V průběhu projektu byly vyvinuty unikátní kolagenní pěny z kolagenu získaného z kůže sladkovodní ryby (kapr obecný, Cyprinus carpio). Pomocí síťování karbodiimidem byl překonán problém s nestabilitou kolagenní matrix z kolagenu získávaného z chladnokrevných živočichů při tělesné teplotě savců. Následně byly pěny impregnovány antibiotiky (gentamicin a vankomycin) a opětovně lyofilizovány, což je postup, který zajišťuje požadovanou koncentraci antibiotika bez rizika následného vymytí při dalších technologických krocích. Uvedený produkt je, na rozdíl od přípravků z nesíťovanéhokolagenu, stabilní i při sterilizaci gamma zářením. Finální sterilizovaný produkt byl testován in vivo na potkaním modelu infikované rány. Byla prokázána efektivita v léčbě potenciálně letální infekce Pseudomonas aeruginosa a kmene Stafylococcus aureus rezistentní k meticilinu (MRSA). Vzhledem k vysoké potřebě profylaxe a terapie infekcí pooperačních a jiných ran právě výše uvedenými polyrezistentními původci se jedná o slibný prostředek k budoucímu klinickému využití. Zkušenosti, které jsme získali v průběhu uvolnování ATB z kolagenních pěn budou v dalším vyvoji použity pro impregnaci zevní kolagenní vrstvy cévní protézy, čímž bychom mohli eliminovat jednu z největších nevýhod a rizik spojených s použitím umělých materiálu a tím je...

Content: Fish collagen has been considered to be an alternative for mammalian collagen, however, physicochemical properties of fish collagen-based materials such as gels are so far not adequate for actual application. In the present study, we prepared two types of fish collagen gels with sufficient elasticity: i) dehydrated fibrillogenesis collagen gels (DFCG), which were fabricated via collagen self-assembly followed by immersion in different concentrations of ethanol solutions, and ii) dehydrated cross-linking collagen gels (DCCG), which were fabricated via collagen self-assembly and simultaneous cross-linking followed by immersion in ethanol solution. Furthermore, the physicochemical properties of DFCG and DCCG were analyzed by atomic force microscopy, differential scanning calorimetry, enzymatic degradation and dynamic viscoelastic measurements. The microstructure of DFCG was consisted of characteristic Dperiodic collagen fibrils and insusceptible of ethanol concentrations (20-100% (v/v)). However, the thermal stability, remaining weight after enzymatic degradation and mechanical properties of DFCG distinctly increased with the increase of ethanol dose, possiblely ascribing that ethanol with higher polarity might dehydrate partial free water of DFCG and strengthen the interactions of hydrogen bond. Especially, for the gel treated by 100% (v/v) enthanol, Td increased by 32.7 °C and G′ was 55-folds than those of undehydrated gel (43.1 °C and 239.2 Pa). In the case of DCCG, the formation of collagen fibrils was depended on the concentrations of N-hydroxysuccinimide adipic acid derivative (NHS-AA), which was converted to [NHS-AA]/[NH2] ratios (calculated by the [active ester group] of NHS-AA and [ε-NH2] of lysine and hydroxylysine residues of collagen). As the ratio= 0.05, the characteristic D-periodic fibrils were still formed and the treatment of 60% (v/v) ethanol increased the Td (52.5 °C) and G′ (7388 Pa) values of the gel compared with those of uncross-linked gel (49 °C and 2064.32 Pa, respectively), majorly resulting from the effects of covalent cross-linking bonds and hydrogen bonds. However, when the ratio= 0.2, the collagen self-assembly was intensively inhibited and the dehydration of free water within gel structure in the absence of thick fibrils led to the shrinkage of the gel and an obvious decrease in Td (42 °C) and G′ (432 Pa). Although the [NHS-AA]/[NH2] ratio further increased to 0.8, the thermal stability and elasticity of the gel enhanced mildly suggesting that the presence of thick fibrils formed via the self-assembly was significantly crucial for reinforcing the gels. Take-Away: The fish collagen gels with excellent elasticity were prepared via the treatment of ethanol. The physicochemical properties of the dehydrated gels were depended on the concentrations of ethanol. The presence of characteristic D-periodic fibrils was significantly crucial for reinforcing the gels.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-07-22T13:02:35Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Flávia Thuane Duarte do Monte (PDF).pdf: 1029138 bytes, checksum: ded4d1bd5809aa8f26493c20c0169546 (MD5) / Made available in DSpace on 2016-07-22T13:02:35Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Flávia Thuane Duarte do Monte (PDF).pdf: 1029138 bytes, checksum: ded4d1bd5809aa8f26493c20c0169546 (MD5) Previous issue date: 2016-02-22 / FACEPE / O colágeno é a proteína fibrosa de origem animal mais abundante, que representa 30% de proteína total e 6% em peso no corpo humano. A pele e os ossos de bovinos e suínos geralmente são as principais fontes de colágeno e gelatina. No entanto, devido ao risco de transferência de zoonoses, existe uma necessidade de obtenção desta proteína por meio de outras fontes. A pescada amarela (Cynoscion acoupa) é um importante representante da pesca nacional e possui grande valor comercial. O objetivo deste estudo foi utilizar resíduos do processamento de pescada amarela para obter colágeno e sugerir sua utilização como fonte alternativa para o colágeno mamífero. Colágeno pepsino solúvel (PSC) foi isolado a partir de escamas de pescada amarela e caracterizado com sucesso. O rendimento da extração de PSC foi de 8,3% (baseado no peso seco). A SDS-PAGE (7,5%) mostrou que o padrão de bandas do PSC consistiu de uma cadeia α1 e α2 na proporção de 2:1, bem como cadeias β e γ, sendo caracterizado como colágeno do tipo I. O espectro de absorção ultravioleta (UV) mostrou uma máxima absorção em 222 nm. PSC foi solúvel na faixa de pH de 1 à 4, com a máxima solubilidade em pH 1. O colágeno também demonstrou maior solubilidade na faixa de concentração de 0 à 2% (w/v) de NaCl. A temperatura máxima de transição (Tmax) para PSC foi de 30,4°C, tal como determinado por calorimetria exploratória diferencial (DSC). Os resultados obtidos neste estudo indicam a possibilidade do uso de escamas de pescada amarela como uma fonte de colágeno do tipo I, com grande potencial para aplicações biotecnológicas. / Collagen is the most abundant fibrous protein of animal origin, representing 30% of the total protein and 6% in weight of the human body. The skin and bones of bovines and pigs usually are the main sources of collagen. However, due to the risk of transfer of diseases, there is a need for obtaining this protein form other sources. The acoupa weakfish (Cynoscion acoupa) is an important representative of the national fishing and has great commercial value. The aim of this study was to use acoupa weakfish waste processing for obtain collagen and suggest its use as an alternative source mammal collagen. Pepsin soluble collagen (PSC) from scales of acoupa weakfish was isolated and characterized. The yield of PSC was 8.3% (based on dry weight). SDS-PAGE (7.5%) pattern showed that both PSC consisted of one α1 and one α2 chains in proportion 2:1, as well as β and  chains, and were characterized to be type I collagen. The PSC ultraviolet (UV) absorption spectrum showed a maximum absorption at 222 nm. The PSC was soluble at pH between 1 and 4, with maximum solubility at pH 1. He have also shown solubility majority at NaCl concentration from 0 to 2% (w/v). The maximum transition temperature (Tmax) for PSC was 30.4°C, as determined by differential scanning calorimetry (DSC). The results obtained in this study indicate the possibility of using acoupa weakfish scales as a source of type I collagen with great potential for biotechnological application.