Symposium FL
Biological, Biohybrid and Bioinspired Materials: From Electronics and Photonics to Medicine

Session FL-1 - Classes of Materials and their Synthesis and Chemical Modification

FL-1:IL01  Biopolymer based Electrodes for Wooden Batteries and Super Capacitors
O. INGANAS, Biomolecular and organic electronics, Dept. Physics, Chemistry and Biology, Linköpings Universitet, Linköping, Sweden

The biopolymer lignin is the second most abundant biopolymer synthesis on Earth, after cellulose. Lignin is built from monolignols in a complex polymer structure. Some monolignols can be oxidised into quinones, a process which can be driven by electrochemical redox. In hybrid materials of lignin derivatives and electronic polymers, the redox of the quinone group in the lignin derivative can be used for charge storage, and the electronic polymer used for charge transport. This improves the charge storage capacity in the hybrid material, compared to the electroactive polymer, which may be polypyrrole, poly(ethylenedioxythiophene) (PEDOT) or poly(aminoanthraquinone) (PAAQ). By making hybrids with selected lignins of different origin and processing, or fully synthetic lignin models, we extended the materials portfolio. Much improved stability is found with the second generation using PEDOT based hybrids, formed from electrochemical or chemical synthesis. Further improvement comes when combining both PEDOT and poly(aminoanthraquinone) (PAAQ) with lignins. Pathways to scalable synthesis of wooden supercabattery materials are outlined.


FL-1:IL02  Biosilica from Diatoms: Smart Materials from Biomedicine to Photonics
R. RAGNI, Dipartimento di Chimica, Università degli Studi di Bari "Aldo Moro", Bari, Italy

Diatoms are a prolific class of unicellular photosynthetic microalgae encased in a three-dimensional amorphous silica shell (frustule) whose size and morphology are strictly dependent on the algal species.[1] Diatoms can be regarded as low cost bio-factories of highly regular 3-D biosilica nanostructures, with reproducible shape and micro- to nanoscale features, suitable for several applications.[2,3] Various chemical strategies are available to isolate frustules preserving their nanostructure and to modify their chemical composition. Protocols for in vitro and/or in vivo functionalization of frustules with tailored organic molecules result in selective chemical modification either of the surface or of the biosilica bulk and allow to afford new smart materials for photonics, electronics, sensing and biomedicine.[7,8] This lecture will provide an overview of different approaches to chemical modification of diatoms’ biosilica shells as the basis for the description of applications relating to the smart materials thus obtained.
1. R. Wetherbee, Science 2002, 298, 547. 2. R. Ragni, et al., J. Mater. Res. 2017, 32, 279. 3. R. Ragni, et al., Adv. Mater 2017, in press. 4. S. R. Cicco, et al., ChemPlusChem 2015, 80, 1104. 5. D. Vona, et al., MRS Advances 2016, 1(57), 3817.


FL-1:IL03  Mussel and Plant Polyphenol Inspired Materials: From Molecular Phenomena to Applications
P.B. MESSERSMITH, University of California, Berkeley, CA, USA

Phenols and polyphenols are molecules present in numerous natural systems where they perform a variety of biological functions, including wet bioadhesion, pigmentation, infection prevention, metal-binding and antioxidant properties. Their broad distribution in both the animal and plant kingdoms suggest that polyphenols have a wide range of chemical, physical and biological properties. Based upon this, there is a growing recognition that polyphenols are useful building blocks for advanced functional materials. In this talk, I will focus on a few selected examples of biological systems, such as the polyphenolic mussel adhesive proteins and polyphenols found in tea leaves, grapes, cacao beans and other plant tissues that have high concentrations of phenols or polyphenols. The emphasis will be on describing the chemical and mechanical basis for their role in nature, and how we can exploit these molecules as building blocks for synthetic bioinspired adhesives, hydrogels and coatings.


