dr inż. Paweł Nakielski

Zakład Biosystemów i Miękkiej Materii (ZBiMM)
Pracownia Modelowania w Biologii i Medycynie (PMBM)
stanowisko: adiunkt
telefon: (+48) 22 826 12 81 wew.: 423
pokój: 328
e-mail: pnakiel

Doktorat
2015-02-03Systemy uwalniania leków oparte na nanowłóknach  (IBIB PAN)
promotor -- prof. dr hab. Tomasz Kowalewski, IPPT PAN
promotor pomocniczy -- dr inż. Tomasz Kowalczyk, IPPT PAN
1082
 
Ostatnie publikacje
1.Pierini F., Lanzi M., Nakielski P., Pawłowska S., Urbanek O., Zembrzycki K., Kowalewski T.A., Single-Material Organic Solar Cells Based on Electrospun Fullerene-Grafted Polythiophene Nanofibers, Macromolecules, ISSN: 0024-9297, DOI: 10.1021/acs.macromol.7b00857, pp.1-10, 2017
Pierini F., Lanzi M., Nakielski P., Pawłowska S., Urbanek O., Zembrzycki K., Kowalewski T.A., Single-Material Organic Solar Cells Based on Electrospun Fullerene-Grafted Polythiophene Nanofibers, Macromolecules, ISSN: 0024-9297, DOI: 10.1021/acs.macromol.7b00857, pp.1-10, 2017

Abstract:
Highly efficient single-material organic solar cells (SMOCs) based on fullerene-grafted polythiophenes were fabricated by incorporating electrospun one-dimensional (1D) nanostructures obtained from polymer chain stretching. Poly(3-alkylthiophene) chains were chemically tailored in order to reduce the side effects of charge recombination which severely affected SMOC photovoltaic performance. This enabled us to synthesize a donor–acceptor conjugated copolymer with high solubility, molecular weight, regioregularity, and fullerene content. We investigated the correlations among the active layer hierarchical structure given by the inclusion of electrospun nanofibers and the solar cell photovoltaic properties. The results indicated that SMOC efficiency can be strongly increased by optimizing the supramolecular and nanoscale structure of the active layer, while achieving the highest reported efficiency value (PCE = 5.58%). The enhanced performance may be attributed to well-packed and properly oriented polymer chains. Overall, our work demonstrates that the active material structure optimization obtained by including electrospun nanofibers plays a pivotal role in the development of efficient SMOCs and suggests an interesting perspective for the improvement of copolymer-based photovoltaic device performance using an alternative pathway.

45p.
2.Pierini F., Lanzi M., Nakielski P., Pawłowska S., Zembrzycki K., Kowalewski T.A., Electrospun poly(3-hexylthiophene)/poly(ethylene oxide)/graphene oxide composite nanofibers: effects of graphene oxide reduction, Polymers for Advanced Technologies, ISSN: 1042-7147, DOI: 10.1002/pat.3816, Vol.27, No.11, pp.1465-1475, 2016
Pierini F., Lanzi M., Nakielski P., Pawłowska S., Zembrzycki K., Kowalewski T.A., Electrospun poly(3-hexylthiophene)/poly(ethylene oxide)/graphene oxide composite nanofibers: effects of graphene oxide reduction, Polymers for Advanced Technologies, ISSN: 1042-7147, DOI: 10.1002/pat.3816, Vol.27, No.11, pp.1465-1475, 2016

Abstract:
In this article, we report on the production by electrospinning of P3HT/PEO, P3HT/PEO/GO, and P3HT/PEO/rGO nanofibers in which the filler is homogeneously dispersed and parallel oriented along the fibers axis. The effect of nanofillers' presence inside nanofibers and GO reduction was studied, in order to reveal the influence of the new hierarchical structure on the electrical conductivity and mechanical properties. An in-depth characterization of the purity and regioregularity of the starting P3HT as well as the morphology and chemical structure of GO and rGO was carried out. The morphology of the electrospun nanofibers was examined by both scanning and transmission electron microscopy. The fibrous nanocomposites are also characterized by differential scanning calorimetry to investigate their chemical structure and polymer chains arrangements. Finally, the electrical conductivity of the electrospun fibers and the elastic modulus of the single fibers are evaluated using a four-point probe method and atomic force microscopy nanoindentation, respectively. The electrospun materials crystallinity as well as the elastic modulus increase with the addition of the nanofillers while the electrical conductivity is positively influenced by the GO reduction.

Keywords:
electrospun composite nanofibers, poly(3-hexylthiophene), graphene oxide, electrical conductivity, mechanical properties

30p.
3.Pierini F., Zembrzycki K., Nakielski P., Pawłowska S., Kowalewski T.A., Atomic force microscopy combined with optical tweezers (AFM/OT), MEASUREMENT SCIENCE AND TECHNOLOGY, ISSN: 0957-0233, DOI: 10.1088/0957-0233/27/2/025904, Vol.27, pp.025904-1-11, 2016
Pierini F., Zembrzycki K., Nakielski P., Pawłowska S., Kowalewski T.A., Atomic force microscopy combined with optical tweezers (AFM/OT), MEASUREMENT SCIENCE AND TECHNOLOGY, ISSN: 0957-0233, DOI: 10.1088/0957-0233/27/2/025904, Vol.27, pp.025904-1-11, 2016

Abstract:
The role of mechanical properties is essential to understand molecular, biological materials, and nanostructures dynamics and interaction processes. Atomic force microscopy (AFM) is the most commonly used method of direct force evaluation, but due to its technical limitations this single probe technique is unable to detect forces with femtonewton resolution. In this paper we present the development of a combined atomic force microscopy and optical tweezers (AFM/OT) instrument. The focused laser beam, on which optical tweezers are based, provides us with the ability to manipulate small dielectric objects and to use it as a high spatial and temporal resolution displacement and force sensor in the same AFM scanning zone. We demonstrate the possibility to develop a combined instrument with high potential in nanomechanics, molecules manipulation and biological studies. AFM/OT equipment is described and characterized by studying the ability to trap dielectric objects and quantifying the detectable and applicable forces. Finally, optical tweezers calibration methods and instrument applications are given.

