The investigation on sialic acid-modified pectin nanoparticles loaded with oxymatrine for orally targeting and inhibiting the of ulcerative colitis.

The aim of the study was to develop an oral targeting drug delivery system (OTDDS) of oxymatrine (OMT) to effectively treat ulcerative colitis (UC). The OTDDS of OMT (OMT/SA-NPs) was constructed with OMT, pectin, Ca2+, chitosan (CS) and sialic acid (SA). The obtained particles were characterized in terms of particle size, zeta potential, morphology, drug loading, encapsulation efficiency, drug release and stability. The average size of OMT/SA-NPs was 255.0 nm with a zeta potential of -12.4 mV. The loading content and encapsulation efficiency of OMT/SA-NPs were 14.65% and 84.83%, respectively. The particle size of OMT/SA-NPs changed slightly in the gastrointestinal tract. The nanoparticles can delivery most of the drug to the colon region. In vitro cell experiments showed that the SA-NPs had excellent biocompatibility and anti-inflammation, and the uptake of SA-NPs by RAW 264.7 cells was time and concentration-dependent. The conjugated SA can help the internalization of NPs into target cells. In vivo experiments showed that OMT/SA-NPs had a superior anti-inflammation effect and the effect of reducing UC, which was attributed to the delivery most of OMT to the colonic lumen, the specific targeting and retention in colitis site and the combined anti-inflammation of OMT and NPs.

Novel silk protein/hyaluronic acid hydrogel loaded with azithromycin as an immunomodulatory barrier to prevent postoperative adhesions.

Peritoneal adhesions, a common postoperative complication of laparotomy, are still treated with physical barriers, but their efficacy and ease of use are controversial. In this paper, we developed a wound microenvironment-responsive hydrogel composed of Antheraea pernyi silk protein (ASF) from wild cocoons and tyramine-modified hyaluronic acid (HA-Ph) loaded with azithromycin (AZI), glucose oxidase (GOX), and horseradish peroxidase (HRP). In addition, GOX-catalyzed oxygen production enhanced the antibacterial ability of the hydrogel. Moreover, the drug-loaded hydrogel increased macrophage CD206 expression while decreasing IL-6 and TNF-α expression. More importantly, the retarding effect of this novel hydrogel system on AZI almost eliminated the appearance of postoperative adhesions in rats. It was also found that the novel hydrogel enhanced the modulation of the TLR-4/Myd88/NF-κB pathway and TGF-ß/Smad2/3 pathway by azithromycin in the locally damaged peritoneum of rats, which accelerated the remodeling of damaged tissues and dramatically reduced the deposition of collagen. Therefore, spraying the novel drug-loaded hydrogel on postoperative abdominal wounds can effectively inhibit the formation of postoperative adhesions.

The inhibitory effects and mechanisms of polymannuroguluronate sulfate against human papillomavirus infection in vitro and in vivo.

Human papillomaviruses (HPVs) are non-enveloped DNA viruses that infect epithelia and can cause a wide variety of benign and pre-malignant epithelial tumours. The sulfated polysaccharides such as carrageenans were reported to be able to interfere with the binding process of HPV to the cell surface. In this study, brown seaweed derived polysaccharides polymannuroguluronate sulfate (PMGS) were prepared, and their anti-HPV effects were explored in vitro and in vivo. The results indicated that PMGS effectively inhibited high-risk HPV16 and HPV45 infection with very low toxicity. PMGS may inactivate HPV particles or block the binding and entry process of HPV through direct interaction with viral capsid proteins. PMGS can enter into HeLa cells and down-regulate the expression levels of viral oncogene proteins E6 and E7. In addition, PMGS also dramatically inhibited HPV infection on the skin of BALB/c Nude Mice. Thus, marine derived polysaccharide PMGS possessed anti-HPV activities in vitro and in vivo, and may block HPV infection via targeting viral capsid L1 protein, suggesting that it has great potential to be developed into a novel anti-HPV agent in the future.

Ab initio simulation of hydrogen bonding in ices under ultra-high pressure.

In this article, as continuation of the previous publication (P. Zhang, L. Tian, Z. P. Zhang, G. Shao, and J. C. Li, J. Chem. Phys. 137, 044504 (2012)), we report a series of computational simulation results for ices using ab initio DFT methods. The results not only reproduced the main feature of inelastic neutron scattering spectra for ice Ih, but also other phases of ice such as VII and VIII. Furthermore, pressure dependent simulations for ice I and VIII have led us to obtain the spectra for the symmetrical structure of ice X. The transition from normal ice to the symmetrical form shows an extraordinary behaviour of H-bonding in term of vibrations associated with inter- and intra-molecular bonds, revealing a range of phenomena which was not seen before.