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1

Sustained Release of Drug Facilitated Through Chemically Crosslinked Polyvinyl Alcohol-Gelatin (PVA-GE) Hydrogels. A sustainable biomedical approach

Ali Shaukat, Ranjha Nazar Muhammad, Ahmad Bashir, Khan Ayaz Ali, Hassan Fakhr Ul, Aziz Tariq, Alharb Metab, Alshammari Abdulrahman, Alasmari Abdullah F., Alharbi Mousa Esa

Polish Journal of Chemical Technology

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2023

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Vol. 25, nr 2

56--65

EN

The present study aimed to prepare hydrogel based on polyvinyl alcohol (PVA) and gelatin (Ge) and characterization of PVA/Ge hydrogel for their potential use as a sustained drug delivery system. Polyvinyl Alcohol (PVA) and-Gelatin (Ge) were cross-linked using glutaraldehyde (GA) as a crosslinking agent and hydrochloric acid (HCl) as a catalyst. Different feed polymer ratio and crosslinking agent concentration were used to prepare a series of PVA/Ge hydrogels. The obtained PVA/Ge hydrogels were investigated for dynamic and equilibrium swelling studies. The effect of polymers ratio, degree of crosslinking and pH of the medium on swelling of PVA/Ge hydrogels was investigated. Furthermore, the values of diffusion coeficient (D), volume fraction, polymer-solvent interaction parameter, molecular weight between crosslink and crosslink density were calculated. For swelling studies, 0.05M USP phosphate buffer solutions of different pH (1.2, 5.5, 6.5 and 7.5) were used. For the drug release study, ciprofloxacin HCl was loaded into selected samples as a model drug. The release of drug from these samples was performed for 12 hours in USP phosphate buffers of pH 1.2, 5.5 and 7.5. The release data from these samples were fitted into various kinetic models like zero order, first order, Higuchi and Peppas models to investigate the release mechanism. It was found that by varying the composition of PVA/Ge hydrogel and GA concentration, a significant difference was observed in drug release kinetics. FTIR spectroscopy and X-ray diffraction were used for the characterization of hydrogels. PVA/Ge hydrogel showed sustained release of the model drug at various pH values suggesting its potential use as a sustained drug delivery system.

2

Effects of poly(vinyl alcohol) matrix on the release of substances from the fragrance composition

Szajnecki Łukasz, Nowak Agnieszka

Polimery

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2023

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Vol. 68, nr 3

169--176

EN

The chemical composition of two commercially available lavender fragrance oils was determined and compared. The process of concentration by partial evaporation was carried out and its influence on changes in the content of individual components in the analysed mixtures was examined. The effect of poly(vinyl alcohol)-based polymer matrix on the release of volatile substances from oils was tested as well. The presence and chemical composition of the polymer matrix affects the relative content of volatile substances released from the liquid phase containing the tested fragrance composition.

PL

Określono i porównano skład chemiczny dwóch handlowych olejków o zapachu lawendy. Przeprowadzono proces zatężania kompozycji zapachowych na drodze częściowego odparowania oraz zbadano jego wpływ na zmiany zawartości poszczególnych składników w analizowanych mieszaninach. Zbadano także wpływ osnowy polimerowej na bazie poli(alkoholu winylowego) na uwalnianie substancji z olejków. Stwierdzono, że obecność i skład chemiczny osnowy polimerowej wpływają na względną zawartość substancji lotnych uwalnianych z fazy ciekłej zawierającej badaną kompozycję zapachową.

3

Clay/nanocomposite hydrogels : In review

Kurama Haldun, Şengel Sultan Bütün

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 5

art. no. 165991

EN

The development of advanced materials those are stronger, more rigid, lighter, hotter and self-renewable than existing materials has been the rising point of many research studies conducted in recent years. Within this scope, the interest to production of nanostructured materials is received considerable attention worldwide due to their potential positive contribution to wide variety of technological areas such as electronics, catalysis, adsorbents, ceramics, magnetic data storage, structural components etc. In these efforts polymer nanocomposites as the form of hydrogels, reinforced with well-dispersed layered silicate, typically montmorillonite can be given as a one of the promising composite material. However, long-standing problems for polymer-clay nanocomposites include actual exfoliation of clay particles in discrete layers, uniform distribution of clay layers throughout the polymer, and randomness of clay sequences. For the exfoliation of clay particles, although the chemical modification of clay minerals in aqueous media is the well-known and more general way applied by researchers, the physical pathway method performed by high-energy ball mills is also gaining increasing attention as an alternative pretreatment way. Grinding of crushed materials is one of the key processes in the mineral and cement industry, but the increased concern on the preparation of fine-grained powders (nano powders) or the manufacture of composites with desirable properties, especially performed with use of high-energy ball mills, has led to significantly widen the usage field of grinding. Undoubtedly, the main reason for these efforts is to improve the performance of existing materials. In this paper the fundamental concepts, classification, physical and chemical characteristics and the production methods of clay/polymer nanocomposites was briefly reviewed base on the composite hydrogel. Particular attention was paid to the pre-treatment (exfoliation) of clays with high-energy ball mills, which is increasingly being accepted as an alternative method to eliminate the negative effects of chemical treatment in some composite forms.

