Wyniki wyszukiwania - BazTech

1

Evaluation of properties of polymer-ceramic filaments modified with aluminosilicates for use in 3D printing

Twaróg Rafał, Sendor Michał, Rapacz-Kmita Alicja, Gajek Marcin, Marchewka Jakub, Stodolak-Zych Ewa

Composites Theory and Practice

|

2023

|

R. 23, nr 1

56--63

EN

A study was conducted on selected nanoclay fillers, i.e. montmorillonite (MMT) or halloysite (HNT) in polylactic acid (PLA) pellets for the manufacture of filaments for 3D printing. A 1-3 weight fraction of the filler was used. In order to compatibilize the nanofiller with the PLA, two methods were employed to facilitate dispersion of the nanoclay particles: using prewetting of the nanoclay in dichloromethane (DCM) and introducing a short-chain plasticizer (polyethylene glycol, PEG200) during the homogenization process. The effectiveness of filler dispersion was verified by performing thermal analysis, i.e. thermogravimetry and differential scanning calorimetry (DG/DSC), as well as by microscopic observations. The processability of the obtained nanocomposite filament was verified for the finished products manufactured from both of the materials by FDM printing. Mechanical strength and impact tests were conducted on the printed samples. The results showed that the prints made from the nanocomposite filaments have better tensile strength (by 25 and 10% for PLA/HNT and PLA/MMT, respectively) compared to prints made from the pure polymer filament.

2

PAN-Based Carbon Fibers Deposition on NiTi Surface

Goryczka Tomasz, Szaraniec Barbara, Stodolak-Zych Ewa, Kluska Stanisława

Archives of Metallurgy and Materials

|

2023

|

Vol. 68, iss. 3

1109--1114

EN

The main objective of the work was to create a layer of carbon nanofibre on the surface of the NiTi shape memory alloy. The coating process was carried out in three stages. First, polyacrylonitrile was deposited by electrospinning. Then it was stabilized at temperatures up to 250°C. The last stage was the carbonization performed below 1000°C. The microstructure of the obtained coatings was observed using a scanning electron microscope. The X-ray diffraction techniques were applied to analyze the coating structure. After the polyacrylonitrile deposition, the fibers had an average diameter of about 280 nm, and the final fibers were almost twice as tiny. The applied steps also changed the phase and crystalline state of the fibers, finally leading to the formation of amorphous-nanocrystalline graphite.

3

Nonwoven Carbon Fibers with Nanometric Metallic Layers as a Tool to Monitor Regenerative Processes

Stodolak-Zych Ewa, Kudzin Marcin, Kornaus Kamil, Gubernat Maciej, Kaniuk E., Bogun Maciej

Archives of Metallurgy and Materials

|

2023

|

Vol. 68, iss. 3

1151--1156

EN

Still unsolved is the problem of monitoring the tissue regeneration with the use of implants (substrates) in in vivo conditions. The multitude of implant materials combined with their specific immanent often limit standard diagnostic methods, i.e. X-rey or computer tomography (CT). This is particularly difficult in therapies using polymeric high-resistance substrates for tissue engineering. The aim of this study was to fabricate a non-woven carbon fiber composed of carbon fibers (CF) which were then subjected to a surface modification by magnetron sputtering. A layer of iron (Fe) was applied under inert conditions (argon) for different time periods (2-10 min). It was shown that already after 2-4 minutes of iron sputtering, the voxel surface (CF_Fe2’, CF_Fe4’) was covered with a heterogeneous iron layer observed by scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDS). The longer the modification time, the more uniform the layer on the fiber surface becomes. This can be seen by the change in the wettability of the nonwoven surface which decreases from 131° for CF_Fe2 to 120° for CF_Fe10. The fibers do not change their geometry or dimensions (~11.5 um). The determination of pore size distribution by adsorption and desorption techniques (BJH) and specific surface area by nitrogen adsorption method (BET) have shown that the high specific surface area for the CF_Fe2’ fibers decreases by 10% with the increasing iron sputtering time. All the studied CF_Fe fibers show good biocompatibility with osteoblast-like cells MG-63 cells after both 3 and 7 days of culture. Osteoblasts adhere to the fiber surface and show correct morphology.

