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Calcium phosphate bone cements: Synthesis, Characterization and drug release properties
Doubek, Jiří ; Paraskevopoulos, Georgios (advisor) ; Kováčik, Andrej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Author: Jiří Doubek Supervisor: Dr. Georgios Paraskevopoulos, Ph.D. Title of Thesis: Calcium phosphate bone cements: Synthesis, characterization and drug release properties Non-healing bone traumas are currently a complication, which may disable a patient from active life for a long period. Due to the fact that bone mass consists mostly of hydroxyapatite, a derivative of calcium phosphate - calcium phosphate cement (CPC) - is studied as an injectable bone substitute. The cement's characteristics (low setting temperature, injectability, bioactivity, and resorbability) are very promising. Furthermore, the possibility to incorporate a drug in the formulation that would support the healing process opens a way for new therapeutic options. Firstly, the aim of this research was to synthesize a high-quality α-tricalcium phosphate (α-TCP) and characterize its properties. Subsequently, the prepared α-TCP was used for the preparation of an injectable and washout resistant cement paste. Finally, the properties of developed pure or ibuprofen-loaded cement were examined by X-ray diffraction, Raman spectra, compressive strength, scanning electron microscopy, and dissolution studies. The obtained data revealed that...
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Calcium phosphate bone cements: Synthesis, Characterization and drug release properties
Doubek, Jiří ; Paraskevopoulos, Georgios (advisor) ; Kováčik, Andrej (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Author: Jiří Doubek Supervisor: Dr. Georgios Paraskevopoulos, Ph.D. Title of Thesis: Calcium phosphate bone cements: Synthesis, characterization and drug release properties Non-healing bone traumas are currently a complication, which may disable a patient from active life for a long period. Due to the fact that bone mass consists mostly of hydroxyapatite, a derivative of calcium phosphate - calcium phosphate cement (CPC) - is studied as an injectable bone substitute. The cement's characteristics (low setting temperature, injectability, bioactivity, and resorbability) are very promising. Furthermore, the possibility to incorporate a drug in the formulation that would support the healing process opens a way for new therapeutic options. Firstly, the aim of this research was to synthesize a high-quality α-tricalcium phosphate (α-TCP) and characterize its properties. Subsequently, the prepared α-TCP was used for the preparation of an injectable and washout resistant cement paste. Finally, the properties of developed pure or ibuprofen-loaded cement were examined by X-ray diffraction, Raman spectra, compressive strength, scanning electron microscopy, and dissolution studies. The obtained data revealed that...
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UNICELLULAR ALGA CHLORELLA AS A FEED SUPPLEMENT, CURRENT EXPERIENCE AND FUTURE PERSPECTIVES
Kotrbáček, V. ; Doucha, Jiří ; Kuchařová, V. ; Doubek, J.
n experiments with farm animals we studied the effect of Chlorella biomass as a feed supplement. In laying hens we found that diet supplemented with 1 % (i.e. 10 g/kg) of dry disintegrated heterotrophically grown Chlorella biomass significantly increased content of carotenoids in egg yolks of 8 experimental animals already after the first week of supplementation (P<0,01). Compared to 8 control hens these differences remained significantly higher until the end of the eight-week experiment. The average carotenoid concentration was 17,3 mu g per g of yolk in control group and 25,3 mu g per g of yolk in experimental animals (P<0,01). Autotrophically grown Chlorella was supplemented to the 30 gilts one month prior the expected first heat in a dose of 1,5 g per animal per day. These sows entered heat earlier and the number of pregnancy was higher in comparison to the 30 control animals. Other studies observed digestibility of selenium organically bound in Se-enriched Chlorella. The level of selenium in blood, colostrum and also tissues of new born piglets was determined. Group of 8 sows was supplemented with Se-enriched alga during the pregnancy and 3 days after parturition at a dose of 0,3 mg of selenium per 1 kg of feed. The same amount of selenium in the form of sodium selenite was administrated to the control group of 8 individuals. Organic form of selenium significantly increased concentration of Se in blood of sows and colostrum (P<0,05). Piglets born to supplemented sows had also significantly higher level of Se in heart, muscles and liver (P<0.01). The use of fresh Chlorella biomass produced outdoors on a dairy farm was experimentally tested. Location near biogas station enables utilization of flue gas as a source of carbon for algal photosynthesis. The liquid fresh biomass applied to dairy cows during the pregnancy at a dose of 15 g dry mass per cow increased the dry matter content in colostrum from 17,5 g per 100 ml of colostrum in control group to 20,5 g per 100 ml of colostrum in supplemented cows (P<0,05). This pilot experiment demonstrated possibilities of cheaper Chlorella production and its use in ruminant nutrition.
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UNICELLULAR ALGA CHLORELLA AS A FEED SUPPLEMENT, CURRENT EXPERIENCE AND FUTURE PERSPECTIVES
Kotrbáček, V. ; Doucha, Jiří ; Kuchařová, V. ; Doubek, J.
We studied the effect of Chlorella biomass as a feed supplement. In laying hens we found that diet supplemented with 1 % (i.e. 10 g/kg) of dry disintegrated heterotrophically grown Chlorella biomass significantly increased content of carotenoids in egg yolks of 8 experimental animals already after the first week of supplementation (P<0,01). Compared to 8 control hens these differences remained significantly higher until the end of the eight-week experiment. The average carotenoid concentration was 17,3 mu g per g of yolk in control group and 25,3 mu g per g of yolk in experimental animals (P<0,01). Autotrophically grown Chlorella was supplemented to the 30 gilts one month prior the expected first heat in a dose of 1,5 g per animal per day. These sows entered heat earlier and the number of pregnancy was higher in comparison to the 30 control animals. Other studies observed digestibility of selenium organically bound in Se-enriched Chlorella. The level of selenium in blood, colostrum and also tissues of new born piglets was determined. Group of 8 sows was supplemented with Se-enriched alga during the pregnancy and 3 days after parturition at a dose of 0,3 mg of selenium per 1 kg of feed. The same amount of selenium in the form of sodium selenite was administrated to the control group of 8 individuals. Organic form of selenium significantly increased concentration of Se in blood of sows and colostrum (P<0,05). Piglets born to supplemented sows had also significantly higher level of Se in heart, muscles and liver (P<0.01). The use of fresh Chlorella biomass produced outdoors on a dairy farm was experimentally tested. The liquid fresh biomass applied to dairy cows during the pregnancy at a dose of 15 g dry mass per cow increased the dry matter content in colostrum from 17,5 g per 100 ml of colostrum in control group to 20,5 g per 100 ml of colostrum in supplemented cows (P<0,05).
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