Guaiacol photodegradation rate constants in solution, liquid-like regions in ice (frozen solutions), and at the air–ice interface (vapor-deposited to snow).

Some organic pollutants in snowpacks undergo faster photodegradation than in solution. One possible explanation for such effect is that their UV−visible absorption spectra are shifted toward lower energy when the molecules are adsorbed at the air− ice interface. However, such bathochromic shift is difficult to measure experimentally. Here, we employ a multiscale/multimodel approach that combines classical and first-principles molecular dynamics, quantum chemical methods, and statistical learning to compute the light absorption spectra of two phenolic molecules in different solvation environments at the relevant thermodynamic conditions. Our calculations provide an accurate estimate of the bathochromic shift of the lowest-energy UV−visible absorption band when these molecules are adsorbed at the air−ice interface, and they shed light into its molecular origin.

Backgroundα3β1 integrin is overexpressed in several types of human cancer and is associated with poor prognosis, metastasis, and resistance to cancer treatment. We previously identified a cyclic peptide ligand LXY1 that specifically binds to the α3β1 integrin on human glioblastoma U-87MG cells. Here, we optimized LXY1 through one-bead one-compound combinatorial library screening and site-specific modifications to improve its in vivo binding property.MethodsThree bead libraries were synthesized and whole-cell binding assays were performed. The binding capacity of individual peptide ligands against different tumor cells was determined by flow cytometry and confirmed by optical imaging. A complex joining biotinylated ligand with streptavidin-Cy5.5 was used for in vivo target imaging in both subcutaneous and orthotopic U-87MG xenograft mouse models.ResultsLXY30, a cyclic peptide with the sequence cdG-Phe(3,5-diF)-G-Hyp-NcR, emerged as the most potent and selective ligand for the α3 subunit of α3β1 integrin with improved in vitro and in vivo tumor-targeting effects compared to LXY1 in U-87MG cells. LXY30 is considerably stable in plasma as demonstrated in an in vitro stability study in 90 % human plasma. LXY30 also binds to several other known α3β1 integrin-expressing glioblastoma, lung, and breast cancer cell lines with various affinities.ConclusionsOur data support further investigating the role of LXY30 as a human tumor-targeting peptide ligand for systemic and intracranial delivery of imaging agents and cancer therapeutics.Electronic supplementary materialThe online version of this article (doi:10.1186/s13550-016-0165-z) contains supplementary material, which is available to authorized users.

Glioblastoma (GBM) is the most common and deadliest form of brain tumor and remains amongst the most difficult cancers to treat. Brevican (Bcan), a central nervous system (CNS)‐specific extracellular matrix protein, is upregulated in high‐grade glioma cells, including GBM. A Bcan isoform lacking most glycosylation, dg‐Bcan, is found only in GBM tissues. Here, dg‐Bcan is explored as a molecular target for GBM. In this study, a d‐peptide library is screened to identify a small 8‐amino acid dg‐Bcan‐Targeting Peptide (BTP) candidate, called BTP‐7 that binds dg‐Bcan with high affinity and specificity. BTP‐7 is preferentially internalized by dg‐Bcan‐expressing patient‐derived GBM cells. To demonstrate GBM targeting, BTP‐7 is radiolabeled with 18F, a radioisotope of fluorine, and increased radiotracer accumulation is found in intracranial GBM established in mice using positron emission tomography (PET) imaging. dg‐Bcan is an attractive molecular target for GBM, and BTP‐7 represents a promising lead candidate for further development into novel imaging agents and targeted therapeutics.