4

Emulsion electrospinning - method to introduce proteins for biomedical applications

Kurpanik Roksana, Rapacz-Kmita Alicja, Ścisłowska-Czarnecka Anna, Stodolak-Zych Ewa

Engineering of Biomaterials

|

2021

|

Vol. 24, no. 163

48

5

Emulsion electrospinning – method to introduce proteins for biomedical applications

Kurpanik Roksana, Rapacz-Kmita Alicja, Ścisłowska-Czarnecka Anna, Stodolak-Zych Ewa

Engineering of Biomaterials

|

2021

|

Vol. 24, no. 162

20--25

EN

The aim of this work was to obtain polymer fibers by the emulsion electrospinning. For this purpose, polycaprolactone (PCL) was used, which was modified before the electrospinning stage with micelles obtained by the oil-in-water (O/W) emulsion method. Micelles were obtained by combining the non-ionic surfactant Tween 80 or Triton X-100 used at different concentrations with the amino acid alanine. The obtained fibrous substrates had a typical unimodal fiber size distribution and their average size was in the range of 590-800 nm. The effectiveness of the emulsion electrospinning process was confirmed by Fourier Transform Infrared Spectroscopy - Attenuated Total Reflectance (FTIR-ATR) showing the presence of surfactants. The addition of micelles to the polymer solution significantly reduces the contact angle of nonwoven fabrics: from 120° (for PCL) to ~20-30° for surfactant-loaded nonwovens, and the micellar form allows tracking the release of alanine into the solution (UV-Vis). The combination of the core-shell- -morphology of the emulsion electrospun fibers allows comparable amino acid release times. There were no significant differences in both the amount of alanine released and the rate of its release between PCL/ Tween80/alanine and PCL/Triton X-100/alanine fibers, which were characterized by a similar fiber size.

6

Chemical and physical modifications of electrospun fibers as a method to stimulate tissue regeneration – minireview

Kurpanik Roksana, Stodolak-Zych Ewa

Engineering of Biomaterials

|

2021

|

Vol. 24, no. 159

31--41

EN

Fibrous scaffolds based on (bio)polymers are observed as mimicking the microstructure of the extracellular matrix. Thus, they are considered as an example of a utilitarian scaffold, useful for the regeneration of various types of tissues. The techniques described in the literature are well known to obtain submicrometric and nanometric fibers that, when randomly arranged, mimic the ECM. The biomimetic scaffold criterion might be even better reflected if the cell adhesion sites are present on the surface of such fibers. They promote the formation of the focal adhesion contact or facilitate the formation of a protein film on the fiber surface. Such a process is enhanced by an appropriate physical or chemical modification that activates the protein adsorption and the subsequent cell adhesion. The aim of this paper is to present different methods of physical and/or chemical modifications of fibrous materials: which can serve as scaffolds to support the regeneration processes of various tissues. In terms of physical methods, only weak interactions between the surface and the modifier were observed. This technique is simple but not durable. Chemisorption used as a second method of fiber modification is possible if a covalent or ionic bond is formed between the fiber and the modifier. Therefore, the chemical adsorption may not be fully reversible and requires a sequence of chemical actions to form a chemical bond. The most commonly used methods are the combined methods where the first step is the physical activation of the fiber surface, which facilitates the chemical modification step.

7

Antibacterial properties of carbon fibers with layer deposited by magnetron technique

Kurpanik Roksana, Dzierzkowska Ewa, Gubernat Maciej, Kudzin Marcin, Boguń Maciej, Stodolak-Zych Ewa

Engineering of Biomaterials

|

2021

|

Vol. 24, no. 163

103

8

Antibacterial properties of carbon fibers modified with titanium sol

Wołowczyk Patrycja, Długoń Elżbieta, Syguła-Cholewińska Justyna, Bezkosty Patryk, Stodolak-Zych Ewa, Błażewicz Marta, Sitarz Maciej

Engineering of Biomaterials

|

2021

|

Vol. 24, no. 163

119

9

The influence of microstructure of fibrous PLA/PVA membranes on physicochemical and biological properties

Dzierzkowska Ewa, Żmuda Przemysław, Ścisłowska-Czarnecka Anna, Kornaus Kamil, Stodolak-Zych Ewa

Engineering of Biomaterials

|

2020

|

Vol. 23, no. 158 spec. iss.

52

10

Fibrous carbon scaffold modified by polysaccharides with potential biological activity

Gubernat Maciej, Dzierzkowska Ewa, Ścisłowska-Czarnecka Anna, Boguń Maciej, Chadzińska Magdalena, Stodolak-Zych Ewa

Engineering of Biomaterials

|

2020

|

Vol. 23, no. 158 spec. iss.

