Template‐Mediated Assembly of DNA into Microcapsules for Immunological Modulation

There is a need for effective vaccine delivery systems and vaccine adjuvants without extraneous excipients that can compromise or minimize their efficacy. Vaccine adjuvants cytosine–phosphate–guanosine oligodeoxynucleotides (CpG ODNs) can effectively activate immune responses to secrete cytokines. However, CpG ODNs are not stable in serum due to enzymatic cleavage and are difficult to transport through cell membranes. Herein, DNA microcapsules made of CpG ODNs arranged into 3D nanostructures are developed to improve the serum stability and immunostimulatory effect of CpG. The DNA microcapsules allow encapsulation and co‐delivery of cargoes, including glycogen. The DNA capsules, with >4 million copies of CpG motifs per capsule, are internalized in cells and accumulate in endosomes, where the Toll‐like receptor 9 is engaged by CpG. The capsules induce up to 10‐fold and 20‐fold increases in tumor necrosis factor (TNF)‐α and interleukin (IL)‐6 secretion, respectively, in RAW264.7 cells compared with CpG ODNs. Furthermore, the microcapsules stimulate TNF‐α and IL‐6 secretion in a concentration‐ and time‐dependent manner. The immunostimulatory activity of the capsules correlates to their intracellular trafficking, endosomal confinement, and degradation, assessed by confocal and super‐resolution microscopy. These DNA capsules can serve as both adjuvants to stimulate an immune reaction and vehicles to encapsulate vaccine peptides/genes to achieve synergistic immune effects.     

Thermographic Investigation of Bronze Artefacts: Characterization of Structure Elements and Casting Faults in Masterpieces of the Bronze Statuary of Rome

In this paper, the thermographic results obtained by studying some masterpieces of the bronze statuary of Rome are presented. More specifically, a quantitative approach has been adopted in the investigation of the Capitoline She Wolf, hosted in the Musei Capitolini, and of the Boxer at Rest and the Hellenistic Prince belonging to the collection of the Museo Nazionale Romano. The obtained results provided data useful to characterize the properties of the bronze alloy and several subsurface features of the statue, such as casting faults and patches. In particular, the interface between different kind of patches and the main body of the statue has been investigated in order to determine the way they were applied. Moreover, the thermal diffusivity of the alloy of the Capitoline She Wolf has been evaluated and quantitative investigations have been carried out in order to determine the depth of some features, such as the cavities originating from air bubbles in the casting melt.     

SupraCells: Living Mammalian Cells Protected within Functional Modular Nanoparticle‐Based Exoskeletons

Creating a synthetic exoskeleton from abiotic materials to protect delicate mammalian cells and impart them with new functionalities could revolutionize fields like cell‐based sensing and create diverse new cellular phenotypes. Herein, the concept of “SupraCells,” which are living mammalian cells encapsulated and protected within functional modular nanoparticle‐based exoskeletons, is introduced. Exoskeletons are generated within seconds through immediate interparticle and cell/particle complexation that abolishes the macropinocytotic and endocytotic nanoparticle internalization pathways that occur without complexation. SupraCell formation is shown to be generalizable to wide classes of nanoparticles and various types of cells. It induces a spore‐like state, wherein cells do not replicate or spread on surfaces but are endowed with extremophile properties, for example, resistance to osmotic stress, reactive oxygen species, pH, and UV exposure, along with abiotic properties like magnetism, conductivity, and multifluorescence. Upon decomplexation cells return to their normal replicative states. SupraCells represent a new class of living hybrid materials with a broad range of functionalities.     

Silica Films with Bimodal Pore Structure Prepared by Using Membranes as Templates and Amphiphiles as Porogens

Extended porous silica films with thicknesses in the range of 60 to 130 μm and pores on both the meso‐ and macroscale have been prepared by simultaneously using porous membrane templates and amphiphilic supramolecular aggregates as porogens. The macropore size is determined by the cellulose acetate or polyamide membrane structure and the mesopores by the chosen ethylene‐oxide‐based molecular self‐assembly (block copolymer or non‐ionic surfactants). Both the template and the porogen are removed during an annealing step leaving the amorphous silica material with a porous structure that results from sol–gel chemistry occurring in the aqueous domains of the amphiphilic liquid‐crystalline phases and casting of the initial template membrane. The surface area and total pore volume of the inorganic films vary from 473 to 856 m² g^–1, and 0.50 to 0.73 cm³ g^–1, respectively, depending on the choice of template and porogen. The combined benefits of both macro‐ and mesopores can potentially be obtained in one film. Such materials are envisaged to have applications in areas of large molecule (biomolecule) separation and catalysis. Enhanced gas and liquid flow rates through such membranes, due to the presence of the larger pores, also makes them attractive as supports for other catalytic materials.     

Intracellularly Degradable Hydrogen‐Bonded Polymer Capsules

The assembly of low‐fouling polymer capsules with redox‐responsive behavior and intracellular degradability is reported. Thiol‐containing poly(2‐ethyl‐2‐oxazoline) (PEtOxMA_SH) brushes are synthesized by atom transfer radical polymerization (ATRP) of oligo(2‐ethyl‐2‐oxazoline)methacrylate and glycidyl methacrylate (GMA) and subsequent ring‐opening reaction of the GMA. Sequential deposition of PEtOxMA_SH/poly(methacrylic acid) (PMA) multilayers onto silica (SiO₂) particle templates and crosslinking through disulfide formation yield stable capsules after the removal of the SiO₂ templates by buffered hydrofluoric acid (HF). The redox‐responsive nature of the disulfide crosslinking groups enables the degradation of these capsules under simulated intracellular conditions at pH 5.9 and 5 mm glutathione (GSH). Furthermore, capsule degradation is observed after incubation with dendritic (JAWS II) cells. Even at high capsule‐to‐cell ratios, PEtOxMA_SH capsules show only negligible cytotoxicity. Quartz crystal microgravimetry (QCM) studies, using 100% human serum, reveal that films prepared from PEtOxMA_SH exhibit low‐fouling properties. The degradation and low‐fouling properties are promising for application of PEtOxMA_SH films/capsules for the delivery and triggered release of therapeutics.