Keywords:
optical trap, nanomanipulation, nanomechanics, femtonewton forces

30p.
4.Sulejczak D., Taraszewska A., Chrapusta S.J., Dziewulska D., Nakielski P., Rafałowska J., Nanofiber mat spinal cord dressing-released glutamate impairs blood-spinal cord barrier, FOLIA NEUROPATHOLOGICA, ISSN: 1641-4640, DOI: 10.5114/fn.2016.64818, Vol.54, No.4, pp.392-404, 2016
Sulejczak D., Taraszewska A., Chrapusta S.J., Dziewulska D., Nakielski P., Rafałowska J., Nanofiber mat spinal cord dressing-released glutamate impairs blood-spinal cord barrier, FOLIA NEUROPATHOLOGICA, ISSN: 1641-4640, DOI: 10.5114/fn.2016.64818, Vol.54, No.4, pp.392-404, 2016

Abstract:
An excessive glutamate level can result in excitotoxic damage and death of central nervous system (CNS) cells, and is involved in the pathogenesis of many CNS diseases. It may also be related to a failure of the blood-spinal cord barrier (BSCB). This study was aimed at examining the effects of extended administration of monosodium glutamate on the BSCB and spinal cord cells in adult male Wistar rats. The glutamate was delivered by subarachnoidal application of glutamate-carrying electrospun nanofiber mat dressing at the lumbar enlargement level. Half of the rats with the glutamate-loaded mat application were treated systemically with the histone deacetylase inhibitor valproic acid. A group of intact rats and a rat group with subarachnoidal application of an ‘empty’ (i.e., carrying no glutamate) nanofiber mat dressing served as controls. All the rats were euthanized three weeks later and lumbar fragments of their spinal cords were harvested for histological, immunohistochemical and ultrastructural studies. The samples from controls revealed normal parenchyma and BSCB morphology, whereas those from rats with the glutamate-loaded nanofiber mat dressing showed many intraparenchymal microhemorrhages of variable sizes. The capillaries in the vicinity of the glutamate-carrying dressing (in the meninges and white matter alike) were edematous and leaky, and their endothelial cells showed degenerative changes: extensive swelling, enhanced vacuo­lization and the presence of vascular intraluminal projections. However, endothelial tight junctions were generally well preserved. Some endothelial cells were dying by necrosis or apoptosis. The adjacent parenchyma showed astrogliosis with astrocytic hypertrophy and swelling of perivascular astrocytic feet. Neurons in the parenchyma revealed multiple symptoms of degeneration, including, inter alia, perikaryal, dendritic and axonal swelling, and destruction of organelles. All the damage symptoms were slightly less severe in the rats given valproic acid treatment, and were absent from both the intact rats and the rats with ‘empty’ nanofiber mat dressing. These results demonstrate that glutamate-loaded nanofiber mat dressing can locally create glutamate levels capable of damaging BSCB and that the resulting damage can be mitigated with concurrent systemic valproate treatment.

Keywords:
astrocyte, blood-spinal cord barrier, CNS damage, degeneration, endothelium, excitotoxicity, glutamate, neuron, valproate, vessels

20p.
5.Nakielski P., Pawłowska S., Pierini F., Liwińska W., Hejduk P., Zembrzycki K., Zabost E., Kowalewski T.A., Hydrogel nanofilaments via core-shell electrospinning, PLOS ONE, ISSN: 1932-6203, DOI: 10.1371/journal.pone.0129816, Vol.10, No.6, pp.e0129816-1-16, 2015
Nakielski P., Pawłowska S., Pierini F., Liwińska W., Hejduk P., Zembrzycki K., Zabost E., Kowalewski T.A., Hydrogel nanofilaments via core-shell electrospinning, PLOS ONE, ISSN: 1932-6203, DOI: 10.1371/journal.pone.0129816, Vol.10, No.6, pp.e0129816-1-16, 2015

Abstract:
Recent biomedical hydrogels applications require the development of nanostructures with controlled diameter and adjustable mechanical properties. Here we present a technique for the production of flexible nanofilaments to be used as drug carriers or in microfluidics, with deformability and elasticity resembling those of long DNA chains. The fabrication method is based on the core-shell electrospinning technique with core solution polymerisation post electrospinning. Produced from the nanofibers highly deformable hydrogel nanofilaments are characterised by their Brownian motion and bending dynamics. The evaluated mechanical properties are compared with AFM nanoindentation tests.

Correction: Hydrogel Nanofilaments via Core-Shell Electrospinning, Nakielski P., Pawłowska S., Pierini F., Liwińska W., Hejduk P., Zembrzycki K., Zabost E., Kowalewski T.A., PLOS ONE, ISSN: 1932-6203, DOI: 10.1371/journal.pone.0133458, Vol.10, No.7, pp.e0133458-1-2, 2015

Keywords:
Gels, Nanomaterials, Atomic force microscopy, Polymerization, Bending, Mass diffusivity, Mechanical properties, Hydrodynamics

40p.
6.Nakielski P., Kowalczyk T., Zembrzycki K., Kowalewski T.A., Experimental and numerical evaluation of drug release from nanofiber mats to brain tissue, Journal of Biomedical Materials Research Part B: Applied Biomaterials, ISSN: 1552-4973, DOI: 10.1002/jbm.b.33197, Vol.103B, No.2, pp.282-291, 2015
Nakielski P., Kowalczyk T., Zembrzycki K., Kowalewski T.A., Experimental and numerical evaluation of drug release from nanofiber mats to brain tissue, Journal of Biomedical Materials Research Part B: Applied Biomaterials, ISSN: 1552-4973, DOI: 10.1002/jbm.b.33197, Vol.103B, No.2, pp.282-291, 2015

Abstract:
Drug delivery systems based on nanofibrous mats appear to be a promising healing practice for preventing brain neurodegeneration after surgery. One of the problems encountered during planning and constructing optimal delivery system based on nanofibrous mats is the estimation of parameters crucial for predicting drug release dynamics. This study describes our experimental setup allowing for spatial and temporary evaluation of drug release from nanofibrous polymers to obtain data necessary to validate appropriate numerical models. We applied laser light sheet method to illuminate released fluorescent drug analog and CCD camera for imaging selected cross-section of the investigated volume. Transparent hydrogel was used as a brain tissue phantom. The proposed setup allows for continuous observation of drug analog (fluorescent dye) diffusion for time span of several weeks. Images captured at selected time intervals were processed to determine concentration profiles and drug release kinetics. We used presented method to evaluate drug release from several polymers to validate numerical model used for optimizing nanofiber system for neuroprotective dressing.

