Wyniki wyszukiwania - BazTech

1

Whey protein isolate-aragonite composites for bone tissue engineering

Gupta D., Kocot M., Serafim A., Jaegermann Z., Talari A., Riedel S., Tryba A. M., Stancu I. C., Pietryga K., Reilly G., Pamuła E., Douglas T. E. L.

Engineering of Biomaterials

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2018

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Vol. 21, no. 148

97

2

Osteoblast behaviour on novel whey protein isolate hydrogels

Stählke S., Mazur K., Krężel A., Żydek J., Pietryga K., Pamuła E., Keppler J. K., Nebe J. B., Douglas T. E. L.

Engineering of Biomaterials

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2018

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Vol. 21, no. 148

105

3

Carbon nanotube-reinforced hydrogels for bone tissue regeneration

Ward D., Kudlačková R., Benko A., Vanhoorne V., Vervaet C., Hanson J., D’sa R., Tryba A., Pietryga K., Pamuła E., Fullwood N. J., Douglas T. E. L.

Engineering of Biomaterials

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2018

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Vol. 21, no. 148

61

4

The effect of titanium dioxide addition on physical and biological properties of Na2O-B2O3-P2O5 and CaO-Na2O-P2O5 glasses

Kalwasińska O., Gajc M., Kłos A., Orliński K., Pawlak D. A., Krok-Borkowicz M., Rumian Ł., Pietryga K., Reczyńska K., Pamuła E.

Engineering of Biomaterials

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2016

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Vol. 19, no. 134

2--7

EN

Two types of phosphate glasses 50Na2O-20B2O3-30P2O5 (NBP) and 30CaO-20Na2O-50P2O5 (CNP) with different content of TiO2 (0, 3 and 5 mol%) have been prepared by melt-quenching process. TiO2 was added to increase glass network stability. Physical properties of glasses were investigated by density measurements, differential scanning calorimetry and degradation in phosphate buffered saline (PBS). Biological performance of glasses in a direct contact with osteoblast-like MG-63 cells was analysed with the use of resazurin test and live-dead staining. The results show that TiO2 addition increased density, glass transition temperature (Tg) and melting temperature (Tm) of both types of glasses. In the case of NBP glasses presence of TiO2 resulted in their fast degradation in PBS and acidification of cell culture medium. As a consequence such glasses did not support cell adhesion and growth, but they can be considered for e.g. drug delivery systems. On the other hand addition of TiO2 to CNP glasses resulted in enhanced cell adhesion and viability. Particularly positive results were found for CNP glass containing 5% TiO2, so it can be a good candidate as a scaffold material for bone tissue engineering.

5

Novel injectable, self-gelling hydrogel-microparticle composites for bone regeneration consisting of gellan gum and calcium and magnesium carbonate microparticles

Douglas T. E. L., Łapa A., Reczyńska K., Krok-Borkowicz M., Pietryga K., Samal S. K., Schaubroeck D., Boone M., Voort P. van der, Schamphelaere K. de, Stevens C. V., Bliznuk V., Parakhonskiy B. V., Cnudde V., Pamuła E., Skirtach A. G.

Engineering of Biomaterials

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2016

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Vol. 19, no. 138 spec. iss.

111

6

Enrichment of thermosensitive chitosan hydrogels with glycerol and alkaline phosphatase for bone tissue engineering applications

Douglas T. E. L., Krok-Borkowicz M., Macuda A., Pietryga K., Pamuła E.

Acta of Bioengineering and Biomechanics

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2016

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Vol. 18, no. 2

51--57

EN

Thermosensitive injectable chitosan hydrogels can be formed by neutralization of acidic chitosan solutions with sodium betaglycerophosphate (Na-β-GP) coupled with increasing temperature to body temperature. Such hydrogels have been considered for applications in bone regeneration. In this study, chitosan hydrogels were enriched with glycerol and the enzyme alkaline phosphatase (ALP) with a view to improving their suitability as materials for bone tissue engineering. Mineral formation was confirmed by infrared spectroscopy (FTIR) and increases in the mass fraction of the hydrogel not consisting of water. Incorporation of ALP in hydrogels followed by incubation in a solution containing calcium ions and glycerophosphate, a substrate for ALP, led to formation of calcium phosphate within the hydrogel. MG-63 osteoblast-like cells were cultivated in eluates from hydrogels containing ALP and without ALP at different dilutions and directly on the hydrogel samples. Hydrogels containing ALP exhibited superior cytocompatibility to ALP-free hydrogels. These results pave the way for the use of glycerol- and ALP-enriched hydrogels in bone regeneration.

