Instytut Podstawowych Problemów Techniki

Dumbill R., Rabcuka J., Fallon J., Knight S., Hunter J., Voyce D., Barrett Jacob T., Ellen M., Weissenbacher A., Kurniawan T., Błoński S., Korczyk P.M., Ploeg Rutger J., Coussios C., Friend P., Świętach P., Impaired O2 unloading from stored blood results in diffusion-limited O2 release at tissues: evidence from human kidneys, Blood, ISSN: 0006-4971, DOI: 10.1182/blood.2023022385, Vol.143, No.8, pp.721-733, 2024

Abstract:
The volume of oxygen drawn from systemic capillaries down a partial pressure gradient is determined by the oxygen content of red blood cells (RBCs) and their oxygen-unloading kinetics, although the latter is assumed to be rapid and, therefore, not a meaningful factor. Under this paradigm, oxygen transfer to tissues is perfusion-limited. Consequently, clinical treatments to optimize oxygen delivery aim at improving blood flow and arterial oxygen content, rather than RBC oxygen-handling. Whilst the oxygen-carrying capacity of blood is increased with transfusion, previous studies have shown that stored blood undergoes kinetic attrition of oxygen release, which may compromise overall oxygen delivery to tissues, i.e. transport became diffusion-limited. We sought evidence for diffusion-limited oxygen release in viable human kidneys normothermically perfused with stored blood. In a cohort of kidneys that went on to be transplanted, ex-vivo renal respiration correlated inversely with the time-constant of oxygen-unloading from RBCs used for perfusion. Furthermore, the renal respiratory rate did not correlate with arterial O2 delivery unless this factored the rate of oxygen-release from RBCs, as expected from diffusion-limited transport. In kidneys deemed unsuitable for transplantation, perfusion was alternated between stored and rejuvenated RBCs of the same donation to control oxygen-unloading without intervening ischemia and holding all non-RBC parameters constant. Rejuvenated oxygen-unloading kinetics reversibly improved the kidney's oxygen diffusion capacity and increased cortical oxygen partial pressure by 60%. Thus, oxygen delivery to tissues can become diffusion-limited during perfusion with stored blood, which has implications in scenarios such as ex-vivo organ perfusion, major hemorrhage, and pediatric transfusion.

Green R., Wang H., Botchey C., Zhang S. N. N., Wadsworth C., Tyrrell F., Letton J., McBain A. J., Paszek P., Krašovec R., Knight C. G., Collective peroxide detoxification determines microbial mutation rate plasticity in E. coli, PLOS Biology, ISSN: 1544-9173, DOI: 10.1371/journal.pbio.3002711, Vol.22, No.7, pp.e3002711-1-36, 2024

Abstract:
Mutagenesis is responsive to many environmental factors. Evolution therefore depends on the environment not only for selection but also in determining the variation available in a population. One such environmental dependency is the inverse relationship between mutation rates and population density in many microbial species. Here, we determine the mechanism responsible for this mutation rate plasticity. Using dynamical computational modelling and in culture mutation rate estimation, we show that the negative relationship between mutation rate and population density arises from the collective ability of microbial populations to control concentrations of hydrogen peroxide. We demonstrate a loss of this density-associated mutation rate plasticity (DAMP) when Escherichia coli populations are deficient in the degradation of hydrogen peroxide. We further show that the reduction in mutation rate in denser populations is restored in peroxide degradation-deficient cells by the presence of wild-type cells in a mixed population. Together, these model-guided experiments provide a mechanistic explanation for DAMP, applicable across all domains of life, and frames mutation rate as a dynamic trait shaped by microbial community composition.

Kosik-Kozioł A., Nakielski P., Rybak D., Frączek W., Rinoldi C., Lanzi M., Grodzik M., Pierini F., Adhesive Antibacterial Moisturizing Nanostructured Skin Patch for Sustainable Development of Atopic Dermatitis Treatment in Humans, ACS Applied Materials and Interfaces, ISSN: 1944-8244, DOI: 10.1021/acsami.4c06662, Vol.16, No.25, pp.32128-32146, 2024

Abstract:
Atopic dermatitis (AD) is a chronic inflammatory skin disease with a complex etiology that lacks effective treatment. The therapeutic goals include alleviating symptoms, such as moisturizing and applying antibacterial and anti-inflammatory medications. Hence, there is an urgent need to develop a patch that effectively alleviates most of the AD symptoms. In this study, we employed a “green” cross-linking approach of poly(vinyl alcohol) (PVA) using glycerol, and we combined it with polyacrylonitrile (PAN) to fabricate core–shell (CS) nanofibers through electrospinning. Our designed structure offers multiple benefits as the core ensures controlled drug release and increases the strength of the patch, while the shell provides skin moisturization and exudate absorption. The efficient PVA cross-linking method facilitates the inclusion of sensitive molecules such as fermented oils. In vitro studies demonstrate the patches’ exceptional biocompatibility and efficacy in minimizing cell ingrowth into the CS structure containing argan oil, a property highly desirable for easy removal of the patch. Histological examinations conducted on an ex vivo model showed the nonirritant properties of developed patches. Furthermore, the eradication of Staphylococcus aureus bacteria confirms the potential use of CS nanofibers loaded with argan oil or norfloxacin, separately, as an antibacterial patch for infected AD wounds. In vivo patch application studies on patients, including one with AD, demonstrated ideal patches’ moisturizing effect. This innovative approach shows significant promise in enhancing life quality for AD sufferers by improving skin hydration and avoiding infections.

