The ability of drug release from SF materials was governed largely by their secondary structure. It is known that the breakage degree of the peptide chain during the silk fibroin (SF) dissolution can affect the structure, property, and applications of SF materials. To deeply understand this effect, we designed a reaction system based on CaCl2/H2O/C2H5OH ternary solvent with different ethanol content to obtain the regenerated SF films with different morphologies and secondary structures. The results showed that the globule-like nanostructure was observed in all regenerated SF films, and their size decreased significantly with reducing the ethanol content in the solvent. Correspondingly, the β-sheet structure content of the SF films increased. In addition, the contact angle and the elongation ratio increased, and water absorption decreased significantly with decreasing the ethanol content in the solvent. The accumulated release percents of doxorubicin from these SF films were significantly different with increasing the time. With smaller nanostructure size and more β-sheet content, the SF films had a slower drug release at the beginning. This study indicated the importance of the ethanol content in the solvent in controlling the structure and properties of the regenerated SF films, which would improve the application of SF in drug delivery.

Gas-phase silver nanoparticles were coated with silicon dioxide (SiO2) by photoinduced chemical vapor deposition (photo-CVD). Silver nanoparticles, produced by inert gas condensation, and a SiO2 precursor, tetraethylorthosilicate (TEOS), were exposed to vacuum ultraviolet (VUV) radiation at atmospheric pressure and varying temperatures. The VUV photons dissociate the TEOS precursor, initiating a chemical reaction that forms SiO2 coatings on the particle surfaces. Coating thicknesses were measured for a variety of operation parameters using tandem differential mobility analysis and transmission electron microscopy. The chemical composition of the particle coatings was analyzed using energy dispersive x-ray spectrometry and Fourier transform infrared spectroscopy. The highest purity films were produced at 300-400 degrees C with low flow rates of additional oxygen. The photo-CVD coating technique was shown to effectively coat nanoparticles and limit core particle agglomeration at concentrations up to 10(7) particles cm(-3).

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Engineering self‐propelled micro‐/nanomachines with ultrafast speeds and high towing forces is crucial for the efficient transportation of important objects in key biomedical and environmental applications. In this study, rolled‐up nanomembrane technology is used for the first time for the controlled fabrication of layer‐by‐layer (LbL)‐assembled microtubes and the corresponding chemical‐powered microrockets. By integrating LbL assembly, microcontact printing, and a rolled‐up nanomembrane technique, polyelectrolyte multilayer microplates of different shapes are transformed into well‐defined microtubes. Coupled with platinum nanoparticles, the as‐prepared microtubes can act as bubble‐propelled microrockets with a very rapid speed and a large towing force. As a proof of concept, the rolled LbL microrockets confirm the feasibility of transporting single or multiple cells at high speed. Integrating the rolled‐up nanomembrane technology and LbL assembly results in a simple, versatile, and low‐cost approach and expands the scope of both polymer multilayer‐based multifunctional tubes and artificial machines at the micro‐/nanoscale.

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