53

11

Porous poly(lactic acid) based fibres as drug carriers in active dressings

Dzierzkowska Ewa, Ścisłowska-Czarnecka Anna, Matwally Sara, Romaniszyn Dorota, Chadzińska Magdalena, Stodolak-Zych Ewa

Acta of Bioengineering and Biomechanics

|

2020

|

Vol. 22, no. 2

185--197

EN

Purpose: The polymeric porous surface of fibres (PLA) may influence the kinetics of release of biologically active compounds (gentamicin, G and ethacridine lactate, R) affecting development of a bacterial biofilm. Methods: The porous fibres with different morphology were manufactured by the electrospinning method from ternary systems composed of PLA and selected solvents. Fibres morphology was examined using a scanning electron microscopy (SEM), their structure was analyzed by FT-IR ATR spectroscopy and differential scanning calorimetry (DSC). Changes in the drug release profile were measured using ICP/UV-Vis methods and the resulting bactericidal or bacteriostatic properties were tested by two-layer disk diffusion test in relation to various drug incorporation methods. Results: The porous fibres can be applied to produce drug-bearing membranes. The spectroscopic studies confirmed incorporation of gentamicin into the fibres and the presence of ethacridine lactate on their surface. Bimodal fibres distribution (P3) promoted faster release of gentamicin and ethacridine lactate from P3G and P3R materials. The electrospinning process coupled with the vapor induced phase separation influenced the glass transition temperature of the porous polymer fibres. The pre/post-electrospinning modification influenced the glass transition, maximum temperature of cold crystallization and melting point of the porous membrane, compared to the neat polymer. The polylactide fibres with gentamicin showed strong bactericidal effect on Gram-positive bacteria, while fibres with ethacridine lactate were bacteriostatic. Conclusions: The obtained fibres with complex surface morphology can be used as a membrane in active dressings as they make it possible to control the release profile of the active compounds.

12

Multifunctional biodegradable polymer/clay nanocomposites with antibacterial properties in drug delivery systems

Rapacz-Kmita Alicja, Szaraniec Barbara, Mikołajczyk Maciej, Stodolak-Zych Ewa, Dzierzkowska Ewa, Gajek Marcin, Dudek Piotr

Acta of Bioengineering and Biomechanics

|

2020

|

Vol. 22, no. 2

83--92

EN

Purpose: The aim of this study was to investigate the possibility of intercalation of gentamicin and neomycin in montmorillonite (MMT) nanofillers, as well as to study the in vitro antimicrobial properties of nanocomposite films containing a small amount of thus obtained nanofillers. Methods: The polylactide matrix (PLA) nanocomposite films with drug-intercalated montmorillonite fillers were obtained by casting after intercalation of drugs in aqueous solutions. The efficiency of intercalation has been confirmed by X-ray diffraction (XRD) and Zeta potential measurements. The materials were studied for surface wettability, roughness and mechanical properties during 6 weeks of incubation in phosphate buffer saline, and their bactericidal activity was tested against Escherichia coli bacteria before and after 6 weeks of incubation in distilled water at 37 C. The presence of antibiotics during the incubation was monitored by conductivity and pH measurements. Results: The results indicate that nanocomposite polylactide films with montmorillonite filler intercalated with gentamicin and neomycin tend to degrade faster that their counterparts with non-intercalated fillers, which affects their mechanical properties. However, drug intercalation provided an antibacterial activity, which was confirmed by the presence of zones inhibiting the growth of Gram-negative bacteria for both antibiotics. It was also confirmed that the interaction of antibiotics with clay and polymer matrix did not adversely affect this bactericidal effect. Conclusions: Montmorillonite can be successfully intercalated with both gentamicin and neomycin, and then used as active filler for polylactide films having very good antibacterial properties, therefore their use in biomedical applications can be significantly expanded.

