The exciting commercial application potential of graphene materials may inevitably lead to their increasing release into the environment where they may pose ecological risks. This study focused on using carbon-14 labeled few-layer graphene (FLG) to determine whether the size of graphene plays a role in its uptake, depuration and biodistribution in adult zebrafish. After 48 h exposure to larger FLG (L-FLG) at 250 μg/L, the amount of graphene in the organism was close to 48 mg/kg fish dry mass, which was more than 170-fold greater than the body burden of those exposed to the same concentration of smaller FLG (S-FLG). The amount of uptake for both L-FLG and S-FLG increased by a factor of 2.5 and 16, respectively, when natural organic matter (NOM) was added in the exposure suspension. While the L-FLG mainly accumulated in the gut of adult zebrafish, the S-FLG was found in both the gut and liver after exposure with or without NOM. Strikingly, the S-FLG was able to pass through the intestinal wall and enter the intestinal epithelial cells and blood. The presence of NOM increased the quantity of S-FLG in these cells. Exposure to L-FLG or S-FLG also had a significantly different impact on the intestinal microbial community structure.

Periodontitis is a prevalent infectious disease worldwide, causing the damage of periodontal support tissues, which can eventually lead to tooth loss. The goal of periodontal treatment is to control the infections and reconstruct the structure and function of periodontal tissues including cementum, periodontal ligament (PDL) fibers, and bone. The regeneration of these three types of tissues, including the re-formation of the oriented PDL fibers to be attached firmly to the new cementum and alveolar bone, remains a major challenge. This article represents the first systematic review on the cutting-edge researches on the regeneration of all three types of periodontal tissues and the simultaneous regeneration of the entire bone-PDL-cementum complex, via stem cells, bio-printing, gene therapy, and layered bio-mimetic technologies. This article primarily includes bone regeneration; PDL regeneration; cementum regeneration; endogenous cell-homing and host-mobilized stem cells; 3D bio-printing and generation of the oriented PDL fibers; gene therapy-based approaches for periodontal regeneration; regenerating the bone-PDL-cementum complex via layered materials and cells. These novel developments in stem cell technology and bioactive and bio-mimetic scaffolds are highly promising to substantially enhance the periodontal regeneration including both hard and soft tissues, with applicability to other therapies in the oral and maxillofacial region.

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Here SrTaO2N has been found to exhibit photoelectrochemical water splitting, with a theoretical solar‐to‐hydrogen efficiency of 14.4%. Ameliorating the interparticle charge transport by H2 annealing, the solar photocurrent of the SrTaO2N(H) granular film at 1.23 V versus reversible hydrogen electrode (RHE) is increased by ≈250% in comparison with the SrTaO2N film. Using an aberration corrected scanning transmission electron microscope and super‐X energy dispersive spectroscopy, the atomic scale observation has proved a decrease of oxygen concentrations in the surface of SrTaO2N(H) particle, which may allow its electrical conductivity to be increased from 0.77 × 10−6 to 2.65 × 10−6 S cm−1 and therefore the charge separation efficiency has been greatly increased by ≈330%. After being modified by Co–Pi water oxidation catalyst, the SrTaO2N(H) photoanode shows a solar photocurrent of 1.1 mA cm−2 and an incident photo‐to‐current efficiency value of ≈20% at 400–460 nm and 1.23 V versus RHE, which suggests that it is a new promising photoanode material for solar water splitting.