Keywords:
atopic dermatitis, core−shell electrospun nanofibers, antibacterial, mucoadhesive, moisturizing patch

Zaccagnini F., De Biase D., Bovieri F., Perotto G., Quagliarini E., Bavasso I., Mangino G., Iuliano M., Calogero A., Romeo G., Pratap Singh D., Pierini F., Caracciolo G., Petronella F., De Sio L., Multifunctional FFP2 Face Mask for White Light Disinfection and Pathogens Detection using Hybrid Nanostructures and Optical Metasurfaces, Small, ISSN: 1613-6810, DOI: 10.1002/smll.202400531, Vol.20, No.38, pp.2400531-1-15, 2024

Abstract:
A new generation of an FFP2 (Filtering Face Piece of type 2) smart face mask is achieved by integrating broadband hybrid nanomaterials and a self-assembled optical metasurface. The multifunctional FFP2 face mask shows simultaneously white light-assisted on-demand disinfection properties and versatile biosensing capabilities. These properties are achieved by a powerful combination of white light thermoplasmonic responsive hybrid nanomaterials, which provide excellent photo-thermal disinfection properties, and optical metasurface-based colorimetric biosensors, with a very low limit of pathogens detection. The realized system is studied in optical, morphological, spectroscopic, and cell viability assay experiments and environmental monitoring of harmful pathogens, thus highlighting the extraordinary properties in reusability and pathogens detection of the innovative face mask.

Nakielski P., Kosik-Kozioł A., Rinoldi C., Rybak D., Namdev M., Jacob W., Lehmann T., Głowacki M., Bogusz S., Rzepna M., Marinelli M., Lanzi M., Dror S., Sarah M., Dmitriy S., Pierini F., Injectable PLGA Microscaffolds with Laser-Induced Enhanced Microporosity for Nucleus Pulposus Cell Delivery, Small, ISSN: 1613-6810, DOI: 10.1002/smll.202404963, pp.2404963-1-15, 2024

Abstract:
Intervertebral disc (IVD) degeneration is a leading cause of lower back pain (LBP). Current treatments primarily address symptoms without halting the degenerative process. Cell transplantation offers a promising approach for early-stage IVD degeneration, but challenges such as cell viability, retention, and harsh host environments limit its efficacy. This study aimed to compare the injectability and biocompatibility of human nucleus pulposus cells (hNPC) attached to two types of microscaffolds designed for minimally invasive delivery to IVD. Microscaffolds are developed from poly(lactic-co-glycolic acid) (PLGA) using electrospinning and femtosecond laser structuration. These microscaffolds are tested for their physical properties, injectability, and biocompatibility. This study evaluates cell adhesion, proliferation, and survival in vitro and ex vivo within a hydrogel-based nucleus pulposus model. The microscaffolds demonstrate enhanced surface architecture, facilitating cell adhesion and proliferation. Laser structuration improved porosity, supporting cell attachment and extracellular matrix deposition. Injectability tests show that microscaffolds can be delivered through small-gauge needles with minimal force, maintaining high cell viability. The findings suggest that laser-structured PLGA microscaffolds are viable for minimally invasive cell delivery. These microscaffolds enhance cell viability and retention, offering potential improvements in the therapeutic efficiency of cell-based treatments for discogenic LBP.

Loayza-Aguilar Rómulo E., Carhuapoma-Garay J., Ramos-Falla K., Saldaña-Rojas Guillermo B., Huamancondor-Paz Yolanda P., Campoverde-Vigo L., Merino F., Olivos-Ramirez G. E., Epibionts affect the growth and survival of Argopecten purpuratus (Lamarck, 1819) cultivated in Samanco Bay, Peru, Aquaculture, ISSN: 0044-8486, DOI: 10.1016/j.aquaculture.2023.740042, Vol.578, pp.740042-1-10, 2024

Abstract:
Argopecten purpuratus, a mollusk very cultivated in Peru, is a species whose ecological relations with respect to the epibionts that colonize it are not well known. For that reason, the objective of this research was to determine the effect of epibionts on valvar growth, total weight, gonad weight, adductor muscle weight, and survival of this cultured species in Samanco Bay. Four lanterns of 2 m and 10 floors were placed with 25 organisms, of 7 cm each, per floor, in two treatments: with epibiont removal (T1) and without removal (T2). The data was obtained after harvest, and the epibiont species on the right and left valves were identified and quantified in T1 and T2. In addition, the Absolute Growth Rate (AGR) was calculated for the meristic records, and the t Student test was applied to compare averages. Furthermore, mortality was recorded at harvest. The analyses allowed the identification of 43 epibiont species, 3 of them endolithic. The greatest biomass is of filter feeders: 70.1% in T1 and 90.9% in T2, and concentrated in 4 species, with limited development in T1. The biomass on the right valve at T1 and T2 represented 80.7 and 151.8% of the weight of the organism, respectively, and on the left valve 89.3 and 95.1%. All Absolute Growth Rates at T1 were higher than at T2, although without statistical significance. Mortality at T1 and T2 was negligible. This research has determined that the epibionts S. patagonicus, C. intestinalis, Hidroydes sp., and B. neritina, qualified as engineered species, are the predominant species on A. purpuratus in suspended cultures. Likewise, treatments with epibiont removal showed a lower development of these and 39 other associated species of lesser importance in terms of number and biomass. Our results allow us to infer that the development of epibionts can generate important stress in A. purpuratus, resulting in losses in the profitability of companies dedicated to this activity.

