Dorota Biniaś

Innovative wool geotextiles designed for erosion protection

Innovative geotextiles built from meandrically arranged thick ropes were produced. For the production of the geotextiles, the strips of woollen nonwoven were used. The segments of the geotextiles were installed on the bank of a drainage ditch. The behaviour of the geotextiles during 1 year was observed. It was demonstrated that the geotextiles installed in the ditch provide immediate protection of the bank. In the soil-covered wool, the process of slow biodegradation was initiated. Because of a low biodegradation rate at the end of the growing season, when the protective vegetation was not well developed, the geotextiles maintained their protective potential. In the following months, the biodegradation led to further destruction of wool fibres. During the biodegradation, the organic compounds rich in nitrogen were released into the soil. In spring, at the beginning of new growing season, the compounds acted as effective fertilizers, promoting the growth of protective vegetation. The vegetation growing on the bank provided an effective protection and took over the protective function of the geotextiles.

STRUCTURAL RESEARCH OF THERMOSENSITIVE CHITOSAN-COLLAGEN GELS CONTAINING ALP

Introducing collagen, which is basic ingredient of bone tissue, into the structure of chitosan gels which are formed at the physiological body temperature, is aimed at creating the so-called biomimetic structures, i.e. close in their composition to the natural composition of bone tissue. Within the research the influence of collagen on structural properties of thermosensitive chitosan gels and the influence of ALP on structural properties of chitosan and chitosan-collagen gels was determined.

Application of Raman Spectroscopy for Evaluation of Chemical Changes in Dibutyrylchitin Fibres

Microporous dibutyrylchitin (DBC) fibres formed by means of a dry-wet method were treated with aqueous solutions of potassium hydroxide. By applying various parameters of the alkaline treatment, fibres can be transformed into fibres from regenerated chitin or even into chitosan fibres. In the first stage, with the application of 5% KOH solutions and temperatures ranging from 20 to 90 °C, fibres from regenerated chitin were obtained. The subsequent treatment stage with saturated KOH solutions and the temperature range 70 140 °C resulted in obtaining fibres from chitosan with different deacetylation degrees.Structural changes in the fibres occurring in the course of their chemical treatment were analysed using RAMAN spectroscopy. Raman spectra were next mathematically processed by means of GRAMS software within the range 1800 820 cm-1 in order to evaluate the changes quantitatively. A new method is described for the determination of butyrylation and deacetylation degrees of dibutyrylchitin, chitin and chitosan. Analysis of the fibres obtained carried out by means of RAMAN spectroscopy proves that in the process gradual degradation of the polymer chains takes place.

Sodium ascorbate (SA) and l-ascorbic acid (AA) as modifiers of burn affected skin – A comparative analysis

Proper functioning of living organisms requires controlling the factors which govern the level of oxidative stress in the system, that is presence of free radicals at a given, rather low, level and preventing their excess. In this work it is shown that SA and AA active antioxidants, governing the oxidative stress in the wound, modify standard serum solution as well as burn affected necrotic eschar at the molecular structure level. In the case of incubation of skin fragments in SA and AA, the following findings were reported: modification of serum, that is appearance of low molecular weight oligomer bands in AA and recreation of native serum bands in SA. In frozen serum solutions modified by AA FTIR 1759 and 1420-1053 cm-1 bands are observed, whereas in SA FTIR 1603, 1411-1054 and 536 cm-1 bands appear. In the case of modification of the burn affected necrotic eschar in SA and AA - frequency shifts in the fingerprint region 1780-1000 cm-1 can be biomarkers indicating tissue regeneration process under the influence of antioxidants. 1780-1580 cm-1 and 1418-1250 cm-1 regions on the Raman spectra are particularly rich in spectral information. Modification of samples of skin burnt with AA activates the regions of the β-sheet aggregates whereas treatment of the samples with SA ascorbate demonstrates changes which testify to reconstruction of α-helix structure (SAXS studies).

The role of dimethyl sulfoxide (DMSO) in ex-vivo examination of human skin burn injury treatment

