Partner: Emilia Choińska

Warsaw University of Technology (PL)

Recent publications
1.Dulnik J., Denis P., Sajkiewicz P., Kołbuk D., Choińska E., Biodegradation of bicomponent PCL/gelatin and PCL/collagen nanofibers electrospun from alternative solvent system, Polymer Degradation and Stability, ISSN: 0141-3910, DOI: 10.1016/j.polymdegradstab.2016.05.022, Vol.130, pp.10-21, 2016
Abstract:

Bicomponent polycaprolactone/gelatin and polycaprolactone/collagen nanofibers formed by electrospinning using various solvents were subjected to biodegradation and compared. Hexafluoroisopropanol (HFIP) was used as a reference solvent, while the second, alternative solvent system was the mixture of acetic acid (AA) with formic acid (FA). Biodegradation of investigated materials was manifested mainly by the gelatin leaching, including collagen which is indeed denaturated to gelatin during electrospinning, leading to nanofibers erosion. There was no molecular degradation of PCL during 90 days of biodegradation procedure as deduced from no change in the elongation stress at break. The rate of biopolymer leaching was very fast from all materials during the first 24 h of biodegradation, being related to surface leaching, followed by a slower rate leaching from deeper material layers. Mass measurements showed much faster biopolymer leaching from nanofibers electrospun from AA/FA than from HFIP because of strongly emulsive nature of the solution in the former case. Irrespective of the solvent used, the leaching rate increased with initial content of gelatin. The analysis of Young modulus during biodegradation indicated complex mechanism of changes, including biopolymer mass loss, increase of PCL crystallinity and partial gelatin renaturation.

Keywords:

Bicomponent nanofibers, Biodegradation, Biopolymer

Affiliations:
Dulnik J.-IPPT PAN
Denis P.-IPPT PAN
Sajkiewicz P.-IPPT PAN
Kołbuk D.-IPPT PAN
Choińska E.-Warsaw University of Technology (PL)
2.Urbanek O., Pierini F., Choińska E., Sajkiewicz P., Bil M., Święszkowski W., Effect of hydroxyapatite nanoparticles addition on structure properties of poly(L-lactide-co-glycolide) after gamma sterilization, Polymer Composites, ISSN: 0272-8397, DOI: 10.1002/pc.24028, Vol.1, pp.1-9, 2016
Abstract:

Physical and chemical factors resulting from the sterilization methods may affect the structure and properties of the materials which undergo this procedure. Poly(l-lactide-co-glicolide) (PLGA) is commonly used for medical applications, but, due to its inadequate mechanical properties, it is not recommended for load-bearing applications. One of the methods for improving PLGA mechanical properties is addition of hydroxyapatite nanoparticles (nHAp). The aim of this study was to evaluate the effect of nanoparticles addition on PLGA structure and properties after gamma radiation. According to our results, reduction of the molecular mass caused by gamma radiation was lower for PLGA with nHAp addition. Differential scanning calorimetry (DSC) analysis indicates an increase of crystallinity caused both by nHAp and gamma radiation. The first phenomenon can be explained by heteronucleation, while the second one is most probably related to higher molecular mobility of degrading polymer. Moreover, addition of nanoparticles increases thermal stability and affects the Young's modulus changes after gamma radiation.

Affiliations:
Urbanek O.-IPPT PAN
Pierini F.-IPPT PAN
Choińska E.-Warsaw University of Technology (PL)
Sajkiewicz P.-IPPT PAN
Bil M.-Warsaw University of Technology (PL)
Święszkowski W.-other affiliation
3.Enayati M.S., Behzad T., Sajkiewicz P., Bagheri R., Ghasemi‑Mobarakeh L., Kuśnieruk S., Rogowska-Tylman J., Pahlevanneshan Z., Choińska E., Święszkowski W., Fabrication and characterization of electrospun bionanocomposites of poly (vinyl alcohol)/ nanohydroxyapatite/cellulose nanofibers, International Journal of Polymeric Materials and Polymeric Biomaterials, ISSN: 0091-4037, DOI: 10.1080/00914037.2016.1157798, Vol.65, No.13, pp.660-674, 2016
Abstract:

The aim of the present study was preparation, optimization, and systematic characterization of electrospun bionanocomposite fibers based on polyvinyl alcohol (PVA) as matrix and nanohydroxy apatite (nHAp) and cellulose nanofibers (CNF) as nanoreinforcements. The presence of nHAp and nHAp-CNF affected the morphology of electrospun mats and reduced fiber diameter, particularly at a higher content of nanofillers. The obtained results of FTIR, DSC, and WAXS proved the crystallinity reduction of electrospun nancomposites. Both nHAp and nHAp-CNF addition led to a significant increase of Young modulus with the highest stiffness for nanocomposite fibers at 10 wt% of nHAp and 3 wt% of CNF.

