IPC PAS Articles

Displaying 1 - 5 of 164 records

Microfluidic Formulationof Topological Hydrogels for Microtissue Engineering
(ACS Publications, 2022-09-15) Rojek, Katarzyna O.; Ćwiklińska, Monika; Kuczak, Julia; Guzowski, Jan; Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
Microfluidics has recently emerged as a powerful tool in generation of submillimeter-sized cell aggregates capable of performing tissue-specific functions, so-called microtissues, for applications in drug testing, regenerative medicine, and cell therapies. In this work, we review the most recent advances in the field, with particular focus on the formulation of cell-encapsulating microgels of small “dimensionalities”: “0D” (particles), “1D” (fibers), “2D” (sheets), etc., and with nontrivial internal topologies, typically consisting of multiple compartments loaded with different types of cells and/or biopolymers. Such structures, which we refer to as topological hydrogels or topological microgels (examples including core–shell or Janus microbeads and microfibers, hollow or porous microstructures, or granular hydrogels) can be precisely tailored with high reproducibility and throughput by using microfluidics and used to provide controlled “initial conditions” for cell proliferation and maturation into functional tissue-like microstructures. Microfluidic methods of formulation of topological biomaterials have enabled significant progress in engineering of miniature tissues and organs, such as pancreas, liver, muscle, bone, heart, neural tissue, or vasculature, as well as in fabrication of tailored microenvironments for stem-cell expansion and differentiation, or in cancer modeling, including generation of vascularized tumors for personalized drug testing. We review the available microfluidic fabrication methods by exploiting various cross-linking mechanisms and various routes toward compartmentalization and critically discuss the available tissue-specific applications. Finally, we list the remaining challenges such as simplification of the microfluidic workflow for its widespread use in biomedical research, bench-to-bedside transition including production upscaling, further in vivo validation, generation of more precise organ-like models, as well as incorporation of induced pluripotent stem cells as a step toward clinical applications.
Long-term day-by-day tracking of microvascular networks sprouting in fibrin gels: From detailed morphological analyses to general growth rules
(AIP Publishing, 2024-02-06) Rojek, Katarzyna O.; Wrzos, Antoni; Żukowski, Stanisław; Bogdan, Michał; Lisicki, Maciej; Szymczak, Piotr; Guzowski, Jan; Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland; Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland; Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057, CNRS & Université Paris Cité , Paris, France
Understanding and controlling of the evolution of sprouting vascular networks remains one of the basic challenges in tissue engineering. Previous studies on the vascularization dynamics have typically focused only on the phase of intense growth and often lacked spatial control over the initial cell arrangement. Here, we perform long-term day-by-day analysis of tens of isolated microvasculatures sprouting from endothelial cell-coated spherical beads embedded in an external fibrin gel. We systematically study the topological evolution of the sprouting networks over their whole lifespan, i.e., for at least 14 days. We develop a custom image analysis toolkit and quantify (i) the overall length and area of the sprouts, (ii) the distributions of segment lengths and branching angles, and (iii) the average number of branch generations—a measure of network complexity. We show that higher concentrations of vascular endothelial growth factor (VEGF) lead to earlier sprouting and more branched networks, yet without significantly affecting the speed of growth of individual sprouts. We find that the mean branching angle is weakly dependent on VEGF and typically in the range of 60°–75°, suggesting that, by comparison with the available diffusion-limited growth models, the bifurcating tips tend to follow local VEGF gradients. At high VEGF concentrations, we observe exponential distributions of segment lengths, which signify purely stochastic branching. Our results—due to their high statistical relevance—may serve as a benchmark for predictive models, while our new image analysis toolkit, offering unique features and high speed of operation, could be exploited in future angiogenic drug tests.
Dissociation constants of relevant secondary organic aerosol components in the atmosphere
(Elsevier, 2024-03) Kołodziejczyk, Agata; Wróblewska, Aleksandra; Pietrzak, Mariusz; Pyrcz, Patryk; Szmigielski, Rafał; Błaziak, Kacper; Institute of Physical Chemistry, Polish Academy of Sciences; Faculty of Chemistry, University of Warsaw; Biological and Chemical Research Center, University of Warsaw
