Poly(acrylic acid) grafted mesoporous silica nanoparticles (PAA-MSNs) were prepared by a facile graftonto strategy, i.e., the amidation between PAA homopolymer and amino group functionalized MSNs. The resultant PAA-MSNs were uniform spherical nanoparticles with a mean diameter of approximately 150 nm, and the graft amount of PAA evaluated by thermogravimetric analysis (TGA) was about 12 wt %. Due to the covalent graft of hydrophilic and pHresponsive PAA, the PAA-MSNs could be well dispersed in aqueous solution, which is favorable to be utilized as drug carriers to construct a pH-responsive controlled drug delivery system. N 2 adsorptionÀdesorption isotherm results demonstrated that doxorubicin hydrochloride (DOX), a well-known anticancer drug, could be effectively loaded into the channels of PAA-MSNs through the electrostatic interaction. The loading content and the entrapment efficiency of DOX could reach up to 48% and 95%, respectively. The drug release rate of DOX@PAA-MSN was pH dependent and increased with the decrease of pH. The in vitro cytotoxicity test indicated that PAA-MSNs were highly biocompatible and suitable to use as drug carriers. The drug-loaded DOX@PAA-MSNs were distinctly cytotoxic to HeLa cells, due to the sustained release of drug, and showed higher clinical effects than free DOX. These results imply that the PAA-MSNs are promising platforms to construct pH-responsive controlled drug delivery systems for cancer therapy.

At present, the clinical strategies for treating chronic wounds are limited, especially when it comes to pain relief and rapid wound healing. Therefore, there is an urgent need to develop...

Lignin is the most abundant by-product from the pulp and paper industry as well as the second most abundant natural renewable biopolymer after cellulose on earth. In recent years, transforming unordered and complicated lignin into ordered and uniform nanoparticles has attracted wide attention due to their excellent properties such as controlled structures and sizes, better miscibility with polymers, and improved antioxidant activity. In this review, we first introduce five important technical lignin from different sources and then provide a comprehensive overview of the recent progress of preparation techniques which are involved in the fabrication of various lignin-based nanoparticles and their industrial applications in different fields such as drug delivery carriers, UV absorbents, hybrid nanocomposites, antioxidant agents, antibacterial agents, adsorbents for heavy metal ions and dyes, and anticorrosion nanofillers.

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Chronic pain is still a basic science and clinical challenge. Unraveling of the neurobiological mechanisms involved in chronic pain will offer novel targets for the development of therapeutic strategies. It is well known that central sensitization in the anterior cingulate cortex (ACC) plays a critical role in initiation, development, and maintenance of chronic pain. However, the underlying mechanisms still remain elusive. Here, we reported that caveolin-1 (Cav-1), a scaffolding protein in membrane rafts, was persistently upregulated and activated in the ACC neurons after chronic constriction injury (CCI) in mice. Knockdown or blocking of Cav-1 in the contralateral ACC to the injury side reversed CCI-induced pain behavioral and neuronal sensitization and overexpression of Cav-1 in the ipsilateral ACC-induced pain behavior in the unaffected hindpaw. Furthermore, we found that Cav-1 directly binding with NMDA receptor 2B subunit (NR2B) and promotion of NR2B surface levels in the ACC contributed to modulation of chronic neuropathic pain. Disrupting the interaction of Cav-1 and NR2B through microinjection of a short peptide derived from the C-terminal of NR2B into the ACC exhibited a significant antinociception effect associated with decrease of surface NR2B expression. Moreover, Cav-1 increased intracellular Ca 2ϩ concentration and activated the ERK/CREB signaling pathway in an NR2B-dependent manner in the ACC. Our findings implicate that Cav-1 in the ACC neurons modulates chronic neuropathic pain via regulation of NR2B and subsequent activation of ERK/CREB signaling, suggesting a possible caveolin-mediated process would participate in neuronal transmission pathways implicated in pain modulation.