13

2D-Raman correlation spectroscopy as a method to recognize of the interaction at the interface of carbon layer and albumin

Kołodziej A., Wesełucha-Birczyńska Aleksandra, Moskal Paulina, Stodolak-Zych Ewa, Dużyja Maria, Długoń Elżbieta, Sacharz Julia, Błażewicz Marta

Journal of Automation Mobile Robotics and Intelligent Systems

|

2019

|

Vol. 13, No. 3

74--83

EN

In modern nanomaterial production, including those for medical purposes, carbon based materials are important, due to their inert nature and interesting properties. The essential attribute for biomaterials is their biocompatibility, which indicates way of interactions with host cells and body fluids. The aim of our work was to analyze two types of model carbon layers differing primarily in topography, and developing their interactions with blood plasma proteins. The first layer was formed of pyrolytic carbon C (CVD) and the second was constructed of multi-walled carbon nanotubes obtained by electrophoretic deposition (EPD), both set on a Ti support. The performed complex studies of carbon layers demonstrate significant dissimilarities regarding their interaction with chosen blood proteins, and points to the differences related to the origin of a protein: whether it is animal or human. However the basic examinations, such as: wettability test and nano sctatch tests were not sufficient to explain the material properties. In contrast, Raman microspectroscopy thoroughly decodes the phenomena occurring at the carbon structures in contact with the selected blood proteins. The 2D correlation method selects the most intense interaction and points out the different mechanism of interactions of proteins with the nanocarbon surfaces and differentiation due to the nature of the protein and its source: animal or human. The 2D correlation of the Raman spectra of the MWCNT layer+HSA interphase proves an increase in albumin β-conformation. The presented results explain the unique properties of the Clayers (CVD) in contact with human albumin.

14

Synthetic extracellular matrix as a substrate for regenerative medicine

Stodolak-Zych Ewa, Menaszek Elżbieta, Twardy Aleksandra, Ścisłowska-Czarnecka Anna, Boguń Maciej, Kolesińska Beata

Engineering of Biomaterials

|

2019

|

Vol. 22, no. 152

10--15

EN

The work presents materials characteristics of fibrous polysaccharide substrates (calcium alginate, CA) modified with short peptides. Three types of synthesized peptides (hexapeptides) were composed of: cysteine (C) and tryptophan (W) named - (WWC)2or cysteine (C) and tyrosine (Y) named (YYC)2 or phenyloalanine (F) named 6F. The peptides size distribution (DLS method) showed that they agglomerated in an alcohol medium. These results were used to select a modification method of the fibrous substrates i.e. the peptides were deposited on the fibrous alginate substrate by the electrospraying technique. Using this method three kinds of polysaccharide- peptides systems were obtained i.e.: CA/(WWC)2, CA/(YYC)2CA/6F. As a reference material, the pure calcium alginate fibrous substrate was used. The results of modification with short peptides were evaluated via scanning electron microscopy (SEM): small aggregates were observed (40-100 nm) on the surface of fibers, and the fibers size remained the same after modification (11-12 μm). The size of aggregates depended on the kind of short peptide; the smaller (40 nm) aggregates were observed when the peptide had only aromatic chain (6F), the bigger (<100 nm) ones were observed when the peptide had heterocyclic rings in the chain (WWC and YYC). All materials were contacted with osteoblast-like cells (MG-63) to test biocompatibility (cells viability after 3 and 7 days) and the results proved showed higher viability in the polysaccharide-peptide system which increased with the time of observation. The durability of polysaccharide-peptide systems was tested using the enzymatic assay: collagenase confirmed the stability of materials. The progress of degradation rate was observed using infrared spectroscopy (FTIR-ATR) - the ratio on bands with C-O and C-OH increased after degradation under in vitro conditions.Results of the investigations on the fibrous substrates have confirmed that the system is a good model of an extracellular matrix (ECM) due to its chemical composition and microstructure which both have biomimetic characteristics. Thus, it may be used as a filling of bone defects supporting the regeneration of the damaged tissue. Additionally, it may also serve as the model research system of ECM.

15

Preliminary investigations on silicone resin composites with carbon filler for dry electrodes application

Grochala Dominik, Kajor Marcin, Smoleń Paweł, Stodolak-Zych Ewa

Engineering of Biomaterials

|

2019

|

Vol. 22, no. 149

20--24

EN

The paper presents results of investigations of basic material properties of novel composites based on silicone resin and carbon nanotubes as a filler. The motivation for the research is a need for materials which provide better mechanical properties than standard wet Ag/AgCl electrodes. However, a critical issue is also obtaining defined electrical characteristics in order to preserve an ability to effectively record biomedical signals such as electrocardiography (ECG). Within the introduction chapter, related researches and the current state-of-the-art in the context of dry electrodes technology were described. In the next step technological aspects of components processing and forming as well as the morphology of substrates used in the research were presented. Thermally-cured silicone resin was utilized to obtain elastic properties of the resulting material. The carbon nanotubes (CNT) were chosen as a conductive medium which provides defined electrical impedance. A developed technological process allowed to deliver samples of reproducible structure and properties. In the next chapter, methods and results of conducted experiments involving electrical, mechanical and thermal examination were presented. Finally, achieved outcomes are promising in the context of improvements of the designed composite. Especially the conductivity below 100 Ohms constitutes a significant motivation for further research in the field of dry electrodes for biosignals acquisition.

