A Shear-Thinning, Self-Healing, Dual-Cross Linked Hydrogel Based on Gelatin/Vanillin/Fe3+ /AGP-AgNPs: Synthesis, Antibacterial, and Wound-Healing Assessment.

A shear-thinning and self-healing hydrogel based on a gelatin biopolymer is synthesized using vanillin and Fe3+ as dual crosslinking agents. Rheological studies indicate the formation of a strong gel found to be injectable and exhibit rapid self-healing (within 10 min). The hydrogels also exhibited a high degree of swelling, suggesting potential as wound dressings since the absorption of large amounts of wound exudate, and optimum moisture levels, lead to accelerated wound healing. Andrographolide, an anti-inflammatory natural product is used to fabricate silver nanoparticles, which are characterized and composited with the fabricated hydrogels to imbue them with anti-microbial activity. The nanoparticle/hydrogel composites exhibit activity against Escherichia coli, Staphylococcus aureus, and Burkholderia pseudomallei, the pathogen that causes melioidosis, a serious but neglected disease affecting southeast Asia and northern Australia. Finally, the nanoparticle/hydrogel composites are shown to enhance wound closure in animal models compared to the hydrogel alone, confirming that these hydrogel composites hold great potential in the biomedical field.

Polygonum odoratum leaf extract attenuates oxidative stress and cell death of Raw 264.7 cells exposed to low dose ionizing radiation.

This study aims to investigate the effect of Polygonum odoratum leaf extract (POE) on oxidative stress markers and cell death induced by low dose ionizing radiation (LDIR) in Raw 264.7 cells. The biological activities, chromatographic fingerprint, and cytotoxicity of POE were investigated. To determine the radioprotective effect of POE, Raw 264.7 cells were incubated with POE for 1 hr prior to 100 mGy x-irradiation. The cell viability, oxidative stress damage marker (malondialdehyde level; MDA), and endogenous antioxidant markers (superoxide dismutase: SOD, catalase: CAT, and glutathione peroxidase: GSH-Px) were also determined. The results showed that POE contained 8 essential substances and exhibited a potent antioxidant without any cytotoxicity. It was found that POE significantly decreased the MDA level and activated cell viability, SOD, CAT, and GSH-Px activities. The results from this study indicate that POE is a potent antioxidant, which can be developed as a radioprotector for diagnostic procedures. PRACTICAL APPLICATIONS: Polygonum odoratum leaf extract (POE) is a potent antioxidant that attenuates oxidative stress and cell death induced by low dose ionizing radiation (LDIR). POE might protect against cell damage from LDIR, particularly in diagnostic radiology procedures. Therefore, the development of functional food containing POE might be beneficial for patients who plan to undergo the diagnostic radiology procedure. The functional food containing POE might prevent stochastic and deterministic effects for these patients.

Emilia sonchifolia extract activity against white spot syndrome virus and yellow head virus in shrimp cell cultures.

Emilia sonchifolia (L.) DC is a plant used in traditional medicine to treat several viral and bacterial diseases. The antiviral activities of selected Sephadex LH-20 column fractions and HPLC subfractions of an acetone extract of E. sonchifolia leaves were determined in shrimp Penaeus merguiensis primary lymphoid cells infected with either white spot syndrome virus (WSSV) or yellow head virus (YHV). WSSV and YHV replication was quantified using quantitative real-time PCR tests targeted to the VP19 and ORF1b gene transcripts, respectively. In lymphoid organ cells exposed to 100 µg ml⁻¹ of either the Sephadex fraction F14 or the HPLC F14 subfraction SF4, both fractions caused reduced replication, but YHV replication was reduced only by SF4. In the asthiazolyl blue mitochondrial enzyme activity assays to assess extract cytotoxicity, >60% of primary lymphoid organ cells remained viable following exposure to 100 µg ml⁻¹ of either F14 or SF4. GC-MS analysis of the HPLC F14 subfraction SF4 showed that it contained 2,4-di-tert-butylphenol. This study is the first to show that E. sonchifolia leaf extracts might be useful as bioactive agents to protect shrimp against viruses such as WSSV and YHV.