Session Chair: Terry Steele, Nanyang Technological University
10:30am - 11:00am Invited
Designer Capsules Through Microfluidic Emulsification
Andre R. STUDART
ETH Zürich, Switzerland
Engineered microcompartments and capsules that respond to multiple external stimuli and partly replicate key features of the fascinating dynamic response of living cells have attracted growing interest in academia and industry. In this talk, I will present our efforts to create a library of chemically- and mechanically-responsive microcompartments that are able to release cargo molecules on-demand through different triggering mechanisms. To obtain microcapsules with unprecedented functionalities, we use complex emulsions made in microfluidic devices as soft templates. Conversion of soft double emulsions into functional microcapsules is accomplished by a polymerization reaction or dissolution of the oil phase into the continuous medium, thus generating polymer-based compartments or colloidosomes with predictable size, shell thickness, mechanical behavior and shell microstructure. The resulting microcapsules can be designed to undergo one-time release or can be made sufficiently robust to enable multiple release events without impairing the compartment’s mechanical integrity. Release is triggered by a variety of external stimuli, including pH, temperature or magnetic fields. Proof-of-concept experiments are shown to illustrate the potential of these microcompartments in modifying on-demand the mechanical response of organic or inorganic matrices in capsule-loaded composite materials.
11:00am - 11:30am Invited
Core-Shell Nanoparticle Assembly at Oil and Amphiphile Interfaces: Responsive Magnetic Particles, Droplets and Capsules
University of Natural Resources and Life Sciences, Vienna, Austria
Carefully controlled core-shell nanoparticles can be used in biomedical applications, e.g., as biomedical imaging contrast agents, for hyperthermia and in drug delivery [1, 2]. To enable functions of nanoparticles in a biological environment, as well as to control their interactions assembled into superstructures, a dense organic shell formed around the core can be used to control colloidal interactions with biomolecules, cells and other nanoparticles. Stimuli-interacting cores and responsive organic shells can furthermore be used to change the interactions with the environment or the phase behavior and properties of material close to the core-shell nanoparticles.
We will describe multiple recent developments from our lab regarding the synthesis and assembly of superparamagnetic iron oxide core-shell nanoparticles that allow tailoring of self-assembled superparamagnetic membranes. Unsurpassed precision in tailoring the structure of such nanoparticles has provided us with detailed control also over nanoparticle self-assembly at liquid interfaces, creation of nanoscale Pickering-type emulsions and lipid and polymer vesicles that comprise superparamagnetic particles as an integral part. In particular, we will focus on how lipid and polymer hybrid vesicles containing nanoparticles can be formed for which the local membrane phase state is controlled using magnetic fields to reversibly switch the permeability of small molecules on and off. This type of control over assembly, colloidal stability and release from nanovesicular and nanoemulsion systems heralds a new generation of transport and release vehicles that could impact future directions in drug delivery and organelles for synthetic biology.
 E. Amstad, M. Textor, E. Reimhult, Nanoscale3, 2819-43 (2011).
 E. Reimhult, New Biotechnology32, 665-72 (2015).
11:30am - 11:45am Oral
Alginate Based Nanoassemblies for Encapsulation
Jatin Nitin KUMAR
Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), Singapore
Alginate is an abundant natural polysaccharide which has been thoroughly investigated in the realm of drug & cell delivery as well as tissue engineering, primarily because it’s structural conformation closely resembles extra-cellular matrices and it demonstrates little to no immune response with a high biocompatibility. Alginate cross-links readily in the presence of divalent cations (eg. Ca2+, Mg2+, Ba2+) – a function which has been long exploited by the personal care, medical and culinary industries in encapsulation strategies. However, the true potential of these polymers have not been realized due to limited modification options. There have been no reported instances where alginate has been modified while still affording it’s cross-linking characteristics.
This paper seeks to demonstrate how alginates can be polymer functionalized via either the ‘click’ approach or by controlled radical polymerization, thereby affording access to previously unreported comb copolymers which retain alginate’s natural ability to crosslink. In the case of hydrophilic grafted polymer chains such as PEG, it allows the copolymer the ability to self-assemble into core-crosslinked nanoparticles upon the addition of calcium ions. The PEG chains stabilize the polymer and afford a directed self-assembly and do so once a critical amount calcium is added.
Performance of these spontaneously self-assembled nanoparticles in encapsulation and drug delivery strategies, particularly in personal care applications will be shown.
 A J Vegas, O Veiseh, J C Doloff, M Ma, H H Tam, K Bratlie et al, Nature Biotechnology, 2016, 34, 345-352
11:45am - 12:00pm Oral
Facile Preparation and Characterization of Chitin-Polyaniline Nanocomposite
Praveen P., Vijayalakshmi RAO
Mangalore University, India
Chitin/Polyaniline nanofiber composite films have been prepared by solution casting. Polyaniline self assembled nanofibers (PANF) were synthesized by direct mixed oxidation performed in an aqueous HCl (1M HCl) in the presence of ammonium peroxodisulfate as oxidant. Dedoped nanofibers were homogeneously dispersed in N,N-dimethylacetamide by the aid of ultrasonication and then mixed with chitin solution made in the 5% LiCl/ N,N-dimethylacetamide solvent system according to pre determined weight ratios. The characterization of the composites were done by UV-Vis spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA) and Field Emission Scanning Electron Microscopy (FESEM). No observable interaction has been noted from FTIR studies which indicate polyaniline nanofibers are physically entrapped in the chitin matrix. When compared to pure chitin, thermal studies show that the overall decomposition rate of composites is decreased due to the incorporation of polyaniline nanofiber into the chitin matrix. FESEM results show that polyaniline has nanofiber morphology and composite structure has uniform structure with porous morphology.