FL-1:IL04  Molecular Bases of Cadherin-mediated Cell-cell Adhesion
E. PARISINI, Center for Nano Science and Technology @Polimi, Istituto Italiano di Tecnologia, Milano, Italy

Cadherins are transmembrane cell adhesion proteins that mediate cellular adherens junction formation and tissue morphogenesis. As such, they play a crucial role in the cell adhesion mechanism. Loss of cadherin-mediated adhesion has been implicated in many different steps of tumor progression such as invasion and migration, and is strongly related to cell–cell detachment and metastasis. Moreover, cadherins provide tissues with specific mechanical properties such as elasticity and the ability to withstand mechanical stress. Mutational, computational and biophysical studies have so far allowed only for a partial comprehension of the complex cadherin dimerization mechanism. However, some of the most recent structural and functional studies have bridged some critical gaps in our understanding of cadherin mediated cell-cell adhesion. Recently, we have been able to identify a druggable cadherin interface and an effective small molecule adhesion inhibitor/modulator. These findings will pave the way not only to a structure-guided design of cell adhesion inhibitors against cadherin-expressing solid tumors, but also to the development of a toolbox of cell adhesion modulators for cell-based biotechnological applications such as tissue engineering, cell sorting, drug delivery and others.


FL-1:IL05  Synthesis and Characterization of Micro- and Nanostructured Surfaces for Controlling Selective Cell Response
C. AKTAS, AYMAN HAIDAR, MICHAEL VEITH, FRANZ FAUPEL, HASHIM ABDUL-KHALIQ, Kiel, Germany

Surface properties of biomaterials play a major role in the response of the cell to the substratum. The interaction of cells with the surface is governed by the physicochemical characteristics such as chemical composition, roughness, topography, surface energy and Zeta potential (surface charge). Mainly these parameters are examined in two main groups: surface chemistry and topography (physical landscape). The main reason behind the lack of our knowledge in cellular reaction to the biomaterials is the difficulty in varying surface chemistry and topography independently. It has been shown that not only the chemical composition of the surface influence cellular adherence, migration, proliferation and differentiation but also the surface topography of a biomaterial. While a cell type exhibits a good attachment and proliferation on micro‐ and nanostructured (combination of both scales) surface, the same cell type exhibits a reduced adhesion on the same surface composed of only nanostructures. Moreover using ordered structures (at the same scale/size) instead of randomly distributed surface features leads to alignment of cells on the same surface. This study presents a systematic work on selective cell response control by the surface topography.


FL-1:IL06  Photosynthetic Enzymes as Photoactive Soft Materials
F. MILANO, S. LA GATTA, A. AGOSTIANO, M. DELL’EDERA, R. RAGNI, G.M. FARINOLA, M. TROTTA, Istituto per i Processi Chimico Fisici - CNR - Bari; Dipartimento di Chimica, Università di Bari, Bari, Italy

The complexity of the natural photosynthetic systems is difficult to reproduce in vitro; however, complexity is inherently associated to the efficiency of the living multienzyme character of photosynthesis and any biomimetic attempts must cope with this stringent requirement. In this regard, we have designed and assembled efficient organic-biological hybrid systems formed by small to medium size organics molecules responsible of a given specific role and the photoenzyme responsible for energy transduction in photosynthetic organisms. Applications of photoresponsive enzymes as soft photoconverting material in different environment will be presented to show drawbacks, limitations and potentials of such hybrid systems, along with some future interesting developments. Enhancing light harvesting capability of the photosynthetic reaction centre by a tailored molecular fluorophore. 2012 Angew. Chemie Int. Ed. 51, Synthetic Antenna Functioning As Light Harvester in the Whole Visible Region for Enhanced Hybrid Photosynthetic Reaction Centers 2016 Bioconj. Chem 27 Highly oriented photosynthetic reaction centers generate a proton gradient in synthetic protocells 2017 PNAS 114 Functional Enzymes in Nonaqueous Environment: the Case of Photosynthetic reaction center in DES 2017 ACS SC&E 5


FL-1:L07  Investigation of Leaf Shape and Edge Design for Faster Evaporation in Biomimetic Heat Dissipation Systems
P. GRUBER, A. RUPP, University of Akron, Biomimicry Research and Innovation Center BRIC, Akron, OH, USA

In previous projects theromodynamics of plants was identified as an interesting field delivering concept generators for technical, especially architectural application. So leaf morphology is determined by a variety of factors, and also significant for plant water and energy balance. However, how leaf design affects evapotranspiration and, consequently, leaf thermal performance and energy budget, has not been investigated in detail. Many leaf-inspired models in the literature overlook leaf hydraulics, capillarity, wetting phenomena in porous materials and the thermal properties of cellulose. To further the knowledge in this field, we have started to research on the relation between wetting, thermal dynamics and shape. We recorded with a thermal camera free convection of wetted models made of laser-cut paper towel, soaked in water and drying naturally. Families of shapes were abstracted from leaves of deciduous trees: white oak, for their crenations and lobes; maple, for their relatively large teeth; elm, for their smaller hierarchically-ordered serrations. In this abstracted experimental setup we observed distinct evaporation rates for models with normalized surface area but different boundary perimeters.