Dimethyl sulfoxide (DMSO) is one of the most versatile solvents in biological science, therefore it is frequently used as a solvent in biological studies and as a vehicle for drug therapy. DMSO readily penetrates, diffuses through biological membranes and ipso facto increases fluidity of liposomal membranes modelling stratum corneum. Thermal injury is associated with the appearance of lipid peroxidation products in the burned skin. The influence of DMSO on protein structure and stability is concentration and temperature dependant. The aim of this study was to assess the impact of DMSO on human burn wounds and examine the interactions between DMSO and skin surface. The real problem in burn treatment is hypoalbuminemia. At the level of the laboratory studies there was an attempt at answering the question of whether the DMSO will modify the standard serum solution. In the case of the incubation of skin fragments in 1%-100% DMSO, the following findings were reported: modification of the serum, appearance of low molecular weight oligomer bands, disappearance of albumin bands or reconstruction of native serum bands during incubation in antioxidant solutions. The result of the modification is also the exposure of FTIR 1603 and 1046cm-1 bands observed in frozen serum solutions. In the case of modification of the burned skin by DMSO solutions or antioxidants - frequency shifts, an increase in the intensity of amide I band as well as the appearance of the 1601cm-1 band can be specific biomarkers of the tissue regeneration process. In this study the areas 1780-1580cm-1 and 1418-1250cm-1 on the Raman spectra are particularly rich in spectral information.

Modification of chitin structure with tailored ionic liquids

Chitin, poly N-acetylglucosamine, has a great potential for use on an industrial scale as an enzyme carrier but it has an unfavorable particle structure that can be modified using ionic liquids (ILs). Several ionic liquids were investigated that have the same substituents on the ring (methyl- and propyl-) but differed in the type of cationic ring (pyrrolidinium, piperidinium, and piperazinium). Organic acid ions (acetic and lactic) were used as counter ions. 1-ethyl-3-methyl-imidazolium acetate and 1-ethyl-3-methyl-imidazolium lactate were used as a reference. The results confirm that the chitin particle structure or size, or both, simultaneously changes if chitin is dissolved in an IL and then precipitated. Organic acid anions and short substituents on the cationic ring of ILs influenced particle modification substantially, whereas the type of ring played a minor role. Additionally, the ionic liquids [MPpyrr][OAc], [MPpip][OAc] and [DMPpz][OAc] could be reused up to at least 4 times without losing their ability to dissolve chitin.

Properties and Structure of Cellulosic Membranes Obtained from Solutions in Ionic Liquids Coagulated in Primary Alcohols

Abstract This paper presents the results of studies on the preparation of cellulosic membranes, from a solution in 1-ethyl-3- methylimidazolium acetate (EMIMAc), using the phase inversion method. Initially, the membranes were obtained by coagulation of the polymer film in water and primary alcohols (methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol), 1-hexanol, 1-octanol) resulting in membranes with significantly differing morphologies. Subsequently, composite membranes were produced, with the support layer being a membrane with the largest pores, and the skin layer a membrane with smaller pores. The resulting membranes were tested for physicochemical and transport properties. The morphology of the membrane surfaces and their cross-sections were investigated by using a scanning electron microscope (SEM). The structure of the membranes, on the other hand, was investigated by FTIR spectroscopy and WAXS structural analysis.

Active antioxidants in ex-vivo examination of burn wound healing by means of IR and Raman spectroscopies-Preliminary comparative research.

Being a complex traumatic event, burn injury also affects other organ systems apart from the skin. Wounds undergo various pathological changes which are accompanied by alterations in the molecular environment. Information about molecules may be obtained with the use of Raman spectroscopy and Fourier-transform infrared spectroscopy, and when combined, both methods are a powerful tool for providing material characterization. Alterations in the molecular environment may lead to identifying objective markers of acute wound healing. In general, incubation of samples in solutions of l-ascorbic acid and 5% and 7% orthosilicic acid organizes the collagen structure, whereas the increased intensity of the Raman bands in the region of 1500-800cm-1 reveals regeneration of the burn tissue. Since oxidative damage is one of the mechanisms responsible for local and distant pathophysiological events after burn, antioxidant therapy can prove to be beneficial in minimizing burn wounds, which was examined on the basis of human skin samples and chicken skin samples, the latter being subject to modification when heated to a temperature sufficient for the simulation of a burn incident.

FORMATION AND PROPERTIES OF DBC/PLA MICROFIBRES

In this study, a solution of dibutyrylchitin (DBC)/polylactide (PLA) blend micro and nanofibres were successfully fabricated using blends of 2,2,2-trifluoroethanol (TFE) as solvents. Fibres were produced from the solutions by electrospinning. The DBC/PLA blend solutions in various ratios were studied for electrospinning into micro/nanofibres. The morphology of the micro and nanofibres was observed by scanning electron microscope (SEM). The biggest diameters of DBC/PLA fibres were obtained for the blended microfibres in ratios of 10/90 and 25/75. The smallest diameter was observed for pure polymers. The antibacterial properties were examined for materials obtained by electrospinning. In the experiments, materials with antibacterial properties were made. It is likely that the electrospun micro and nanofibres will be used in the native extracellular matrix for tissue engineering.