Do We Need to Design Course-Based Undergraduate Research Experiences for Authenticity?

The recent push for more authentic teaching and learning in science, technology, engineering, and mathematics indicates a shared agreement that undergraduates require greater exposure to professional practices. There is considerable variation, however, in how "authentic" science education is defined. In this paper we present our definition of authenticity as it applies to an "authentic" large-scale undergraduate research experience (ALURE); we also look to the literature and the student voice for alternate perceptions around this concept.

A novel strategy for preparing mechanically robust ionically cross-linked alginate hydrogels.

The properties of alginate films modified using two cross-linker ions (Ca(2+) and Ba(2+)), comparing two separate cross-linking techniques (the traditional immersion (IM) method and a new strategy in a pressure-assisted diffusion (PD) method), are evaluated. This was achieved through measuring metal ion content, water uptake and film stability in an ionic solution ([Ca(2+)] = 2 mM). Characterization of the internal structure and mechanical properties of hydrated films were established by cryogenic scanning electron microscopy and tensile testing, respectively.

Phosphorylation of alginate: synthesis, characterization, and evaluation of in vitro mineralization capacity.

Phosphorylation of alginate was achieved using a heterogeneous urea/phosphate reaction. The degree and stereoselectivity of phosphorylation as well as the effects on the physical properties of the polysaccharide were investigated by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies, inductively coupled plasma optical-emission spectroscopy (ICP-OES), and size exclusion chromatography (SEC). Multidimensional NMR studies of the phosporylated alginate revealed that phosphorylation of the M residues occurred predominantly at the C3 (equatorial) carbon of the polysaccharide ring.

Modification and optimization of organosilica microspheres for peptide synthesis and microsphere-based immunoassays.

A new generation of optically encoded organosilica microspheres, suitable for both solid phase synthesis and multiplexed microsphere-based assays, has recently been described. One of the challenges of producing this type of dual-purpose solid support is that the particles must maintain their morphology as well as their encoding during exposure to the solvents used for solid phase synthesis. In this article, organosilica microspheres are subjected to ammonia treatment methods for enhancing the condensation of the silica matrix and their subsequent resilience toward organic solvents and peptide synthesis reagents is described.

Development of a multiplexed bead-based assay for detection of DNA methylation in cancer-related genes.

Herein we report a method for the detection of methylated CpG dinucleotides located within CpG islands in genomic DNA using multiplexed bead-based assays and standard flow cytometry instrumentation. Four CpG "clusters" were identified in the TFPI2 and SPARC CpG islands whose methylation status was highly correlated with the incidence of invasive cervical cancer in our previous studies. Eight probes in total were designed for both the methylated and unmethylated forms of each cluster and attached to different fluorescently-encoded organosilica bead sets.

Encapsulation of a glycosaminoglycan in hydroxyapatite/alginate capsules.

The development of suitable vehicles for the delivery of growth-inducing factors to fracture sites is a challenging area of bone repair. Bone-specific glycosaminoglycan molecules are of particular interest because of their high stability and proven effect on bone growth. Calcium alginate capsules are popular as delivery vehicles because of their low immunogenic response; they offer a versatile route that enables the controlled release of heparin (a member of the glycosaminoglycan family).

Synthesis and characterization of alginate/poly-L-ornithine/alginate microcapsules for local immunosuppression.

Alginate/poly-L-ornithine/alginate (APA) coherent microencapsulation, which provides an immunoselective and highly biocompatible membrane, creates a viable option for cellular or tissue transplantation. This study explored the potential of incorporating immunosuppressive drugs onto the capsule surface to provide local immunosuppression in addition to immunoisolation. A thorough investigation has been conducted to optimize and characterize alginate biotinylation via carbodiimide chemistry by a 4'-hydroxyazobenzene-2-carboxylic acid (HABA) based assay and by ATR-FTIR, H-NMR and XPS.

Interactions between alginate and chitosan biopolymers characterized using FTIR and XPS.

This study investigates alginate-chitosan polyelectrolyte complexes (PECs) in the form of a film, a precipitate, as well as a layer-by-layer (LbL) assembly. The focus of this study is to fully characterize, using the complementary techniques of Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) in combination with solution stability evaluation, the interactions between alginate and chitosan in the PECs. In the FTIR spectra, no significant change in the band position of the two carbonyl vibrations from alginate occurs upon interaction with different ionic species.