Nanoscopy for nanomedicine


Lorenzo Albertazzi | Junior Group Leader
Pietro Delcanale | Postdoctoral Researcher
Silvia Pujals Riatós | Postdoctoral Researcher
Maria Arista Romero | PhD Student
Natàlia Feiner Gracia | PhD Student
Adrianna Glinkowska Mares | PhD Student
Boris Arts | Masters Student
Roger Riera Brillas | Masters Student

About

The main goal of our group is to use Super Resolution Microscopy (nanoscopy) to visualize and track in living cells and tissues self-assembled nanomaterials with therapeutic potential (nanomedicine).

TEM image of novel self-assembled nanofibers synthesized in the group.

The understanding of materials-cell interactions is the key towards the development of novel nanotechnology-based therapies for treatment of cancer and infectious diseases.
Our group aims to use a multidisciplinary approach, at the interface of chemistry, physics and biology, to develop novel nanomaterials for the treatment of cancer and infectious diseases.

We aim at the development of novel nanocarriers for drug delivery based on self-assembly, i.e. able to build themselves. Molecular self-organization is ubiquitous in the biological world and represents for us a source of inspiration for the design of nanostructures with biomedical potential. In particular we focus on the development of self-assembled nanoparticles and nanofibers able to selectively target diseased cells and deliver locally therapeutic moieties such as drugs and genetic material (e.g. DNA, siRNA, mRNA).

Right: Nanoparticles interactions with blood components imaged with conventional optical microscopy (left) and super resolution STORM microscopy (right).

A key point towards the development of novel nanotechnology-based therapies is the understanding of the behavior of nanomaterials in the complex biological environment. Here we use super resolution microscopy to track nanomaterials during their voyage in the biological environment and to visualize the interactions with blood components, immune system and target cells. We make use of a variety of super resolution techniques based on single molecule detection such a stochastic optical reconstruction microscopy (STORM), photoactivated localization microscopy (PALM), point accumulation for imaging in nanoscale topography (PAINT), and single particle tracking (SPT). These methods allow to achieve a resolution down to few nanometers and are therefore ideal to visualize nanosized synthetic objects in the biological environment. Super resolution microscopy provides a molecular picture of structure-activity relations and represent a guide towards the design of innovative materials for nanomedicine.

News/Jobs

“STORMing their way to Nanoparticle–Protein Interaction Understanding”
06/10/2017

A paper published in Small last month by Lorenzo Albertazzi’s group is featured in Advanced Science News, Wiley publishing company’s in-house news website. This platform presents advances in various fields of research for a general audience.


ERC success for Lorenzo Albertazzi
07/09/2017

The Nanoscopy for Nanomedicine junior group leader was successful in the European Research Council’s 2017 call for Starting Grants, of which just 17 out of the total of 406 have been awarded to scientists working in Spain.


IBEC research features in ChemComm’s “Emerging Investigators” issue
05/07/2017

IBEC junior group leader Lorenzo Albertazzi is a contributor to the 2017 edition of ChemComm Emerging Investigators, which is published annually by the UK’s Royal Society of Chemistry.


IBEC project among 44 funded by AXA
20/04/2016

The AXA Research Fund, the international scientific philanthropy initiative of global insurer AXA, officially announced last week that it will devote €15.6m in 2016 to 44 new research projects with leading academic institutions in 16 countries.


Playing with molecular Lego to build the next generation of drug delivery vectors
11/02/2016

New IBEC junior group leader Lorenzo Albertazzi and his former colleagues at the Eindhoven University of Technology, working together with industry partner Novartis, have made a leap in drug delivery vectors by developing a new type of carrier with some groundbreaking improvements.


“Wrapping Up Pandemics in New Nanomaterials”
01/02/2016

Lorenzo Albertazzi’s research project funded by AXA, Novel approaches for Pandemic Virus Targeting Using Adaptive Polymers, is featured on the Granted Projects section of their website.


‘Submarinos’ en la sangre para llevar el medicamento a las células dañadas
06/10/2015

New IBEC junior group leader Lorenzo Albertazzi is profiled in El Mundo’s “Personajes Únicos” section this week.


Expert in novel drug delivery systems joins IBEC
08/09/2015

Dr Lorenzo Albertazzi, a nanoscientist whose research focuses on creating smart self-assembling materials for therapeutic applications, is joining IBEC this September.