Keywords:
Argopecten purpuratus, Aquaculture, Epibiosis, Biofouling, Bivalve

Ziai Y., Rinoldi C., Petronella F., Zakrzewska A., De Sio L., Pierini F., Lysozyme-sensitive plasmonic hydrogel nanocomposite for colorimetric dry-eye inflammation biosensing, NANOSCALE, ISSN: 2040-3364, DOI: 10.1039/d4nr01701c, Vol.16, No.28, pp.13492-13502, 2024

Abstract:
Detection of lysozyme levels in ocular fluids is considered crucial for diagnosing and monitoring various health and eye conditions, including dry-eye syndrome. Hydrogel-based nanocomposites have been demonstrated to be one of the most promising platforms for fast and accurate sensing of different biomolecules. In this work, hydrogel, electrospun nanofibers, and plasmonic nanoparticles are combined to fabricate a sensitive and easy-to-use biosensor for lysozyme. Poly(L-lactide-co-caprolactone) (PLCL) nanofibers were covered with silver nanoplates (AgNPls), providing a stable plasmonic platform, where a poly(N-isopropylacrylamide)-based (PNIPAAm) hydrogel layer allows mobility and good integration of the biomolecules. By integrating these components, the platform can also exhibit a colorimetric response to the concentration of lysozyme, allowing for easy and non-invasive monitoring. Quantitative biosensing operates on the principle of localized surface plasmon resonance (LSPR) induced by plasmonic nanoparticles. Chemical, structural, thermal, and optical characterizations were performed on each platform layer, and the platform's ability to detect lysozyme at concentrations relevant to those found in tears of patients with dry-eye syndrome and other related diseases was investigated by colorimetry and UV-Vis spectroscopy. This biosensor's sensitivity and rapid response time, alongside the easy detection by the naked eye, make it a promising tool for early diagnosis and treatment monitoring of eye diseases.

Cofas Vargas L. F., Olivos-Ramirez G. E., Chwastyk M., Moreira R.A., Baker J. L., Marrink S. J., Poma Bernaola A.M., Nanomechanical footprint of SARS-CoV-2 variants in complex with a potent nanobody by molecular simulations, NANOSCALE, ISSN: 2040-3364, DOI: 10.1039/D4NR02074J, Vol.16, No.40, pp.18824-18834, 2024

Abstract:
Rational design of novel antibody therapeutics against viral infections such as coronavirus relies on surface complementarity and high affinity for their effectiveness. Here, we explore an additional property of protein complexes, the intrinsic mechanical stability, in SARS-CoV-2 variants when complexed with a potent antibody. In this study, we utilized a recent implementation of the GōMartini 3 approach to investigate large conformational changes in protein complexes with a focus on the mechanostability of the receptor-binding domain (RBD) from WT, Alpha, Delta, and XBB.1.5 variants in complex with the H11-H4 nanobody. The analysis revealed moderate differences in mechanical stability among these variants. Also, we identified crucial residues in both the RBD and certain protein segments in the nanobody that contribute to this property. By performing pulling simulations and monitoring the presence of specific native and non-native contacts across the protein complex interface, we provided mechanistic insights into the dissociation process. Force-displacement profiles indicate a tensile force clamp mechanism associated with the type of protein complex. Our computational approach not only highlights the key mechanostable interactions that are necessary to maintain overall stability, but it also paves the way for the rational design of potent antibodies that are mechanostable and effective against emergent SARS-CoV-2 variants.

Keywords:
SARS-CoV-2, GōMartini 3, Nanomechanics, Protein complexes, protein engineering, MD, native contacts

Melikhov Y., Ekiel-Jeżewska M. L., Attracting dynamical modes of highly elastic fibres settling under gravity in a viscous fluid, JOURNAL OF FLUID MECHANICS, ISSN: 0022-1120, DOI: 10.1017/jfm.2024.729, Vol.994, pp.A13-1-20, 2024

Abstract:
The dynamics of a single highly elastic fibre settling under gravity in a very viscous fluid is studied numerically. We employ the bead model and multipole expansion of the Stokes equations, corrected for lubrication that is implemented in the precise Hydromultipole numerical codes. Four attracting regular dynamical modes of highly elastic fibres are found: two stationary shapes (one translating and the other rotating and translating), and two periodic oscillations around such shapes. The phase diagram of these modes is presented. It illustrates that the existence of each mode depends not only on the elasto-gravitation number but also on the fibre aspect ratio. Characteristic time scales, fibre deformation patterns and motion in the different modes are determined.