FL-1:L08  Polymer Brushes Grafted into Supported Porous Oxide Films Generating 3-D Non-fouling Surfaces
M. ES-SOUNI, Institute for Materials & Surface Technology, Kiel University of Applied Sciences, Kiel, Germany

Polymer brushes containing poly(ethylene glycol) (PEG) are non-toxic, release-free non-fouling polymers that have promising technological applications. Usually, they are grafted on flat substrates yielding ultra-thin 2-D films with the fragility inherent to them. For technology relevant applications, however, a certain degree of scratch resistance is required. Herein we propose 3D-non-fouling films based on the grafting of PEG-brushes directly onto the pores of supported inorganic porous films. In this way we aim at realizing an organic-inorganic nanocomposite film combining the desirable functionality with mechanical stability. Two kinds of such films are presented: i) anodized alumina films on glass that lead to transparent non-fouling films; ii) anodized Ti-oxide nanotubes on a titanium substrates that could be used for making non-fouling implant devices. There are undeniable advantages to these substrates: on the one hand they afford a huge surface area with a pore density in the range from 10^10 to 10^12/cm2, and on the other hand they consist of oxides that easily adsorbs the initiator (APTMS) for polymerization. The results show that the polymers are grafted onto the pore surface, reaching down to the pore base, generating non-fouling and scratch resistant films.


FL-1:IL10  From Melanins to OLED Devices: Designing Electroluminescent Materials Inspired to Human Pigments
P. MANINI, C.T. PRONTERA, V. CRISCUOLO, A. PEZZELLA, O. CRESCENZI, M. PAVONE, M. D'ISCHIA, Department of Chemical Science, University of Naples Federico II, Napoli, Italy; M.G. MAGLIONE, P. TASSINI, C. MINARINI, Lab. Nanomaterials and Devices, ENEA C.R. Portici, Portici, Italy

The growing expansion and impact of OLED devices in our everyday life have stimulated the synthesis of a wide plethora of electroluminescent materials with the aim of improving the efficiency and the life-time of the device as well as of selectively tuning the wavelength of the emitting light. In the frame of our research activity aimed at exploring the role of melanins, the dark pigments found in mammalian skin, hair and eyes, as soft organic semiconductors in bio-electronic devices, we have undertaken a new challenge: to obtain innovative electroluminescent compounds from black melanin pigments. The strategy of this research activity has been based on the use of melanin precursors, such as 5,6-dihydroxyindole and dopamine, as starting compounds for the synthesis of fluorescent or phosphorescent materials for applications as emitting layer in OLED devices. In this communication we will discuss the synthesis of a set melanin-inspired electroluminescent compounds; we will report on their photo-physical and electrical properties; the fabrication and characterization of the corresponding OLED devices will also be presented.


FL-1:IL11  Bioinspired Self-organization of Functional Materials
L. HELMBRECHT, H.C. HENDRIKSE, A. VAN DER WEIJDEN, W.L. NOORDUIN, AMOLF, Amsterdam, The Netherlands

Over the course of evolution, organisms have developed a gamut of strategies for controlling nucleation, polymorphism, material composition, shape and hierarchical organization of mineralized components. Although the complexity of these biominerals has fascinated scientists for centuries, the underlying mechanisms often remain poorly understood. Harnessing the basic principles that guide such self-organizing processes is therefore of fundamental scientific interest, but also promises a paradigm shift in the manufacturing of nano- and micromaterials. We recently demonstrated that the subtle balance between the diffusion of reactants and their reaction rates could lead to a wide range of microscopic shapes that could be further sculpted and hierarchically organized by rationally modulating the environmental conditions. Based on fundamental insights in the underlying mechanism, we now present new ways to steer the nucleation and growth of mineralizing microstructures. These results contribute to our understanding of biomineralization processes and outline a new nano-fabrication strategy for functional self-organizing materials.