Projects

International grants
Novel approaches for Pandemic Virus Targeting Using Adaptive Polymers AXA Research Fund Lorenzo Albertazzi
NANOSTORM Design of Nanomaterials for Targeted Therapies Guided by Super Resolution Imaging ERC Lorenzo Albertazzi
National grants
TARGETSTORM Nanomateriales para terapias dirigidas contra el cáncer visualizados con microscopia de súper resolución STORM (2016-2019) MINECO Retos investigación: Proyectos I+D Lorenzo Albertazzi
NANOVAX Nanovacunas diseñadas para inmunoterapia antitumoral MINECO Acciones de Programación Conjunta Internacional Lorenzo Albertazzi/Josep Samitier
Ayudas para contratos Ramón y Cajal MINECO Ramon y Cajal Lorenzo Albertazzi

Publications

(See full publication list in ORCID)

Labernadie, A., Kato, T., Brugués, A., Serra-Picamal, X., Derzsi, S., Arwert, E., Weston, A., González-Tarragó, V., Elosegui-Artola, A., Albertazzi, L., Alcaraz, J., Roca-Cusachs, P., Sahai, E., Trepat, X., (2017). A mechanically active heterotypic E-cadherin/N-cadherin adhesion enables fibroblasts to drive cancer cell invasion Nature Cell Biology 19, (3), 224-237

Cancer-associated fibroblasts (CAFs) promote tumour invasion and metastasis. We show that CAFs exert a physical force on cancer cells that enables their collective invasion. Force transmission is mediated by a heterophilic adhesion involving N-cadherin at the CAF membrane and E-cadherin at the cancer cell membrane. This adhesion is mechanically active; when subjected to force it triggers β-catenin recruitment and adhesion reinforcement dependent on α-catenin/vinculin interaction. Impairment of E-cadherin/N-cadherin adhesion abrogates the ability of CAFs to guide collective cell migration and blocks cancer cell invasion. N-cadherin also mediates repolarization of the CAFs away from the cancer cells. In parallel, nectins and afadin are recruited to the cancer cell/CAF interface and CAF repolarization is afadin dependent. Heterotypic junctions between CAFs and cancer cells are observed in patient-derived material. Together, our findings show that a mechanically active heterophilic adhesion between CAFs and cancer cells enables cooperative tumour invasion.


Van Onzen, A. H. A. M., Albertazzi, L., Schenning, A. P. H. J., Milroy, L. G., Brunsveld, L., (2017). Hydrophobicity determines the fate of self-assembled fluorescent nanoparticles in cells Chemical Communications 53, (10), 1626-1629

The fate of small molecule nanoparticles (SMNPs) composed of self-assembling intrinsically fluorescent π-conjugated oligomers was studied in cells as a function of side-chain hydrophobicity. While the hydrophobic SMNPs remained intact upon cellular uptake, the more hydrophilic SMNPs disassembled and dispersed throughout the cytosol.


Pujals, S., Tao, K., Terradellas, A., Gazit, E., Albertazzi, L., (2017). Studying structure and dynamics of self-Assembled peptide nanostructures using fluorescence and super resolution microscopy Chemical Communications 53, (53), 7294-7297

Understanding the formation and properties of self-Assembled peptide nanostructures is the basis for the design of new architectures for various applications. Here we show the potential of fluorescence and super resolution imaging to unveil the structural and dynamic features of peptide nanofibers with high spatiotemporal resolution.


Duro-Castano, Aroa, Nebot, Vicent J., Niño-Pariente, Amaya, Armiñán, Ana, Arroyo-Crespo, Juan J., Paul, Alison, Feiner-Gracia, Natalia, Albertazzi, Lorenzo, Vicent, María J., (2017). Capturing “extraordinary” soft-assembled charge-like polypeptides as a strategy for nanocarrier design Advanced Materials Early View (Online Version of Record published before inclusion in an issue)

The rational design of nanomedicines is a challenging task given the complex architectures required for the construction of nanosized carriers with embedded therapeutic properties and the complex interface of these materials with the biological environment. Herein, an unexpected charge-like attraction mechanism of self-assembly for star-shaped polyglutamates in nonsalty aqueous solutions is identified, which matches the ubiquitous “ordinary–extraordinary” phenomenon previously described by physicists. For the first time, a bottom-up methodology for the stabilization of these nanosized soft-assembled star-shaped polyglutamates is also described, enabling the translation of theoretical research into nanomaterials with applicability within the drug-delivery field. Covalent capture of these labile assemblies provides access to unprecedented architectures to be used as nanocarriers. The enhanced in vitro and in vivo properties of these novel nanoconstructs as drug-delivery systems highlight the potential of this approach for tumor-localized as well as lymphotropic delivery.