Keywords:
stokesian dynamics, particle/fluid flows

Sznajder P., Zdybel P., Liu L., Ekiel-Jeżewska M. L., Scaling law for a buckled elastic filament in a shear flow, PHYSICAL REVIEW E, ISSN: 2470-0045, DOI: 10.1103/PhysRevE.110.025104, Vol.110, No.2, pp.025104-1-12, 2024

Abstract:
We analyze the three-dimensional (3D) buckling of an elastic filament in a shear flow of a viscous fluid at low Reynolds number and high Péclet number. We apply the Euler-Bernoulli beam (elastica) theoretical model. We show the universal character of the full 3D spectral problem for a small perturbation of a thin filament from a straight position of arbitrary orientation. We use the eigenvalues and eigenfunctions for the linearized elastica equation in the shear plane, found earlier by Liu et al. [Phys. Rev. Fluids 9, 014101 (2024)] with the Chebyshev spectral collocation method, to solve the full 3D eigenproblem. We provide a simple analytic approximation of the eigenfunctions, represented as Gaussian wave packets. As the main result of the paper, we derive the square-root dependence of the eigenfunction wave number on the parameter χ˜ = −η sin 2φ sin2 θ, where

Bartolewska M., Kosik-Kozioł A., Korwek Z., Krysiak Z., Devis M., Mazur M., Giuseppe F., Pierini F., Eumelanin-Enhanced Photothermal Disinfection of Contact Lenses Using a Sustainable Marine Nanoplatform Engineered with Electrospun Nanofibers, ADVANCED HEALTHCARE MATERIALS, ISSN: 2192-2659, DOI: 10.1002/adhm.202402431, pp.2402431-1-21, 2024

Abstract:
Bacterial keratitis (BK) is a severe eye infection commonly associated with Staphylococcus aureus (S. aureus), posing a significant risk to vision, especially among contact lens wearers. This research introduces a novel smart nanoplatform (deMS@cNF), developed from demineralized mussel shells (deMS) and reinforced with chitin (CT) nanofibrils, specifically designed for portable photothermal disinfection of contact lenses. The nanoplatform leverages the photothermal properties of eumelanin in mussel shells (MS), which, when activated by a simple bike flashlight, rapidly heats to temperatures up to 95 °C, effectively destroying bacterial contamination. In vitro tests demonstrate that the nanoplatform is biocompatible and non-toxic, making it suitable for medical applications. This study highlights an innovative approach to converting marine biowaste into a safe, effective, and low-cost portable method for disinfecting contact lenses, showcasing the potential of the deMS@cNF platform for broader antimicrobial applications.

Rybak D., Rinoldi C., Nakielski P., Du J., Haghighat Bayan Mohammad A., Zargarian S.S., Pruchniewski M., Li X., Strojny-Cieślak B., Ding B., Pierini F., Injectable and self-healable nano-architectured hydrogel for NIR-light responsive chemo- and photothermal bacterial eradication, JOURNAL OF MATERIALS CHEMISTRY B , ISSN: 2050-7518, DOI: 10.1039/D3TB02693K, Vol.12, No.7, pp.1905-1925, 2024

Abstract:
Hydrogels with multifunctional properties activated at specific times have gained significant attention in the biomedical field. As bacterial infections can cause severe complications that negatively impact wound repair, herein, we present the development of a stimuli-responsive, injectable, and in situ-forming hydrogel with antibacterial, self-healing, and drug-delivery properties. In this study, we prepared a Pluronic F-127 (PF127) and sodium alginate (SA)-based hydrogel that can be targeted to a specific tissue via injection. The PF127/SA hydrogel was incorporated with polymeric short-filaments (SFs) containing an anti-inflammatory drug – ketoprofen, and stimuli-responsive polydopamine (PDA) particles. The hydrogel, after injection, could be in situ gelated at the body temperature, showing great in vitro stability and self-healing ability after 4 h of incubation. The SFs and PDA improved the hydrogel injectability and compressive strength. The introduction of PDA significantly accelerated the KET release under near-infrared light exposure and extended its release validity period. The excellent composites’ photo-thermal performance led to antibacterial activity against representative Gram-positive and Gram-negative bacteria, resulting in 99.9% E. coli and S. aureus eradication after 10 min of NIR light irradiation. In vitro, fibroblast L929 cell studies confirmed the materials’ biocompatibility and paved the way toward further in vivo and clinical application of the system for chronic wound treatments.

Słowicka A.M., Xue N., Liu L., Nunes J.K., Sznajder P., Stone H.A., Ekiel-Jeżewska M.L., Highly elastic fibers in a shear flow can form double helices, NEW JOURNAL OF PHYSICS, ISSN: 1367-2630, DOI: 10.1088/1367-2630/ad56c0, Vol.26, pp.073011-1-18, 2024

Abstract:
The long-time behavior of highly elastic fibers in a shear flow is investigated experimentally and numerically. Characteristic attractors of the dynamics are found. It is shown that for a small ratio of bending to hydrodynamic forces, most fibers form a spinning elongated double helix, performing an effective Jeffery orbit very close to the vorticity direction. Recognition of these oriented shapes, and how they form in time, may prove useful in the future for understanding the time history of complex microstructures in fluid flows and considering processing steps for their synthesis.