Session FL-2 - Electronic Devices with Biological and Bio-inspired Materials

FL-2:IL01  Self-organized and Self-assembled Organic Bioelectronics for Applications in Medicine and Plant Biology
M. BERGGREN, Laboratory of Organic Electronics, Linköping University, Norrköping, Sweden

Organic electronics can process ionic and electronic signals, are flexible and soft, and can operate at high stability in harsh aqueous media. Together, these features make the technology unique as a translator of signals in between technology and biology, i.e. as a combined recorder and actuator of physiology and functions. Further, organic electronics can be manufactured from solutions utilizing various self-organization and self-assembly techniques. Here, organic bioelectronic fibers are reported that is manufactured using self-organization approaches to achieve device and system structures to interface with biology. Organic electronic fibers have successfully been applied to biological systems in order to achieve signal translation at high spatiotemporal resolution and accuracy. Organic electronic fibers defines an interesting technology platform for bio-interfacing, since it can both be manufactured inside vascular systems and also capillary systems, thus enabling positioning of the technology inside organs possible.


FL-2:IL02  Electronic Interface with Plants
E. STAVRINIDOU, Linköping University, Norrköping, Sweden

Plants are an indispensable part of our ecosystem and are essential for our survival and quality of life. Recently we have demonstrated the first example of electronic interface with plants and introduced the concept of Electronic Plants. We used water-soluble conducting polymers and oligomers that self organise or polymerise in vivo, reactions that are aided by the plant. We demonstrated analogue and digital circuits manufactured in the organs of a plant as well as supercapacitors for energy storage. In addition we are using organic bioelectronics devices to sense and actuate plant functions. In this talk, recent advancements of our technology will be presented and potential applications will be discussed.

 
Session FL-3 - Photonic Devices with Biological and Bio-inspired Materials

FL-3:IL01  Photonic Crystals Composed of 99% Water and 1% Inorganic Nanosheet
YASUHIRO ISHIDA, RIKEN Center for Emergent Matter Science, Japan

Photonic materials are ordered nanostructures with a periodicity of visible-light wavelength, which can control the properties of lights, such as exhibiting structural colors. If a fluid forms such a nanostructure, its structural color could be dynamically modulated by external stimuli. Indeed, some fish modulate their color using dynamic photonic materials, composed of fluidic cytoplasm containing long-periodic 2D guanine crystals. We discovered that water doped with 2D colloidal electrolytes (< 0.5 vol%) exhibits a structural color. In this ‘photonic fluid’, the 2D electrolytes adopt a lamellar geometry with an ultralong periodicity up to 675 nm due to their enhanced electrostatic repulsion. Consequently, the photonic fluid reflects even near-infrared lights up to 1,750 nm. The structural color becomes more vivid in a magnetic flux, owing to the magneto-induced monodomain structure of the 2D electrolytes. Upon external stimuli, the photonic fluid quickly tunes its nanostructure, leading to color modulation over a visible region.


FL-3:IL02  Biologically Inspired Soft and Fluid Optical Materials
M. KOLLE, S. NAGELBERG, J. SANDT, Massachusetts Institute of Technology, Cambridge, MA, USA

A curious look at biological photonic systems reveals versatile approaches for the creation of multifunctional, hierarchically structured, dynamic bio-inspired materials. Here, we present a choice of materials that employ bio-inspired photonic architectures, implemented in soft, and fluid materials, with tunable and stimuli-responsive behavior. The first part of this presentation will be focused on elastic, mechano-sensitive, color-tunable bio-inspired photonic fibers, which mimic the photonic structures found in a tropical plant’s blue seed coat. The fibers' reflection color can be tuned reversibly by applying an axial strain or a lateral compression. We demonstrate potential applications for mechano-responsive, color-tunable photonic fibers in medical sensing. In the second part, we explore the use of emulsions for the creation of liquid compound micro-lenses with dynamically tunable focal lengths, inspired by the architectures found in the retina of nocturnal animals. We employ bi-phase emulsion droplets in responsive micro-lenses that can be reconfigured to focus or scatter light, and to form images. We provide evidence of the micro-lenses’ functionality for two potential applications – integral micro-scale imaging devices and light field display technology.