4

Biphasic monolithic osteochondral scaffolds obtained by diffusion-limited enzymatic mineralization of gellan gum hydrogel

Pietryga Krzysztof, Reczyńska-Kolman Katarzyna, Reseland Janne E., Haugen Håvard, Larreta-Garde Véronique, Pamuła Elżbieta

Biocybernetics and Biomedical Engineering

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2023

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Vol. 43, no. 1

189--205

EN

Biphasic monolithic materials for the treatment of osteochondral defects were produced from polysaccharide hydrogel, gellan gum (GG). GG was enzymatically mineralized by alkaline phosphatase (ALP) in the presence of calcium glycerophosphate (CaGP). The desired distribution of the calcium phosphate (CaP) mineral phase was achieved by limiting the availability of CaGP to specific parts of the GG sample. Therefore, mineralization of GG was facilitated by the diffusion of CaGP, causing the formation of the CaP gradient. The distribution of CaP was analyzed along the cross section of the GG. The formation of a CaP gradient was mainly affected by the mineralization time and the ALP concentration. The formation of CaP was confirmed by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and mapping, as well as energy-dispersive X-ray spectroscopy (EDX) mapping of the interphase. The microstructure of mineralized and non-mineralized parts of the material was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) showing sub-micrometer CaP crystal formation, resulting in increased surface roughness. Compression tests and rheometric analyzes showed a 10-fold increase in stiffness of the GG mineralized part. Concomitantly, micromechanical tests performed by AFM showed an increase of Young’s modulus from 17.8 to more than 200 kPa. In vitro evaluation of biphasic scaffolds was performed in contact with osteoblast-like MG-63 cells. The mineralized parts of GG were preferentially colonized by the cells over the non-mineralized parts. The results showed that osteochondral scaffolds of the desired structure and properties can be made from GG using a diffusion-limited enzymatic mineralization method.

5

Kinetics models of hydrogen sulphide adsorption from hydrogel biochar derived from empty fruit bunch (EFB)

Alias A.B., Ariffin A.Y., Norain N.M.R., Rashid Z.A.

Archives of Materials Science and Engineering

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2023

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Vol. 120, nr 1

15--21

EN

Purpose: This research aims to investigate the detailed state of adsorption kinetics modelling and research on the application of hydrogen sulfide adsorption by hydrogel derived from empty fruit bunch (EFB), the determination of the kinetics parameters, and the comparison between models in a selection of the best-fit model. Design/methodology/approach: The kinetics modelling used are pseudo-first-order and pseudo-second-order models. The correlation coefficient was used to evaluate the suitability of the equation R2. After obtaining the results, the comparison was made by comparing the R2 of each model. The pseudo-second-order model has a higher value of correlation coefficient, R2, making it the most suitable kinetics model for adsorption systems. Findings: The R2 for pseudo-first-order on the effect of dry bed height was 0.8814, whereas its effect on powder bed height was 0.9537, and that of the wet bed height was 0.9607. Meanwhile, the R2 for pseudo-second-order on the effect of dry bed height was 0.89, on the effect of the powder bed height was 0.99, and on the effect of the bed height of wet was 0.99, the highest among kinetic models. Based on the results, the pseudo-second-order model best describes the adsorption of hydrogen sulfide (H2S) by hydrogel biochar. Research limitations/implications: The kinetics modelling used are pseudo-first-order, and pseudo-second-order models for hydrogen sulfide adsorption by hydrogel originating from empty fruit bunches (EFB). Practical implications: Based on the results, the pseudo-second-order model best describes the adsorption of hydrogen sulfide (H2S) by hydrogel biochar. Kinetic studies are important in understanding the reactions and design of the process. Originality/value: The authenticity results of this article were found to be 17% similar. The novelty of this paper is the kinetics study of the new adsorbent developed based on EFB to adsorb H2S.

6

Mikroenkapsulacja mikroalg (Chlamydomonas reinhardtii) metodą emulsyfikacji membranowej

Dawiec-Liśniewska Anna

Przemysł Chemiczny

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2022

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T. 101, nr 9

694--698

PL

W module membranowym umieszczano fazę ciągłą, którą stanowił olej parafinowy z dodatkiem 1% obj. surfaktantu. Następnie dostarczano fazę zdyspergowaną, którą stanowił 2-proc. roztwór wodny alginianu sodu z mikroalgami o stężeniu 10, 15, 20% obj. Fazę zdyspergowaną podawano z szybkością 2–5 mL/min przy stałej prędkości mieszania równej 250–400 rpm. Otrzymaną emulsję przelewano do zlewki, mieszano z prędkością 300–700 rpm i dodawano czynnik sieciujący i stabilizator emulsji. Aktywność fotosyntetyczną unieruchomionych mikroalg określano poprzez pomiar stężenia tlenu w czasie.

EN

Paraffin oil with the addn. of 1% vol. surfactant was placed in a membrane module (continuous phase) and then a 2% aq. soln. of Na alginate with microalgae at a concn. of 10, 15, or 20% by vol. was added (dispersed phase) at a rate of 2–5 mL/min at a constant stirring speed of 250–400 rpm. The resulting emulsion was poured into a beaker, mixed at 300–700 rpm, and the crosslinker and emulsion stabilizer were added. The photosynthetic activity of the immobilized microalgae was detd. by measuring the O2 concn. over time.