Keywords:
Stokes equations, shear flow, elastic fibers

Haghighat Bayan M.A., Rinoldi C., Rybak D., Zargarian S.S., Zakrzewska A., Miler O., Põhako-Palu K., Zhang S., Stobnicka-Kupiec A., Górny Rafał L., Nakielski P., Kogermann K., De Sio L., Ding B., Pierini F., Engineering surgical face masks with photothermal and photodynamic plasmonic nanostructures for enhancing filtration and on-demand pathogen eradication, Biomaterials Science, ISSN: 2047-4849, DOI: 10.1039/d3bm01125a, Vol.12, No.4, pp.949-963, 2024

Abstract:
The shortage of face masks and the lack of antipathogenic functions has been significant since the recent pandemic's inception. Moreover, the disposal of an enormous number of contaminated face masks not only carries a significant environmental impact but also escalates the risk of cross-contamination. This study proposes a strategy to upgrade available surgical masks into antibacterial masks with enhanced particle and bacterial filtration. Plasmonic nanoparticles can provide photodynamic and photothermal functionalities for surgical masks. For this purpose, gold nanorods act as on-demand agents to eliminate pathogens on the surface of the masks upon near-infrared light irradiation. Additionally, the modified masks are furnished with polymer electrospun nanofibrous layers. These electrospun layers can enhance the particle and bacterial filtration efficiency, not at the cost of the pressure drop of the mask. Consequently, fabricating these prototype masks could be a practical approach to upgrading the available masks to alleviate the environmental toll of disposable face masks.

Liu L., Sznajder P., Ekiel-Jeżewska M.L., Spectral analysis for elastica dynamics in a shear flow, Physical Review Fluids, ISSN: 2469-990X, DOI: 10.1103/PhysRevFluids.9.014101, Vol.9, No.1, pp.014101-1-12, 2024

Abstract:
We present the spectral analysis of three-dimensional dynamics of an elastic filament in a shear flow of a viscous fluid at a low Reynolds number in the absence of Brownian motion. The elastica model is used. The fiber initially is almost straight at an arbitrary orientation, with small perpendicular perturbations in the shear plane and out-of-plane. To analyze the stability of both perturbations, equations for the eigenvalues and eigenfunctions are derived and solved by the Chebyshev spectral collocation method. It is shown that their crucial features are the same as in the case of the two-dimensional elastica dynamics in shear flow [Becker and Shelley, Phys. Rev. Lett. 87, 198301 (2001)] and the three-dimensional elastica dynamics in the compressional flow [Chakrabarti et al., Nat. Phys. 16, 689 (2020)]. We find a similar dependence of the buckled shapes on the ratio of bending to hydrodynamic forces as in the simulations for elastic fibers of a nonzero thickness [Słowicka et al., New J. Phys. 24, 013013 (2022)].

Medrano-Cerano Jorge L., Cofas Vargas Luis F.F., Leyva E., Rauda-Ceja Jesús A., Calderón-Vargas M., Cano-Sánchez P., Titaux-Delgado G., Melchor-Meneses Carolina M., Hernández-Arana A., del Rio-Portilla F., García-Hernandez E., Decoding the mechanism governing the structural stability of wheat germ agglutinin and its isolated domains: A combined calorimetric, NMR, and MD simulation study, Protein Science, ISSN: 0961-8368, DOI: 10.1002/pro.5020, Vol.33, No.6, pp.e5020-1-15, 2024

Abstract:
Wheat germ agglutinin (WGA) demonstrates potential as an oral delivery agent owing to its selective binding to carbohydrates and its capacity to traverse biological membranes. In this study, we employed differential scanning calorimetry and molecular dynamics simulations to comprehensively characterize the thermal unfolding process of both the complete lectin and its four isolated domains. Furthermore, we present the nuclear magnetic resonance structures of three domains that were previously lacking experimental structures in their isolated forms. Our results provide a collective understanding of the energetic and structural factors governing the intricate unfolding mechanism of the complete agglutinin, shedding light on the specific role played by each domain in this process. The analysis revealed negligible interdomain cooperativity, highlighting instead significant coupling between dimer dissociation and the unfolding of the more labile domains. By comparing the dominant interactions, we rationalized the stability differences among the domains. Understanding the structural stability of WGA opens avenues for enhanced drug delivery strategies, underscoring its potential as a promising carrier throughout the gastrointestinal environment.

Keywords:
homodimer,hydrogen bonding,lectin,multidomain protein,structural stability,thermal unfolding

Feltham L., Moran J., Goldrick M., Lord E., Spiller D. G., Cavet J. S., Muldoon M., Roberts I. S., Paszek P., Bacterial aggregation facilitates internalin-mediated invasion of Listeria monocytogenes, Frontiers in Cellular and Infection Microbiology, ISSN: 2235-2988, DOI: 10.3389/fcimb.2024.1411124, Vol.14, pp.1411124-01-18, 2024