Keywords: Charge-like, Drug delivery, Polymer therapeutics, Polypeptides, Self-assembly


Feiner-Gracia, Natalia, Beck, Michaela, Pujals, Sílvia, Tosi, Sébastien, Mandal, Tamoghna, Buske, Christian, Linden, Mika, Albertazzi, Lorenzo, (2017). Super-resolution microscopy unveils dynamic heterogeneities in nanoparticle protein corona Small Early View (Online Version of Record published before inclusion in an issue)

The adsorption of serum proteins, leading to the formation of a biomolecular corona, is a key determinant of the biological identity of nanoparticles in vivo. Therefore, gaining knowledge on the formation, composition, and temporal evolution of the corona is of utmost importance for the development of nanoparticle-based therapies. Here, it is shown that the use of super-resolution optical microscopy enables the imaging of the protein corona on mesoporous silica nanoparticles with single protein sensitivity. Particle-by-particle quantification reveals a significant heterogeneity in protein absorption under native conditions. Moreover, the diversity of the corona evolves over time depending on the surface chemistry and degradability of the particles. This paper investigates the consequences of protein adsorption for specific cell targeting by antibody-functionalized nanoparticles providing a detailed understanding of corona-activity relations. The methodology is widely applicable to a variety of nanostructures and complements the existing ensemble approaches for protein corona study.

Keywords: Heterogeneity, Mesoporous silica nanoparticles, Protein corona, Super-resolution imaging, Targeting


Caballero, David, Blackburn, Sophie M., de Pablo, Mar, Samitier, Josep, Albertazzi, Lorenzo, (2017). Tumour-vessel-on-a-chip models for drug delivery Lab on a Chip Advance Article

Nanocarriers for drug delivery have great potential to revolutionize cancer treatment, due to their enhanced selectivity and efficacy. Despite this great promise, researchers have had limited success in the clinical translation of this approach. One of the main causes of these difficulties is that standard in vitro models, typically used to understand nanocarriers' behaviour and screen their efficiency, do not provide the complexity typically encountered in living systems. In contrast, in vivo models, despite being highly physiological, display serious bottlenecks which threaten the relevancy of the obtained data. Microfluidics and nanofabrication can dramatically contribute to solving this issue, providing 3D high-throughput models with improved resemblance to in vivo systems. In particular, microfluidic models of tumour blood vessels can be used to better elucidate how new nanocarriers behave in the microcirculation of healthy and cancerous tissues. Several key steps of the drug delivery process such as extravasation, immune response and endothelial targeting happen under flow in capillaries and can be accurately modelled using microfluidics. In this review, we will present how tumour-vessel-on-a-chip systems can be used to investigate targeted drug delivery and which key factors need to be considered for the rational design of these materials. Future applications of this approach and its role in driving forward the next generation of targeted drug delivery methods will be discussed.


Bakker, Maarten H., Lee, Cameron C., Meijer, E. W., Dankers, Patricia Y. W., Albertazzi, Lorenzo, (2016). Multicomponent supramolecular polymers as a modular platform for intracellular delivery ACS Nano 10, (2), 1845-1852

Supramolecular polymers are an emerging family of nanosized structures with potential use in materials chemistry and medicine. Surprisingly, application of supramolecular polymers in the field of drug delivery has received only limited attention. Here, we explore the potential of PEGylated 1,3,5-benzenetricarboxamide (BTA) supramolecular polymers for intracellular delivery. Exploiting the unique modular approach of supramolecular chemistry, we can coassemble neutral and cationic BTAs and control the overall properties of the polymer by simple monomer mixing. Moreover, this platform offers a versatile approach toward functionalization. The core can be efficiently loaded with a hydrophobic guest molecule, while the exterior can be electrostatically complexed with siRNA. It is demonstrated that both compounds can be delivered in living cells, and that they can be combined to enable a dual delivery strategy. These results show the advantages of employing a modular system and pave the way for application of supramolecular polymers in intracellular delivery.