7

Optimization of the preparation process stages of the bioink compositions based on sodium alginate and gelatin to improve the viability of biological material contained in hydrogel 3d printouts

Wierzbicka Adrianna, Bartniak Mateusz, Rosińska Karolina, Bociąga Dorota

Engineering of Biomaterials

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2022

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vol. 25, no. 165

7--16

EN

Currently developing on a large scale, the opportunities for 3D printing represent more and more perspective solutions in the area of tissue engineering and personalized medicine. Due to their ability to reproduce the natural extracellular matrix and unique properties, hydrogels are popularly used materials to produce bioinks designated for 3D printing. Today, solutions based on sodium alginate and gelatin are frequently used compositions for this purpose. The high viability of the cells incorporated into bioink is the key parameter determining the application opportunities of printed structures. The parameters of the process used for the preparation of hydrogel compositions may have a direct impact on the viability of the cells incorporated within the printed structure. This study aims to develop a protocol for the preparation of hydrogel materials based on alginate and gelatin, providing the highest viability of the model osteoblast-like cell line Saos-2 incorporated directly into the bioink before the 3D bioprinting process. In the scope of this study, the analyzed process parameters of the preparation of the hydrogel bioinks are the method of combination of a polymer solution with biological material, the applied concentration, the cross-linking solution, and also the waiting time of the prepared hydrogel bioink for the 3D printing process. A key aspect of the study is the evaluation of the influence of 3D printing on changes in the survival rate of biological material directly after the manufacturing process and after individual incubation periods of the printouts in conditions reflecting the body’s environment.

8

Composite scaffolds enriched with calcium carbonate microparticles loaded with epigallocatechin gallate for bone tissue regeneration

Pietryga Krzysztof, Panaite Anca-Alexandra, Pamuła Elżbieta

Engineering of Biomaterials

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2022

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vol. 25, no. 166

12--21

EN

There is a need to develop advanced multifunctional scaffolds for the treatment of bone tissue lesions, which apart from providing support for infiltrating cells could assure the delivery of drugs or biologically active molecules enhancing bone formation. We developed composite scaffolds for bone tissue engineering based on gellan gum (GG) and gelatin (Gel) hydrogel enriched with epigallocatechin gallate (EGCG) loaded CaCO3 microparticles and subjected to enzymatic mineralization with calcium phosphate (CaP). The method of manufacturing CaCO3 microparticles was optimized. The EGCG-loaded microparticles were smaller than those unloaded, and the release of EGCG was prolonged for up to 14 days, as shown by the Folin-Ciocalteu test. The particles reduced the viability of the MG-63 cells as compared to the control. However, when they were loaded with EGCG, their cytotoxicity was reduced. The particles were suspended in a GG/Gel hydrogel containing alkaline phosphatase (ALP), soaked in calcium glycerophosphate (CaGP) solution to create CaP deposits, and submitted to freeze-drying, in order to produce a porous scaffold. The microstructure of the scaffolds was characterized by optical and scanning electron microscopy and showed that the size of the pores corresponds to that of the spongy bone. In vitro tests with MG-63 cells confirmed that mineralized scaffolds support cell adhesion and growth to a higher extent than nonmineralized ones.

9

Comparison of hydrogel- and xerogel-based sorbent from Empty Fruit Bunch (EFB)

Alias A.B., Qarizada D., Malik N.S.A., Noraini N.M.R., Rashid Z.A.

Archives of Materials Science and Engineering

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2022

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Vol. 118, nr 2

49--60

EN

Purpose: This paper focuses on the synthesis and comparison of hydrogel- and xerogel-based sorbents from EFB. Design/methodology/approach: Hydrogels were synthesised by polymerisation of EFB biochar with acrylamide (AAm) as a monomer, N, N'-Methylenebisacrylamide (MBA) as cross-linker and ammonium persulfate (APS) as initiator, as well as by internal gelation method of sodium alginate, empty fruit bunch (EFB), calcium carbonate (CaCO3), and glucono delta-lactone (GDL). From the alginate hydrogels obtained, xerogels were synthesised via the oven-drying method. Then, EFB-based hydrogel and xerogel sorbents were analysed and compared based on characterisation analysis by using scanning electron microscopy (SEM), Brunauer− Emmett−Teller (BET), Fourier-Transform Infrared Spectroscopy (FTIR), and thermogravimetric analysis (TGA). Findings: The xerogel-based EFB is a better adsorbent than the hydrogel-based EFB because it has a larger pore volume (0.001449 cm3/g), larger pore size (63.7987 nm), higher moisture content (7.97%), lower ash content (12.55%), and is more thermally stable. Research limitations/implications: The research is to compare two new adsorbents, namely Hydrogel and Xerogel, from EFB in terms of their characteristics. Practical implications: Both adsorbents show a highly toxic material uptake, especially EFB xerogel. This adsorbent is comparable with the other commercialised adsorbent. Thus, this product can be a highly potential adsorbent for gas and wastewater adsorption. Originality/value: The authenticity results of this article were found to be 15% similar. The novelty of this paper is to compare the two adsorbents, namely hydrogel and xerogel, that originated from EFB.

10

Pielęgnacja wewnętrzna polimerami superabsorpcyjnymi i jej wpływ na właściwości betonu

Kalinowski Maciej, Woyciechowski Piotr

Inżynieria i Budownictwo

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2021

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R. 77, nr 1-2

59--62

PL

Pielęgnacja betonu ogranicza negatywny wpływ środowiska na warunki wilgotnościowe i temperaturowe decydujące o przebiegu hydratacji spoiwa. Jedną z nowych metod pielęgnacji jest zastosowanie polimerów superabsorpcyjnych jako środka pielęgnacji wewnętrznej. W artykule przedstawiono cel i zasady stosowania tego rodzaju modyfikacji kompozytów cementowych oraz jej wpływ na wybrane właściwości betonu.