Abstract:
Dissemination of food-borne L. monocytogenes in the host relies on internalin-mediated invasion, but the underlying invasion strategies remain elusive. Here we use live-cell microscopy to follow single cell interactions between individual human cells and L. monocytogenes and elucidate mechanisms associated with internalin B (InlB)-mediated invasion. We demonstrate that whilst a replicative invasion of nonphagocytic cells is a rare event even at high multiplicities of invasion, L. monocytogenes overcomes this by utilising a strategy relaying on PrfA-mediated ActA-based aggregation. We show that L. monocytogenes forms aggregates in extracellular host cell environment, which promote approximately 5-fold more host cell adhesions than the non-aggregating actA-ΔC mutant (which lacks the C-terminus coding region), with the adhering bacteria inducing 3-fold more intracellular invasions. Aggregation is associated with robust MET tyrosine kinase receptor clustering in the host cells, a hallmark of InlB-mediated invasion, something not observed with the actA-ΔC mutant. Finally, we show via RNA-seq analyses that aggregation involves a global adaptive response to host cell environment (including iron depletion), resulting in metabolic changes in L. monocytogenes and upregulation of the PrfA virulence regulon. Overall, our analyses provide new mechanistic insights into internalin-mediated host-pathogen interactions of L. monocytogenes.

Keywords:
Listeria monocytogenes, host-pathogen interactions, aggregation, PrfA regulon, livecell microscopy

Haghighat Bayan M.A., Rinoldi C., Kosik-Kozioł A., Bartolewska M., Rybak D., Zargarian S., Shah S., Krysiak Z., Zhang S., Lanzi M., Nakielski P., Ding B., Pierini F., Solar-to-NIR Light Activable PHBV/ICG Nanofiber-Based Face Masks with On-Demand Combined Photothermal and Photodynamic Antibacterial Properties, Advanced Materials Technologies, ISSN: 2365-709X, DOI: 10.1002/admt.202400450, pp.2400450-1-18, 2024

Abstract:
Hierarchical nanostructures fabricate by electrospinning in combination with light-responsive agents offer promising scenarios for developing novel activable antibacterial interfaces. This study introduces an innovative antibacterial face mask developed from poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers integrated with indocyanine green (ICG), targeting the urgent need for effective antimicrobial protection for community health workers. The research focuses on fabricating and characterizing this nanofibrous material, evaluating the mask's mechanical and chemical properties, investigating its particle filtration, and assessing antibacterial efficacy under photothermal conditions for reactive oxygen species (ROS) generation. The PHBV/ICG nanofibers are produced using an electrospinning process, and the nanofibrous construct's morphology, structure, and photothermal response are investigated. The antibacterial efficacy of the nanofibers is tested, and substantial bacterial inactivation under both near-infrared (NIR) and solar irradiation is demonstrated due to the photothermal response of the nanofibers. The material's photothermal response is further analyzed under cyclic irradiation to simulate real-world conditions, confirming its durability and consistency. This study highlights the synergistic impact of PHBV and ICG in enhancing antibacterial activity, presenting a biocompatible and environmentally friendly solution. These findings offer a promising path for developing innovative face masks that contribute significantly to the field of antibacterial materials and solve critical public health challenges.

Pawłowska S., Cysewska K., Ziai Y., Karczewski J., Jasiński P., Molin S., Influence of conductive carbon and MnCo2O4 on morphological and electrical properties of hydrogels for electrochemical energy conversion, Beilstein Journal of Nanotechnology, ISSN: 2190-4286, DOI: 10.3762/bjnano.15.6, Vol.15, pp.57-70, 2024

Keywords:
electrical properties, energy, hydrogel, hydrogen, oxygen evolution reaction, polymer composites

Zargarian S., Zakrzewska A., Kosik-Kozioł A., Bartolewska M., Shah S., Li X., Su Q., Petronella F., Marinelli M., De Sio L., Lanzi M., Ding B., Pierini F., Advancing resource sustainability with green photothermal materials: Insights from organic waste-derived and bioderived sources, nanotechnology reviews, ISSN: 2191-9097, DOI: 10.1515/ntrev-2024-0100, Vol.13, No.1, pp.20240100-1-39, 2024

Abstract:
Recently, there has been a surge of interest in developing new types of photothermal materials driven by the ongoing demand for efficient energy conversion, environmental concerns, and the need for sustainable solutions. However, many existing photothermal materials face limitations such as high production costs or narrow absorption bands, hindering their widespread application. In response to these challenges, researchers have redirected their focus toward harnessing the untapped potential of organic waste-derived and bioderived materials. These materials, with photothermal properties derived from their intrinsic composition or transformative processes, offer a sustainable and cost-effective alternative. This review provides an extended categorization of organic waste-derived and bioderived materials based on their origin. Additionally, we investigate the mechanisms underlying the photothermal properties of these materials. Key findings highlight their high photothermal efficiency and versatility in applications such as water and energy harvesting, desalination, biomedical applications, deicing, waste treatment, and environmental remediation. Through their versatile utilization, they demonstrate immense potential in fostering sustainability and support the transition toward a greener and more resilient future. The authors’ perspective on the challenges and potentials of platforms based on these materials is also included, highlighting their immense potential for real-world implementation.

