Partner: Marcin Heljak

Warsaw University of Technology (PL)

Recent publications
1.Kołbuk D., Heljak M., Choińska E., Urbanek O., Novel 3D hybrid nanofiber scaffolds for bone regeneration, Polymers, ISSN: 2073-4360, DOI: 10.3390/polym12030544, Vol.12, No.3, pp.544-1-18, 2020
Abstract:

Development of hybrid scaffolds and their formation methods occupies an important place in tissue engineering. In this paper, a novel method of 3D hybrid scaffold formation is presented as well as an explanation of the differences in scaffold properties, which were a consequence of different crosslinking mechanisms. Scaffolds were formed from 3D freeze-dried gelatin and electrospun poly(lactide-co-glicolide) (PLGA) fibers in a ratio of 1:1 w/w. In order to enhance osteoblast proliferation, the fibers were coated with hydroxyapatite nanoparticles (HAp) using sonochemical processing. All scaffolds were crosslinked using an EDC/NHS solution. The scaffolds' morphology was imaged using scanning electron microscopy (SEM). The chemical composition of the scaffolds was analyzed using several methods. Water absorption and mass loss investigations proved a higher crosslinking degree of the hybrid scaffolds than a pure gelatin scaffold, caused by additional interactions between gelatin, PLGA, and HAp. Additionally, mechanical properties of the 3D hybrid scaffolds were higher than traditional hydrogels. In vitro studies revealed that fibroblasts and osteoblasts proliferated and migrated well on the 3D hybrid scaffolds, and also penetrated their structure during the seven days of the experiment.

Keywords:

hybrid scaffolds, electrospinning, freeze-drying, gelatin, hydroxyapatite, sonochemical covering/grafting

Affiliations:
Kołbuk D.-IPPT PAN
Heljak M.-Warsaw University of Technology (PL)
Choińska E.-Warsaw University of Technology (PL)
Urbanek O.-IPPT PAN
2.Rinoldi C., Costantini M., Kijeńska-Gawrońska E., Testa S., Fornetti E., Heljak M., Ćwiklińska M., Buda R., Baldi J., Cannata S., Guzowski J., Gargioli C., Khademhosseini A., Święszkowski W., Tendon tissue engineering: effects of mechanical and biochemical stimulation on stem cell alignment on cell‐laden hydrogel yarns, ADVANCED HEALTHCARE MATERIALS, ISSN: 2192-2659, DOI: 10.1002/adhm.201801218, Vol.8, No.7, pp.1801218-1-10, 2019
Abstract:

Fiber-based approaches hold great promise for tendon tissue engineering enabling the possibility of manufacturing aligned hydrogel filaments that can guide collagen fiber orientation, thereby providing a biomimetic micro-environment for cell attachment, orientation, migration, and proliferation. In this study, a 3D system composed of cell-laden, highly aligned hydrogel yarns is designed and obtained via wet spinning in order to reproduce the morphology and structure of tendon fascicles. A bioink composed of alginate and gelatin methacryloyl (GelMA) is optimized for spinning and loaded with human bone morrow mesenchymal stem cells (hBM-MSCs). The produced scaffolds are subjected to mechanical stretching to recapitulate the strains occurring in native tendon tissue. Stem cell differentiation is promoted by addition of bone morphogenetic protein 12 (BMP-12) in the culture medium. The aligned orientation of the fibers combined with mechanical stimulation results in highly preferential longitudinal cell orientation and demonstrates enhanced collagen type I and III expression. Additionally, the combination of biochemical and mechanical stimulations promotes the expression of specific tenogenic markers, signatures of efficient cell differentiation towards tendon. The obtained results suggest that the proposed 3D cell-laden aligned system can be used for engineering of scaffolds for tendon regeneration.

Keywords:

hydrogel fibers, static mechanical stretching, stem cell alignment, tenogenic differentiation, wet spinning

Affiliations:
Rinoldi C.-other affiliation
Costantini M.-Sapienza University of Rome (IT)
Kijeńska-Gawrońska E.-Warsaw University of Technology (PL)
Testa S.-Tor Vergata Rome University (IT)
Fornetti E.-Tor Vergata Rome University (IT)
Heljak M.-Warsaw University of Technology (PL)
Ćwiklińska M.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Buda R.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Baldi J.-Tor Vergata Rome University (IT)
Cannata S.-Tor Vergata Rome University (IT)
Guzowski J.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Gargioli C.-Tor Vergata Rome University (IT)
Khademhosseini A.-Massachusetts Institute of Technology (US)
Święszkowski W.-other affiliation
3.Woźniak M., Chlanda A., Oberbek P., Heljak M., Czarnecka K., Janeta M., John Ł., Binary bioactive glass composite scaffolds for bone tissue engineering — structure and mechanical properties in micro and nano scale. A preliminary study, Micron, ISSN: 0968-4328, DOI: 10.1016/j.micron.2018.12.006, Vol.119, pp.64-71, 2019
Abstract:

Composite scaffolds of bioactive glass (SiO2-CaO) and bioresorbable polyesters: poly-L-lactic acid (PLLA) and polycaprolactone (PCL) were produced by polymer coating of porous foams. Their structure and mechanical properties were investigated in micro and nanoscale, by the means of scanning electron microscopy, PeakForce Quantitative Nanomechanical Property Mapping (PF-QNM) atomic force microscopy, micro-computed tomography and contact angle measurements. This is one of the first studies in which the nanomechanical properties (elastic modulus, adhesion) were measured and mapped simultaneously with topography imaging (PF-QNM AFM) for bioactive glass and bioactive glass – polymer coated scaffolds. Our findings show that polymer coated scaffolds had higher average roughness and lower stiffness in comparison to pure bioactive glass scaffolds. Such coating-dependent scaffold properties may promote different cells-scaffold interaction.

Keywords:

bone tissue engineering, composite scaffold, bioactive glass, mmechanical properties

Affiliations:
Woźniak M.-Warsaw University of Technology (PL)
Chlanda A.-Warsaw University of Technology (PL)
Oberbek P.-Warsaw University of Technology (PL)
Heljak M.-Warsaw University of Technology (PL)
Czarnecka K.-IPPT PAN
Janeta M.-University of Wrocław (PL)
John Ł.-University of Wrocław (PL)
4.Chlanda A., Oberbek P., Heljak M., Górecka Ż., Czarnecka K., Chen K.-S., Woźniak M.J., Nanohydroxyapatite adhesion to low temperature plasma modified surface of 3D-printed bone tissue engineering scaffolds - qualitative and quantitative study, SURFACE AND COATINGS TECHNOLOGY, ISSN: 0257-8972, DOI: 10.1016/j.surfcoat.2019.07.070, Vol.375, pp.637-644, 2019
Abstract:

Biodegradable 3D-printed polycaprolactone scaffolds for bone tissue engineering applications have been extensively studied as they can provide an attractive porous architecture mimicking natural bone, with tunable physical and mechanical properties enhancing positive cellular response. The main drawbacks of polycaprolactone-based scaffolds, limiting their applications in tissue engineering are: their hydrophobic nature, low bioactivity and poor mechanical properties compared to native bone tissue. To overcome these issues, the surface of scaffolds is usually modified and covered with a ceramic layer. However, a detailed description of the adhesion forces of ceramic particles to the polymer surface of the scaffolds is still lacking. Our present work is focused on obtaining PCL-based composite scaffolds to strengthen the architecture of the final product. In this manuscript, we report qualitative and quantitative evaluation of low temperature plasma modification followed by detailed studies of the adhesion forces between chemically attached ceramic layer and the surface of polycaprolactone-nanohydroxyapatite composite 3D-printed scaffolds. The results suggest modification-dependent alteration of the internal structure and morphology, as well as mechanical and physical scaffold properties recorded with atomic force microscopy. Moreover, changes in the material surface were followed by enhanced adhesion forces binding the ceramic layer to polymer-based scaffolds.

Keywords:

surface modification, low temperature plasma, atomic force microscopy, bone tissue engineering

Affiliations:
Chlanda A.-Warsaw University of Technology (PL)
Oberbek P.-Warsaw University of Technology (PL)
Heljak M.-Warsaw University of Technology (PL)
Górecka Ż.-Warsaw University of Technology (PL)
Czarnecka K.-IPPT PAN
Chen K.-S.-Tatung University (TW)
Woźniak M.J.-Warsaw University of Technology (PL)
5.Costantini M., Guzowski J., Żuk P.J., Mozetic P., De Panfilis S., Jaroszewicz J., Heljak M., Massimi M., Pierron M., Trombetta M., Dentini M., Święszkowski W., Rainer A., Garstecki P., Barbetta A., Electric Field Assisted Microfluidic Platform for Generation of Tailorable Porous Microbeads as Cell Carriers for Tissue Engineering, Advanced Functional Materials, ISSN: 1616-301X, DOI: 10.1002/adfm.201800874, Vol.28, pp.1800874-1-13, 2018
Abstract:

Injection of cell‐laden scaffolds in the form of mesoscopic particles directly to the site of treatment is one of the most promising approaches to tissue regeneration. Here, a novel and highly efficient method is presented for preparation of porous microbeads of tailorable dimensions (in the range ≈300–1500 mm) and with a uniform and fully interconnected internal porous texture. The method starts with generation of a monodisperse oil‐in‐water emulsion inside a flow‐focusing microfluidic device. This emulsion is later broken‐up, with the use of electric field, into mesoscopic double droplets, that in turn serve as a template for the porous microbeads. By tuning the amplitude and frequency of the electric pulses, the template droplets and the resulting porous bead scaffolds are precisely produced. Furthermore, a model of pulsed electrodripping is proposed that predicts the size of the template droplets as a function of the applied voltage. To prove the potential of the porous microbeads as cell carries, they are tested with human mesenchymal stem cells and hepatic cells, with their viability and degree of microbead colonization being monitored. Finally, the presented porous microbeads are benchmarked against conventional microparticles with nonhomogenous internal texture, revealing their superior performance.