FL-3:IL04  Fluorescent Proteins and Carbon Nanotubes: Unconventional Materials for Strong Light-matter Interaction and Solid-state Lasers
C. DIETRICH^1,2, A. GRAF^1,3, L. TROPF¹, M. KARL¹, A. KÄMPF¹, M. SCHUBERT¹, N.M. KRONENBERG¹, Y. ZAKHARKO³, S. HÖFLING^1,2, J. ZAUMSEIL³, M.C. GATHER¹, ¹School of Physics and Astronomy, University of St Andrews, St Andrews, UK; ²Technische Physik, Universität Würzburg, Würzburg, Germany; ³Institute for Physical Chemistry, Universität Heidelberg, Heidelberg, Germany

Organic materials offer attractive properties for solid-state lasers but despite impressive improvements in performance, important fundamental limitations remain, many of which are linked to parasitic exciton recombination and low charge carrier mobility. Here, we present results from two collaborations that look at unconventional materials for solid-state lasers: Biologically produced fluorescent proteins and single walled carbon nanotubes. We show that the barrel-like molecular structure of fluorescent proteins prevents concentration-induced quenching of fluorescence and reduces annihilation at high exciton densities. This facilitates low-threshold lasing in various configurations and recently enabled the realization of the first organic polariton laser that can be pumped in a quasi-continuous ns-regime. These findings inspired another collaboration, on polymer-sorted semiconducting single-walled carbon nanotubes for strong light-matter coupling, possibly up to the ultra-strong coupling regime. We found that the high charge carrier mobility and stability of nanotubes also enable efficient electrical generation of exciton polaritons. Using a light-emitting transistor geometry, we achieved current densities up to 18,000 A/cm2 while maintaining strong coupling conditions.


FL-3:IL06  Peptide Integrated Optics: From Optical Waveguides To Implantable BioChips
G. ROSENMAN, N. LAPSHINA, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University, Israel; B. APTER, A. HANDEMAN, Faculty of Engineering, Holon Institute of Technology, Holon, Israel

Bionanophotonics is a wide field where advanced optical materials, photonics, fundamental physics and nanotechnology are combined and result in development of optical biochips. In this work a novel concept of integrated biooptics applying new generation of bioinspired peptide optical nanomaterials is proposed. These peptide materials demonstrate unique multifunctional optical properties such as nonlinear optical and electrooptical and visible fluorescence effects. We demonstrate peptide optical waveguiding (POW) and POW devices based on new nanotechnology combining bottom-up controlled deposition of peptide wafers of a large area and top-down high resolution patterning for fabrication of multifunctional POW integrated optical devices. We observe a deep modification of POW optical properties by reconformation of their biological secondary structure from native to beta-sheets which is followed by appearance of visible fluorescence and switching from native passive optical waveguiding to active waveguiding. Found passive and active light waveguiding effects and visible fluorescence in these bioinspired peptide nanomaterials, switchable multifunctional optical properties combined with original biocompatibility make these POW attractive for application in implantable biochips.


FL-3:IL07  Circular Polarization Reflections from Beetles - What do they tell us?
K. WEIR, Blackett Laboratory, Department of Physics, Imperial College London, London, UK

The iridescent colours of certain species of beetles have always proved attractive, indeed they have been used in many different situations as jewellery and decorations. However, the reflected light tells us much more about the structure of the beetle’s shells that give rise to this appealing appearance. In the study of Lomaptera (Scarabaeinae) beetles the reflected light is found to be strongly circularly polarised, something that was first noticed over 100 years ago, and which Michelson noted was probable due to a screw-like structure in the beetle’s shell. In the many years since this observation the helical structure has been identified and a simple consideration of this suggests that a single wavelength (matching the pitch of the helix) would be reflected, giving rise to the colour that is observed. However, many beetles have subtle variations in colour. Here work is reported investigating the polarisation and spectrum of light reflected from a wide range of beetles. Comparison of the observations with models suggest that the structure is very rarely this simple, single pitch helical structure. The results presented will illustrate the wide variety of structures which are present and explore the range of parameters which influence the optical response of the structures.