Beun, L. H., Albertazzi, L., Van Der Zwaag, D., De Vries, R., Cohen Stuart, M. A., (2016). Unidirectional living growth of self-assembled protein nanofibrils revealed by super-resolution microscopy ACS Nano 10, (5), 4973-4980

Protein-based nanofibrils are emerging as a promising class of materials that provide unique properties for applications such as biomedical and food engineering. Here, we use atomic force microscopy and stochastic optical reconstruction microscopy imaging to elucidate the growth dynamics, exchange kinetics, and polymerization mechanism for fibrils composed of a de novo designed recombinant triblock protein polymer. This macromolecule features a silk-inspired self-assembling central block composed of GAGAGAGH repeats, which are known to fold into a β roll with turns at each histidine and, once folded, to stack, forming a long, ribbon-like structure. We find several properties that allow the growth of patterned protein nanofibrils: the self-assembly takes place on only one side of the growing fibrils by the essentially irreversible addition of protein polymer subunits, and these fibril ends remain reactive indefinitely in the absence of monomer ("living ends"). Exploiting these characteristics, we can grow stable diblock protein nanofibrils by the sequential addition of differently labeled proteins. We establish control over the block length ratio by simply varying monomer feed conditions. Our results demonstrate the use of engineered protein polymers in creating precisely patterned protein nanofibrils and open perspectives for the hierarchical self-assembly of functional biomaterials.

Keywords: Nanofibrils, Protein polymers, Self-assembly, STORM microscopy


Garzoni, M., Baker, M. B., Leenders, C. M. A., Voets, I. K., Albertazzi, L., Palmans, A. R. A., Meijer, E. W., Pavan, G. M., (2016). Effect of H-bonding on order amplification in the growth of a supramolecular polymer in water Journal of the American Chemical Society 138, (42), 13985-13995

While a great deal of knowledge on the roles of hydrogen bonding and hydrophobicity in proteins has resulted in the creation of rationally designed and functional peptidic structures, the roles of these forces on purely synthetic supramolecular architectures in water have proven difficult to ascertain. Focusing on a 1,3,5-benzenetricarboxamide (BTA)-based supramolecular polymer, we have designed a molecular modeling strategy to dissect the energetic contributions involved in the self-assembly (electrostatic, hydrophobic, etc.) upon growth of both ordered BTA stacks and random BTA aggregates. Utilizing this set of simulations, we have unraveled the cooperative mechanism for polymer growth, where a critical size must be reached in the aggregates before emergence and amplification of order into the experimentally observed fibers. Furthermore, we have found that the formation of ordered fibers is favored over disordered aggregates solely on the basis of electrostatic interactions. Detailed analysis of the simulation data suggests that H-bonding is a major source of this stabilization energy. Experimental and computational comparison with a newly synthesized 1,3,5-benzenetricarboxyester (BTE) derivative, lacking the ability to form the H-bonding network, demonstrated that this BTE variant is also capable of fiber formation, albeit at a reduced persistence length. This work provides unambiguous evidence for the key 1D driving force of hydrogen bonding in enhancing the persistency of monomer stacking and amplifying the level of order into the growing supramolecular polymer in water. Our computational approach provides an important relationship directly linking the structure of the monomer to the structure and properties of the supramolecular polymer.


Aloi, Antonio, Vargas Jentzsch, Andreas, Vilanova, Neus, Albertazzi, Lorenzo, Meijer, E. W., Voets, Ilja K., (2016). Imaging nanostructures by single-molecule localization microscopy in organic solvents Journal of the American Chemical Society 138, (9), 2953-2956

The introduction of super-resolution fluorescence microscopy (SRM) opened an unprecedented vista into nanoscopic length scales, unveiling a new degree of complexity in biological systems in aqueous environments. Regrettably, supramolecular chemistry and material science benefited far less from these recent developments. Here we expand the scope of SRM to photoactivated localization microscopy (PALM) imaging of synthetic nanostructures that are highly dynamic in organic solvents. Furthermore, we characterize the photophysical properties of commonly used photoactivatable dyes in a wide range of solvents, which is made possible by the addition of a tiny amount of an alcohol. As proof-of-principle, we use PALM to image silica beads with radii close to Abbe’s diffraction limit. Individual nanoparticles are readily identified and reliably sized in multicolor mixtures of large and small beads. We further use SRM to visualize nm-thin yet


da Silva, Ricardo M. P., van der Zwaag, Daan, Albertazzi, Lorenzo, Lee, Sungsoo S., Meijer, E. W., Stupp, Samuel I., (2016). Super-resolution microscopy reveals structural diversity in molecular exchange among peptide amphiphile nanofibres Nature Communications 7, 11561

