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Local drug release in close vicinity of solid tumors is a promising therapeutic approach in cancer therapy. Implantable drug delivery systems can be designed to achieve controlled and sustained drug release. In this study, ultrathin porous membranes of silicon wafer were employed as compatible drug reservoir models. An anticancer model drug, curcumin (CUR), was successfully loaded into porous silicon containers (8.94 ± 0.72% w/w), and then, cerium oxide nanocapping was performed on the open pores for drug protection and release rate prolongation. Next, layer-by-layer surface coating of the drug container with anionic (alginate) and cationic (chitosan) polymers rendered pH-responsivity to the device. The drug release profile was studied using reflectometric interference Fourier transform spectroscopy at different pH conditions. It was determined that faster decomposition of the polymeric layers and subsequent CUR release occur in acidic buffer (pH 5.5) compared to a neutral buffer. Various characterization studies, including dynamic light scattering, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy, contact angle measurement, ultraviolet–visible spectroscopy, and X-ray powder diffraction revealed that our system has the required physicochemical properties to serve as a novel pH-sensitive drug delivery implant for cancer therapy.

Bacterial cellulose (BC) was investigated for the first time for the preparation of capsule shells for immediate and sustained release of drugs. The prepared capsule shells were characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The BC capsule shells were studied for drug release using an USP type-I dissolution apparatus. Irrespective of the drying method and the thickness of the BC sheet, the capsule shells displayed an immediate drug release profile. Moreover, the addition of release-retardant cellulosic polymers sustained the drug release having first-order kinetics for hydroxypropylmethylcellulose and carboxymethyl cellulose sodium with R 2 values of 0.9995 and 0.9954, respectively. Furthermore, these capsules shells remained buoyant in 0.1 N HCl (pH 1.2) solution up to 12 h. This study showed that BC is a promising alternative to gelatin capsules with both immediate and sustained drug release properties depending upon the compositions of the encapsulated materials.

A time dependent Eulerian thermal/material flow model of friction stir welding was developed and applied to the dissimilar joining of pure copper and aluminum 1050-H16 alloy to investigate the maximum penetration of base metals. Thermal and material flow analysis was done with the assumed velocity field in the stir zone and considering a thermal source of energy obtained from the both Coulomb type of friction and the loss of shear stress in a non-Newtonian viscous behavior of metal flow. The developed model was used to estimate temperature gradient and penetration of material under three different conditions of tool offset and compared with the experimental results. The model shows that the penetration of the base metals is closely related to tool offset. In all of the cases, the metal fixed in the advancing side is copper. Nevertheless, when considering tool offset in the copper side and also when considering tool offset in the aluminum side, penetrating metals are copper and aluminum, respectively. Also, the model shows that the maximum temperature achieved in the base metals significantly depends on the tool offset.

Combination therapy via nanoparticulate systems has already been proposed as a synergistic approach for cancer treatment. Herein, undecylenic acid modified thermally hydrocarbonized porous silicon nanoparticles (UnTHCPSi NPs) loaded with sorafenib and surface-biofunctionalized with anti-CD326 antibody (Ab) were developed for cancer chemo-immunotherapy in MCF-7 and MDA-MB-231 breast cancer cells. The cytocompatibility study showed no significant toxicity for the bare and antibody-conjugated UnTHCPSi (Un-Ab) NPs at concentrations lower than 200 μg·mL−1. Compared to the bare UnTHCPSi, Un-Ab NPs loaded with sorafenib reduced the premature drug release in plasma, increasing the probability of proper drug targeting. In addition, high cellular interaction and subsequent internalization of the Un-Ab NPs into the cells expressing CD326 antigen demonstrated the possibility of improving antigen-mediated endocytosis via CD326 targeting. While an in vitro antitumor study revealed a higher inhibitory effect of the sorafenib-loaded Un-Ab NPs compared to the drug-loaded UnTHCPSi NPs in the CD326 positive MCF-7 cells, there was no difference in the anti-proliferation impact of both the abovementioned NPs in the CD326 negative MDA-MB-231 cells, suggesting CD326 as an appropriate receptor for Ab-mediated drug delivery. It was also shown that the anti-CD326 Ab can act as an immunotherapeutic agent by inducing antibody dependent cellular cytotoxicity and enhancing the interaction of effector immune and cancer cells for subsequent phagocytosis and cytokine secretion. Hence, the developed nanovectors can be applied for simultaneous tumor-selective drug targeting and immunotherapy.

Zinc oxide (ZnO) nanorods were manufactured using the aqueous chemical growth (ACG) method, and the effect of thermal acetylene treatment on their morphology, chemical composition, and optical properties was investigated. Changes in the elemental content of the treated rods were found to be different than in previous reports, possibly due to the different defect concentrations in the samples, highlighting the importance of synthesis method selection for the process. Acetylene treatment resulted in a significant improvement of the ultraviolet photoluminescence of the rods. The greatest increase in emission intensity was recorded on ZnO rods treated at the temperature of 825 °C. The findings imply that the changes brought on by the treatment are limited to the surface of the ZnO rods. Electronic supplementary material The online version of this article (doi:10.1186/s11671-016-1627-y) contains supplementary material, which is available to authorized users.

Advances in nanotechnology have prompted rapid progress and versatile imaging modalities for diagnostics and treatment of diseases. Molecular imaging is a powerful technique for quantifying physiological changes in vivo using noninvasive imaging probes. These probes are used to image specific cells and tissues within a whole organism. Currently, imaging is an essential part of clinical protocols providing morphological, structural, metabolic and functional information. Using theranostic micro- or nanoparticles, which combine both therapeutic and diagnostic capabilities in one single entity, holds a true promise to propel the biomedical field toward personalized medicine. With this approach, biological processes can be directly and simultaneously monitored with the treatment of the diseases. This mini-review highlights the recent innovative diagnostic imaging aspects of porous silicon (PSi) materials and emphasizes their potential as theranostic platforms and tools for the clinic. Multiple biomedical imaging applications of the PSi materials are also outlined.