EN

Curing of concrete mitigates the negative influence of the environment on the humidity and temperature conditions influencing the course of the binder hydration. One of the new methods of curing is the use of superabsorbent polymers as an internal curing agent. The article presents the purpose and principles of this type of modification of cement composites and its impact on selected properties of concrete.

11

Synteza hydrożeli na bazie soli poli(kwasu asparaginowego) i poli(kwasu akrylowego) wykazujących strukturę przenikających się sieci polimerowych

Grzesik Ryszard, Lukosek Marek, Torchała Kamila, Kotyrba Łukasz, Wójcik Jan

Przemysł Chemiczny

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2020

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T. 99, nr 12

1712--1716

PL

W środowisku wodnym sporządzono mieszaniny typu przenikających się sieci polimerowych w wyniku sieciowania poli(kwasu akrylowego) wobec soli potasowej lub amonowej poli(kwasu asparaginowego). Wykazano, że wartość pH ma duży wpływ na przebieg tego procesu. Otrzymane substancje miały właściwości hydrożelu.

EN

Interpenetrating polymer networks (IPN) of poly(aspartic acid) and poly(acrylic acid) salts were produced by crosslinking of poly(acrylic acid) in the presence of K or NH salts of poly(aspartic acid) (PAs-K and PAs-A, resp.) 4 in aq. soln. The pH of reaction mixts. had a high impact on the process. IPN of PAs-A and poly(acrylic acid) showed hydrogel-like properties and were recommended as water absorbing additives to mineral fertilizers.

12

Hydraulic efficiency of green roof retrofitted with additional sand-agrogel layer - numerical studies

Widomski Marcin K., Musz-Pomorska Anna, Gołębiowska Justyna

Proceedings of ECOpole

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2020

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Vol. 14, No. 1

47--55

EN

This paper contains the attempt of numerical assessment of hydraulic efficiency of intensive green roof utilizing two different, commercially available substrates, additionally retrofitted with layer of fractioned sand 1.0-0.5 and 0.5-0.25 mm mixed in mass concentration of 0.1 % with hydrogel. The numerical modelling of green roof efficiency was performed by the means of the popular modelling software FEFLOW, Wasy-DHI. The developed model reflected the selected cross section of the tested green roof. The required input data for modelling covering the saturated hydraulic conductivity and water retention characteristics were determined under the laboratory conditions as well as were based on information available in technical descriptions of tested substrates. The applied boundary conditions were based on previously performed in-situ measurements. The obtained results of numerical modelling showed relation between porosity, saturated hydraulic conductivity, retention properties of substrate, rainfall characteristics, duration of dry period and presence of additional sand-hydrogel mixture layer and water retention efficiency of tested green roofs.

PL

W pracy przedstawiono próbę numerycznej oceny efektywności hydraulicznej intensywnego zielonego dachu wykorzystującego dwa różne, dostępne komercyjnie, wypełnienia, dodatkowo wzbogacone warstwą frakcjonowanego piasku, 1,0-0,5 i 0,5-0,25 mm, zmieszanego w stężeniu masowym 0,1 % z hydrożelem. Obliczenia numeryczne efektywności badanego zielonego dachu zostały przeprowadzone za pomocą programu obliczeniowego FEFLOW, Wasy-DHI. Opracowany model odzwierciedlał wybrany przekrój poprzeczny przez badany zielony dach. Wymagane dane wejściowe do obliczeń modelowych, obejmujące współczynnik filtracji oraz charakterystykę retencyjną badanych materiałów porowatych, określono w czasie drogą badań laboratoryjnych oraz oparto o upublicznione opisy techniczne wykorzystanych wypełnień. Zastosowane warunki brzegowe wykorzystały poprzednio przeprowadzone pomiary terenowe. Wyniki obliczeń modelowych wykazały związek pomiędzy porowatością, współczynnikiem filtracji, właściwościami retencyjnymi wypełnienia oraz charakterystyką opadu, długością okresu suchego i obecnością dodatkowej warstwy mieszaniny piasku z hydrożelem a efektywności zielonego dachu.

13

Influence of the Hydrogel Amendment on the Water Retention Capacity of Extensive Green Roof Models

Deska Iwona, Mrowiec Maciej, Ociepa Ewa, Lewandowska Agnieszka

Journal of Ecological Engineering

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2020

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Vol. 21, nr 1

195--204

EN

The goal of the research was to investigate the retention capacity of six green roof models (SHP1, SHP2, SHP3, SH, S, and SP) constructed with the use of the square-shaped plastic trays, Floradrain FD 25 drainage elements, SF filter sheets, and the specified extensive substrates (with or without the hydrogel amendment). The SHP1 and SHP2 models were constructed in March 2017, SHP3 and SH – in November 2017, while S and SP – in April 2018. Four models (SHP1, SHP2, SHP3, and SP) contained the plants (the goldmoss stonecrop Sedum Acre), whereas two models (S and SH) did not contain the vegetation. The substrates of SHP1, SHP2, SHP3, and SH models contained the hydrogel admixtures. The investigations were conducted with the use of simulated (and partially natural) precipitations. The water retention capacity of each green roof model was established based on the difference between the precipitation volume and the volume of runoff from a model. The results show that green roofs can be useful stormwater management tools. The calculated stormwater retention rates ranged from 29.50% to 85.15%. In most cases, the best water retention capacity was exhibited by the SHP3 model, constructed in November 2017 and planted in April 2018, containing the substrate amended with superabsorbent (cross-linked potassium polyacrylate). The similarly constructed SHP1 and SHP2 models, which were built in March 2017, in some cases had lower water retention capacity. These models contained older hydrogel and were overgrown with older, smaller, and worse looking plants, partially supplanted by mosses. Such results indicate that the efficiency of hydrogel may decrease over time. In many cases, the S (not vegetated, without hydrogel), SH (not vegetated, with substrate containing hydrogel), and SP (vegetated, without hydrogel) models had slightly lower water retention capacity. The results of investigations indicate that there was a relatively strong positive linear correlation between the retention depth and duration of the antecedent period elapsed from the preceding total (or substantial) saturation of the green roof models (labelled in this article as period since total saturation – PSTS). The weather conditions i.e. air temperature and relative humidity as well as PSTS are very important parameters that influence the retention capacity of the green roof models. The result show that duration of PSTS can be stronger correlated with the retention depth than antecedent dry period (ADP) elapsed from the end of last precipitation, regardless of its depth and intensity.