Keywords:
neural therapy, brain phantom, drug delivery, laser light sheet, computational modeling, nanofibers

30p.
7.Pokrywczyńska M., Jundziłł A., Adamowicz J., Kowalczyk T., Warda K., Rasmus M., Buchholz Ł., Krzyżanowska S., Nakielski P., Chmielewski T., Bodnar M., Marszałek A., Dębski R., Frontczak-Baniewicz M.M., Mikułowski G., Nowacki M., Kowalewski T.A., Drewa T., Is the Poly (L- Lactide- Co– Caprolactone) Nanofibrous Membrane Suitable for Urinary Bladder Regeneration?, PLOS ONE, ISSN: 1932-6203, DOI: 10.1371/journal.pone.0105295, Vol.9, No.8, pp.105295-1-12, 2014
Pokrywczyńska M., Jundziłł A., Adamowicz J., Kowalczyk T., Warda K., Rasmus M., Buchholz Ł., Krzyżanowska S., Nakielski P., Chmielewski T., Bodnar M., Marszałek A., Dębski R., Frontczak-Baniewicz M.M., Mikułowski G., Nowacki M., Kowalewski T.A., Drewa T., Is the Poly (L- Lactide- Co– Caprolactone) Nanofibrous Membrane Suitable for Urinary Bladder Regeneration?, PLOS ONE, ISSN: 1932-6203, DOI: 10.1371/journal.pone.0105295, Vol.9, No.8, pp.105295-1-12, 2014

Abstract:
The purpose of this study was to compare: a new five-layered poly (L–lactide–co–caprolactone) (PLC) membrane and small intestinal submucosa (SIS) as a control in rat urinary bladder wall regeneration. The five-layered poly (L–lactide–co–caprolactone) membrane was prepared by an electrospinning process. Adipose tissue was harvested from five 8-week old male Wistar rats. Adipose derived stem cells (ADSCs) were seeded in a density of 3×106 cells/cm2 onto PLC membrane and SIS scaffolds, and cultured for 5-7 days in the stem cell culture medium. Twenty male Wistar rats were randomly divided into five equal groups. Augmentation cystoplasty was performed in a previously created dome defect. Groups: (I) PLC+ 3×106ADSCs; (II) SIS+ 3×106ADSCs; (III) PLC; (IV) SIS; (V) control. Cystography was performed after three months. The reconstructed urinary bladders were evaluated in H&E and Masson's trichrome staining. Regeneration of all components of the normal urinary bladder wall was observed in bladders augmented with cell-seeded SIS matrices. The urinary bladders augmented with SIS matrices without cells showed fibrosis and graft contraction. Bladder augmentation with the PLC membrane led to numerous undesirable events including: bladder wall perforation, fistula or diverticula formation, and incorporation of the reconstructed wall into the bladder lumen. The new five-layered poly (L–lactide–co–caprolactone) membrane possesses poorer potential for regenerating the urinary bladder wall compared with SIS scaffold.

Keywords:
urinary bladder regeneration, electrospinning

40p.
8.Sulejczak D., Andrychowski J., Kowalczyk T., Nakielski P., Frontczak-Baniewicz M.M., Kowalewski T.A., Electrospun nanofiber mat as a protector against the consequences of brain injury, FOLIA NEUROPATHOLOGICA, ISSN: 1641-4640, DOI: 10.5114/fn.2014.41744, Vol.52, No.1, pp.56-69, 2014
Sulejczak D., Andrychowski J., Kowalczyk T., Nakielski P., Frontczak-Baniewicz M.M., Kowalewski T.A., Electrospun nanofiber mat as a protector against the consequences of brain injury, FOLIA NEUROPATHOLOGICA, ISSN: 1641-4640, DOI: 10.5114/fn.2014.41744, Vol.52, No.1, pp.56-69, 2014

Abstract:
Traumatic/surgical brain injury can initiate a cascade of pathological changes that result, in the long run, in severe damage of brain parenchyma and encephalopathy. Excessive scarring can also interfere with brain function and the glial scar formed may hamper the restoration of damaged brain neural pathways. In this preliminary study we aimed to investigate the effect of dressing with an L-lactide-caprolactone copolymer nanofiber net on brain wound healing and the fate of the formed glial scar. Our rat model of surgical brain injury (SBI) of the fronto-temporal region of the sensorimotor cortex imitates well the respective human neurosurgery situation. Brains derived from SBI rats with net-undressed wound showed massive neurodegeneration, entry of systemic inflammatory cells into the brain parenchyma and the astrogliosis due to massive glial scar formation. Dressing of the wound with the nanofiber net delayed and reduced the destructive phenomena. We observed also a reduction in the scar thickness. The observed modification of local inflammation and cicatrization suggest that nanofiber nets could be useful in human neurosurgery.

