszechnie wiadomo, że reaktywne jonowo biomateriały indukują różne interakcje z otaczającym środowiskiem, powodując zmiany stężenia jonów, zwłaszcza kluczowych jonów takich jak wapń, magnez i fosfor, co może wpływać na metabolizm i żywotność komórek. Głównym składnikiem części mineralnej kości i zębów jest hydroksyapatyt (HAp) (Ca10(PO4)6(OH)2). W celu polepszenia własności mechanicznych oraz poręczności chirurgicznej hydroksyapatytu można połączyć go z dodatkowym komponentem organicznym np. polisacharydowym. W niniejszej pracy oznaczano reaktywność jonową oraz cytotoksyczność 2 typów kompozytów na bazie glukanu (kompozytu glukan-HAp i kompozytu glukan-C-HAp) oraz poszczególnych ich składników: wysokoporowatych granul hydroksyapatytu (HAp), wysokoporowatych granul HAp węglanowo-magnezowych (C-HAp) oraz glukanu. Reaktywność jonową testowanych materiałów oznaczono za pomocą absorpcyjnej spektrometrii atomowej (ASA). Badania in vitro przeprowadzono z zastosowaniem linii komórkowej hFOB 1.19 (ludzkie płodowe osteoblasty) oraz pierwotnej hodowli fibroblastów skóry (HSF). Cytotoksyczność ekstraktów z biomateriałów określono z użyciem 2 testów - MTT i NRU. Wyniki badań wyraźnie wskazały, że dodatek wysokoporowatych granul HAp i C-HAp do glukanu powoduje, że kompozyt jest reaktywny jonowo, co wpływa na metabolizm i żywotność hodowanych komórek.It is widely known that surface-reactive biomaterials induce various interaction with surrounded environment, causing changes in the ion concentration, especially with respect to the crucial ions such as calcium, magnesium and phosphorous, what may significantly affect the cell metabolism and viability. Hydroxyapatite (HAp) (Ca10(PO4)6(OH)2) is the main inorganic component of bones and teeth. In order to improve mechanical properties and surgical handiness of hydroxyapatite, an organic component e.g. polysaccharide can be added. In this work, the ion reactivity and cytotoxicity of 2 types of glucan-based composites (composite glucan-HAp and composite glucan-C-HAp) were evaluated. Additionally, the ion reactivity and cytotoxicity of each component of the composites: highly porous hydro- xyapatite (HAp), highly porous carbonated-Mg-HAp (C-HAp) and glucan were evaluated. The ion reactivity of tested materials was assessed by atomic absorption spectrometry (AAS). In vitro tests were carried out using hFOB 1.19 cell line (human fetal osteoblast cells) and human skin fibroblast primary cell culture (HSF). The cytotoxicity of biomaterials extracts was estimated by 2 methods - MTT and NRU. Our studies clearly indicated that addition of highly porous HAp and C-HAp granules to the glucan, make the composite ion reactive, what affects the metabolism and viability of cultured cells

Physicochemical properties of the novel biphasic hydroxyapatite–magnesium phosphate biomaterial

Besides high-temperature calcium phosphates (CaPs), low-temperature calcium phosphate bone cements (CPCs), due to excellent biological properties: bioactivity, biocompability and osteoconductivity, are successfully used as bone substitutes. However, some disadvantages, related mainly to their low resorption rate and poor mechanical properties result in limited range of applications of these implant materials to non-loaded places in the skeletal system. To overcome this problem, magnesium phosphate cements (MPCs) with high strength have been considered as biomaterials. The main disadvantage of MPCs is that the acid-base setting reaction is an exothermic process that must be strictly controlled to avoid tissue necrosis. In this work, a new composite bone substitute (Hydroxyapatite Magnesium Phosphate Material – HMPM) based on hydroxyapatite (HA) and magnesium phosphate cement (MPC) with sodium pyrophosphate applied as a retardant of setting reaction was obtained. Its setting time was adequate for clinical applications. Combining properties of HA and MPC has made it possible to obtain microporous (showing bimodal pore size distribution in the range of 0.005–1.700 micrometers) potential implant material showing good surgical handiness and sufficient mechanical strength. Effectiveness of sodium pyrophosphate as a retardant of exothermic setting reaction of the new cement formulation was confirmed. After setting and hardening, the material consisted of hydroxyapatite and struvite as crystalline phases. Unreacted magnesium oxide was not detected