14

Double crosslinking of chitosan/vanillin hydrogels as a basis for mechanically strong gradient scaffolds for tissue engineering

Hunger Martyna, Domalik-Pyzik Patrycja, Reczyńska Katarzyna, Chłopek Jan

Engineering of Biomaterials

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2020

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Vol. 23, no. 155

2--11

EN

Polysaccharides, such as chitosan (CS), are widely used in many biomedical applications. However, they require crosslinking agents to achieve chemical stability and appropriate mechanical properties. In this work, chitosan-based hydrogels were crosslinked using vanillin and/or sodium tripolyphosphate, as chemical and physical crosslinking agents, respectively. Microstructural (digital microscope, SEM), structural (FTIR-ATR), mechanical (static compression test), and in vitro biological (chemical stability and swelling ratio in PBS, cytotoxicity) properties of the obtained materials were evaluated to assess materials potential as biomedical scaffolds. The optimal ratio of vanillin to chitosan (DD = 89%) to crosslink the polymer was found to be 1.2:1. Moreover, the double crosslinking with vanillin caused a two-time increase in the compression strength of the samples and led to the slower biodegradability. Cytotoxicity studies showed that the cells prefer double vanillin crosslinked hydrogels over those treated with TPP. Further studies, such as bioactivity are required to determine the specific functionality of the hydrogels and the specific tissue which may be treated with the tested materials. The optimal material was chosen to the next step of the study, which may be obtaining composite hydrogels with hydroxyapatite and/or graphene oxide to tailor or improve properties towards specific tissue regeneration.

15

Impact of the hydrogel amendment and the dry period duration on the green roof retention capacity

Deska Iwona, Mrowiec Maciej, Ociepa Ewa, Michniewski Michał

Ecological Chemistry and Engineering. S

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2020

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Vol. 27, nr 3

357--371

EN

Abstract: Climate changes as well as the urbanisation and economic development influence the characteristics of the stormwater runoff in the cities. The sealing of drainage basin surface leads to an increase of the runoff intensity, thereby decreasing the rainwater infiltration. This situation can lead to the risk of flooding in urban areas. Therefore, especially in great cities there is a need for application of such solutions that will support the operation of the sewage systems. The examples of such solutions are, among others, the green roofs. The paper presents the results of investigation of the water retention capacity of 4 green roof models containing following growing media: (1) the typical green roof substrate without any amendments, (2) the substrate with addition of about 1 % by weight of hydrogel (the cross-linked potassium polyacrylate), (3) the substrate containing about 0.25 % by weight of hydrogel, (4) the substrate with addition of expanded clay and perlite. The models were not vegetated in order to investigate only the water retention capacity of drainage elements and substrates. The water retention capacity of green roof models was investigated in the laboratory conditions with use of artificial precipitations simulated after diverse antecedent dry weather periods (ADWP) amounting to: 1, 2, 5, 7, and 12 days. The intensities of artificial precipitations were relatively high and ranged from 1.14 to 1.27 mm/min, whereas their durations ranged from 7.75 to 12.56 min. These values of intensities and durations corresponded to the design rainfall intensities calculated using Blaszczyk’s equation for annual rain depth equal to 600 mm and the return periods ranged from 5 to 15 years. The obtained results indicate that the water retention capacity of green roof models, expressed as the volumes (or depths) of rainwater retained within their structures, increases with an increase of ADWP. Results indicate that the relation between ADWP and the amount of water retained in the layers of green roofs in the case of relatively short antecedent dry weather periods provided for the analysis (from 1 to 7 days) may be approximately linear. The results of the one-way ANOVA indicate that in the case of all models there is a statistically significant difference between the values of retention depth for specified ADWP (p < 0.001). During more than half of simulated precipitations, especially in the case of longer ADWPs lasting 5, 7, and 12 days the best water retention capacity had Model 3, with substrate containing about 0.25 % by weight of hydrogel. On the other hand, the results show that the weakest retention capacity had Model 2 (with substrate containing 1 % by weight of hydrogel). In the case of longer ADWPs (lasting 7 and 12 days) relatively weak water retention capacity had Model 4 (with substrate containing the addition of expanded clay and perlite). It can be concluded that too large amount of hydrogel added to the substrate can have an unfavourable impact on the water retention capacity of green roofs.