Affiliations:
Costantini M.-Sapienza University of Rome (IT)
Guzowski J.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Żuk P.J.-IPPT PAN
Mozetic P.-Università Campus Bio-Medico di Roma (IT)
De Panfilis S.-Sapienza Istituto Italiano di Tecnologia (IT)
Jaroszewicz J.-other affiliation
Heljak M.-Warsaw University of Technology (PL)
Massimi M.-University of L’Aquila (IT)
Pierron M.-Telecom Physique Strasbourg (FR)
Trombetta M.-Università Campus Bio-Medico di Roma (IT)
Dentini M.-Sapienza University of Rome (IT)
Święszkowski W.-other affiliation
Rainer A.-Università Campus Bio-Medico di Roma (IT)
Garstecki P.-Institute of Physical Chemistry, Polish Academy of Sciences (PL)
Barbetta A.-Sapienza University of Rome (IT)
6.Sajkiewicz P., Heljak M.K., Gradys A., Choińska E., Rumiński S., Jaroszewicz T., Bissenik I., Święszkowski W., Degradation and related changes in supermolecular structure of poly(caprolactone) in vivo conditions, Polymer Degradation and Stability, ISSN: 0141-3910, DOI: 10.1016/j.polymdegradstab.2018.09.023, Vol.157, pp.70-79, 2018
Abstract:

The degradation in vivo and its effect on the supermolecular structure of poly(caprolactone) was examined. Poly(caprolactone) (PCL) samples were prepared in the form of porous scaffolds implanted into rat calvarial defects. The degradation was investigated by means of gel permeation chromatography, wide angle X-ray scattering (WAXS), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The study showed that the observed decrease of PCL crystallinity during degradation is accompanied by reduction of crystal size and/or perfection. The observed phenomenon could be explained by the presence of the high content of the low mobile fraction of investigated polymer, consisting not only almost 50% of crystal fraction but also most probably relatively high fraction of s.c. rigid amorphous fraction (RAF). Considering the type of structure characterized by the dominance of low mobile fraction, it is expected that the degradation will mainly concern these fractions, which in turn will lead to a decrease in the degree of crystallinity as well as crystal size and/or perfection.

Keywords:

PCL degradation, In-vivo conditions, Crystallinity, Rigid amorphous fraction

Affiliations:
Sajkiewicz P.-IPPT PAN
Heljak M.K.-Warsaw University of Technology (PL)
Gradys A.-IPPT PAN
Choińska E.-Warsaw University of Technology (PL)
Rumiński S.-Medical University of Warsaw (PL)
Jaroszewicz T.-Warsaw University of Technology (PL)
Bissenik I.-Warsaw University of Life Sciences (PL)
Święszkowski W.-other affiliation

Conference abstracts
1.Kukla D., Staszczak M., Pieczyska E.A., Heljak M., Szlązak K., Święszkowski W., Cristea M., Tobushi H., Hayashi S., Evaluation of the properties of polymeric foams with shape memory under load, PCM-CMM 2015, 3rd Polish Congress of Mechanics and 21st Computer Methods in Mechanics, 2015-09-08/09-11, Gdańsk (PL), pp.143-144, 2015
Abstract:

The paper presents the results of experimental investigation on polymer foam with shape memory properties. The research is focused on characterization of the microstructure of the foam and understanding the mechanisms of deformation under static and dynamic loading. Up till now, selected experimental techniques have been applied. Dynamic Mechanical Analysis (DMA) allows determining the extent of the value of the glass transition temperature under different load conditions, which also reveals the transformation temperature range for the SMP foam. Scanning electron microscopy (SEM) shows the foam microstructure in various scales, while X-ray tomography gave 3D microstructure results presenting in addition mechanism of the cells deformation and changes in their geometry under 30 % and 50% strain. BOSE system enables obtaining the results on dynamic loading.

Keywords:

Shape memory polymer foam, Dynamic mechanical analysis, Glass transition temperature, X-ray tomography

Affiliations:
Kukla D.-IPPT PAN
Staszczak M.-IPPT PAN
Pieczyska E.A.-IPPT PAN
Heljak M.-Warsaw University of Technology (PL)
Szlązak K.-other affiliation
Święszkowski W.-other affiliation
Cristea M.-Petru Poni Institute of Macromolecular Chemistry (RO)
Tobushi H.-Aichi Institute of Technology (JP)
Hayashi S.-SMP Technologies Inc. (JP)