The dynamic behaviour of supramolecular systems is an important dimension of their potential functions. Here, we report on the use of stochastic optical reconstruction microscopy to study the molecular exchange of peptide amphiphile nanofibres, supramolecular systems known to have important biomedical functions. Solutions of nanofibres labelled with different dyes (Cy3 and Cy5) were mixed, and the distribution of dyes inserting into initially single-colour nanofibres was quantified using correlative image analysis. Our observations are consistent with an exchange mechanism involving monomers or small clusters of molecules inserting randomly into a fibre. Different exchange rates are observed within the same fibre, suggesting that local cohesive structures exist on the basis of [beta]-sheet discontinuous domains. The results reported here show that peptide amphiphile supramolecular systems can be dynamic and that their intermolecular interactions affect exchange patterns. This information can be used to generate useful aggregate morphologies for improved biomedical function.


De Koker, Stefaan, Cui, Jiwei, Vanparijs, Nane, Albertazzi, Lorenzo, Grooten, Johan, Caruso, Frank, De Geest, Bruno G., (2016). Engineering polymer hydrogel nanoparticles for lymph node-targeted delivery Angewandte Chemie - International Edition 55, (4), 1334-1339

The induction of antigen-specific adaptive immunity exclusively occurs in lymphoid organs. As a consequence, the efficacy by which vaccines reach these tissues strongly affects the efficacy of the vaccine. Here, we report the design of polymer hydrogel nanoparticles that efficiently target multiple immune cell subsets in the draining lymph nodes. Nanoparticles are fabricated by infiltrating mesoporous silica particles (ca. 200 nm) with poly(methacrylic acid) followed by disulfide-based crosslinking and template removal. PEGylation of these nanoparticles does not affect their cellular association in vitro, but dramatically improves their lymphatic drainage in vivo. The functional relevance of these observations is further illustrated by the increased priming of antigen-specific T cells. Our findings highlight the potential of engineered hydrogel nanoparticles for the lymphatic delivery of antigens and immune-modulating compounds.

Keywords: Dendritic cells, Disulfides, Hydrogels, Nanoparticles, Vaccines


Li, Hui, Fierens, Kaat, Zhang, Zhiyue, Vanparijs, Nane, Schuijs, Martijn J., Van Steendam, Katleen, Feiner Gracia, Natàlia, De Rycke, Riet, De Beer, Thomas, De Beuckelaer, Ans, De Koker, Stefaan, Deforce, Dieter, Albertazzi, Lorenzo, Grooten, Johan, Lambrecht, Bart N., De Geest, Bruno G., (2016). Spontaneous protein adsorption on graphene oxide nanosheets allowing efficient intracellular vaccine protein delivery ACS Applied Materials & Interfaces 8, (2), 1147-1155

Nanomaterials hold potential of altering the interaction between therapeutic molecules and target cells or tissues. High aspect ratio nanomaterials in particular have been reported to possess unprecedented properties and are intensively investigated for their interaction with biological systems. Graphene oxide (GOx) is a water-soluble graphene derivative that combines high aspect ratio dimension with functional groups that can be exploited for bioconjugation. Here, we demonstrate that GOx nanosheets can spontaneously adsorb proteins by a combination of interactions. This property is then explored for intracellular protein vaccine delivery, in view of the potential of GOx nanosheets to destabilize lipid membranes such as those of intracellular vesicles. Using a series of in vitro experiments, we show that GOx nanosheet adsorbed proteins are efficiently internalized by dendritic cells (DCs: the most potent class of antigen presenting cells of the immune system) and promote antigen cross-presentation to CD8 T cells. The latter is a hallmark in the induction of potent cellular antigen-specific immune responses against intracellular pathogens and cancer. Nanomaterials hold potential of altering the interaction between therapeutic molecules and target cells or tissues. High aspect ratio nanomaterials in particular have been reported to possess unprecedented properties and are intensively investigated for their interaction with biological systems. Graphene oxide (GOx) is a water-soluble graphene derivative that combines high aspect ratio dimension with functional groups that can be exploited for bioconjugation. Here, we demonstrate that GOx nanosheets can spontaneously adsorb proteins by a combination of interactions. This property is then explored for intracellular protein vaccine delivery, in view of the potential of GOx nanosheets to destabilize lipid membranes such as those of intracellular vesicles. Using a series of in vitro experiments, we show that GOx nanosheet adsorbed proteins are efficiently internalized by dendritic cells (DCs: the most potent class of antigen presenting cells of the immune system) and promote antigen cross-presentation to CD8 T cells. The latter is a hallmark in the induction of potent cellular antigen-specific immune responses against intracellular pathogens and cancer.


