Anti-Biotin polyclonal antibody [FITC]

Macroporous cryogels that are amenable to facile functionalization are attractive platforms for biomolecular immobilization, a vital step for fabrication of scaffolds necessary for areas like tissue engineering and diagnostic sensing. In this work, thiol-reactive porous cryogels are obtained via photopolymerization of a furanprotected maleimide-containing poly(ethylene glycol) (PEG)-based methacrylate (PEGFuMaMA) monomer. A series of cryogels are prepared using varying amounts of the masked hydrophilic PEGFuMaMA monomer, along with poly(ethylene glycol) methyl ether methacrylate and poly(ethylene glycol) dimethacrylate, a hydrophilic monomer and cross-linker, respectively, in the presence of a photoinitiator. Subsequent activation to the thiol-reactive form of the furan-protected maleimide groups is performed through the retro Diels-Alder reaction. As a demonstration of direct protein immobilization, bovine serum albumin is immobilized onto the cryogels. Furthermore, ligand-directed immobilization of proteins is achieved by first attaching mannose- or biotin-thiol onto the maleimide-containing platforms, followed by ligand-directed immobilization of concanavalin A or streptavidin, respectively. Additionally, we demonstrate that the extent of immobilized proteins can be controlled by varying the amount of thiol-reactive maleimide groups present in the cryogel matrix. Compared to traditional hydrogels, cryogels demonstrate enhanced protein immobilization/detection. Additionally, it is concluded that utilization of a longer linker, distancing the thiol-reactive maleimide group from the gel scaffold, considerably increases protein immobilization. It can be envisioned that the facile fabrication, conjugation, and control over the extent of functionalization of these cryogels will make these materials desirable scaffolds for numerous biomedical applications.

CD44v6, a splice variant of the cell surface glycoprotein CD44, acts as a co-receptor for c-Met and is upregulated in tumors with high metastatic potential. Methods: We screened a phage-displayed peptide library for peptides that selectively bind to CD44v6-overexpressing cells and exploited them to block CD44v6 and deliver a pro-apoptotic peptide to tumors for cancer therapy. Results: CNLNTIDTC (NLN) and CNEWQLKSC (NEW) peptides bound preferentially to CD44v6-high cells than to CD44v6-low cells. The binding affinities of NLN and NEW to CD44v6 protein were 253 79 and 85 +/- 18 nM, respectively. Peptide binding to CD44v6-high cells was inhibited by the knockdown of CD44v6 gene expression and competition with an anti-CD44v6 antibody. A pull-down assay with biotin-labeled peptides enriched CD44v6 from cell lysates. NLN and NEW induced CD44v6 internalization and inhibited hepatocyte growth factor-induced c-Met internalization, c-Met and Erk phosphorylation, and cell migration and invasion. In mice harboring tumors, intravenously administered NLN and NEW homed to the tumors and inhibited metastasis to the lungs. When combined with crizotinib, a c-Met inhibitor, treatment with each peptide inhibited metastatic growth more efficiently than each peptide or crizotinib alone. In addition, KLAKLAKKLAKLAK pro-apoptotic peptide guided by NLN (NLN-KLA) or NEW (NEW-KLA) killed tumor cells and inhibited tumor growth and metastasis. No significant systemic side effects were observed after treatments. Conclusions: These results suggest that NLN and NEW are promising metastasis-inhibiting peptide therapeutics and targeting moieties for CD44v6-expressing metastases.