Nano LIFE

Highly specific deoxyribonucleic acid (DNA) base-pairing not only carries genetic information, but also provides the basis for self-assembly of novel nanostructures with programmable shapes and sizes. Unlike single-stranded and double-stranded DNA, DNA nanostructures exhibit good cellular permeability. They also have characteristics of uniform size, easy functionalization, precise addressability, excellent water solubility and high biocompatibility. Due to their unique properties, these tailored molecular devices are ideal nanoscale systems for targeting cells and triggering cellular responses. Recent progress in the field of DNA nanotechnology has demonstrated effectiveness and advantages of DNA nanostructures as smart and targeted drug delivery systems or imaging agents within living organisms. In this review, we summarize the recent advances in structure design, cargo loading and cellular delivery of DNA nanocarriers, and discuss their potential in therapeutic applications.

Ionizing radiation, which includes X-rays and gamma rays, is used in a variety of different applications, including in human health. However, high levels of exposure can result in significant morbidity and mortality in humans. Molecular and nanoscale systems that can detect different levels of ionizing radiation can ultimately lead to effective sensing platforms for a variety of applications. In the current work, we describe the use of polypeptide-templated formation of bimetallic metal nanoparticles with potential applications as a colorimetric reporter of elevated levels of ionizing radiation typically used in blood irradiation. Cysteine-containing elastin-like polypeptides were employed together with reducing agents in order to engender radiation-facilitated formation of bimetallic gold–silver bimetallic nanoparticles from a mixture of their respective metal salts. This formation of colored nanoparticle dispersions from colorless metal salt solutions acted as a visual reporter of ionizing radiation in the dose range of 25–100 Gy. Nanoparticles were characterized using UV–visible spectroscopy, transmission electron microscopy, elemental analyses and dynamic light scattering. Our results indicate that polypeptide-bimetallic nanoparticle systems may be attractive reporters of elevated levels of ionizing radiation.

The aim of this study was to find the effect of carbon nanotube functionalized with Morin molecule (CNTFM) on normal and mutant forms of amyloid precursor protein (APP), found in Alzheimer’s disease. In this study, one mutant and one normal APP were separately modeled in Hyperchem software. After minimization of system energy, molecular dynamic (MD) simulation was separately carried out for 30000ps in NVT ensemble at 310K. At the end of simulation, different parameters, such as free energy, intermolecular energy and root mean square displacement (RMSD) were separately monitored for each APP. Finally, the ratio of change was calculated for each parameter. To confirm simulation results, one mL of mutant APP (10 mM) was incubated with one mL of CNTFM (10mg/mL) for 1h. Finally, the percentages of the different secondary structures of both treated and untreated APP were separately estimated by FTIR analysis. Based on MD simulation, high ratio of change was seen for mutant APP. Experimental study showed that the proportion of $\beta$-sheets (parallel $+$ anti-parallel) and random coil was decreased when incubated with CNTFM. Moreover, the proportion of $\alpha$-turns was increased. Interestingly, the proportion of $\beta$-sheets (anti-parallel) was not changed.

An exuberant inflammatory response may exacerbate the primary tissue damage caused by injuries to the skin due to burns, surgery, excessive pressure, and other etiologies, thus increasing the time to heal. We hypothesized that application of factors that decrease inflammation would allow the skin to more quickly restore its barrier function, and promote the return to homeostasis. Resolvins are endogenous, pro-resolving lipid mediators derived from omega-3 fatty acids that serve to inhibit neutrophil migration and enhance macrophage phagocytosis, thus promoting the resolution of inflammation and the beginning of the proliferative phase of wound healing. Resolvins are derived either from docosahexaenoic (D-series) or eicosapentaenoic (E-series) acid. Herein, we compare the effects of resolvins D1 (RvD1), D2 (RvD2) and E1 (RvE1) on their abilities to inhibit neutrophil migration in vitro and to promote wound healing in vivo. In Transwell experiments, all resolvins inhibited neutrophil migration, with RvE1 being the most effective at a 2000nM concentration. In an in vivo murine excisional wound (1cm$\times$1cm) healing model, topically applied resolvins accelerated wound closure. RvE1-treated wounds healed by 19.4$\pm$1.5 days post-wounding, which was significantly shorter than the RvD2-treated and RvD1-treated groups ($p<$0.05), which closed by an average of 22.8$\pm$1.8 and 24.4$\pm$2.2 days, respectively. Furthermore, all resolvin-treated groups healed faster than vehicle controls ($p<$0.05), which closed at 28.6$\pm$1.5 days. There was a strong linear correlation ($R^2=$0.9384) between each resolvin’s potency in inhibiting neutrophil migration in vitro versus accelerating wound healing in vivo. Furthermore, upon histological analysis, the RvE1-treated group exhibited more mature collagen organization and re-epithelialization.