FL-3:IL08  Lasers and Optical Cavities Made out of Biological Materials
M. HUMAR, J. Stefan Institute, Ljubljana, Slovenia; and Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia 

Micro-sized lasers completely embedded within single live cells and biological tissues have been demonstrated. The lasers were made out of solid beads including biocompatible and biodegradable materials. The lasers inside cells can act as very sensitive sensors, enabling us to better understand cellular processes. Further, lasers were used for cell tagging. Each laser within a cell emits light with a slightly different fingerprint that can be easily detected and used as a barcode to tag the cell. With careful laser design and multiplexing, up to a trillion cells could be uniquely tagged. This would enable to uniquely tag every single cell in the human body, providing the ability the study cell migration including cancer metastasis. We have also demonstrated that small lasers embedded in the sample can be used for novel nonlinear microscopy, including super resolution imaging. The narrow spectra and nonlinear power dependence of stimulated emission from the laser particles yield optical sectioning, sub-diffraction resolution, and low out-of-focus background. A proof-of-concept is demonstrated using perovskite nanowires. Small lasers embedded into cells and tissues may enable new diagnostic, treatment and imaging tools in medicine and biology.


FL-3:IL09  Up-scaling of Bio-inspired Polymer Films for Optical Applications
F. VÜLLERS, S. SCHAUER, J. SYURIK, M. KAVALENKA, H. HÖLSCHER, Karlsruhe Institute of Technology, Karlsruhe, Germany

Many nano- and microstructured surfaces found in nature can serve as an inspiration for improving state-of-the-art technical applications. Although most biomimetic archetypes can be replicated with advanced techniques on a lab-scale, it remains a challenge to develop processes for large-scale fabrication techniques suitable for commercial applications. Here, we review some of our approaches with high potential for up-scaling. Hot pulling of a dense fur of nanoscale hair from polymer surfaces mimics the super-hydrophobic surfaces of water ferns. This nanofur can be utilized as a coating for solar cells and enables self-cleaning while improving optical efficiency. Inspired by white beetles, we fabricated microporous polymer films by CO2 saturation. Despite their micrometer thickness, the films feature an exceptional whiteness due to efficient light scattering on pores. Motivated by leaf and petal surfaces, we developed a mechanically directed self- assembly process to create micro- and nanosized surface wrinkles in an all-polymer bi-layer system based on a shape-memory polymer substrate. It provides a large-scale, mold-free, and very cost-effective way for the full-polymer fabrication of micro and sub-microstructures with adjustable structure size and intrinsic irregularity.


FL-3:IL10  Structural Colours in Plants: Mechanisms and Functions
S. VIGNOLINI, Department of Chemistry, University of Cambridge, Cambridge, UK

Nature’s most vivid colours rely on ordered, quasi-ordered or disordered structures with dimensions in the range of the wavelength of visible light [1]. Knowledge of the interplay between the morphology, composition and optical appearance of biological photonic systems is fundamental to understanding their functions and evolution [2]. In plants, we find several architectures responsible for such colorations: from surface striations, as in the case of flowers [3,4], to complex multilayer structures present in leaves and fruits [5-7]. In this seminar, these mechanisms responsible of structural colours will be described and related to their biological function. Finally, some insights on the underpinning development principle of such photonic structures in nature will be discussed with the example of the structurally coloured fruit Pollia Condesata.
[1] Kinoshita, S. et al. (2008). Physics of structural colors. Rep. Prog. Phys. 71(7), 076401. [2] Cuthill, I. C. et al. (2017) The biology of color Science, 357, (6350), eaan0221. [3] Vignolini et al. (2015) The flower of Hibiscus trionum is both visibly and measurably iridescent. 205 (1), 97. [4] H.M. Whitney et al. (2010) Floral iridescence, produced by diffractive optics, acts as a cue for animal pollinators. Science 323 (5910), 130


FL-3:IL11  Bioabsorbable Polymer Optical Waveguides for Deep-tissue Photomedicine
S. NIZAMOGLU, Koc University, Istanbul, Turkey

The depth of light penetration in tissue is still the fundamental limitation for all of the photomedical techniques. When penetrating through tissue from an external light source, light is quickly attenuated by scattering and absorption. Light delivery into the body of a patient or an animal is currently achieved via fiber-optic catheters or lens-based endoscopes that are made of materials such as glass or plastic, which are readily available, but generally not biocompatible. Such devices can only be used for bringing a light source close to the target tissue in the body and they must be taken out from the body soon after use. In this talk I will discuss biodegradable and biocompatible waveguides that can gradually resorbed by the tissue and thus these waveguides do not need to be removed from the tissue. As a proof of concept, this paradigm-shifting approach will be demonstrated for photochemical tissue bonding.