16

Systemy Cell-on-a-chip jako zaawansowane modele hodowli komórek in vitro

Jastrzębska Elżbieta

Wiadomości Chemiczne

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2019

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[Z] 73, 11-12

715--735

EN

In vitro study at the cellular level is an important step in evaluation of biological properties of newly developed drugs. In addition, thanks to the use of cell cultures, it is possible to study the function of the cells of a specific tissue and to mimic the conditions of cell growth or disease state. Standard (conventional) cell cultures are most often based on monolayer (two-dimensional, 2D) culture. In such culture, the cells adhere to the surface of the bottle/plate in which they grow. Nevertheless, spatial (three-dimensional, 3D) cultures are also increasingly used in culture research. However, conventional cell cultures still have a limited ability to mimic the natural environment of cell growth. Lab-on-a-chip systems (called Cell-on-a-chip) are new miniature constructional and methodical solutions useful for in vitro cell cultures. Microsystems allow the development of more advanced cell models than standard in vitro cultures so far used in biological laboratories. Thanks to this, it is possible to study cell functions under conditions that mimic the natural environment of cell growth. It should be emphasized, that the microsystems cannot completely replace animal testing. Cell-on-a-chip systems can provide alternative or complementary solutions / tools for in vivo tests, while ensuring high reliability of the obtained results. So far, Lab-on-a-chip systems have been used to assess the cytotoxicity of compounds, model intercellular interactions and mimic the function of various tissues. In this article we describe Cell-on-a-chip systems which can be used as advanced models of cell cultures. At the beginning of the manuscript, Cell-on-a- chip systems and materials used for fabrication microsystems are characterized. Next, the microsystems used as platforms for cytotoxicity study are presented. A special attention has been paid to Cell-on-a-chip for spatial cell cultures using: spheroids, hydrogels, multilayers and nanoscaffolds. Finally, Organ-on-a-chip systems are shortly discussed. Schemes of Cell-on-a-chip system, types of cell cultures obtained in microscale are presented in the article. A table showing a construction materials is also added. At the end, the article is summarized.

17

Wpływ warstwy roślinności oraz dodatku hydrożelu do substratu na zdolności retencyjne zielonych dachów

Deska Iwona, Mrowiec Maciej, Ociepa Ewa, Ślęzak Katarzyna

Proceedings of ECOpole

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2019

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Vol. 13, No. 1-2

107--118

PL

Na terenach zlewni zurbanizowanych, obok tradycyjnych systemów kanalizacyjnych, coraz częściej stosuje się zrównoważone systemy drenażu (ZSD, ang. SUDS - Sustainable Urban Drainage Systems), które umożliwiają zagospodarowanie wód opadowych możliwie jak najbliżej miejsca wystąpienia opadu. Jednym z przykładów takich rozwiązań są zielone dachy. W artykule zaprezentowano wyniki badań zdolności retencyjnych sześciu modeli zielonych dachów, oznaczonych w tekście artykułu symbolami: SHR1, SHR2, SHR3, SH, S i SR. W przypadku modeli SHR1, SHR2, SHR3 i SH zastosowano dwie warstwy substratu ekstensywnego o nazwie handlowej „Skalny kobierzec”. Dolna warstwa substratu zawierała domieszkę 0,5 % wag. hydrożelu potasowego (usieciowanego poliakrylanu potasu), natomiast górną warstwę stanowił ww. substrat bez domieszek. W przypadku modeli SHR1, SHR2, SHR3 zastosowano warstwę roślinności - rozchodnik ostry (Sedum Acre), natomiast model SH nie zawierał warstwy roślinności. Z kolei w przypadku modeli S i SR zastosowano jednolitą warstwę substratu ekstensywnego „Skalny kobierzec” bez dodatku hydrożelu, przy czym model SR posiadał warstwę roślinności (rozchodnik ostry), a model S był pozbawiony roślin. Modele SHR1 i SHR2 zostały skonstruowane w marcu 2017 r., modele SH i SHR3 w listopadzie 2017 r., a modele S i SR w kwietniu 2018 r. Badania były prowadzone z zastosowaniem opadów naturalnych oraz sztucznych (symulowanych). Na podstawie otrzymanych wyników można stwierdzić, że zastosowanie zielonych dachów może pozwolić na zmniejszenie natężenia odpływu wody opadowej ze zlewni. Uzyskane wyniki wskazują, że w większości przypadków najlepsze zdolności retencyjne wykazywały modele zielonych dachów obsadzone dobrze ukorzenioną, gęstą warstwą roślinności, które równocześnie zawierały substrat z domieszką hydrożelu (SHR1, SHR2). W niewielkim stopniu niższą zdolnością retencyjną charakteryzował się model o bardzo zbliżonej konstrukcji (SHR3), posiadający rzadszą i słabiej ukorzenioną warstwę roślinności. W większości przypadków mniejsze objętości wody były retencjonowane w warstwach pozostałych modeli: S (niezawierającego roślin ani domieszki hydrożelu), SR (zawierającego roślinność, ale niezawierającego hydrożelu) i SH (zawierającego domieszkę hydrożelu, lecz nieposiadającego warstwy roślinności). Otrzymane wyniki wskazują, że dodatek hydrożelu może wpływać pozytywnie na zdolności retencyjne dachów obsadzonych roślinnością, pod warunkiem, że okres bezdeszczowy poprzedzający opad nie będzie bardzo krótki i dach częściowo odzyska zdolność do retencjonowania wody. Na podstawie uzyskanych wyników można stwierdzić, że dodatek hydrożelu do substratu w przypadku modelu pozbawionego roślinności nie powodował znaczącego zwiększenia jego zdolności retencyjnych. Otrzymane wyniki wskazują, że dużą rolę w retencjonowaniu wody opadowej odgrywa warstwa roślinności, zwłaszcza w okresie późnej wiosny i lata, kiedy panują stosunkowo wysokie temperatury.

