Regioselective functionalization of 2,3,5,6,8-pentachloro-BODIPY 1 produced unsymmetric BODIPY 5, bearing an isothiocyanate group suitable for conjugation, in only four steps. The X-ray structure of 5 reveals a nearly planar BODIPY core with aryl dihedral angles in the range 47.4° – 62.9°. Conjugation of 5 to two EGFR-targeting pegylated peptides, 3PEG-LARLLT (6) and 3PEG-GYHWYGYTPQNVI (7), under mild conditions (30 min at room temperature), afforded BODIPY conjugates 8 and 9 in 50–80% isolated yields. These conjugates show red-shifted absorption and emission spectra compared with 5, in the near-IR region, and were evaluated as potential fluorescence imaging agents for EGRF over-expressing cells. SPR and docking investigations suggested that conjugate 8 bearing the LARLLT sequence binds to EGFR more effectively than 9 bearing the GYHWYGYTPQNVI peptide, in part due to the lower solubility of 9, and its tendency for aggregation at concentrations above 10 μM. Studies in human carcinoma HEp2 cells over-expressing EGFR, demonstrated low dark and photo-cytotoxicities for BODIPY 5 and the two peptide conjugates, and remarkably high cellular uptake for both conjugates 8 and 9, up to 90-fold compared with BODIPY 5 after 1 h. Fluorescence imaging studies in HEp2 cells revealed subcellular localization of the BODIPY-peptide conjugates mainly in the Golgi apparatus and the cell lysosomes. The low cytotoxicity of the new conjugates and their remarkably high uptake into EGFR over-expressing cells renders them promising imaging agents for cancers over-expressing EGFR.

Colorectal cancer (CRC) is the third most common solid internal malignancy among cancers. Early detection of cancer is key to increasing the survival rate of colorectal cancer patients. Overexpression of the EGFR protein is associated with CRC. We have designed a series of peptides that are highly specific for the extracellular domain of EGFR, based on our earlier studies on linear peptides. The previously reported linear peptide LARLLT, known to bind to EGFR, was modified with the goals of increasing its stability and its specificity toward EGFR. Peptide modifications, including D-amino acid substitution, cyclization, and chain reversal, were investigated. In addition, to facilitate labeling of the peptide with a fluorescent dye, an additional lysine residue was introduced onto the linear (KLARLLT) and cyclic peptides cyclo(KLARLLT) (Cyclo.L1). The lysine residue was also converted into an azide group in both a linear and reversed cyclic peptide sequences cyclo(K(N3)larllt) (Cyclo.L1.1) to allow for subsequent "click" conjugation. The cyclic peptides showed enhanced binding to EGFR by SPR. NMR and molecular modeling studies suggest that the peptides acquire a β-turn structure in solution. In vitro stability studies in human serum show that the cyclic peptide is more stable than the linear peptide.

Although institutions of higher education have placed a large emphasis on increasing the number of underrepresented minority (URM) students matriculating in higher education, the disparities in STEM retention and graduation rates between URM and non-URM students emphasize the dire need for increased support to help URM students navigate challenges including stereotype threat, impostor phenomenon, and lack of social connectedness that disproportionately affect URM students in majority-dominated fields. Prior research has demonstrated that structured mentoring has the potential to generate substantial improvements in academic, social, and career outcomes for URM STEM students. In particular, network-based mentoring approaches that allow for students to receive both professional and peer mentoring, as well as the opportunity to mentor other students, have demonstrated success in this realm. In this article, we discuss how the current state of academia often fails URM STEM students and faculty, review literature regarding the ways in which structured mentoring approaches can alleviate barriers to success among URM groups in STEM fields, and offer recommendations regarding how academic institutions can successfully implement holistic student and faculty mentoring programs.

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Three BODIPY‐peptide conjugates designed to target the epidermal growth factor receptor (EGFR) at the extracellular domain were synthesized, and their specificity for binding to EGFR was investigated. Peptide sequences containing seven amino acids, GLARLLT (2) and KLARLLT (4), and 13 amino acids, GYHWYGYTPQNVI (3), were conjugated to carboxyl BODIPY dye (1) by amide bond formation in up to 73% yields. The BODIPY‐peptide conjugates and their “parent” peptides were determined to bind to EGFR experimentally using SPR analysis and were further investigated using computational methods (AutoDock). Results of SPR, competitive binding and docking studies propose that conjugate 6 including the GYHWYGYTPQNVI sequence binds to EGFR more effectively than conjugates 5 and 7, bearing the smaller peptide sequences. Findings in human carcinoma HEp2 cells overexpressing EGFR showed nontoxic behavior in the presence of activated light (1.5 J cm−2) and in the absence of light for all BODIPYs. Furthermore, conjugate 6 showed about five‐fold higher accumulation within HEp2 cells compared with conjugates 5 and 7, localizing preferentially in the cell ER and lysosomes. Our findings suggest that BODIPY‐peptide conjugate 6 is a promising contrast agent for detection of colorectal cancer and potentially other EGFR‐overexpressing cancers.