 
Session FL-4 - Bio-medical Devices with Biological and Bio-inspired Materials

FL-4:IL01  Optoelectronic Cellular Interfaces with Nanocrystalline Organic Semiconductors
E.D. GLOWACKI, V. DEREK, Laboratory of Organic Electronics, Physics and Electronics Division, Linköping University, Norrköping, Sweden

Optical stimulation of neurons offers spatial and temporal resolution combined with simplicity and minimal invasiveness. We focus on developing novel optoelectronic techniques in applied medicine, for selective peripheral or central nervous therapeutics, and implants such as retinal prostheses. Our approaches are based on efficient nanoscale semiconducting optoelectronic system optimized for neuronal stimulation. The devices comprise semiconducting organic nanocrystals. When illuminated in physiological solution, these semiconductor devices operate as photocapacitors transducing light pulses into localized displacement currents that are strong enough to electrically stimulate neurons with safe light intensities, one hundred times below the safe ocular limit at 660 nm. The devices are freestanding, requiring no wiring or external bias, and are stable in physiological conditions. The semiconductor layers are made using ubiquitous and nontoxic commercial pigments via simple and scalable deposition techniques. We present results on the level of single cells, cultured neural networks, explanted tissues, and preliminary in vivo experiments.


FL-4:IL02  Phostimulation of Semiconducting Nanoparticles to Control Physiological Functions In Vivo
M. MOROS¹, M.R. ANTOGNAZZA², C. BOSSIO², G. ONORATO¹, A. BAUDUIN¹, V. MARCHESANO¹, M. ZANGOLI³, A. TINO¹, G. LANZANI², C. TORTIGLIONE¹, ¹Istituto di Scienze Applicate e Sistemi Intelligenti “E.Caianiello”, CNR, Pozzuoli, Italy; ²Center for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia, Italy; ³Istituto per la Sintesi Organica e la Fotoreattività, CNR, Italy 

The latest designs of optoelectronic devices powered research on fundamental properties of light and how it interacts with matter. In the context of a living cell, this interaction is hampered by the complexity of the living matter, making technological advancement key aspect of this research. Nanotechnologies may provide unique tools to finely tune biological functions, through development of biocompatible light nanotransducers. Here we show the possibility to modulate cell function by photostimulation of polymer nanoparticles based on poly(3-hexylthiophene) (NP-P3HT), a conjugated polymer widely used in photovoltaic application. By using a freshwater polyp as model organism, presenting photic behaviour despite the absence of proper eyes, we show that NP-P3HT internalized into animal tissue enhances animal photosensitivity. Moreover, the peculiar capabilities of the polyp to regenerate missing parts of amputated body allowed us to investigate the potential of P3HT-NP to enhance tissue regeneration. We observed in treated animals a boost in the regeneration efficiency under light illumination, uncovering a new function of these light nanotransducers in regenerative medicine and opening up new scenario on future therapeutic purposes.


FL-4:L03  Bioengineering Fluorescent Conductive Microfibrils in Vivo
M. MOROS^1,2, F. DI MARIA³, P. DARDANO⁴, M. ZANGOLI³, G. ONORATO², A. BAUDUIN², A. TINO², L. DESTEFANO⁴, G. BARBARELLA³, C. TORTIGLIONE², ¹Aragon Materials Science Institute, CSIC, Zaragoza, Spain; ²Istituto di Scienze Applicate e Sistemi Intelligenti “E.Caianiello”, CNR, Napoli, Italy; ³Istituto per la Sintesi Organica e la Fotoreattività, CNR, Bologna, Italy; ⁴Istituto di Microelettronica e Microsistemi, CNR, Napoli, Italy 

Conductive polymers are very attractive for biomedical applications. Their responsiveness to electrical stimulation found application in nerve regeneration strategies, enhanced neuronal growth or tissue regeneration. Often their broad use is hampered by low biocompatibility,lack of recognition elements for endogenous components, thus alternative strategies may rely on improvement of fibrillar proteins properties in situ. In this direction, the fluorophore dithienothiophene-S,S-dioxide (DTTO) is able to spontaneously enter human fibroblasts and become incorporated into collagen quaternary structures giving rise to fluorescent and conducting fibrils. In order to translate to an in vivo system, we employed the freshwater Hydra vulgaris, which structural simplicity resembles a living tissue, without organs. By challenging polyps with DTTO we demonstrated the incorporation of this thiophene into supramolecular structures giving rise to microfibrils. Electronic force microscopy showed electrical conductivity and circular dichroism confirmed the presence of proteins within the fibrils. Besides the possibility of engineering endogenous components with synthetic moieties, this approach opens the path to a sort of ‘live animal factory’ for the production of innovative biomaterials.


