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Biodegradable and antimicrobial polycaprolactone nanofibers with and without silver precipitates

Dobrzański L. A., Hudecki A., Chladek G., Król W., Mertas A.

Archives of Materials Science and Engineering

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2015

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Vol. 76, nr 1

5--26

EN

Purpose: The purpose of the paper is to present the results of own researches, including the study of the structure and the properties of new obtained single- and doublecomponent polycaprolactone polymer nanofibers as well as of composite nanofibers with and without silver precipitates produced by electrospinning including the results of biological research, proving the usefulness of the newly developed nano-engineering materials and their applicability in regenerative medicine, as well as tissue engineering. Design/methodology/approach: On the basis of the data available from the fundamental literature and based on the criteria of potential and attractiveness, polycaprolactone was selected for research from among a number of polymer materials, using a method of procedural benchmarking and weighted scores. The obtained nanomaterials undergone the following examinations to confirm the assumed aim of the work: infrared spectroscopy FTIR, Wide-angle X-ray scattering (WAXS), BET, Langmuir specific surface area and DTF porosity assessed with the gas adsorption method, in a transmission electron microscope (TEM), a scanning electron microscope (SEM), a fluorescence microscope, antibacterialness and antifungalness investigations and examinations of biological properties in vitro. Findings: The applicability of polymer fibers in medicine depends on biocompatibility and non-toxicity of the applied material, which is influenced by the chemical purity of the materials applied and the toxicity of the input solvents. The potential toxicity of nanofibers should therefore be eliminated, starting with selection of materials used for obtaining solutions. Many other factors fundamental for the quality and properties of polycaprolactone nanofibers need to be taken into account to create single- and doublecomponent and composite nanofibers. Practical implications: The obtained composite materials, due to their non-toxicity resulting from the components applied, including solvents, bacteriocidity and bioactivity, may find their applications in tissue engineering as membranes in controlled regeneration of bone tissue, as carriers of medicinal agents in bone surgery, as implantable surgical meshes and as scaffolds for a tissue culture. In turn, the composite core-shell nanofibers, by combining the antibacterial properties of the coating with bioactive properties of the core, are attractive materials for three-dimensional tissue scaffold. Such materials can be used as a carrier of medicine, a treatment of hard healing wounds, invasive surgery, neurosurgery, as substrate for the culturing of a retina, material to reconstruct nerves and in dentistry or oncology, to replace the natural tissue removed because of a cancer with the possibility of applying a therapeutic agent, e.g., an antibiotic or a medicine used in cancer therapies, released after the dissolution of the coating of nanofibers. Originality/value: The present paper is the original report from a personal own research and explains the concept and scope of own research of a new obtained single- and doublecomponent polycaprolactone polymer nanofibers as well as of composite nanofibers produced by electrospinning for application in regenerative medicine, the presentation of technological conditions and methodology of own research into polymer nanofibers, and above all very detailed description of the results of own investigations

2

Surface properties and antimicrobial activity of composite nanofibers of polycaprolactone with silver precipitations

Dobrzański L., Hudecki A., Chladek G., Król W., Mertas A.

Archives of Materials Science and Engineering

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2014

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Vol. 70, nr 2

53--60

EN

Purpose: The purpose of the article is to investigate the structure and antimicrobial properties of composite nanofibers with silver particles precipitated onto the nanofibers surface. Design/methodology/approach: A solution was prepared in the first place made of the following solvents to fabricate antimicrobial composite nanofibers of polycaprolactone with silver precipitations: formic acid and acetic acid at a rate of 70:30. Then, silver nitrate was introduced into the fabricated solution of the solvents and it was subjected to the interaction of ultrasounds, and after 10 minutes polycaprolactone was added to the solution, and then the solution was mixed for 12 hours and a solution was obtained with a 10% concentration and the mass fraction of 0, 1, 3 and 5% of silver nitrate additives. The solution was forced into a positive voltage electrode placed above a negative voltage electrode; the solution was then subjected to the activity of a strong electrostatic field transforming the solution into micro- and nanofibers. After electrospinning, the fibers obtained underwent the activity of a 2% ascorbic acid solution, by means of which silver was precipitated on the nanofibers surface. Viscosity and electrical conductivity tests were performed of single-component and double-component solutions, of the fibers’ structure in a transmission electron microscope, of the BET, Langmuir specific surface area and DTF porosity with the method of gas adsorption and antimicrobial activity of the nanocomposites produced on the nanocomposites on following bacteria: Staphylococcus aureus, Escherichia coli, Candida albicans. Findings: The use of a formic acid and acetic acid solution at a rate of 70:30 for preparation of a polycaprolactone solution for its electrospinning enables to obtain a non-toxic and fully biodegradable polymer nanofibers of polycaprolactone with PCL/Ag silver precipitations possessing high antimicrobial performance against Gram+, Gram- bacteria and fungi. Practical implications: Antimicrobial composite nanofibers with silver nanoparticles precipitated onto the nanofibers surface can be applied in biodegradable antiseptic dressings in the form of mats or other textiles containing polymer nanofibers of polycaprolactone with PCL/Ag silver precipitations obtained as a result of electrospinning. Originality/value: The research outcomes confirm that it is feasible to manufacture polycaprolactone nanofibers with PCL/Ag silver precipitations possessing high antimicrobial performance against Gram+, Gram- bacteria and fungi.

