Beyond glass microspheres, high strength, high temperature hollow shells

The great potential of syntactic foams often requires material beyond the more commonly available glass and polymer microspheres. Through various partnerships, Deep Springs Technology, (DST) has explored more exotic shell materials from refractory and functional ceramics to stainless steels. This talk will highlight some of these recent developments. Yttrium silicate and mullite hollow shells are being investigated for use in refractory insulation for hypersonic systems, for their lower thermal expansion and good environmental resistance. Although challenging to fabricate due to the high temperature requirements, hollow shells were produced that met the specification and demonstrated good strength. Yttrium-iron-garnet is a unique functional ceramic used in microwave, acoustic, optical, and magneto-optical applications. This material was successfully synthesized into hollow three millimeter magnets. Finally this talk will cover recent stainless steel shell which, like other metal shell produced at DST, poses both high strength and deformability. These properties are particularly useful in light-weighting applications were high toughness and corrosion resistance is require. Preliminarily results on work to failure of the individual shells will be shown

Cowpea Mosaic Virus Capsid: A Promising Carrier for the Development of Carbohydrate Based Antitumor Vaccines

Immunotherapy targeting tumor cell surface carbohydrates is a promising approach for cancer treatment. However, the low immunogenecity of carbohydrates presents a formidable challenge. We describe here the enhancement of carbohydrate immunogenicity by an ordered display on the surface of the cowpea mosaic virus (CPMV) capsid. The Tn glycan, which is overexpressed on numerous cancer cell surfaces, was selected as the model antigen for our study. Previously it has been shown that it is difficult to induce a strong T cell-dependent immune response against the monomeric form of Tn presented in several ways on different carriers. In this study, we first synthesized Tn antigens derivatized with either a maleimide or a bromoacetamide moiety that was conjugated selectively to a cysteine mutant of CPMV. The glyco-conjugate was then injected into mice and pre-and post-immune antibody levels in the mice sera were measured by enzyme linked immunosorbant assays. High total antibody titers and, more importantly, high IgG titers specific for Tn were obtained in the post-immune day 35 serum, suggesting the induction of T cell-dependent antibody isotype switching by the glyco-conjugate. The antibodies generated were able to recognize Tn antigens presented in their native conformations on the surfaces of both MCF-7 breast cancer cells and the multi-drug resistant breast cancer cell line NCI-ADR RES. These results suggest that the CPMV capsid can greatly enhance the immunogenicity of weak antigens such as Tn and this can provide a promising tool for the development of carbohydrate based anti-cancer vaccines

Tobacco Mosaic Virus as a New Carrier for Tumor Associated Carbohydrate Antigens

Tumor associated carbohydrate antigens (TACAs) are being actively studied as targets for anti-tumor vaccine development. One serious challenge was the low immunogenecity of these antigens. Herein, we report the results on using the tobacco mosaic virus (TMV) capsid as a promising carrier of a weakly immunogenic TACA, the monomeric Tn antigen. The copper(I) catalyzed azide-alkyne cycloaddition reaction was highly efficient in covalently linking Tn onto the TMV capsid without resorting to a large excess of the Tn antigen. The location of Tn attachment turned out to be important. Tn introduced at the N terminus of TMV was immunosilent, while that attached to tyrosine 139 elicited strong immune responses. Both Tn specific IgG and IgM antibodies were generated as determined by enzyme linked immunosorbent assay and a glycan microarray screening study. The production of high titers of IgG antibodies suggested that the TMV platform contained the requisite epitopes for helper T cells and was able to induce antibody isotype switching. The antibodies exhibited strong reactivities towards Tn antigen displayed in its native environment, i.e., cancer cell surface, thus highlighting the potential of TMV as a promising TACA carrier

Tobacco Mosaic Virus as a New Carrier for Tumor Associated Carbohydrate Antigens

Tumor-associated carbohydrate antigens (TACAs) are being actively studied as targets for antitumor vaccine development. One serious challenge was the low immunogenecity of these antigens. Herein, we report the results of using the tobacco mosaic virus (TMV) capsid as a promising carrier of a weakly immunogenic TACA, the monomeric Tn antigen. The copper­(I) catalyzed azide–alkyne cycloaddition reaction was highly efficient in covalently linking Tn onto the TMV capsid without resorting to a large excess of the Tn antigen. The location of Tn attachment turned out to be important. Tn introduced at the N terminus of TMV was immunosilent, while that attached to tyrosine 139 elicited strong immune responses. Both Tn specific IgG and IgM antibodies were generated as determined by enzyme-linked immunosorbent assay and a glycan microarray screening study. The production of high titers of IgG antibodies suggested that the TMV platform contained the requisite epitopes for helper T cells and was able to induce antibody isotype switching. The antibodies exhibited strong reactivities toward Tn antigen displayed in its native environment, i.e., cancer cell surface, thus highlighting the potential of TMV as a promising TACA carrier

Varia

Ce numéro est dédié à la mémoire de Dino Ambaglio, ami, lecteur et compagnon de voyage de toutes nos «Anabases». ἐν κοινωνίᾳ τε καὶ συμφωνί