Synthesis and Screen of a Proline-Rich Combinatorial Library Towards the Identification of Sickle Cell Hemoglobin Polymerization Inhibitors

Sickle cell disease is a genetic disorder that affects the hemoglobin within red blood cells. A point mutation in the gene coding for the β-subunit of hemoglobin allows the mutant chain to interact with a hydrophobic pocket of another hemoglobin in a deoxygenated environment, causing polymerization of the proteins. This creates the characteristic sickle-shape of the diseased blood cells that can clog capillaries, leading to tissue damage and cell death. Currently, there are limited options for those affected with sickle cell disease. The research to be presented is focused on discovering peptides that can interact with the mutated hemoglobin and prevent aggregation. A novel proline-rich peptide ligand, ZSF39, was identified through a phage display against deoxygenated sickle cell hemoglobin. A combinatorial peptide library based on the structure of ZSF39 was synthesized and screened for binding affinity using an ELISA. A tightly binding peptide, LHSl, was discovered through the ELISA and found to have a significant inhibitory effect on the polymerization of sickle cell hemoglobin. This work represents a novel approach for the discovery of therapeutics for this debilitating disorder

Multimode PDMS waveguides fabricated using a hot-embossing technique

A novel method for fabricating multimode PDMS waveguides is presented. This process is based on a hot-embossing technique and generates high quality optical waveguides without a substantial residual layer after embossing. Furthermore, the process allows for low-cost fabrication since it relies on a replication technique and additionally only commercially available materials are used. The measured propagation loss is smaller than 0.24dB/cm and can be further reduced by improving the master mould quality

Flexible photonic sensors realized using printing technologies

Making sensors flexible and thin, is key to apply them on curved, moving surfaces, e.g. for wearable applications or to embed them in mechanical structures. Photonic sensor systems require the integration of microstructures (e.g. polymer waveguides), nanostructures (e.g. gratings), which can be realized using nanoimprint lithography, but may also need additional active or passive optical components, which can be integrated using laser printing technologies

Mid-infrared resonant ablation of PMMA

Laser ablation proved to be a reliable micro-fabrication technique for patterning and structuring of both thin film and bulk polymer materials. In most of the industrial applications ultra-violet (UV) laser sources are employed, however they have limitations such as maintenance costs and practical issues. As an alternative and promising approach, mid-infrared resonant laser ablation (RIA) has been introduced, in which the laser wavelength is tuned to one of the molecular vibrational transi-tions of the polymer to be ablated. Consequently, the technique is selective in respect of processing a diversity of polymers which usually have different infrared absorption bands. In this paper, we present mid-infrared resonant ablation of PolyMethyl MethAcrylate (PMMA), employing nanosec-ond laser pulses tunable between 3 and 4 microns. This RIA nanosecond laser set-up is based on a commercial laser at 1064 nm pumping a singly resonant Optical Parametric Oscillator (OPO) built around a Periodically-Poled Lithium Niobate (PPLN) crystal with several Quasi-Phase Matching (QPM) periods. RIA has been successfully demonstrated for structuring bulk PMMA, and selective patterning of PMMA thin films on a glass substrate has been implemented

Fully embedded optical and electrical interconnections in flexible foils

This paper presents the development of a technology platform for the full integration of opto-electronic and electronic components, as well as optical interconnections in a flexible foil. A technology is developed to embed ultra thin (20 μ m) VCSEL's and Photodiodes in layers of optical transparent material. These layers are sandwiched in between two Polyimide layers to get a flexible foil with a final stack thickness of 150 μ m. Optical waveguides are structured by photolithography in the optical layers and pluggable mirror components couple the light from the embedded opto-electronics in and out of the waveguides. Besides optical links and optoelectronic components, electrical circuitry is also embedded by means of embedded copper tracks and thinned down Integrated Circuits (20 μ m). Optical connection towards the outer world is realized by U-groove passive alignment coupling of optical fibers with the embedded waveguides

Expanded-beam backside coupling interface for alignment-tolerant packaging of silicon photonics

We demonstrate an alignment-tolerant backside coupling interface in the O-band for silicon photonics by generating an optimized through-substrate (downward) directionality beam from a TE-mode grating coupler and hybrid integrating the chip with backside silicon microlenses to achieve expanded beam collimation. The key advantage of using such an expanded beam interface is an increased coupling tolerance to lateral and longitudinal misalignment. A 34 mu m beam diameter was achieved over a combined substrate thickness of 630 mu m which was then coupled to a thermally expanded core single-mode fiber to investigate the tolerances. A 1-dB fiber-to-microlens lateral alignment tolerance of 14 mu m and an angular alignment tolerance of 1 degrees was measured at a wavelength of 1310 nm. In addition, a large +/- 2.5 mu m 1-dB backside alignment accuracy was measured for the placement of microlens with respect to the grating. The radius of curvature of Si microlens to achieve a collimated beam was 480 mu m, and a 1-dB longitudinal alignment tolerance of 700 mu m was measured for coupling to a single-mode expanded core fiber. The relaxation in alignment tolerances make the demonstrated coupling interface suitable for chip-to-package or chip-to-board couplin