EN

In urbanized areas, in addition to the traditional sewer systems, increasingly are used the sustainable urban drainage systems (SUDS), inter alia, the green roofs. The focus of the research described in the article was to investigate the retention capacities of six green roof models denoted in the paper by symbols: SHR1, SHR2, SHR3, SH, S, and SR. The models were constructed with use of the plastic garden trays (with internal dimensions 55.7 × 55.7 × 7 cm). On the bottom of each tray the drainage element Floradrain FD 25 was placed. On each drainage element the filter sheet SF (70 × 70 cm) was spread. On the surface of each filter sheet the required amount of the specified substrate was placed. The total thickness of substrate layer on each model was equal. Models SHR1, SHR2, SHR3, SH were built of two layers of the extensive substrate “Sedum Carpet”. The lower layer contained the admixture of 0.5 % by weight of hydrogel (the cross-linked potassium polyacrylate). The upper layer consisted of the substrate “Sedum Carpet” without hydrogel amendment. Models SHR1, SHR2, and SHR3 contained the layer of vegetation - the goldmoss stonecrop (Sedum Acre), while model SH did not contain the plants. The models S and SR contained the uniform layer of extensive substrate “Sedum Carpet” without hydrogel amendment. The model SR contained the vegetation (the goldmoss stonecrop) and S did not contain plants. Models SHR1 and SHR2 were constructed in March 2017, models SH and SHR3 were constructed in November 2017, and models S and SR were constructed in April 2018. The investigations were conducted with use of natural and artificial (simulated) precipitations. The obtained results show that the green roofs can help to reduce the outflow of rainwater from the catchment. The results indicate that in most cases the best retention capacities had models prepared in March 2017, with dense, well-rooted plants and substrate layer amended with hydrogel (SHR1 and SHR2). The similarly constructed model (SHR3) having a less dense and less rooted vegetation layer had a slightly lower retention capacity. In most cases smaller volumes of water were stored in the layers of other models: S (substrate without hydrogel amendment and without plants), SR (substrate without hydrogel amendment + plants), and SH (substrate with hydrogel amendment and without plants). The obtained results indicate that the addition of hydrogel into the growing medium can have a positive effect on the retention capacity of vegetated roof, provided that the antecedent dry period will not be very short. On the other hand, the results show that the hydrogel amendment did not cause a significant increase in retention capacity in the case of model without plants. The obtained results indicate that the vegetation layer plays an important role in the retention of rainwater, especially in the late spring and summer, when the temperatures were relatively high.

18

Rheological and textural properties of hydrogels, containing sulfur as a model drug, made using different polymers types

Wróblewska Magdalena, Słyż Joanna, Winnicka Katarzyna

Polimery

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2019

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T. 64, nr 3

208--215

EN

The preparation technology and the optimal composition of hydrogels with sulfur prepared using various types of polymers – hydroxyethyl cellulose (HEC), Carbopol 980, and sodium alginate – have been developed. Designed hydrogels were evaluated microscopically, for pH, viscosity and mechanical parameters. In addition, ex vivo bioadhesive properties of obtained hydrogels with hairless mice skin model as adhesive layer were estimated. Hydrogels with sulfur based on sodium alginate possessed the most favorable application properties and were stable at different temperature and humidity conditions during 90 days of storage.

PL

Opracowano technologię otrzymywania i optymalny skład hydrożeli z siarką sporządzonych z wykorzystaniem różnych rodzajów polimerów: hydroksyetylocelulozy (HEC), Carbopolu 980 oraz alginianu sodu. Przygotowane hydrożele oceniano mikroskopowo, poprzez pomiary pH i lepkości oraz na podstawie analizy ich właściwości mechanicznych. Ponadto przeprowadzono badanie bioadhezji ex vivo z wykorzystaniem skóry bezwłosych myszy jako modelu warstwy adhezyjnej. Hydrożele z siarką na bazie alginianu sodu charakteryzowały się najlepszymi właściwościami aplikacyjnymi i były trwałe podczas 90 dni przechowywania w różnych warunkach temperatury i wilgotności.

19

Phenolic plant extract enrichment of enzymatically mineralized hydrogels

Douglas Timothy E.L, Lopez-Heredia Marco A., Pułczyńska Aleksandra, Łapa Agata, Pietryga Krzysztof, Schaubroeck David, Santos Sónia A.O., Pais Adriana, Brackman Gilles, Schamphelaere Karel de, Samal Sangram Keshari, Keppler Julia K., Bauer Jonas L, Chai Feng, Blanchemain Nicolas, Coenye Tom, Pamuła Elżbieta, Skirtach Andre G

Engineering of Biomaterials

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2019

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Vol. 22, no. 149

2--9

EN

Hydrogel mineralization with calcium phosphate (CaP) and antibacterial activity are desirable for applications in bone regeneration. Mineralization with CaP can be induced using the enzyme alkaline phosphatase (ALP), responsible for CaP formation in bone tissue. Incorporation of polyphenols, plant-derived bactericidal molecules, was hypothesized to provide antibacterial activity and enhance ALP-induced mineralization. Three phenolic rich plant extracts from: (i) green tea, rich in epigallocatechin gallate (EGCG) (herafter referred to as EGCG-rich extract); (ii) pine bark and (iii) rosemary were added to gellan gum (GG) hydrogels and subsequently mineralized using ALP. The phenolic composition of the three extracts used were analyzed by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MSn). EGCG-rich extract showed the highest content of phenolic compounds and promoted the highest CaP formation as corroborated by dry mass percentage meassurements and ICP-OES de-termination of mass of elemental Ca and P. All three extracts alone exhibited antibacterial activity in the following order EGCG-rich > PI > RO, respectively. However, extract-loaded and mineralized GG hydro-gels did not exhibit appreciable antibacterial activity by diffusion test. In conclusion, only the EGCG-rich extract promotes ALP-mediated mineralization.