Keywords:
brain injury, L-lactide-caprolactone copolymer nanofiber net, glial scar, neurodegeneration

20p.
9.Rafałowska J., Sulejczak D., Chrapusta S.J., Gadamski R., Taraszewska A., Nakielski P., Kowalczyk T., Dziewulska D., Non-woven nanofiber mats – a new perspective for experimental studies of the central nervous system?, FOLIA NEUROPATHOLOGICA, ISSN: 1641-4640, DOI: 10.5114/fn.2014.47841, Vol.52, No.4, pp.407-416, 2014
Rafałowska J., Sulejczak D., Chrapusta S.J., Gadamski R., Taraszewska A., Nakielski P., Kowalczyk T., Dziewulska D., Non-woven nanofiber mats – a new perspective for experimental studies of the central nervous system?, FOLIA NEUROPATHOLOGICA, ISSN: 1641-4640, DOI: 10.5114/fn.2014.47841, Vol.52, No.4, pp.407-416, 2014

Abstract:
(Sub)chronic local drug application is clearly superior to systemic administration, but may be associated with substantial obstacles, particularly regarding the applications to highly sensitive central nervous system (CNS) structures that are shielded from the outer environment by the blood-brain barrier. Violation of the integrity of the barrier and CNS tissues by a permanently implanted probe or cannula meant for prolonged administration of drugs into specific CNS structures can be a severe confounding factor because of the resulting inflammatory reactions. In this study, we tested the utility of a novel way for (sub)chronic local delivery of highly active (i.e., used in very low amounts) drugs to the rat spinal cord employing a non-woven nanofiber mat dressing. To this end, we compared the morphology and motoneuron ( + ) counts in spinal cord cervical and lumbar segments between rats with glutamate-loaded nanofiber mats applied to the lumbar enlargement and rats with analogical implants carrying no glutamate. Half of the rats with glutamate-loaded implants were given daily valproate treatment to test its potential for counteracting the detrimental effects of glutamate excess. The mats were prepared in-house by electrospinning of an emulsion made of a solution of the biocompatible and biodegradable poly(L-lactide-co-caprolactone) polymer in a mixture of organic solvents, an aqueous phase with or without monosodium glutamate, and sodium dodecyl sulfate as an emulsifier; the final glutamate content was 1.4 µg/mg of the mat. Three weeks after mat implantation there was no inflammation or considerable damage of the spinal cord motoneuron population in the rats with the subarachnoid dressing of a glutamate-free mat, whereas the spinal cords of the rats with glutamate-loaded nanofiber mats showed clear symptoms of excitotoxic damage and a substantial increase in dying/damaged motoneuron numbers in both segments studied. The rats given systemic valproate treatment showed significantly lower percentages of damaged/dying motoneurons in their lumbar enlargements. These results demonstrate the capacity of nanofiber mats for generation of neurotoxic glutamate in the rat CNS. However, the tested nanofiber mats need further improvements aimed at extending the period of effective drug release and rendering the release more steady.

Keywords:
CNS injury, electrospinning, excitotoxicity, glutamate, motoneuron, nanofibers, neurodegeneration, spinal cord, valproate

20p.
10.Nakielski P., Symulacje numeryczne procesu desorpcji i dyfuzji leku w materiale z nanowłókien, MODELOWANIE INŻYNIERSKIE, ISSN: 1896-771X, Vol.48, pp.99-111, 2013
Nakielski P., Symulacje numeryczne procesu desorpcji i dyfuzji leku w materiale z nanowłókien, MODELOWANIE INŻYNIERSKIE, ISSN: 1896-771X, Vol.48, pp.99-111, 2013

Abstract:
W pracy przedstawiono symulacje metodą elementów skończonych procesu desorpcji leku z powierzchni nanowłókien oraz dyfuzji wewnątrz porowatego materiału w zależności od wzajemnej konfiguracji włókien. Zbadano uwalnianie leku w różnych typach ułożenia włókien w materiale od idealnie ukierunkowanych po włókna ułożone nieregularnie. Dodatkowo przeanalizowano wpływ lokalnego zagęszczenia włókien i porowatości materiału na proces dyfuzji w macie. Przedstawiony model porównano z wynikiem eksperymentalnym uwalniania Rodaminy B z elektroprzędzonych nanowłókien oraz rozwiązaniem analitycznym dyfuzji z płaskiej płyty z homogenicznie rozmieszczonym lekiem. Celem przeprowadzonych obliczeń jest znalezienie kluczowych parametrów materiału, stosowanego jako system uwalniania leków w zapobieganiu neurodegeneracji po operacjach neurochirurgicznych.

Keywords:
desorpcja, dyfuzja, FRAP, nanowłókna, uwalnianie leków

4p.
11.Nakielski P., Kowalczyk T., Kowalewski T.A., Drug delivery system based on polymer nano-fibers, IPPT REPORTS, ISSN: 2299-3657, Vol.4b, pp.1-6, 2013
Nakielski P., Kowalczyk T., Kowalewski T.A., Drug delivery system based on polymer nano-fibers, IPPT REPORTS, ISSN: 2299-3657, Vol.4b, pp.1-6, 2013

Abstract:
This work presents our attempts to characterize release of two model drugs from electrospun polymer nanofibers. Such drug delivery system offers great potential for applications in medicine especially as neurosurgery protective membranes. Proper delivery of drugs requires precise control of the drug diffusion process during the release for days or even weeks. Lipophilic model drug Rhodamine B and hydrophilic Bovine Serum Albumin conjugated with Fluoresceine (BSA - FITC) were embedded in electrospun poly(L -lactide-co -ε-caprolactone) (PLC) nanofibers. Release of Rhodamine B showed saturation in cumulative release profile at 60% and 86% for 1.5% and 3% wt. initial drug content, respectively. Nanofibers electrospun from emulsion released almost entire drug encapsulated in water vesicles inside the nanofibers. Possible location of vesicles close to the surface of the nanofibers exposed them for surrounding fluid and caused leaching of the drug. In this case encapsulation of drug in emulsion prevented the initial burst release.Dependence of a drug release and composition of nanofiber is essential for production of drug delivery systems. Mathematical model constructed with this data allows to avoid tedious experimental work. This research was supported by Ministry of Science and Higher Education, National Centre for Research and Development Project grant no. R13008110. The first author has been supported with a scholarship from the European Social Fund, Human Capital Operational Programme.

