Citations of interest !
Diabetes and insulin, improving solar energy,  drug delivery for cancer treatment & tumors,
microbiology In situ visualization of newly synthesized proteins

Brand, C.; Abdel-Atti, D.; Zhang, Y.; Carlin, S.D.; Clardy, S.M.; Keliher, E.J.; Weber, W.A.; Lewis, J.S.; Reiner, T.
 
Bioconjugate Chem. Just Accepted.
doi: 10.1021/bc500178d

Accurate visualization and quantification of β-cell mass is critical for the improved understanding, diagnosis, and treatment of both type 1 diabetes (T1D) and insulinoma. Here, we describe the synthesis of a bimodal imaging probe (PET/fluorescence) for imaging GLP-1R expression in the pancreas and in pancreatic islet cell tumors. The conjugation of a bimodal imaging tag containing a near-infrared fluorescent dye, and the copper chelator sarcophagine to the GLP-1R targeting peptide exendin-4 provided the basis for the bimodal imaging probe. Conjugation was performed via a novel sequential one-pot synthetic procedure including 64Cu radiolabeling and copper-catalyzed click-conjugation. The bimodal imaging agent 64Cu-E4-Fl was synthesized in good radiochemical yield and specific activity (RCY = 36%, specific activity: 141 μCi/μg, >98% radiochemical purity). The agent showed good performance in vivo and ex vivo, visualizing small xenografts (<2 mm) with PET and pancreatic β-cell mass by phosphor autoradiography. Using the fluorescent properties of the probe, we were able to detect individual pancreatic islets, confirming specific binding to GLP-1R and surpassing the sensitivity of the radioactive label. The use of bimodal PET/fluorescent imaging probes is promising for preoperative imaging and fluorescence-assisted analysis of patient tissues. We believe that our procedure could become relevant as a protocol for the development of bimodal imaging agents.

A novel photo-responsive protein–graphene–protein (PGP) capsule that doubles as a photothermal agent with core/shell structure is constructed by anchoring reduced graphene oxide nanosheets on one-component protein (lactoferrin) shell through a double emulsion method. PGP capsules can transport fully concealed hydrophilic anticancer cargo, doxorubicin (Dox), with a large payload (9.43 μmol g-1) to be later unloaded in a burst-like manner by photo-actuation triggered by near-infrared irradiation. Being biocompatible yet with a high cancer cell targeting efficiency, PGP capsules have successfully eradicated subcutaneous tumors in 10 d following a single 5 min NIR irradiation without distal damage. Besides, the photochemothermal therapy of PGP capsules eradicates tumor cells not only in the light-treating area but also widely light-omitted tumor cells, overcoming the tumor recurrence due to efficient cell killing efficacy. These results demonstrate that the PGP capsule is a potential new drug delivery platform for local-targeting, on-demand, photoresponsive, combined chemotherapy/hyperthermia for tumor treatment and other biomedical applications.

Near-infrared harvesting transparent luminescent solar concentrators

Zhao,Y.; Meek, G.A.; Levine, B.G.; Lunt, R.R.
Advanced Optical Materials
doi: 10.1002/adom.201400103

Near-infrared (NIR) harvesting transparent luminescent solar concentrators (TLSC) with non-tinted transparency are demonstrated by exploiting the excitonic nature of organic luminescent salts that provide perfectly tuned NIR-selective absorption and even deeper NIR emission. NIR TLSCs provide an entirely new route to more aesthetically pleasing light harvesting systems that can be widely deployed in energy scavenging windows and displays.

In situ visualization of newly synthesized proteins in environmental microbes using amino acid tagging and click chemistry.

Hatzenpichler, R.; Scheller, S.; Tavormina, P.L.; Babin, B.M.; Tirrell, D.A.; Orphan, V.J.
Environmental Microbiology, in press.
doi: 10.1111/1462-2920.12436

Here we describe the application of a new click chemistry method for fluorescent tracking of protein synthesis in individual microorganisms within environmental samples. This technique, termed bioorthogonal non-canonical amino acid tagging (BONCAT), is based on the in vivo incorporation of the non-canonical amino acid L-azidohomoalanine (AHA), a surrogate for l-methionine, followed by fluorescent labelling of AHA-containing cellular proteins by azide-alkyne click chemistry. BONCAT was evaluated with a range of phylogenetically and physiologically diverse archaeal and bacterial pure cultures and enrichments, and used to visualize translationally active cells within complex environmental samples including an oral biofilm, freshwater and anoxic sediment. We also developed combined assays that couple BONCAT with ribosomal RNA (rRNA)-targeted fluorescence in situ hybridization (FISH), enabling a direct link between taxonomic identity and translational activity. Using a methanotrophic enrichment culture incubated under different conditions, we demonstrate the potential of BONCAT-FISH to study microbial physiology in situ. A direct comparison of anabolic activity using BONCAT and stable isotope labelling by nano-scale secondary ion mass spectrometry (15NH3 assimilation) for individual cells within a sediment-sourced enrichment culture showed concordance between AHA-positive cells and 15N enrichment. BONCAT-FISH offers a fast, inexpensive and straightforward fluorescence microscopy method for studying the in situ activity of environmental microbes on a single-cell level.

Here is a protocol:

1. Dissolve the carbonyl compound (such as protein bearing carbonyl group) in aqueous buffer (e.g acetate) with pH 5.5. Protein concentration of around 10 mg/mL is recommended for optimal labeling.
2. Dissolve 1 mg of Cy5 hydrazide in 50 uL of DMSO.
3. Add 5 eq. of hydrazide solution to a solution of carbonyl compound so that final concentration of DMSO is around 10%.
4. Vortex and keep for 1 h at room temperature.
5. Purify the conjugate by gel filtration, electrophoresis, or HPLC.