Wyniki wyszukiwania - BazTech

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Fabrication, properties and cytotoxicity evaluation of degradable poly(trimethylene carbonate-co-lactide) for the use as nerve guidance channels

Bednarz P.

Tarnowskie Colloquia Naukowe. Nauki Techniczne i Ścisłe

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2017

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T. 4, nr 3

39--48

EN

Strategies to improve healing of damaged nerves include the application of specialized nerve guides, which hold the promise for allowing reanastomosis of the severed or damaged fibers. Studies have demonstrated that the use of a slowly degradable polymeric nerve guide can improve the nature and rate of nerve regeneration across a short gap in small nerves. The objective of this study was to characterize a biodegradable nerve guide based on poly(trimethylene carbonate-co-lactide) for peripheral nerve regeneration and to evaluate its cytotoxicity. The obtained copolymer films were incubated in two different media (distilled water and simulated body fluid), and while the degradation process appeared, pH and ion conductivity changes of solutions were monitored as well as mass loss of the samples. Additionally, mechanical tests (tensile strength, elongation at break and Young’s modulus parameters) before and after different time points were carried out. To evaluate cytotoxicity biological test were done on fibroblasts cells (NIH 3T3). Cell metabolic activity was determined using Alamar Blue reagent and their morphology was observed under fluorescence microscopy. The growth of pH in both media were mostly caused by steadily degradation of carbonate units into alkaline diols. The growth of ion conductivity value at the beginning of the incubation process was associated with the releasing of free ions to the solution. The mechanical parameters decreased with the progress of degradation process. Ringer’s fluid, as more aggressive, caused higher decrease in mechanical properties. The measured contact angles showed good surface wettability. Both surfaces, the top and the bottom, had similar hydrophilicity. Moreover, activity of fibroblasts cells were similar on both sides as well as on the reference TCPS. Good adhesion of NIH 3T3 cells to the surface suggests that the hydrophilic polymers promote colonization of fibroblasts cells on their surface. Biological studies have shown that used cells are very sensitive to surface topography which they colonize and cell viability was higher at the bottom surface, which has a slightly higher average roughness Ra. Thus, fibroblasts cell preferred colonizing rougher than smoother surfaces. Fabricated films does not affect negatively, namely, toxic on cell cultures and forms substrate with favourable surface properties. This was confirmed by the Alamar Blue tests and microscopic observations.

2

Zmiany wybranych własności mieszanin LD PE z recyklatami degradowanymi po ich kompostowaniu

Wróbel G., Chmielnicki B., Bortel K.

Przetwórstwo Tworzyw

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2015

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T. 21, Nr 1 (163)

65--75

PL

W niniejszym artykule przedstawiono charakterystykę tworzyw degradowalnych ze szczególnym uwzględnieniem materiałów biodegradowalnych. Wskazano na obserwowany obecnie dynamiczny rozwój tej grupy tworzyw jako będący odpowiedzią na wzrastającą ilość generowanych odpadów i związaną z nią konieczność ich utylizacji czy też zagospodarowania. Opisano jedną z metod zapobieżenia bezpowrotnej utracie energii włożonej w syntezę, a także przetwórstwo tworzyw degradowalnych, jaką jest ich ponowne wykorzystanie jako modyfikatorów tworzyw stabilnych np. poliolefin. Wybrane właściwości takich mieszanek po ich kompostowaniu zaprezentowano w niniejszym artykule. Kompostowanie prowadzono przez 3 i 18 miesięcy w warunkach poligonowych, a uzyskane wyniki świadczą o przydatności recyklatów okso- i biodegradowalnych jako modyfikatorów LD PE.

EN

This article presents the characteristics of degradable plastics with particular emphasis on biodegradable materials. The currently observed rapid development of this group of materials as a response to the increasing amount of waste generated and the associated need for their disposal or management has been indicated. One method to prevent the irrecoverable loss of energy input into the synthesis and processing of degradable plastics as their re-use as modifiers of stable plastics such as polyolefin's has been described. Selected properties of such mixtures, after their composting, are presented in this article. Composting was carried out for 3 and 18 months in polygon conditions, and the results support the suitability of oxo- and biodegradable recyclates as LD PE modifiers.

3

Poli(oksyetyleno-b-tereftalan trimetylenu) : synteza, struktura, degradacja

Rokicka J., Kotowski D., Ukielski R.

Przetwórstwo Tworzyw

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2012

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[R.] 18, nr 6

632-636

PL

Otrzymano poli(estro-b-etery) składające się z poli(tereftalanu trimetylenu) (PTT) jako bloku sztywnego oraz poli(oksyetyleno)diolu (PEG) jako bloku giętkiego. Metodami 1H NMR oraz FTIR potwierdzono zakładaną strukturę kopolimerów. Metodami DSC i DMTA zdefiniowano właściwości termiczne i rozdział fazowy otrzymanych układów. Materiały poddano testom podatności na degradację hydrolityczną w roztworach o pH=4,9; 7; 8,5 oraz na degradację w glebie. Degradację polimerów po 8 tygodniach oceniono mierząc zmianę lepkości istotnej.

EN

New poly(ester-b-ether) multiblock elastomers containing poly(trimethylene terephthalate) hard segments and polyoxyethylene soft segment were prepared and studied by 1H NMR and FTIR methods to confirme their assumed chemical structures and by DSC and DMTA methods to define the phase separation and thermal properties. Materials were subjected to hydrolytic degradation in solutions of pH: 4,9; 7; 8,5; and degradation in soil. The degradation after a period of 8 weeks was measured by the change of intrinsic viscosity of the polymers.