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Number of results: 8
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Abstract

Some areas intended for afforestation are characterised by a lack of moisture and mineral nutrients. One of the approaches to improve water retention capacity of soils is the use of hydrogels (polymer soil conditioners). The presented experiment was performed with 4 different methods of hydrogel applications and control in a post-industrial area – a dumping ground of the Brown Coal Mine Bełchatów (Forest District Administration Bełchatów). The Aquaterra product (pure hydrogel) and hydrogel with nutrients (TerraVit) produced by Terra-Gubin company were used in all experiments. From 292 to 306 one-year old seedlings of Pinus sylvestris L. of an average height of 80–101 mm were planted in each plot. The influence of hydrogel application method on successful afforestation and growth of seedling was analyzed after the first vegetation year. Maximum number of surviv seedlings (93.3%) was observed for hydrogel applied through roots coating, minimum (72.4%) for hydrogel with fertilizers applied under plants. Results obtained for pure hydrogel surface application (89.1%) and pure hydrogel applied under plants (85.3%) can be compared with results from control plot (89.7%). Mean heights of surviving seedlings were similar (128–130 mm) for root coating, and both methods of hydrogel application under plants, in contrast with surficial hydrogel application (117 mm) and control where they were minimal (111 mm). Mean height increments in surviving seedlings were minimum in control plot (31 mm), and similar (38–40 mm) for root coating and surface application. The best results of height increments (47 mm) were obtained when hydrogel mixed with fertiliser was applied under plants. To sum up, in view of plant survival the best method of polymer soil conditioner (hydrogel) application was root coating; this method gave also satisfactory increments of plant height.

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Authors and Affiliations

Wiesław Ptach
Andrzej Boczoń
Michał Wróbel
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Abstract

When designing injectable scaffolds for biomedical applications, it is crucial to determine the conditions for the formation of unlimited structures, in particular the kinetics at constant temperature. Despite many studies, these conditions have not been characterized so far after injection, which is such an important application aspect. The aim of the research is to discuss the impact of the injection application on the polymer structure and to propose new criteria for assessing the potential of thermosensitive biopolymer sols, considering the flow under high shear rates during the administration.
Based on the analysis of the obtained results of rheological tests, it was shown that the flow through the needles causes a significant change in the elastic properties that define the polymer structure, with almost unchanged viscous properties. As a consequence, the parameters characterizing the polymer coil change, which, combined with the quantitatively proven fragmentation, indicates that injection application may affect the size of the coils that will not reach the critical size of the aggregating nucleus.
Finally, extended research procedures for the conscious design of injectable scaffolds are proposed as well as key rheological parameters to ensure thermoinduced aggregation preceded by shear during injection are provided.
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Authors and Affiliations

Anna Rył
1
ORCID: ORCID
Piotr Owczarz
1
ORCID: ORCID

  1. Department of Chemical Engineering, Lodz University of Technology, Wolczanska 213, 93-005 Lodz
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Abstract

Biobased hydrogels are three-dimensional polymeric matrices with a unique high water-holding capacity, which are mainly obtained from polysaccharides and proteins. Such a variety of natural polymer structures offers a range of hydrogel products with interesting physicochemical and biological properties. Nowadays, these matrices are already used in many industrial and environmental fields, which is considered extremely important. Moreover, the literature on the subject is constantly expanding, especially in areas of scientific research. The main purpose of this article is to briefly review the current development of matrices composition and properties of hydrogels of natural origin, considered as functional platforms in three application areas, primarily in biocatalysis, nutrition and medicine. The description of individual issues in the present article is supported by examples of case studies described in our previously published research papers, as well as considered in current projects of our research group.
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Authors and Affiliations

Karolina Labus
1
ORCID: ORCID
Halina Maniak
1
ORCID: ORCID
Katarzyna Kołodzińska
1
Łukasz Radosiński
1
ORCID: ORCID

  1. Wrocław University of Science and Technology, Faculty of Chemistry, Department of Micro, Nano and Bioprocess Engineering, Norwida 4/6 50-373 Wrocław, Poland
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Abstract

This study aims at the immobilization and characterization of thermoalkalophilic lipases produced recombinantly from Bacillus thermocatenulatus BTL2 and Bacillus pumilus MBB03. For this purpose, immobilization of the produced enzymes in calcium-alginate@gelatin (Ca–Alg@gelatin) hydrogel beads, immobilization optimization and characterization measurements of the immobilized-enzyme hydrogels were conducted. Optimum temperature and pH values were determined for B. thermocatenulatus and B. pumilus MBB03 immobilized-enzyme hydrogels (60–70 °C, 55 °C and pH 9.5, pH 8.5). Thermal stability was determined between 65 °C and 60 °C of B. thermocatenulatus and B. pumilus MBB03 immobilized enzymes, respectively. The pH stability was determined between pH 7.0–11.0 at +4°C and pH 8.0–10.0 at +4 °C, respectively.
In conclusion, the entrapment technique provided controlled production of small diameter hydrogel beads (~ 0:19 and ~ 0:29) with negligible loss of enzyme. These beads retained high lipase activity at high pH and temperature. The activity of Ca–Alg@gelatin-immobilized lipase remained relatively stable for up to three cycles and then markedly decreased. With this enzyme immobilization, it may have a potential for use in esterification and transesterification reactions carried out in organic solvent environments. We can conclude that it is one of the most promising techniques for highly efficient and economically competent biotechnological processes in the field of biotransformation, diagnostics, pharmaceutical, food and detergent industries.
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Authors and Affiliations