Evaluation of bioactivity of biphasic implant materials based on the calcium phosphates and calcium sulfate hemihydrate

Fosforany wapnia (Calcium Phosphates - CaPs), stosowane z powodzeniem w regeneracji i rekonstrukcji tkanki kostnej, należą do grupy bioaktywnych materiałów zdolnych do bezpośredniego wiązania z kością. Interesującymi materiałami implantacyjnymi w postaci łatwo formujących się past cementowych są materiały dwufazowe na bazie HA (hydroksyapatytu) i α-TCP (α-fosforanu trójwapniowego) oraz HA i CSH (półwodnego siarczanu (VI) wapnia). Wprowadzenie do struktury hydroksyapatytu różnych jonów np. srebra lub magnezu wpływa na zmianę jego właściwości fizykochemicznych jak również biologicznych. Połączenie hydroksyapatytu i półwodnego siarczanu (VI) wapnia (ten drugi stosowany jest w medycynie od wielu lat pod nazwą Plaster of Paris) prowadzi do wytworzenia materiałów o wysokiej poręczności chirurgicznej i kontrolowanej biodegradacji. Celem pracy było wytworzenie oraz ocena potencjału bioaktywnego in vitro nowych materiałów kościozastępczych typu cementowego na bazie CaPs i CSH. W skład wyjściowych proszków cementowych wchodziły: zsyntezowany na wydziale Inżynierii Materiałowej i Ceramiki - AGH hydroksyapatyt dotowany srebrem (AgHA), węglanowy hydroksyapatyt dotowany magnezem (MgCHA), α-TCP oraz CSH (Acros Or- ganics). Jako płyny do zarabiania proszków cementowych zastosowano 1% roztwór chitozanu w 0,3% kwasie octowym oraz 0,75% roztwór metylocelulozy w 2% Na2HPO4. Opracowane materiały implantacyjne poddano badaniom czasu wiązania, składu fazowego oraz wytrzymałości mechanicznej. Wytworzone preparaty kościozastępcze przetrzymywano w symulowanym płynie fizjologicznym (SBF) przez okres 14 dni. Oznaczono zmiany stężenia pierwiastków: Ag, Ca, K, Mg, Na, S, P w płynie SBF w czasie trwania inkubacji wykorzystując technikę emisyjnej spektrometrii optycznej z indukcyjnie sprzężoną plazmą (IC- P-OES). Przeprowadzono przy pomocy skaningowego mikroskopu elektronowego obserwacje morfologii powierzchni uzyskanych materiałów po 7 i 14 dniach przetrzymywania ich w symulowanym płynie fizjologicznym. Badania SEM potwierdziły narastanie warstwy apatytowej na powierzchniach badanych preparatów, co wskazuje na ich charakter bioaktywny. Materiały implantacyjne, w których zastosowano półwodny siarczan (VI) wapnia, w związku z ich dużą podatnością do dezintegracji i biodegradacji, wykazywały odmienną morfologię powierzchni w porównaniu do preparatów, w których składnikiem wiążącym był α-TCP Wzrost zawartości: Ca i S w płynie SBF podczas trwania inkubacji badanych cementów z udziałem CSH po twierdziło ich stopniową degradację in vitro.Calcium Phosphates (CaPs), used successfully in the regeneration and reconstruction of bone tissue, belong to the group of bioactive materials, capable to form a direct bond with natural bone. Biphasic materials (bone substitutes) based on HA (hydroxyapatite) and α-TCP (α-tricalcium phosphate) as well as HA and CSH (calcium sulfate hemihydrate) in the form of easily shapeable cement pastes are very interesting implant materials. Introduction of different ions such as silver or magnesium into the structure of hydroxyapatite changes its physicochemical and biological properties. The combination of hydroxyapatite and calcium sulfate hemihydrate (the last one has been used in medicine for many years under the name of Plaster of Paris) leads to the fabrication of materials with high surgical handiness and controlled biodegradation. The aim of this study was development and evaluation of the bioactive potential in vitro of the new cement type bone substitutes based on CaPs and CSH. Initial cement powders consisted of synthesized at the Faculty of Materials Science and Ceramics - AGH-UST silver doped hydroxyapatite (AgHA), magnesium doped carbonated hydroxyapatite (MgCHA), α-TCP and CSH (Acros Organics). 1 wt.% chitosan solution in 0.3 wt.% acetic acid as well as 0.75 wt. % methylcellulose solution in 2 wt.% Na2HPO4 were applied as liquid phases. Setting time, phase composition and mechanical strength of developed implant materials were examined. Obtained bone substitutes were incubated in simulated body fluid (SBF) for 14 days. Changes in the concentration of the following elements: Ag, Ca, K, Mg, Na, S, P in SBF were determined by simultaneous inductively coupled plasma optical emission spectrometry (ICP-OES). Observations of the surface morphology of obtained materials after 7 and 14 days of incubation in simulated body fluid were carried out using scanning electron microscopy. SEM studies confirmed the growth of an apatite layer on the surfaces of tested materials, what indicates on their bioactivity. Implant materials based on calcium sulfate hemihydrate, due to their high susceptibility to disintegration and biodegradation, showed a different surface morphology compared to the materials based on a-TCP as a binding agent. The increase in the content of Ca and S elements in SBF during the incubation of studied bone cements with CSH confirmed their gradual degradation in vitro