7

The influence of mineralization conditions on the effectiveness of enzymatic mineralization of hydrogels

Pietryga K., Reczyńska K., Pamuła E.

Engineering of Biomaterials

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2015

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Vol. 18, no. 131

2--7

EN

Polysaccharide hydrogels are widely used in food industry and medicine. Gellan gum (GG) recently gained a lot of attention as a promising material for tissue regeneration proposes due to its excellent biocompatibility and similarity to natural extracellular matrix. However, in unmineralized form it is not suitable for bone tissue engineering because of weak mechanical properties. Enzymatic mineralization (e.g. using alkaline phosphatase – ALP) is one of the methods of calcifying of hydrogels and it resembles natural processes occurring during bone healing. The aim of this research was to investigate mineralization of hydrogels and to improve properties of gellan gum scaffolds by adjusting processing conditions. Since ALP does not form with GG covalent bonds, during incubation in mineralization medium (solution of calcium glycerophosphate - CaGP) it is diffusing from the samples. Therefore, mineralization effectiveness depends on the interplay between incoming CaGP and outgoing ALP molecules. We hypothesize that better CaGP availability, especially in the first hours of incubation, can result in more effective and homogenous precipitation of calcium phosphates (CaP) in GG samples. To this end, samples with different GG and ALP concentration were subjected to two different mineralization regimes (more and less frequent CaGP exchanges). We proved that better CaGP availability (more frequent CaGP exchange) resulted in better mechanical properties (Young’s modulus) and more effective mineral formation (higher dry mass percentage) of the samples compared to the same samples mineralized with lower accessibility of CaGP. This may be related to the fact, that in presence of fresh organic substrates, more CaP are formed in the outer parts of the samples at the beginning of the process, that limit ALP diffusion and allow more uniform mineralization.

8

Wspomaganie wzrostu komórek kostnych na hydrożelach z gumy gellan za pomocą mineralizacji enzymatycznej

Pietryga K., Costa J, Pereira P., Douglas T. E. L., Pamuła E.

Engineering of Biomaterials

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2014

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Vol. 17, no. 125

6--12

PL

Enzymatyczna mineralizacja hydrożeli jest obiecującym sposobem uzyskiwania materiałów do leczenia ubytków tkanki kostnej. Dzięki wytworzeniu wewnątrz materiału fosforanów wapnia (CaP), hydrożele stają się sztywniejsze, przez co bardziej odpowiednie do regeneracji tkanki kostnej. W przedstawionych badanych hydrożele z gumy gellan (GG) zawierające enzym – fosfatazę alkaliczną (ALP, 0,5 mg/ml) były mineralizowane poprzez inkubację w roztworze glicerofosforanu wapnia (CaGP). Porównano trzy różne stężenia GG: 0,7; 1,2 i 1,6%. W celu oceny zawartości CaP oznaczono suchą masę mineralizowanych próbek. Rozmieszczenie fazy mineralnej obserwowano w mikroskopie świetlnym na przekrojach. Przeprowadzono również testy mechaniczne w próbie ściskania. W badaniach komórkowych komórki osteoblastopodobne MG-63 hodowano na powierzchni materiałów jak i na przekrojach w okresie 1 oraz 7 dni. Żywotność komórek oznaczono przy pomocy barwienia live/dead. Badania mechaniczne wykazały znacznie wyższy moduł Younga w przypadku materiałów zmineralizowanych w porównaniu z czystymi hydrożelami jednak wzrost ten nie był tak wyraźny dla hydrożeli o wyższym stężeniu GG. Z powodu wypłukiwania ALP, rozmieszczenie fazy mineralnej w obrębie próbek nie było jednorodne: większość CaP tworzyła się wewnątrz materiału. Obecność fazy mineralnej sprzyjała adhezji komórek MG-63 do materiału, ich rozpłaszczeniu jak również przeżywalności.