Keywords:
nanofibres, drug delivery, vesicles


Lista ostatnich monografii
1.
471
Zembrzycki K., Pawłowska S., Nakielski P., Pierini F., Development of a hybrid Atomic Force microscope and Optical Tweezers apparatus , IPPT Reports on Fundamental Technological Research, 2, pp.1-58, 2016
2.
371
Nakielski P., Systemy uwalniania leków oparte na nanowłóknach, rozprawa doktorska, IPPT Reports on Fundamental Technological Research, 1, pp.1-216, 2015
Lista rozdziałów w ostatnich monografiach
1.
467
Kowalewski T.A., Nakielski P., Pierini F., Zembrzycki K., Pawłowska S., Advances in Mechanics: Theoretical, Computational and Interdisciplinary Issues, rozdział: Micro and nano fluid mechanics, CRC Press/Balkema, Taylor & Francis Group, M. Kleiber et al. (Eds.), pp.27-34, 2016

Prace konferencyjne
1.Nakielski P., Kowalczyk T., Kowalewski T.A., Modeling Drug Release from Materials Based on Electrospun Nanofibers, COMSOL 2013, COMSOL Conference, 2013-10-23/10-25, Rotterdam (NL), pp.1-6, 2013
Nakielski P., Kowalczyk T., Kowalewski T.A., Modeling Drug Release from Materials Based on Electrospun Nanofibers, COMSOL 2013, COMSOL Conference, 2013-10-23/10-25, Rotterdam (NL), pp.1-6, 2013

Abstract:
Comprehensive studies of drug transport in nanofibres based mats have been performed to predict drug release kinetics. The paper presents our approach to analyze the impact of fibers arrangement, one of the parameters varied in our parallel experimental studies. Drug encapsulation in submicron fibers and subsequent controlled release of drugs is a tedious task due to the large number of process and material parameters involved. In the numerical study we constructed a 3D finite element geometry representing nanofibrous cubic element. COMSOL Multiphysics has been used to assess the impact of the various purposed arrangements of fibers within the mat. Drug release from nanofibers was modeled by adsorption -desorption and diffusion equation, where drug diffusion coefficient in the fluid between the fibers was altered depending on porosity of the material. Our study shows that for the same material porosity drug release from the matrix of regularly oriented fibers is slower than from randomly oriented, isotropic nanofibrous material. Also by decreasing distance between the fibers drug transport rate is reduced.

Keywords:
Nanofibres, finite elements, drug release modelling


Abstrakty konferencyjne
1.Pawłowska S., Nakielski P., Pierini F., Zembrzycki K., Piechocka I.K., Kowalewski T.A., Tumbling, rotating and coiling of nanofilaments in an oscillating microchannel flow, BioNano6, Biomolecules and Nanostructures 6, 2017-05-10/05-14, Podlesice (PL), No.41E, pp.60, 2017
2.Nakielski P., Pierini F., Piechocka I.K., Blood clotting in the contact with nanofibers, NanoTech, NanoTech Poland International Conference & Exhibition, 2017-06-01/06-03, Poznań (PL), pp.178-178, 2017
Nakielski P., Pierini F., Piechocka I.K., Blood clotting in the contact with nanofibers, NanoTech, NanoTech Poland International Conference & Exhibition, 2017-06-01/06-03, Poznań (PL), pp.178-178, 2017

Abstract:
Nanofibers have received considerable attention in the past years, mainly due to their vast application in medicine [1]. One of the fastest growing areas of application are wound dressings and hemostats. Among the major causes of death from trauma, massive bleeding is responsible for 30 – 40% of mortality. In the hospital, massive bleeding are the second most common cause of death (22%) just after cardiac factors (33%) [2].
Despite a large number of experiments done in the topic of blood-biomaterial interactions, coagulation mechanisms are still not fully understood. Therefore, the main objective of our work is the analysis of protein adsorption, platelet adhesion and aggregation, and blood plasma coagulation in the contact with polymer nanofibers. Various synthetic polymers, their blends with natural polymers of confirmed hemostatic effect e.g. collagen and gelatine, and additionally nanofibers made of chitosan are investigated for their potential to stop bleeding. In the final, controlled release of drugs affecting coagulation cascade will be an important step providing accelerated blood clot formation.

3.Pawłowska S., Nakielski P., Pierini F., Zembrzycki K., Kowalewski T.A., Mobility of highly deformable nanofilaments, ICTAM XXIV, 24th International Congress of Theoretical and Applied Mechanics, 2016-08-21/08-26, Montréal (CA), pp.1196-1197, 2016
Pawłowska S., Nakielski P., Pierini F., Zembrzycki K., Kowalewski T.A., Mobility of highly deformable nanofilaments, ICTAM XXIV, 24th International Congress of Theoretical and Applied Mechanics, 2016-08-21/08-26, Montréal (CA), pp.1196-1197, 2016

Abstract:
Mobility of hydrogel nanofilaments suspended in liquid is investigated to gain basic knowledge on hydrodynamic interactions biased by Brownian fluctuations. Typical for long macromolecules effects like spontaneous conformational changes and cross-flow migration are observed and evaluated. The collected experimental data can be used to validate assumptions present in numerical models describing intercellular transport of long biomolecules.