van der Zwaag, Daan, Vanparijs, Nane, Wijnands, Sjors, De Rycke, Riet, De Geest, Bruno G., Albertazzi, Lorenzo, (2016). Super resolution imaging of nanoparticles cellular uptake and trafficking ACS Applied Materials & Interfaces 8, (10), 6391-6399

Understanding the interaction between synthetic nanostructures and living cells is of crucial importance for the development of nanotechnology-based intracellular delivery systems. Fluorescence microscopy is one of the most widespread tools owing to its ability to image multiple colors in native conditions. However, due to the limited resolution, it is unsuitable to address individual diffraction-limited objects. Here we introduce a combination of super-resolution microscopy and single-molecule data analysis to unveil the behavior of nanoparticles during their entry into mammalian cells. Two-color Stochastic Optical Reconstruction Microscopy (STORM) addresses the size and positioning of nanoparticles inside cells and probes their interaction with the cellular machineries at nanoscale resolution. Moreover, we develop image analysis tools to extract quantitative information about internalized particles from STORM images. To demonstrate the potential of our methodology, we extract previously inaccessible information by the direct visualization of the nanoparticle uptake mechanism and the intracellular tracking of nanoparticulate model antigens by dendritic cells. Finally, a direct comparison between STORM, confocal microscopy, and electron microscopy is presented, showing that STORM can provide novel and complementary information on nanoparticle cellular uptake. Understanding the interaction between synthetic nanostructures and living cells is of crucial importance for the development of nanotechnology-based intracellular delivery systems. Fluorescence microscopy is one of the most widespread tools owing to its ability to image multiple colors in native conditions. However, due to the limited resolution, it is unsuitable to address individual diffraction-limited objects. Here we introduce a combination of super-resolution microscopy and single-molecule data analysis to unveil the behavior of nanoparticles during their entry into mammalian cells. Two-color Stochastic Optical Reconstruction Microscopy (STORM) addresses the size and positioning of nanoparticles inside cells and probes their interaction with the cellular machineries at nanoscale resolution. Moreover, we develop image analysis tools to extract quantitative information about internalized particles from STORM images. To demonstrate the potential of our methodology, we extract previously inaccessible information by the direct visualization of the nanoparticle uptake mechanism and the intracellular tracking of nanoparticulate model antigens by dendritic cells. Finally, a direct comparison between STORM, confocal microscopy, and electron microscopy is presented, showing that STORM can provide novel and complementary information on nanoparticle cellular uptake.


Beuwer, Michael A., Knopper, M. F., Albertazzi, Lorenzo, van der Zwaag, Daan, Ellenbroek, Wouter G., Meijer, E. W., Prins, Menno W. J., Zijlstra, Peter, (2016). Mechanical properties of single supramolecular polymers from correlative AFM and fluorescence microscopy Polymer Chemistry 7, (47), 7260-7268

We characterize the structure and mechanical properties of 1,3,5-benzenetricarboxamide (BTA) supramolecular polymers using correlative AFM and fluorescence imaging. AFM allows for nanoscale structural investigation but we found that statistical analysis is difficult because these structures are easily disrupted by the AFM tip. We therefore correlate AFM and fluorescence microscopy to couple nanoscale morphological information to far-field optical images. A fraction of the immobilized polymers are in a clustered or entangled state, which we identify based on diffraction limited fluorescence images. We find that clustered and entangled polymers exhibit a significantly longer persistence length that is broader distributed than single unentangled polymers. By comparison with numerical simulations we find significant heterogeneity in the persistence length of single unentangled polymers, which we attribute to polymer-substrate interactions and the presence of structural diversity within the polymer.


Equipment

  • Nikon NSTORM Super Resolution Microscope
  • Super Resolution microscopy
  • Single particles tracking
  • TIRF fluorescence imaging

Collaborations

  • Roey Amir
    Tel Aviv University, Israel
  • Mika Linden
    Ulm University, Germany
  • Ilja Voets
    Eindhoven University of Technology, The Netherlands
  • Giovanni Pavan
    SUPSI, Switzerland
  • Bruno De Geest
    University of Ghent, Belgium
  • Salvador Borros
    IQS, Barcelona

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