Cancer vaccines from cryogenically silicified tumour cells functionalized with pathogen-associated molecular patterns.

The production of personalized cancer vaccines made from autologous tumour cells could benefit from mechanisms that enhance immunogenicity. Here we show that cancer vaccines can be made via the cryogenic silicification of tumour cells, which preserves tumour antigens within nanoscopic layers of silica, followed by the decoration of the silicified surface with pathogen-associated molecular patterns. These pathogen-mimicking cells activate dendritic cells and enhance the internalization, processing and presentation of tumour antigens to T cells. In syngeneic mice with high-grade ovarian cancer, a cell-line-based silicified cancer vaccine supported the polarization of CD4+ T cells towards the T-helper-1 phenotype in the tumour microenvironment, and induced tumour-antigen-specific T-cell immunity, resulting in complete tumour eradication and in long-term animal survival. In the setting of established disease and a suppressive tumour microenvironment, the vaccine synergized with cisplatin. Silicified and surface-modified cells from tumour samples are amenable to dehydration and room-temperature storage without loss of efficacy and may be conducive to making individualized cancer vaccines across tumour types.

Immunoaffinity based methods are superior to kits for purification of prostate derived extracellular vesicles from plasma samples.

BACKGROUND: The ability to isolate extracellular vesicles (EVs) such as exosomes or microparticles is an important method that is currently not standardized. While commercially available kits offer purification of EVs from biofluids, such purified EV samples will also contain non-EV entities such as soluble protein and nucleic acids that could confound subsequent experimentation. Ideally, only EVs would be isolated and no soluble protein would be present in the final EV preparation. METHODS: We compared commercially available EV isolation kits with immunoaffinity purification techniques and evaluated our final EV preparations using atomic force microscopy (AFM) and nanoscale flow cytometry (NFC). AFM is the only modality capable of detecting distinguishing soluble protein from EVs which is important for downstream proteomics approaches. NFC is the only technique capable of quantitating the proportion of target EVs to non-target EVs in the final EV preparation. RESULTS: To determine enrichment of prostate derived EVs relative to non-target MPs, anti-PSMA (Prostate Specific Membrane Antigen) antibodies were used in NFC. Antibody-based immunoaffinity purification generated the highest quality of prostate derived EV preparations due to the lack of protein and RNA present in the samples. All kits produced poor purity EV preparations that failed to deplete the sample of plasma protein. CONCLUSIONS: While attractive due to their ease of use, EV purification kits do not provide substantial improvements in isolation of EVs from biofluids such as plasma. Immunoaffinity approaches are more efficient and economical and will also eliminate a significant portion of plasma proteins which is necessary for downstream approaches.

Characterization of self-assembled lamellar thermoresponsive silica-hydrogel nanocomposite films.

Mesostructured lamellar nanocomposite films with alternating silica and organic layers containing poly(N-isopropropyl acrylamide) (PNIPAM) were prepared using evaporation-induced self-assembly. A suitable theoretical approach to analyze the small-angle X-ray scattering (SAXS) patterns of oriented lamellar two-phase systems was applied to the SAXS data of films of varying composition, providing details on the self-assembly process, the composition, and the polymerization. In particular, this approach allowed an accurate determination of the thickness of the silica and the organic layer. The applicability of the SAXS approach was carefully tested with simulated data and verified by thermogravimetric analysis (TGA). TGA and (13)C NMR were used to study the polymerization and linkage to the silica matrix. SAXS and time-resolved grazing incidence SAXS revealed that the phase transition of PNIPAM at ca. 32 degrees C leads to a reversible expansion/contraction perpendicular to the layers on a time scale of ca. 30 min.

Dual SAW sensor technique for determining mass and modulus changes.

Surface acoustic wave (SAW) sensors, which are sensitive to a variety of surface changes, have been widely used for chemical and physical sensing. The ability to control or compensate for the many surface forces has been instrumental in collecting valid data. In cases in which it is not possible to neglect certain effects, such as frequency drift with temperature, methods such as the "dual sensor" technique have been utilized. This paper describes a novel use of a dual sensor technique, using two sensor materials (quartz and GaAs) to separate out the contributions of mass and modulus of the frequency change during gas adsorption experiments. The large modulus change in the film calculated using this technique and predicted by the Gassmann equation provide a greater understanding of the challenges of SAW sensing.

Self-assembly of mesoscopically ordered chromatic polydiacetylene/silica nanocomposites.

Nature abounds with intricate composite architectures composed of hard and soft materials synergistically intertwined to provide both useful functionality and mechanical integrity. Recent synthetic efforts to mimic such natural designs have focused on nanocomposites, prepared mainly by slow procedures like monomer or polymer infiltration of inorganic nanostructures or sequential deposition. Here we report the self-assembly of conjugated polymer/silica nanocomposite films with hexagonal, cubic or lamellar mesoscopic order using polymerizable amphiphilic diacetylene molecules as both structure-directing agents and monomers. The self-assembly procedure is rapid and incorporates the organic monomers uniformly within a highly ordered, inorganic environment. Polymerization results in polydiacetylene/silica nanocomposites that are optically transparent and mechanically robust. Compared to ordered diacetylene-containing films prepared as Langmuir monolayers or by Langmuir-Blodgett deposition, the nanostructured inorganic host alters the diacetylene polymerization behaviour, and the resulting nanocomposite exhibits unusual chromatic changes in response to thermal, mechanical and chemical stimuli. The inorganic framework serves to protect, stabilize, and orient the polymer, and to mediate its function. The nanocomposite architecture also provides sufficient mechanical integrity to enable integration into devices and microsystems.

Optically defined multifunctional patterning of photosensitive thin-film silica mesophases.

Photosensitive films incorporating molecular photoacid generators compartmentalized within a silica-surfactant mesophase were prepared by an evaporation-induced self-assembly process. Ultraviolet exposure promoted localized acid-catalyzed siloxane condensation, which can be used for selective etching of unexposed regions; for "gray-scale" patterning of refractive index, pore size, surface area, and wetting behavior; and for optically defining a mesophase transformation (from hexagonal to tetragonal) within the film. The ability to optically define and continuously control both structure and function on the macro- and mesoscales is of interest for sensor arrays, nanoreactors, photonic and fluidic devices, and low-dielectric-constant films.