Keywords:
persistence length, macromolecules, electrospinning, DNA, Brownian motion

4.Pierini F., Nakielski P., Pawłowska S., Zembrzycki K., Kowalewski T.A., Particles double layer evaluation by atomic force microscopy - optical tweezers, ICTAM XXIV, 24th International Congress of Theoretical and Applied Mechanics, 2016-08-21/08-26, Montréal (CA), pp.1204-1205, 2016
Pierini F., Nakielski P., Pawłowska S., Zembrzycki K., Kowalewski T.A., Particles double layer evaluation by atomic force microscopy - optical tweezers, ICTAM XXIV, 24th International Congress of Theoretical and Applied Mechanics, 2016-08-21/08-26, Montréal (CA), pp.1204-1205, 2016

Abstract:
Atomic force microscopy (AFM) is the most commonly used method of direct force evaluation, but due to its technical limitations this single probe technique is unable to detect forces with femtonewton resolution. We present the development of a combined atomic force microscopy and optical tweezers (AFM/OT) instrument. The optical tweezers system provides us the ability to manipulate small dielectric objects and to use it as a high spatial and temporal resolution displacement and force sensor in the same AFM scanning zone. We demonstrate the possibility to develop a combined instrument with high potential in nanomechanics, molecules manipulation and biologic al studies. The presented study is aimed to quantify the interaction forces between two single polystyrene particles in the femtonewton scale by using the developed AFM/OT equipment.

Keywords:
optical trap, nanomanipulation, femtonewtons

5.Pawłowska S., Nakielski P., Pierini F., Zembrzycki K., Kowalewski T.A., Highly Deformable Hydrogel Nanofilaments in Poiseuille Flow, MNF 2016, 5th Micro and Nano Flows Conference, 2016-09-11/09-14, Milan (IT), pp.50, 2016
Pawłowska S., Nakielski P., Pierini F., Zembrzycki K., Kowalewski T.A., Highly Deformable Hydrogel Nanofilaments in Poiseuille Flow, MNF 2016, 5th Micro and Nano Flows Conference, 2016-09-11/09-14, Milan (IT), pp.50, 2016

Keywords:
Hydrogel Nanofilaments, Bending Dynamics, Poiseuille Flow, Electrospinning

6.Pierini F., Zembrzycki K., Nakielski P., Pawłowska S., Kowalewski T.A., Nanomanipulating and sensing single particles interactions with combined atomic force microscopy optical tweezers (AFM/OT), MNF 2016, 5th Micro and Nano Flows Conference, 2016-09-11/09-14, Milan (IT), pp.40-41, 2016
Pierini F., Zembrzycki K., Nakielski P., Pawłowska S., Kowalewski T.A., Nanomanipulating and sensing single particles interactions with combined atomic force microscopy optical tweezers (AFM/OT), MNF 2016, 5th Micro and Nano Flows Conference, 2016-09-11/09-14, Milan (IT), pp.40-41, 2016

Keywords:
Atomic force microscopy/optical tweezers, Nanomanipulation, Single particles analysis, Interaction force measurement, DLVO theory

7.Nakielski P., Pawłowska S., Pierini F., Hejduk P., Zembrzycki K., Kowalewski T.A., Novel hydrogel nanofilaments based on electrospun core-shell fibers, Europhysics Conference Biomolecules and Nanostructures 5, 2015-05-13/05-17, Jaroszowice (PL), Vol.39C, pp.101, 2015
Nakielski P., Pawłowska S., Pierini F., Hejduk P., Zembrzycki K., Kowalewski T.A., Novel hydrogel nanofilaments based on electrospun core-shell fibers, Europhysics Conference Biomolecules and Nanostructures 5, 2015-05-13/05-17, Jaroszowice (PL), Vol.39C, pp.101, 2015

Keywords:
nanofilaments, hydrogel, long molecules flexibility

8.Pawłowska S., Nakielski P., Pierini F., Zembrzycki K., Kowalewski T.A., Mobility of nanofilaments, Experiments in Fluid Mechanics 2015, 2015-10-26/10-27, Warszawa (PL), pp.1, 2015
Pawłowska S., Nakielski P., Pierini F., Zembrzycki K., Kowalewski T.A., Mobility of nanofilaments, Experiments in Fluid Mechanics 2015, 2015-10-26/10-27, Warszawa (PL), pp.1, 2015

Abstract:
We propose a microscale experimental model in form of highly deformable nanofilaments, which permits for precise optical measurements and to evaluate hydrodynamic interactions (mobility). The conducted research includes determination of the mechanical properties of elastic hydrogel nanofilaments obtained by electrospinning that can serve as experimental benchmark to validate theoretical and numerical models describing dynamics of long biological molecules (e.g. proteins, DNA). Nanofilaments mechanical properties are determined by studying their dynamic bending. in shear flow and deformations due to the thermal fluctuations (Brownian motion). These results are compared with AFM nanoindentation measurements. Data obtained from this research project will be a base to crea te biocompatible nanoobjects that can become tools for the regeneration of tissue (e.g. neural tissue).

Keywords:
Biocompatible nanoobjects, highly deformable nanofilaments, regeneration of tissue

9.Nakielski P., Pawłowska S., Pierini F., Hejduk P., Zembrzycki K., Kowalewski T.A., Processing and mechanical properties relationships in hydrogel nanofilamets for biological application, ICMCSF, International Conference on Mechanics of Complex Solids and Fluids, 2015-05-17/05-22, Lille (FR), pp.1, 2015
Nakielski P., Pawłowska S., Pierini F., Hejduk P., Zembrzycki K., Kowalewski T.A., Processing and mechanical properties relationships in hydrogel nanofilamets for biological application, ICMCSF, International Conference on Mechanics of Complex Solids and Fluids, 2015-05-17/05-22, Lille (FR), pp.1, 2015

Keywords:
Nanofilaments, hydrogel filaments, nanofibres, long nanoobjects deformability

10.Pierini F., Nakielski P., Pawłowska S., Zembrzycki K., Kowalewski T.A., Hydrogel nanofilaments via core-shell electrospinning, NanoItaly, Nanotechnology meeting forum for research and market, 2015-09-21/09-24, Roma (IT), pp.1, 2015
Pierini F., Nakielski P., Pawłowska S., Zembrzycki K., Kowalewski T.A., Hydrogel nanofilaments via core-shell electrospinning, NanoItaly, Nanotechnology meeting forum for research and market, 2015-09-21/09-24, Roma (IT), pp.1, 2015