Keywords:

Bionanocomposite, cellulose nanofibers, electrospinning, nanohydroxy apatite

Affiliations:
Enayati M.S.-Isfahan University of Technology (IR)
Behzad T.-Isfahan University of Technology (IR)
Sajkiewicz P.-IPPT PAN
Bagheri R.-Isfahan University of Technology (IR)
Ghasemi‑Mobarakeh L.-Isfahan University of Technology (IR)
Kuśnieruk S.-other affiliation
Rogowska-Tylman J.-other affiliation
Pahlevanneshan Z.-Payame Noor University (IR)
Choińska E.-Warsaw University of Technology (PL)
Święszkowski W.-other affiliation
4.Kołbuk D., Sajkiewicz P., Denis P., Choińska E., Investigations of polycaprolactone/gelatin blends in terms of their miscibility, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.2478/bpasts-2013-0066, Vol.61, No.3, pp.629-632, 2013
Abstract:

Synthetic and natural polymers blends represent a new brand of materials with application in wound healing, scaffolds or drug delivery systems. Polycaprolactone/gelatin (PCL/Gt) blends were analyzed in terms of their miscibility. The PCL structure was investigated as a function of Gt content. Changes in the PCL spherulitic structure with Gt content were investigated by a polarizing-interference microscope. The analysis of the glass transition temperature (Tg) of both components as a function of PCL/Gt ratio by differential scanning calorimetry indicates that the system of polycaprolactone/gelatin belongs to a type of s.c. compatible system, being intermediate between miscible and immiscible systems. There is possibility of very limited miscibility of both components. Supplementary wide angle X-ray scattering results are presented.

Keywords:

lends, compatibility, miscibility, polycaprolactone, gelatin

Affiliations:
Kołbuk D.-IPPT PAN
Sajkiewicz P.-IPPT PAN
Denis P.-IPPT PAN
Choińska E.-Warsaw University of Technology (PL)

Conference papers
1.Kołbuk D., Denis P., Choińska E., Sajkiewicz P., Investigations of polycaprolactone/gelatine blends in terms of their miscibility, 3rd Polish Conference on Nano- and Micromechanics, 2012-07-04/07-07, Warszawa (PL), Vol.1, pp.135-137, 2012

Conference abstracts
1.Kołbuk D., Denis P., Choińska E., Sajkiewicz P., Tailoring of polycaprolactone crystallinity, E-MRS FALL MEETING 2014, 2014-09-15/09-18, Warszawa (PL), pp.91, 2014
Abstract:

Introduction In the case of semicrystalline polymers, crystallinity is the parameter determining their physical properties. Some research groups indicate influence of crystallinity on cells response during in- vitro study. Commonly used methods of three-dimensional scaffolds formation do not take into account crystallinity optimisation. The aim of proposed presentation is to evaluate the effect of molecular weight and solvent on crystallinity and crystal size in case of polycaprolactone (PCL) films. Methodology Material: PCL with Mn:10, 45 and 80k g/mol (Sigma Aldrich) was used. As a solvents: Hexafluoroisopropanole, HFIP (Iris Biotech GmbH.), Acetic Acid, AA and Dichloromethane, DCM (Avantor and Chempol respectively) were used. Methods: Films were prepared from the PCL with different molecular weight using various solvents differing in evaporation rate. Characterization: Films were analysed using polarizing-interference microscopy (MPI) allowing characterization ofspherulities morphology. Degree of crystallinity was analysed by differential scanning calorimetry (DSC) and comparatively bywide angle X-ray scattering (WAXS). Results and Discussion It is evident from MPI observations that conditions of PCL films preparation affect the morphology of spherulites. All samples were birefringent, indicating in general crystallinity, being different for particular samples. Sphorulities size depends on Mw and solvent type; sharp Maltese cross was observed on few samples. Crystallinity of PCL films determined from DSC measurements was in the range 0,45-0,68 depending on solvent and polymer Mn used. Generally crystallinity of films formed from DCM is lower than from AA as a result of lower boiling point of DCM. Additional annealing enables increase in crystallinity to 0,8. WAXS crystallinity correlates with values determined by DSC. Changes of full width of half maximum(FWHM) of crystal peaks indicate variations of crystal size and/or defects depending on molecular weight and solvent what correlates with MPI observations also. Conclusions spherulites shape and crystallinity are strongly dependent on Mn and solvent type. Structural parameters of films decide on Young modulus and elasticity in terms of applications

Keywords:

crystallinity, PCL, solvents WAXS, molecular structure

Affiliations:
Kołbuk D.-IPPT PAN
Denis P.-IPPT PAN
Choińska E.-Warsaw University of Technology (PL)
Sajkiewicz P.-IPPT PAN