EN

Enzymatic mineralization of hydrogels is a promising approach to obtain new materials for the treatment of bone tissue defects. Thanks to creation of calcium phosphates (CaP) inside the material, the hydrogel becomes more rigid and therefore more suitable for bone tissue replacement. In this study, gellan gum (GG) hydrogels containing the enzyme alkaline phosphatase (ALP, 0.5 mg/ml) were mineralized by incubation in mineralization solutions of calcium glycerophosphate (CaGP). Three different concentrations of GG were compared: 0.7, 1.2 and 1.6% (w/v). In order to assess amount of CaP formed, dry mass percentage was calculated while distribution of mineral phase was observed by light microscopy. Mechanical tests in compression mode were also carried out. Osteoblast-like MG-63 cells were cultured for 1 and 7 days on the surface and cross-sections of mineralized and non-mineralized samples. Viability of cells was measured by live/dead staining. Mechanical testing revealed that Young’s modulus of mineralized hydrogels was much higher than unmineralized hydrogels. However, this increase was not particularly pronounced for samples of higher GG content. Due to ALP leaching, the distribution of minerals was inhomogeneous: most of the mineral phase was formed inside the material. The presence of CaP in mineralized samples promoted attachment, spreading and viability of MG-63 cells.

9

Porowate kompozyty poliuretan/ß-TCP do zastosowań ortopedycznych

Szczepańczyk P., Pietryga K., Pielichowska K., Chłopek J.

Engineering of Biomaterials

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2013

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Vol. 16, no. 121

33--41

PL

Celem pracy było otrzymanie serii porowatych kompozytów o osnowie polimerowej modyfikowanych mikrocząstkami ß trifosforanu (V) wapnia (ß-TCP) oraz zbadanie ich właściwości pod kątem zastosowań ortopedycznych. Osnowę otrzymanych kompozytów stanowiły poliuretany ze względu na szereg zalet wynikających z ich budowy chemicznej, m.in. właściwości sprzyjające adhezji żywych komórek i ich proliferacji [1]. Ponadto poliuretany są grupą polimerów o wszechstronnych właściwościach, zmieniających się w zależności od użytych reagentów i średniej masy cząsteczkowej oraz o szerokim wachlarzu zastosowań. Dodatkową zaletą poliuretanów jest potencjalna możliwość wprowadzania ich w miejsce ubytku kostnego metodą iniekcyjną [2]. Kompozyty otrzymywano na drodze jednoetapowej polimeryzacji w masie z 4,4'-diizocyjanianu difenylometanu (MDI), poli(glikolu etylenowego) (PEG) oraz 1,4-butanodiolu (BDO) jako przedłużacza łańcucha. Sulfonowany olej rycynowy (SCO) oraz stearynian wapnia (CS) zastosowano w celu lepszej kontroli porowatości i otrzymania układów o porach otwartych. Struktura otrzymanych materiałów została potwierdzona za pomocą spektroskopii w podczerwieni. Przy użyciu mikroskopu stereoskopowego oszacowano porowatość, ponadto zbadano wytrzymałość na ściskanie oraz przeprowadzono symulacje biologiczne w warunkach in vitro. Przeprowadzono również inkubację w symulowanym płynie fizjologicznym (SBF) w celu wstępnej oceny bioaktywności otrzymanych biomateriałów. Uzyskane wyniki potwierdziły znaczący wpływ dodatku ß-TCP na właściwości mechaniczne otrzymanych układów jak również na poprawę ich bioaktywności. Ponadto zaobserwowano, że dodatek ß-TCP, SCO oraz CS wpływa na porowatość całkowitą i rozmiary porów.

EN

The purpose of the research was to produce a series of porous composite samples with polymeric matrix modified by ß-tri-calcium phosphate (ß-TCP) microparticles and to study their properties considering orthopaedic applications. Polyurethanes were used as the polymeric matrix on account of their advantages resulting from their chemical structure. These materials also promote cell adhesion and proliferation [1]. Moreover these polymers exhibit wide-ranging properties which can be modulated depending on composition and average molecular weight and are used in broad spectrum of applications. Another advantage of polyurethanes is their potential to be injected into the bone defect by minimally invasive technique [2]. The composites were obtained through the one-step synthesis by mixing 4,4'-diphenylmethane diisocyanate (MDI) with poly(ethylene glycol) (PEG) and 1,4-butanediol (BDO) as a chain extender. Sulphonated castor oil (SCO) and calcium stearate (CS) were applied for better porosity control and to obtain interconnected pore system. Structure of the synthesized materials was confirmed by means of infrared spectroscopy. The porosity was assessed using stereoscopic microscopy. Moreover the compressive strength was studied and in vitro simulation was carried out. Composite samples were also incubated in simulated body fluid (SBF) for preliminary evaluation of the in vitro bioactivity. The research results confirmed significant influence of ß-TCP on mechanical properties and preliminary evaluation of the in vitro bioactivity of the obtained samples. Moreover the influence of ß-TCP, SCO and CS on total porosity and pore sizes was investigated.