20

Wpływ sposobu rozmieszczenia hydrożelu w substracie na zdolności retencyjne zielonych dachów

Deska I., Ociepa E., Mrowiec M., Cichecka E., Gmyrek K.

Proceedings of ECOpole

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2018

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Vol. 12, No. 1

139--147

PL

Na terenach zlewni zurbanizowanych, obok tradycyjnych systemów kanalizacyjnych, coraz częściej stosowane są zrównoważone systemy drenażu (ZSD, ang. SUDS - Sustainable Urban Drainage Systems), umożliwiające zagospodarowanie wód opadowych w miejscu wystąpienia opadu. Jednym z takich rozwiązań są zielone dachy. Artykuł prezentuje wstępne wyniki badań zdolności retencyjnych czterech modeli zielonych dachów. W przypadku modelu 1 zastosowano substrat dachowy ekstensywny bez domieszek. Modele 2 i 3 zawierały substrat ekstensywny z domieszką hydrożelu potasowego (usieciowanego poliakrylanu potasu). W przypadku modelu 2 dodatkowo zastosowano warstwę roślinności (rozchodnik ostry Sedum Acre). W modelu 4 zastosowano substrat ekstensywny z wkładkami z agrowłókniny wypełnionymi hydrożelem potasowym. Modele dachów 2, 3 i 4 zawierały taką samą dawkę hydrożelu (30 g). Badania były prowadzone w warunkach terenowych, w dwóch etapach. Wstępny etap obejmował pierwsze nasączenie modeli (wszystkie elementy w stanie powietrzno suchym) przy zastosowaniu opadu symulowanego. Drugi etap obejmował dalsze badania zdolności retencyjnych modeli, głównie z wykorzystaniem opadów naturalnych. Otrzymane wyniki wskazują, że podczas pierwszego, symulowanego opadu najlepsze zdolności retencyjne wykazywały modele 2 i 3 (z domieszką hydrożelu w stanie luźnym), natomiast najmniejsza objętość wody została zretencjonowana przez modele 1 (bez domieszki hydrożelu) i 4 (z wkładkami zawierającymi hydrożel). Wyniki drugiego etapu eksperymentu są zróżnicowane. W przypadku trzech analizowanych opadów naturalnych najlepsze zdolności retencyjne wykazywał model 2 z substratem zawierającym domieszkę hydrożelu, obsadzony roślinnością, ale w przypadku dwóch opadów większa objętość wody została zretencjonowana w warstwach modelu 4 z wkładkami z hydrożelu. Najsłabsze zdolności retencyjne, spośród modeli zawierających hydrożel w składzie substratu, wykazywał model 3 z hydrożelem w stanie luźnym, nieobsadzony roślinnością. Uzyskane wyniki wskazują na odmienne zachowanie się dodatku hydrożelu i inny przebieg cyklu pochłaniania i oddawania wody w zależności od tego, czy superabsorbent jest zastosowany w formie luźnej domieszki czy umieszczony we wkładkach. W celu dokładniejszego zbadania zachowania hydrożelu w substracie konieczne jest kontynuowanie badań, mających na celu określenie wpływu temperatury i wilgotności powietrza oraz warstwy roślinności na zachowanie dodatku hydrożelu.

EN

In urbanized areas, in addition to the traditional sewer systems, increasingly are used the sustainable urban drainage systems (SUDS), inter alia, the green roofs. The article presents the results of research of retention capacities of 4 green roof models. In these models were used: in model 1 - the typical extensive substrate, in models 2 and 3 - the above-mentioned extensive substrate with addition of hydrogel (cross-linked polyacrylate potassium), in model 4 - agrotextile inserts with hydrogel. Model 2 additionally contained the plants (Goldmoss Stonecrop Sedum Acre). Models 2, 3 and 4 contained the same portion of hydrogel (30 g). The field experiments were conducted in two stages under natural atmospheric conditions. The initial stage included the first simulated precipitation (all layers of green roof models were air-dry during these experiments). The second stage included the further investigations of the retention capacities of green roof models, predominantly with use of natural precipitations. The obtained results of initial stage of experiments show that during the first simulated precipitation the best retention capacities had models 2 and 3 (with hydrogel admixtures). The least amount of water was absorbed in model 1 (without hydrogel additive) and model 4 (containing agrotextile inserts with hydrogel). The results of the second stage of the experiment are equivocal. In the case of three natural precipitations, the best retention capacity was demonstrated by model 2, with the substrate containing hydrogel admixture planted with vegetation, but in the case of two rainfalls more water was stored in model 4, with hydrogel inserts. The least amount of water was absorbed in model 3, with hydrogel admixture, not planted with vegetation. The results show the different behavior of hydrogel and the differences in wetting-drying cycle, depending on whether the superabsorbent is used in the form of a loose admixture or placed in the inserts. Further research is needed to evaluate of influence of temperature and humidity and the presence of vegetation on behavior of hydrogel additive in the green roof substrate.