Keywords:
photothermal materials, organic waste valorization, bioderived materials

Nazish J., Sohail M., Mahmood A., Shah S. A., Qalawlus Aya Hamid M., Khaliq T., Nanocrystals loaded collagen/alginate-based injectable hydrogels: A promising biomaterial for bioavailability improvement of hydrophobic drugs, Journal of Drug Delivery Science and Technology, ISSN: 1773-2247, DOI: 10.1016/j.jddst.2023.105291, Vol.91, pp.105291-1-16, 2024

Abstract:
The study aims to improve the solubility of poorly soluble drug by developing an optimized formulation of nanocrystals and extend its release profile by incorporating optimized nanocrystals in a biopolymer based injectable hydrogel. Nanocrystals of Silymarin (SM) were developed by anti-solvent precipitation technique followed by homogenization. Various stabilizers were investigated and combination of polyvinyl pyrrolidine K30 (PVP K30) and sodium lauryl sulfate (SLS) in a specific ratio was chosen as a stabilizer for nanocrystals. The optimized nanocrystals possessed mean particle size 172 ± 5.23 nm and PDI of 0.228 ± 0.02. Sodium alginate (Alg) and collagen (Col) based injectable hydrogel in combination with pluronic F127 showed good biocompatibility, mechanical strength and biodegradability. The developed formulation was characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infra-red spectroscopy (FT-IR) and X-ray diffraction (XRD) analysis. The results of FT-IR and TGA showed structural cross-linking between polymers and promising thermal stability of formulation with increasing temperature, respectively. The nanocrystals loaded Alg-Col-F127 injectable hydrogel was degraded completely in 48 h. The results of in vitro release studies and in vivo pharmacokinetic profiling of silymarin nanocrystals laden Alg-Col-F127 injectable hydrogel exhibited controlled release behavior as compared to coarse silymarin suspension and silymarin nanocrystals. Therefore, nanosuspension integrated biopolymer-based hybrid injectable hydrogel system may be used to assist solubility and bioavailability enhancement as well as serve as platform to provide controlled drug release.

Keywords:
Nanocrystals, Injectable hydrogel, Hydrophobic drug, Solubility, Bioavailability

Zargarian S., Kupikowska-Stobba B., Kosik-Kozioł A., Bartolewska M., Zakrzewska A., Rybak D., Bochenek K., Osial M., Pierini F., Light-responsive biowaste-derived and bio-inspired textiles: Dancing between bio-friendliness and antibacterial functionality, Materials Today Chemistry, ISSN: 2468-5194, DOI: 10.1016/j.mtchem.2024.102281, Vol.41, pp.102281-1-15, 2024

Abstract:
Functional antibacterial textiles fabricated from a hybrid of organic waste-derived and bio-inspired materials offer sustainable solutions for preventing microbial infections. In this work, we developed a novel antibacterial textile created through the valorization of spent coffee grounds (SCG). Electrospinning and electrospraying techniques were employed to integrate the biowaste within a polymeric nanofiber matrix, ensuring uniform particle distribution and providing structural support for enhanced applicability. Modification with polydopamine (PDA) significantly enhanced the textile's photothermal performance. Specific attention was paid to understanding the relation between temperature change and key variables, including the surrounding liquid volume, textile layer stacking, and applied laser power. Developed platforms demonstrated excellent photothermal stability. While the SCG-based textile demonstrated exceptional biocompatibility, the PDA-modified textile effectively eradicated Staphylococcus aureus (S. aureus) under near-infrared (NIR) irradiation. The developed textiles in our work demonstrate a dynamic balance between biocompatibility and on-demand antibacterial functionality, offering adaptable solutions in accordance with the desired application.

Keywords:
Organic waste valorization, Spent coffee grounds, Micro-nanostructured textiles, Bio-inspired photothermal agents, Polydopamine, Antibacterial textiles

Cofas Vargas L.F., Azevedo Rodrigo M., Poblete S., Chwastyk M., Poma Bernaola A.M.^♦, The GōMartini Approach: Revisiting the Concept of Contact Maps and the Modelling of Protein Complexes, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.145.S9, Vol.145, No.3, pp.S9-S20, 2024

Abstract:
We present a review of a series of contact maps for the determination of native interactions in proteins and nucleic acids based on a distance threshold. Such contact maps are mostly based on physical and chemical construction, and yet they are sensitive to some parameters (e.g., distances or atomic radii) and can neglect some key interactions. Furthermore, we also comment on a new class of contact maps that only requires geometric arguments. The contact map is a necessary ingredient to build a robust Gō-Martini model for proteins and their complexes in the Martini 3 force field. We present the extension of a popular structure-based Gō--like approach to the study of protein–sugar complexes, and the limitations of this approach are also discussed. The Gō-Martini approach was first introduced by Poma et al. (J. Chem. Theory Comput. 13, 1366 (2017)) in Martini 2 force field, and recently, it has gained the status of gold standard for protein simulation undergoing conformational changes in Martini 3 force field. We discuss several studies that have provided support for this approach in the context of the biophysical community.