FL-4:IL06  Tailoring Conducting Polymer Scaffolds for Bioelectronics
S. INAL, Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia  

Considering the limited physiological relevance of 2D cell culture experiments, significant effort was devoted to the development of scaffold materials that could support 3D cell cultures in vitro. A prime example of such a material is conducting polymers (CPs) that are capable of hosting cells in 3D due to their possibility into porous architectures, biocompatibility and compliant mechanical properties. CPs aim to integrate functionality into the ‘passive’ scaffolds, while addressing the problem of rigidity of 2D metal electrodes. In this talk, I will demonstrate the development of CP scaffolds with a dual purpose – to both host and monitor/ stimulate cells. The adhesion and pro-angiogenic secretions of mouse fibroblasts cultured within the scaffolds can be controlled by switching the electrochemical state of the polymer prior to cell-seeding. The same device infiltrated by kidney cells, on the other hand, acts as a live-cell monitoring platform that enables electronic sensing of cells. Moreover, the ease of preparation of different compositions of materials allows for the tunability of properties such as mechanical stiffness and conductivity. I will show how such properties influence the performance of the devices, but also enable tailoring scaffolds.


FL-4:IL07  Biomimetic Microfluidics based on Stimuli-responsive Soft Polymers
D. DIAMOND, A. DUNNE, D. BRUEN, C. DELANEY, P. MCCLUSKEY, M. MCCAUL, L. FLOREA, INSIGHT Centre for Data Analytics, National Centre for Sensor Research, Dublin City University, Dublin, Ireland 

Through developments in 3D fabrication technologies in recent years, it is now possible to build and characterize much more sophisticated 3D platforms than was formerly the case. Regions of differing polarity, binding behaviour, flexibility/rigidity, can be incorporated into these fluidic systems. Furthermore, materials that can switch these characteristics can be incorporated, enabling the creation of microfluidic building blocks that exhibit switchable characteristics such as programmed microvehicle movement (chemotaxis), switchable binding and release, switchable soft polymer actuation (e.g. valving), and selective uptake and release of molecular targets. These building blocks can be in turn integrated into microfluidic systems with hitherto unsurpassed functionalities that can contribute to bridging the gap between what is required and what science can currently deliver for many challenging applications. The emerging transition from existing engineering-inspired 2D to bioinspired 3D fluidic concepts appears to represent a major turning point in the evolution of microfluidics. Implementation of these disruptive concepts may open the way to realising biochemical sensing systems with performance characteristics far beyond those of current devices.


FL-4:IL08  Heat Effect of Nanoparticles for Biotechnological Applications
J.M. DE LA FUENTE, Institute of Materials Science of Aragón, Zaragoza, Spain

In this talk we describe the synthesis and functionalization of magnetic and gold nanoparticles as therapeutic and diagnosis tools against cancer: -Gold nanoprisms (NPRs) have been functionalized with PEG, glucose, cell penetrating peptides, antibodies and/or fluorescent dyes, aiming to enhance NPRs stability, cellular uptake and imaging capabilities. Cellular uptake and impact was assayed by a multiparametric investigation on the impact of surface modified NPRs on mice and human primary and transform cell lines. Under NIR illumination, these nanoprobes can cause apoptosis. The nanoparticles have also been used for optoacoustic imaging and tumoral marker detection using a novel type of thermal ELISA nanobiosensor using a thermosensitive support. -Magnetic nanoparticles functionalized with DNA molecules and further hybridizing with different length fluorophore-modified DNA have allowed the determination of temperature spatial mapping induced by the application of an alternating magnetic field. Due to the design of these DNAs, different denaturalization temperatures could be achieved. The quantification of the denaturalized DNA, and by interpolation onto a Boltzmann fitting model, it has been possible to calculate the local temperature increments at different distances.