Biodegradable cement type bone implant materials based on calcium phosphates and calcium sulphate

Calcium phosphates (CaPs) are widely used in hard tissue replacement because of their excellent biocompatibility. Calcium phosphate cements (CPCs) are an interesting alternative for sintered calcium phosphate ceramics due to their mouldability and self-setting properties which allow them to conform to even the most complex bone defects. However, one of the major limitations of CPCs is their relatively low resorption rate, not optimal for bone regeneration. The aim of our studies was to combine a stable hydroxyapatite with more soluble α-tricalcium phosphate (α-TCP) or calcium sulphate (CS) (resorbability: CS>>α-TCP>HA) to develop biomaterial with gradual degradation. Promising materials for use in minimally invasive surgery for bone defects repair were obtained. It was found that the degradation rate of hydroxyapatite based bone substitutes can be controlled by the addition of an appropriate kind and amount of more soluble constituent. The impact of the setting component (α-TCP or CS) on the physicochemical properties of the final products was confirmed. Furthermore the influence of organic additives (chitosan, methylcellulose, alginate) on the final materials characteristic was proven. Solutions of organic additives, applied as the liquid phases, significantly improved the workability of cement pastes. It has been demonstrated that implant materials based on calcium sulphate and α-TCP differed in their setting times, mechanical strength, dissolution rate and morphologies of apatite layers on their surfaces after soaking in simulated body fluid. The reason of observed differences is a higher susceptibility of calcium sulphate to both disintegration and degradation

Apatite formation on flexible bone substitute

Podstawowe cechy materiałów kościozastępczych takie jak bioaktywność i biokompatybilność, mogą być badane in vitro przy wykorzystaniu roztworu imitującego płyn tkankowy tzw. płyn SBF. Dwufazowy kompozyt, przeznaczony do wypełniania ubytków kostnych, został wykonany z granul hydroksyapatytu węglanowego i polimeru polisacharydowego. Biomateriał testowano pod kątem zdolności tworzenia warstwy apatytu w roztworze SBF przez okres 30 dni. Po tym czasie powierzchnię próbek i płyn po inkubacji, poddano analizie z wykorzystaniem SEM-EDX. Wykazano tworzenie warstwy apatytowej na powierzchni kompozytu kościozastępczego.Biocompatibility and bioactivity, elementary characteristics of bone substitute materials, can be examined in vitro using solution that simulates body fluids. Two-phase composite, intended for filling bone defects, was made of carbonated hydroxyapatite granules and polysaccharide polymer. Biomaterial was tested whether it can form apatite layer during soaking in SBF solution for 30 days. After that time, the surface of composite samples and the fluid were analyzed using SEM-EDX. Our observations indicate the ability of a bone substitute biomaterial to form apatite layer on its surface