Size-Switchable Ru Nanoaggregates for Enhancing Phototherapy: Hyaluronidase-Triggered Disassembly to Alleviate Deep Tumor Hypoxia.

Hypoxia is a critical factor for restricting photodynamic therapy (PDT) of tumor, and it becomes increasingly severe with increasing tissue depth. Thus, the relief of deep tumor hypoxia is extremely important to improve the PDT efficacy. Herein, tumor microenvironment (TME)-responsive size-switchable hyaluronic acid-hybridized Ru nanoaggregates (HA@Ru NAs) were developed via screening reaction temperature to alleviate deep tumor hypoxia for improving the tumor-specific PDT by the artful integration multiple bioactivated chemical reactions in situ and receptor-mediated targeting (RMT). In this nanosystem, Ru NPs not only enabled HA@Ru NAs to have near infrared (NIR)-mediated photothermal/photodynamic functions, but also could catalyze endogenous H2O2 to produce O2 in situ. More importantly, hyaluronidase (HAase) overexpressed in the TME could trigger disassembly of HA@Ru NAs via the hydrolysis of HA, offering the smart size switch capability from 60 to 15 nm for enhancing tumor penetration. Moreover, the RMT characteristics of HA ensured that HA@Ru NAs could specially enter CD44-overexpressed tumor cells, enhancing tumor-specific precision of phototherapy. Taken together these distinguishing characteristics, smart HA@Ru NAs successfully realized the relief of deep tumor hypoxia to improve the tumor-specific PDT.

In Situ Polymerization of Aniline Derivative in Vivo for NIR-II Phototheranostics of Tumor.

Natural biopolymers can be controllably in situ synthesized in organisms and play important roles in biological activities. Inspired by this, the manipulation of in situ biosynthesis of functional polymers in vivo will be an important way to obtain materials for meeting biological requirements. Herein, in situ biosynthesis of functional conjugated polymer at the tumor site was achieved via the utilization of specific tumor microenvironment (TME) characteristics for the first time. Specially, a water-soluble aniline dimer derivative (N-(3-sulfopropyl) p-aminodiphenylamine, SPA) was artfully in situ polymerized into polySPA (PSPA) nanoparticles at the tumor site, which was activated via the catalysis of hydrogen peroxide (H2O2) overexpressed in TME to produce hydroxyl radical (•OH) by coinjected horseradish peroxidase (HRP). Benefiting from outstanding near-infrared (NIR)-II absorption of PSPA, the in situ polymerization process can be validly monitored by photoacoustic (PA) signal at the NIR-II region. Meanwhile, in situ polymerization would induce the size of polymeric materials from small to large, improving the distribution and retention of PSPA at the tumor site. On the combination of NIR-II absorption of PSPA and the size variation induced by polymerization, such polymerization can be applied for tumor-specific NIR-II light mediated PA image and photothermal inhibition of tumors, enhancing the precision and efficacy of tumor phototheranostics. Therefore, the present work opens the way to manipulate TME-activated in situ biosynthesis of functional conjugated polymer at the tumor site for overcoming formidable challenges in tumor theranostics.

Physiological and biochemical responses of Microcystis aeruginosa to glyphosate and its Roundup® formulation.

Glyphosate may have dual effect on bloom algae as a phosphorus source or pesticide. The physiological and biochemical responses of Microcystis aeruginosa (M. aeruginosa) to glyphosate and its formulation in the common herbicide, Roundup(®), were compared. The result suggested that both the cell numbers and Chl-a content of M. aeruginosa increased when the glyphosate concentration increased from 0.01 to 5mg P L(-1). However, Roundup(®) showed low-dose (below 1mg P L(-1)) stimulation and high-dose (above 1mg P L(-1)) inhibition on M. aeruginosa cell density and Chl-a content (hormesis effect). Phosphate was more available than glyphosate or Roundup(®), and Roundup(®) was more toxic than glyphosate itself at 3mg P L(-1). Analysis of the maximum yield of PSII indicated that glyphosate stimulated the photosynthesis process while Roundup(®) inhibited the photosynthesis of M. aeruginosa. The photosynthesis process was enhanced on the 21st day compared with that on the 14th day in all P mediums. The extracellular alkaline phosphatase activity (APA) decreased with the increasing glyphosate or Roundup(®) concentration. The change pattern of APA was similar in both the glyphosate and Roundup(®) mediums.

Nutrient uptake of rice roots in response to infestation of Nilaparvata lugens (Stål) (Homoptera: Delphacidae).

This study investigated the uptake of three macronutrients, including nitrogen (N), phosphorus (P), and potassium (K), by rice roots in response to different infestation levels of Nilaparvata lugens (Stål) (Homoptera: Delphacidae). Hydroponics experiments were conducted on the rice variety 'Zhendao 2' (moderately resistant to Tryporyza incertulas, Lepidoptera: Pyralidae) and the variety 'Xiushui 63' (susceptible to N. lugens). In 'Zhendao 2', N. lugens infestation significantly influenced the uptake of P and K but not N, with P and K uptake decreasing as the duration of N. lugens infestation increased. In 'Xiushui 63', N. lugens infestation influenced N, P, and K uptake to a different degree, depending on the infestation level, in which infestation for 2, 4, 6, and 8 d at a density of 60 nymphs did not affect N uptake, but such infestation levels significantly influenced the uptake of P and K. After the removal of N. lugens from rice plants, the N uptake recovered from infestation faster than that for P and K in the variety 'Zhendao 2', whereas the recovery rate of K uptake was faster than that for N and P in the variety 'Xiushui 63'. The recovery rate of the nutrient uptake was negatively correlated to the density and duration of infestation. The experimental results demonstrated that N, P, and K uptake of rice roots were largely not influenced by N. lugens infestation when the pest density was controlled below 15 nymphs per hill. This infestation level was in agreement with the proposed economic thresholds for control measures against the N. lugens infestation on rice plants.