Kezban Yildiz Dalginli
1
ORCID: ORCID
Onur Atakisi
2
ORCID: ORCID

  1. Department of Chemistry and Chemical Processing Technologies, Kars Vocational High School Kafkas University, Kars, Turkey
  2. Department of Chemistry, Faculty Science and Letter, Kafkas University, Kars, Turkey
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Abstract

Biocompatibility, biodegradability and non-toxicity are the main attributes of any material to be used in biomedical applications. Among all the potential stimuli, pH, salt and temperature exist naturally in the internal environment of the human body. Hence internal stimuli responsive hydrogels can be exploited for specific drug delivery and tissue replacement. Poly(vinyl alcohol) (PVA) is the world’s largest volume synthetic polymer, produced for its excellent chemical resistance, physical properties and complete biodegradability, which has resulted in broad practical applications. PVA could be considered a suitable host material due to its good thermo-stability, chemical resistance and film-forming ability. It is also an important material because of its large-scale applications. Novel data analysis techniques were developed to analyze the response of PVA to external stimuli, including temperature and/or pH. The presented non-contact method shows that the PVA polymer gel, physically cross-linked by freezing and thawing, shrinks and swells under the influence of temperature, which is a reversible phenomenon. Under the given conditions, such as temperature, pH and mechanical load, the dominant factor affecting the swelling or contraction of the hydrogel is the change in the temperature of the liquid in which the PVA hydrogel sample is immersed.
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Authors and Affiliations

Katarzyna Kazimierska-Drobny
1

  1. Department of Mechatronics, Bydgoszcz Kazimierz Wielki University, Kopernika 1 street, 85-074 Bydgoszcz, Poland
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Abstract

Currently, there is a tendency for new forms of carrier-drug systems to appear with prolonged and controlled release. However, in order to design medical or pharmaceutical devices, which have to be characterized by high quality and the assumed parameters in real conditions, it is necessary to analyze this process based on in vitro release (IVR) testing methods. For this purpose, extracorporeal studies are carried out, which enable the determination of the release profiles of active substances using a simulated tissue-like environment. Here, we focused on the release tests of poorly water-soluble compounds (salicylic acid and fluocinolone acetonide) from the dual drug delivery system using the flow-through cell method (USP4). Additionally, bio-hybrid hydrogel matrix containing the system of thermosensitive nanocarrier with salicylic acid and fluocinolone acetonide was subjected to the following investigations: physicochemical (swelling ability, gel fraction), morphological (SEM analysis) and structural using FT-IR spectroscopy. On the basis of results, we can conclude that the USP4 method may be suitable, especially for the release tests of poorly water-soluble components introduced into modern forms of drug administration, such as polymeric matrices, hydrogels, nano- and microcarriers as well as hybrid systems.
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Authors and Affiliations

Katarzyna Bialik-Wąs
1
ORCID: ORCID
Paulina Sapuła
1
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Chemical Engineering and Technology, Department of Organic Chemistry and Technology, Warszawska 24, 31-155 Cracow, Poland
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Abstract

In recent years, a growing problem of water deficit has been observed, which is particularly acute for agriculture. To alleviate the effects of drought, hydrogel soil additives – superabsorbent polymers (SAPs) – can be helpful.
The primary objective of this article was to present a comparison of the advantages resulting from the application of synthetic or natural hydrogels in agriculture. The analysis of the subject was carried out based on 129 articles published between 1992 and 2020. In the article, the advantages of the application of hydrogel products in order to improve soil quality, and crop growth.
Both kinds of soil amendments (synthetic and natural) similarly improve the yield of crops. In the case of natural origin polymers, a lower cost of preparation and a shorter time of biodegradation are indicated as the main advantage in comparison to synthetic polymers, and greater security for the environment.
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Authors and Affiliations

Beata Grabowska-Polanowska
1
ORCID: ORCID
Tomasz Garbowski
1
ORCID: ORCID
Dominika Bar-Michalczyk
1
ORCID: ORCID
Agnieszka Kowalczyk
1
ORCID: ORCID

  1. Institute of Technology and Life Sciences – National Research Institute, Falenty, Hrabska Av. 3, 09-090 Raszyn, Poland
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Abstract

This paper discusses the influence of the direction of applied deformation on the ability to gelation of thermosensitive chitosan hydrogels. The application of the shear rate equal in value to the classically performed oscillatory measurements leads to significantly different shapes of experimental curves. It was found that the type of mechanically applied deformation has a significant impact on the gelation ability of colloidal chitosan solutions and conditions of sol-gel phase transition. Simple shear leads to a phase transition at a lower temperature or in a shorter time compared to oscillatory tests. Moreover, based on the final values of dynamic viscosity in rotational measurements, it was found that stronger crosslinking of the polymer structure was observed.

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Authors and Affiliations

Anna Rył
ORCID: ORCID
Piotr Owczarz
ORCID: ORCID

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