Keywords:
Martini 3,Structure-based coarse-graining,SMFS,biomolecules,GoMartini

Marinelli M., Lanzi M., Quadretti D., Ziai Y., Pierini F., Zanelli A., Riccardo M., Salatelli E., A new alcohol-soluble dye-tetraphenyl porphyrin functionalized copolymer: Inside the role as a third component/cathode interlayer in halogen-free OSCs, REACTIVE AND FUNCTIONAL POLYMERS, ISSN: 1381-5148, DOI: 10.1016/j.reactfunctpolym.2024.105928, Vol.200, pp.105928-1-10, 2024

Abstract:
Development and step-by-step characterizations of a novel cationic thiophene based copolymer (P1buP), including ionic phosphonium salt and dye-tetraphenylporphyrin (TPP) moiety in side chains, with an iconic property of solubility in a wide range of polar solvents is reported. Synthesized by using simple, low-cost, and straightforward procedures, the material is used to fabricate completely halogen-free (i.e., from ethanol) ternary organic solar cells (OSCs), in the presence of an alcohol-soluble ionic 3,4-dialkoxythiophene based homopolymer (P2buP) and a serinol-fullerene derivative (C60-Ser). Indeed, thanks to co-sensitization techniques, where multiple dyes harvest different parts of the solar spectrum, the power conversion efficiency of the best final device dramatically increases up to nearly 5.0%, as the light absorption is usually optimized. Additionally, since the use of a cathode interlayer in OSCs also plays a pivotal role in electron extraction and device stability, a possible application of the ionic TPP material as the interfacial layer is also investigated. Furthermore, to improve and optimize the best performing device, a successful post-metalation with Zn of the porphyrin core is carried out, and a ternary OSC (P1buP:P2buP:C60-Ser = 0.33:0.67:1 w/w) is fabricated, resulting in a photoconversion efficiency (PCE) of ∼6.0%.

Keywords:
Ionic dye-tetraphenylporphyrin, Co-sensitization, Ternary OSCs, Cathode interlayers, Halogen-free deposition

Ray A., Thu Thi Minh T., Santos Natividade Rita d., Azevedo Rodrigo M., Joshua S., Danahe M., Koehler M., Simon P., Qingrong Z., Fabrice B., Laurent G., Poma Bernaola A.M., Alsteens D., Single-Molecule Investigation of the Binding Interface Stability of SARS-CoV-2 Variants with ACE2, ACS Nanoscience Au, ISSN: 2694-2496, DOI: 10.1021/acsnanoscienceau.3c00060, pp.1-10, 2024

Abstract:
The SARS-CoV-2 pandemic spurred numerous research endeavors to comprehend the virus and mitigate its global severity. Understanding the binding interface between the virus and human receptors is pivotal to these efforts and paramount to curbing infection and transmission. Here we employ atomic force microscopy and steered molecular dynamics simulation to explore SARS-CoV-2 receptor binding domain (RBD) variants and angiotensin-converting enzyme 2 (ACE2), examining the impact of mutations at key residues upon binding affinity. Our results show that the Omicron and Delta variants possess strengthened binding affinity in comparison to the Mu variant. Further, using sera from individuals either vaccinated or with acquired immunity following Delta strain infection, we assess the impact of immunity upon variant RBD/ACE2 complex formation. Single-molecule force spectroscopy analysis suggests that vaccination before infection may provide stronger protection across variants. These results underscore the need to monitor antigenic changes in order to continue developing innovative and effective SARS-CoV-2 abrogation strategies.

Keywords:
SARS-Cov-2,Molecular Dynamics ,Immunity,SMFS,Nanomechanics,Free Energy,Jarzynski,Receptor,Protein complex,interfaces

Ziai Y., Lanzi M., Rinoldi C., Zargarian S.S., Zakrzewska A., Kosik-Kozioł A., Nakielski P., Pierini F., Developing strategies to optimize the anchorage between electrospun nanofibers and hydrogels for multi-layered plasmonic biomaterials, Nanoscale Advances, ISSN: 2516-0230, DOI: 10.1039/d3na01022h, Vol.6, No.4, pp.1246-1258, 2024

Abstract:
Polycaprolactone (PCL), a recognized biopolymer, has emerged as a prominent choice for diverse biomedical endeavors due to its good mechanical properties, exceptional biocompatibility, and tunable properties. These attributes render PCL a suitable alternative biomaterial to use in biofabrication, especially the electrospinning technique, facilitating the production of nanofibers with varied dimensions and functionalities. However, the inherent hydrophobicity of PCL nanofibers can pose limitations. Conversely, acrylamide-based hydrogels, characterized by their interconnected porosity, significant water retention, and responsive behavior, present an ideal matrix for numerous biomedical applications. By merging these two materials, one can harness their collective strengths while potentially mitigating individual limitations. A robust interface and effective anchorage during the composite fabrication are pivotal for the optimal performance of the nanoplatforms. Nanoplatforms are subject to varying degrees of tension and physical alterations depending on their specific applications. This is particularly pertinent in the case of layered nanostructures, which require careful consideration to maintain structural stability and functional integrity in their intended applications. In this study, we delve into the influence of the fiber dimensions, orientation and surface modifications of the nanofibrous layer and the hydrogel layer's crosslinking density on their intralayer interface to determine the optimal approach. Comprehensive mechanical pull-out tests offer insights into the interfacial adhesion and anchorage between the layers. Notably, plasma treatment of the hydrophobic nanofibers and the stiffness of the hydrogel layer significantly enhance the mechanical effort required for fiber extraction from the hydrogels, indicating improved anchorage. Furthermore, biocompatibility assessments confirm the potential biomedical applications of the proposed nanoplatforms.