The presented studies focus on measuring the determination of the acidity constant (pKa) of relevant secondary organic aerosol components. For our research, we selected important oxidation products (mainly carboxylic acids) of the most abundant terpene compounds, such as α-pinene, β-pinene, β-caryophyllene, and δ-3-carene. The research covered the synthesis and determination of the acidity constant of selected compounds. We used three methods to measure the acidity constant, i.e., 1H NMR titration, pH-metric titration, Bates-Schwarzenbach spectrophotometric method. Moreover, the pKa values were calculated with Marvin 21.17.0 software to compare the experimentally derived values with those calculated from the chemical structure. pKa values measured with 1H NMR titration ranged from 3.51 ± 0.01 for terebic acid to 5.18 ± 0.06 for β-norcaryophyllonic acid. Moreover, the data determined by the 1H NMR method revealed a good correlation with the data obtained with the commonly used potentiometric and UV-spectroscopic methods (R2 = 0.92). In contrast, the comparison with in silico results exhibits a relatively low correlation (R2Marvin = 0.66). We found that most of the values calculated with the Marvin Program are lower than experimental values obtained with pH-metric titration with an average difference of 0.44 pKa units. For di- and tricarboxylic acids, we obtained two and three pKa values, respectively. A good correlation with the literature values was observed, for example, Howell and Fisher (1958) used pH-metric titration and measured pKa1 and pKa2 to be 4.48 and 5.48, while our results are 4.24 ± 0.10 and 5.40 ± 0.02, respectively.
Molecular modification of spiro[fluorene-9,90- xanthene]-based dopant-free hole transporting materials for perovskite solar cells
(Royal Society of Chemistry, 2024-02-20) Kumar, Vinay; Kumar, Deepak; Chavan, Rohit D.; Kumar, Kodali Phani; Yadagiri, Bommaramoni; Ans, Muhammad; Kruszyńska, Joanna; Mahapatra, Apurba; Nawrocki, Jan; Nikiforow, Kostiantin; Mrkyvkova, Nada; Siffalovic, Peter; Yadav, Pankaj; Akin, Seckin; Singh, Surya Prakash; Prochowicz, Daniel; Department of Polymer and Functional Material, CSIR-Indian Institute of Chemical Technology (IICT), Tarnaka, Hyderabad, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India; Institute of Physical Chemistry, Polish Academy of Sciences; Institute of Physics, Slovak Academy of Sciences, Bratislava, Slovakia; Center for Advanced Materials and Applications, Slovak Academy of Sciences, Bratislava, Slovakia; Department of Solar Energy, School of Energy Technology, Pandit Deendayal Energy University, Gandhinagar, Gujarat, India; Department of Physics, School of Energy Technology, Pandit Deendayal Energy University, Gandhinagar, Gujarat, India; Department of Metallurgical and Materials Engineering, Necmettin Erbakan University, Konya, Turkey
The molecular engineering of organic hole-transporting materials (HTMs) plays an important role in enhancing the performance and stability of perovskite solar cells (PSCs) as well as reducing their fabrication cost. Here, two low-cost spiro-OMeTAD analogues, namely SP-Naph and SP-SMe, featuring a spiro[fluorene-9,9-xanthene] (SFX) central core and asymmetric subunits are designed and synthesized. Specifically, the SFX core in the SP-Naph molecule is substituted with dimethoxyphenylnaphthylamine subunits to enhance conductivity and charge transport properties by expansion of the p-conjugated structure. On the other hand, in the molecular structure of SP-SMe, the methoxy groups (–OMe) from diphenylamine units were partially replaced with the methylsulfanyl groups (–SMe) to increase interaction with the perovskite surface through the “Lewis soft” S atoms. By combining various experimental and simulation methods, thestructure–property relationship of the newly synthesized HTMs was thoroughly investigated. The suitable HOMO energy level with the perovskite layer together with superior photoelectric properties and enhanced thermostability and humidity resistivity are obtained for the SP-SMe HTM. As a result, the planar n–i–p PSC with the dopant-free SP-SMe HTM yields a maximum power conversion efficiency (PCE) of 21.95%, which outperforms that with SP-Naph (20.51%) and doped spiro-OMeTAD (19.23%). Importantly, the device with SP-SMe also reveals enhanced operational stability under continuous 1 sun illumination and thermal stability at 65 °C. These findings provide valuable insight for the rational design of dopant-free organic HTMs based on the SFX core, which would promote the development of highly efficient and stable devices.
Metal-Doped MAPbBr3 Single Crystal p-n Junction Photodiode for Self-Powered Photodetection
(Wiley, 2023-12-21) Anilkumar, Vishnu; Mahapatra, Apurba; Nawrocki, Jan; Chavan, Rohit D.; Yadav, Pankaj; Prochowicz, Daniel; Institute of Physical Chemistry, Polish Academy of Sciences; Department of Solar Energy, School of Energy Technology, Pandit Deendayal Energy University, Gandhinagar, Gujarat, India
Lead halide perovskites have emerged as the next-generation materials for self-powered photodetectors enabling operation without an external power source. In this study, a planar-type photodetector based on metal-doped p-type MAPbBr3/n-type MAPbBr3 single crystal showing excellent self-powered photodetection properties is presented. The p-n junction on the MAPbBr3 single crystal is formed by controlled epitaxial growth of Ag+-doped MAPbBr3 SC (p-type) on the facet of Sb3+-doped MAPbBr3 SC (n-type). The as-integrated p-n junction device with asymmetric electrodes shows a typical photovoltaic behavior with a high open circuit voltage of 0.95 V and great sensitivity to 530 nm illumination at zero bias with a responsivity of up to 0.41 A W−1 and a specific detectivity of 6.39 × 1011 Jones, which are among the highest values reported for MAPbBr3 single crystal-based self-powered photodetectors. In addition, the rise time and fall time of this device are as fast as 14 and 10 ms, respectively. These results pave the way for the fabrication of self-powered perovskite-based p-n junction photodiode, which may find potential application in advanced photodiode and future optoelectronic devices.

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