16

Influence of chitosan nonwoven fabric modification on its physicochemical and biological properties

Dzierzkowska Ewa, Ścisłowska-Czarnecka Anna, Kolesińska Beata, Boguń Maciej, Stodolak-Zych Ewa

Engineering of Biomaterials

|

2019

|

Vol. 22, no. 153 spec. iss.

103

17

Electrospinning for drug delivery systems: potential of the technique

Dzierzkowska Ewa, Stodolak-Zych Ewa

Engineering of Biomaterials

|

2019

|

Vol. 22, no. 149

10--14

EN

Electrospinning is a technique used to manufacture nano- and submicron fibers based on synthetic or natural polymers. Additionally, biomaterials used in the electrospinning procedure can be modified by bioactive compounds, e.g. peptides or growth factors. The microstructure of the obtained fibrous scaffolds mimics natural extracellular matrix (ECM) environment. The size and the microstructure of the fibrous scaffolds are considered to be suitable for cells adhesion and proliferation. Various design features of the electrospinning device (e.g. the shape of the collector, the shape of the nozzle, the direction of the applied voltage) or electrospinning conditions (e.g. humidity, temperature) allows to control properties of the fibers (their shape, diameter, porosity). Novel structures, such as core-shell fibers, porous fibers attracted wide attention due to their properties and functionalities. Porous fibers or fibers with nanoscaled structures can be obtained in several ways. These methods are mainly focused on using high humidity and highly volatile solvent applied in the electrospinning process. The core-shell structure can be obtained by coaxial electrospinning. That binary fiber has ability to control the release rate of drug enclosed within the shell or core. The drug release profile can be also modified by loading the pharmacological agent either directly to the spinning solution or its post immobilization.This diversity of the electrospun fibers is a reason for non-woven materials to be considered for application as drug carriers. The review of electrospinning methods presented here proves that the control over fibers surface area, morphology and the choice of polymer enable modelling of drug release kinetics.

18

Biological properties of fibrous membranes modified with natural and synthetic antibiotics

Dzierzkowska Ewa, Scisłowska-Czarnecka Anna, Boguń Maciej, Stodolak-Zych Ewa

Engineering of Biomaterials

|

2019

|

Vol. 22, no. 153 spec. iss.

40

19

Impact of a pulsed magnetic field on selected polymer implant materials

Szponder Tomasz, Stodolak-Zych Ewa, Polkowska Izabela, Sobczyńska-Rak Aleksandra

Acta of Bioengineering and Biomechanics

|

2019

|

Vol. 21, no. 1

87--96

EN

Physiotherapy with the use of pulsed magnetic fields is one of the methods of activating the processes of bone healing and regeneration. Exposing materials serving as membranes in guided bone regeneration (GBR) or guided tissue regeneration (GTR) to magnetic fields is an effective model that allows to monitor changes in the material under the influence of the magnetic field. Methods: Materials engineering methods were used to verify the extent of material degradation resulting from magnetic field exposure in an aqueous environment. Changes in surface morphology were observed under an optical microscope and a scanning electron microscope (SEM). Changes in surface wettability were analysed in relation to the direct contact angle. Chemical structural changes were verified with the use of infrared spectroscopy (FTIR-ATR). Results: The PCL-based membrane materials underwent relatively moderate surface degradation (altered contact angle, changes in surface morphology), but the absence of observable FTIR-ATR spectral shifts evidenced material stability under the influence of magnetic field. More extensive degradation processes were observed in the case of PLDLA-based materials, whose surface character changed from hydrophilic to hydrophobic. The spectra revealed enhanced intensity of the chain terminal groups, provided that modifiers (nanometric SiO2 and TCP (water reservoir)) were present in the polymer matrix. Conclusions: The extent degradation in the polymer membrane was primarily dependent on the presence of aqueous environment, while the influence of the magnetic field on the analysed membrane materials was negligible. Therefore, GBR/GTR membrane implants can be considered to remain stable during rehabilitation with the use of alternating magnetic field.