3

Structure, geometrical characteristics and properties of biodegradable micro- and polycaprolactone nanofibers

Dobrzański L., Hudecki A.

Archives of Materials Science and Engineering

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2014

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Vol. 70, nr 1

5--13

EN

The purpose of the paper is to obtain and examine the structure and properties obtained in the electrostatic field of micro- and nanofibers PCL. Design/methodology/approach: The main problem of the study is to examine the impact of properties of the polymer solutions PCL obtained from the mixture of formic acid and acetic acid in a ratio of 70:30, tetrahydrofuran and dimethylsulfoxide in a ratio of 70:30, and chloroform and methanol in a ratio of 70:30 on the structure and and surface properties of polymer micro and nanofibers PCL. Findings: On the basis of out carried researches the impact of the polymer solutions applied to researches on the diameter and the properties of obtained polymer micro- and nanofibers have been shown. It comes out that from the our carried researches of specific surface area of fibers the highest specific surface area BET was obtained for fibers formed from a mixture of acetic acid and formic acid and it is equalled 8.9 m2/g. Significantly smaller surface area was obtained from a mixture of tetrahydrofuran and dimethyl sulfoxide 3.1 m2/g. However, the lowest surface area for fibers obtained from a mixture of chloroform and methanol, which is 0.9 m2/g, in spite of the observation of the porous surface of fibers. Practical implications: Mixture of formic acid and acetic acid may be an alternative solution for preparing nanofibers PCL. Originality/value: The results confirm the possibility of receiving nanofibers PCL from a mixture of non-toxic solvents.

4

Examination of the surface properties of ceramic micro and nanoparticles

Hudecki A., Pawlyta M., Dobrzański L.A., Chladek G.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 61, nr 2

257--262

EN

Purpose: The purpose of the article is to examine surface properties of ceramic nanoparticles applied as fillers in composite materials of polymeric warps. Design/methodology/approach: For research there were used three types of ceramic micro and nano fillers: silver sodium hydrogen zirconium phosphate AlphaSan RC2000 (Milliken Chemical) and silica Aerosil DT4 and Aerolisl R 812 (Evonik Corporation). For the purpose of mentioned materials above there were used: scanning electron microscope SEM, Transmission Electron Microscope TEM and gas adsorption method for the purpose of qualifying specific surface area BET, Langmuria, porosity BJH and energy adsorption. Findings: On the base of undergone research there were pointed out dependence between size, shape, porosity of particles and specific surface area BET, Langmuira and energy of adsorption. Practical implications: Methods of measurements based on gas adsorption belong to the types of measurement methods that are very intensively developing that allows undergo measurements of various surface properties meaningful both in material engineering as well as in catalectic chemistry. Originality/value: Specific surface area measurement by gas adsorption method execution. Examination with transmission electron microscopy technique.

5

Conceptual study on a new generation of the high-innovative advanced porous and composite nanostructural functional materials with nanofibers

Dobrzański L. A., Pawlyta M., Hudecki A.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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Vol. 49, nr 2

550--565

EN

Purpose: The purpose of the paper is to analyse theoretically the possibilities of the development of a new generation of the high-innovative advanced porous and composite nanostructural functional materials with nanofibers and to study into the material science grounds of synthesis and/or production and formulation of such materials’ structure and properties and to characterise and model their structure and properties depending on the compositional, phase and chemical composition and the applied synthesis and/or production and/or processing processes, without the attitude towards any direct practical application or use, but with confirming the highly probable future application areas, using the unexpected effects of formulating such materials’ functional properties. Design/methodology/approach: In general, the study is of priority cognitive importance as theoretical considerations and the author’s initial analyses related to technology foresight concerning this group of issues as well as sporadical results of research provided in the literature, usually in its incipient phase, indicating a great need to intensify scientific research, to develop the new groups of materials with quite unexpected predictable effects, resulting from the use of nanofibers for fabricating super advanced composite and porous materials. Findings: The description of the state of the art for the subject of the study has been limited to the issues initially selected with an analysis with the method of weighted scores. Practical implications: The outcoming materials may have direct influence on the development of electronics and photonics, medicine and pharmacy, environmental protection, automotive industry, space industry, machine industry, textile and clothing industry, cosmetic industry, agriculture and food sector. Originality/value: The value of this paper lies in the fact that it proposes a new generation of the high-innovative advanced porous and composite nanostructural functional materials with nanofibers.