Abstract:
Controlled drug delivery systems are used to improve the conventional administration of drugs. One of the main challenges is to synthesize materials able to find a defined target and to release drugs in a controlled manner [1]. Several research tasks have been focused on developing ideal drug delivery systems made by hydrogel due to their unique properties [2]. The present study is based on the idea that soft and flexible nanomaterials can easily travel in crowed environments of body fluids and biological tissues. Modification of their mechanical properties obtained by changing of the cross-linker amount may give us the possibility to tune the material rigidity according to desired application. Here, we describe a novel method based on coaxial electrospinning for obtaining highly flexible hydrogel nanofilaments able to transport and release dedicated molecules. Two different types of hydrogels (poly(N,Nisopropyl acrylamide) and polyacrylamide) with three polymer/cross-linker ratios were produced and deeply studied. The nanofilaments morphology was characterized and the release of bovine serum albumin as a function of time was quantified. Mechanical properties of highly deformable hydrogel nanofilaments were evaluated by bending dynamics and Brownian motion observation techniques. The calculated mechanical properties were compared with data obtained by nanoindention. The results highlight the crucial role of morphology and stiffness on mobility of nanofilaments colloid systems. The information gained are fundamental to design nanoobjects with well-defined chemical and physical behaviour.

Keywords:
Nanofilaments, electrospinning, core-shell method, hydrogel

11.Kowalewski T.A., Nakielski P., Pierini F., Zembrzycki K., Pawłowska S., Nanoscale challenges of fluid mechanics, PCM-CMM-2015, 3rd Polish Congress of Mechanics and 21st Computer Methods in Mechanics, 2015-09-08/09-11, Gdańsk (PL), pp.11-16, 2015
Kowalewski T.A., Nakielski P., Pierini F., Zembrzycki K., Pawłowska S., Nanoscale challenges of fluid mechanics, PCM-CMM-2015, 3rd Polish Congress of Mechanics and 21st Computer Methods in Mechanics, 2015-09-08/09-11, Gdańsk (PL), pp.11-16, 2015

Abstract:
In this talk we would like to tackle general question of contemporary fluid dynamics, how far its assumption of a continuous, smooth medium remains useful when size and time scales start to approach molecular ones. The question is not trivial and seems to depend on several additional factors usually minored. For example, when full Navier-Stokes equations are replaced by their linear approximation we are loosing basic characteristics of convective motion, and still we use such approach. Once our fluid becomes granular matter with its own internal properties, proper interpretation of flow interactions with other molecular structures probably needs deeper physics. But still we try to convert such problem to the classical macro/micro scale description. Hence a general question arises, how small does a fluid have to be before it is not a fluid anymore?

Keywords:
microfluidics, nanofluids, Brownian motion, nanofilaments

12.Nakielski P., Kowalczyk T., Kowalewski T.A., Modelowanie procesu uwalniania leków z materiałów opartych na nanowłóknach, 53 Sympozjon „Modelowanie w mechanice”, 2014-02-22/02-26, Ustroń (PL), pp.112-113, 2014
Nakielski P., Kowalczyk T., Kowalewski T.A., Modelowanie procesu uwalniania leków z materiałów opartych na nanowłóknach, 53 Sympozjon „Modelowanie w mechanice”, 2014-02-22/02-26, Ustroń (PL), pp.112-113, 2014

Keywords:
nanomaty, modelowanie uwalniania leku

13.Nakielski P., Kowalczyk T., Kowalewski T.A., Evaluation of drug release from electrospun nanofibers by modification of material morphology, EYEC, 3rd European Young Engineers Conference, 2014-04-29/04-30, Warszawa (PL), pp.220-221, 2014
Nakielski P., Kowalczyk T., Kowalewski T.A., Evaluation of drug release from electrospun nanofibers by modification of material morphology, EYEC, 3rd European Young Engineers Conference, 2014-04-29/04-30, Warszawa (PL), pp.220-221, 2014

Keywords:
drug delivery, electrospinning, mathematical modeling, nanofibres

14.Nakielski P., Kowalczyk T., Kowalewski T.A., Zastosowanie materiałów z nanowłókien w inżynierii regeneracyjnej, I Konferencja Młodych Naukowców „Biotechnologia w produkcji zwierzęcej” SGGW, 2014-04-24/04-25, Warszawa (PL), pp.25, 2014
Nakielski P., Kowalczyk T., Kowalewski T.A., Zastosowanie materiałów z nanowłókien w inżynierii regeneracyjnej, I Konferencja Młodych Naukowców „Biotechnologia w produkcji zwierzęcej” SGGW, 2014-04-24/04-25, Warszawa (PL), pp.25, 2014

Keywords:
elektroprzędzenie, nanowłókna, uwalnianie leków, TBI

15.Pawłowska S., Nakielski P., Hejduk P., Pierini F., Zembrzycki K., Kowalewski T.A., Brownian motion of nanofibers, KKNM, 4th National Conference on Nano- and Micromechanics, 2014-07-08/07-10, Wrocław (PL), pp.162-163, 2014
Pawłowska S., Nakielski P., Hejduk P., Pierini F., Zembrzycki K., Kowalewski T.A., Brownian motion of nanofibers, KKNM, 4th National Conference on Nano- and Micromechanics, 2014-07-08/07-10, Wrocław (PL), pp.162-163, 2014

Keywords:
electrospinning, flexible nanorods, Brownian motion

16.Nakielski P., Kowalczyk T., Kowalewski T.A., Modeling drug delivery from nanofibers to brain tissue, XXI FMC, XXI Fluid Mechanics Conference, 2014-06-15/06-18, Kraków (PL), pp.24, 2014
Nakielski P., Kowalczyk T., Kowalewski T.A., Modeling drug delivery from nanofibers to brain tissue, XXI FMC, XXI Fluid Mechanics Conference, 2014-06-15/06-18, Kraków (PL), pp.24, 2014

Keywords:
brain, drug delivery, nanofibres, mathematical modelling

17.Pierini F., Hejduk P., Nakielski P., Pawłowska S., Zembrzycki K., Kowalewski T.A., Study of surface interaction forces in polystyrene colloidal nanoparticles systems, XXI FMC, XXI Fluid Mechanics Conference, 2014-06-15/06-18, Kraków (PL), pp.115, 2014
Pierini F., Hejduk P., Nakielski P., Pawłowska S., Zembrzycki K., Kowalewski T.A., Study of surface interaction forces in polystyrene colloidal nanoparticles systems, XXI FMC, XXI Fluid Mechanics Conference, 2014-06-15/06-18, Kraków (PL), pp.115, 2014

Keywords:
Nanoparticles, polystyrene beads, surface properties, atomic force microscopy, hydrodynamic properties

18.Pawłowska S., Hejduk P., Nakielski P., Pierini F., Zembrzycki K., Kowalewski T.A., Analysis of nanoparticles hydrodynamic diameters in Brownian motion, XXI FMC, XXI Fluid Mechanics Conference, 2014-06-15/06-18, Kraków (PL), pp.116, 2014
Pawłowska S., Hejduk P., Nakielski P., Pierini F., Zembrzycki K., Kowalewski T.A., Analysis of nanoparticles hydrodynamic diameters in Brownian motion, XXI FMC, XXI Fluid Mechanics Conference, 2014-06-15/06-18, Kraków (PL), pp.116, 2014

Keywords:
Nanoparticles, Brownian motion, hydrodynamic diameter

19.Nakielski P., Kowalczyk T., Kowalewski T.A., Experimental study of drug release system based on electrospun nanofibres, ICTAM XXIII, 23rd International Congress of Theoretical and Applied Mechanics, 2012-08-19/08-24, Beijing (CN), pp.CD-ROM FS10-007, 2012
Nakielski P., Kowalczyk T., Kowalewski T.A., Experimental study of drug release system based on electrospun nanofibres, ICTAM XXIII, 23rd International Congress of Theoretical and Applied Mechanics, 2012-08-19/08-24, Beijing (CN), pp.CD-ROM FS10-007, 2012

Abstract:
The paper contains our attempts to estimate diffusion parameters of nanofibers actually applied as protective mats for neurosurgery. Measurements of concentration profiles of fluorophore released from stained nanofibres are performed. The two release systems are investigated: solid nanofibres and core-shell nanofibres with targeted drug simulator encapsulated inside nanofibres. The gathered information allows us to estimate parameters necessary for controlling drug release profiles.

Keywords:
Nanofibers, Electrospinning, Drug Delivery Systems

20.Nakielski P., Kowalczyk T., Kowalewski T.A., Experimental study of drug release system based on electrospun nanofibers, III National Conference of Nano and Micromechanics, 2012-07-04/07-06, Warszawa (PL), pp.149-150, 2012
Nakielski P., Kowalczyk T., Kowalewski T.A., Experimental study of drug release system based on electrospun nanofibers, III National Conference of Nano and Micromechanics, 2012-07-04/07-06, Warszawa (PL), pp.149-150, 2012

Abstract:
Nanofibers produced by electrospinning of biologically active substances became attractive material for encapsulating living cells, bacteria, and drugs for targeted therapy. Here, we aim to use nanofiber matrices as neurosurgery protective membranes and drug carriers. Proper administration of drugs requires precise control of the diffusion process during the time of release of days or even weeks. Construction of such system is a tedious experimental task. To avoid hundreds of tests it is aimed to build a numerical model including essential information about composition, process conditions, and fibers geometry necessary to construct suitable polymer matrices for dedicated drug delivery systems.

Keywords:
drug delivery, electrospinning, nanofibers

21.Kowalczyk T., Nakielski P., Kowalewski T.A., Application of nanofibers as Drug Delivery Systems, III National Conference of Nano and Micromechanics, 2012-07-04/07-06, Warszawa (PL), pp.39-40, 2012
Kowalczyk T., Nakielski P., Kowalewski T.A., Application of nanofibers as Drug Delivery Systems, III National Conference of Nano and Micromechanics, 2012-07-04/07-06, Warszawa (PL), pp.39-40, 2012

Abstract:
This paper describes the results of our preliminary studies on Drug Delivery Systems. Two distinct types of drugs are being investigated: lipophylic (soluble in organic solvents) and hydrophylic (soluble in water). Direct measurements of drugs and dye release from nanofibers were done for application in an animat model - rat.

Keywords:
Electrospinnig, Nanofibers, Drug Delivery Systems


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pdf
404667
2013-07-12
BUP 2/15
2015-01-19
Andrychowski J., Frontczak-Baniewicz M.M., Czernicki Z.M., Gołąbek-Sulejczak D.A., Kowalczyk T., Kowalewski T.A., Nakielski P.
Zastosowanie siatki izolacyjnej z nanowłókien polimerowych wykonanej w technologii elektroprzędzenia do wytwarzania opatrunków neuroprotekcyjnych do stosowania w zapobieganiu pourazowym zmianom w mózgu
PL, Warszawski Uniwersytet Medyczny, Instytut Medycyny Doświadczalnej i Klinicznej PAN, Instytut Podstawowych Problemów Techniki PAN, PL
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-
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404667
2013-07-12
BUP 02/15
2015-01-19
Andrychowski J., Frontczak-Baniewicz M.M., Czernicki Z.M., Gołąbek-Sulejczak D.A., Kowalczyk T., Kowalewski T.A., Nakielski P.
Zastosowanie siatki izolacyjnej z nanowłókien polimerowych wykonanej w technologii elektroprzędzenia do wytwarzania opatrunków neuroprotekcyjnych do stosowania w zapobieganiu pourazowym zmianom w mózgu
PL, Instytut Podstawowych Problemów Techniki PAN, Instytut Medycyny Doświadczalnej i Klinicznej PAN, Warszawski Uniwersytet Medyczny
225858
WUP 05/17
2017-05-31