Multiclawed SiO2 Nano-Antibacterial Agent Based on Charge Inversed Ce6 Ionic Liquid Polymers for Combating Oral Biofilm Infection

Photodynamic antimicrobial chemotherapy (PACT) is a promising therapy against biofilm infection. However, due to the saliva clearance and obstacle of biofilm, the photosensitizer is difficult to concentrate in the infection site; then, the PACT is less effective on oral biofilm infection. In this article, we report a special nano-antibacterial agent (SiO2-PCe6-IL) to solve the bottleneck problem of PACT in treatment of oral biofilm infections. The SiO2-PCe6-IL was composed of SiO2 and poly ionic liquid photosensitizer (PCe6-IL) and had tri-fold features of eliminate biofilm infection: high binding ability, breaking biofilm barriers, and enrichment photosensitizer in infection site. In oral biofilm, the SiO2-PCe6-IL changed to SiO2-PIL+ like claws of octopus that could hold tightly with biofilm. Then, the poly-dodecyl on the SiO2-PIL+ broke down the barrier of biofilm. The results of HR-MS and zeta potential indicated that SiO2-PCe6-IL could change to positive (SiO2-PIL+) in acidic environment. The interaction forces and morphology results proved that the SiO2-PIL+ had a higher affinity to biofilm and could destroy the biofilm structure. Then, the photosensitizer was enriched in biofilm at sites of infection. The in vitro and in vivo experiments showed that SiO2-PCe6-IL could effectively eradicate oral biofilm infections and control of dental caries.

Antibacterial Activity and Multi-Targeting Mechanism of Dehydrocorydaline From Corydalis turtschaninovii Bess. Against Listeria monocytogenes

Listeria monocytogenes is a foodborne pathogen, with relatively low incidence but high case-fatality. Phytochemicals have been recognized as a promising antimicrobial agent as an alternative to synthetic chemicals due to their safety and high efficacy with multi-target sites. This study identified and characterized a novel antibacterial agent, dehydrocorydaline, in the Corydalis turschaninovii rhizome using HPLC-LTQ-Orbitrap-HRMS, and its antibacterial effect with lowest MIC (1 mg/mL) and MBC (2 mg/mL) values. In addition, an in vitro growth kinetic assay, cytoplasmic nucleic acid and protein leakage assay, and observation of morphological changes in bacterial cells supported the strong antibacterial activity. Dehydrocorydaline also displayed effective inhibitory effects on biofilm formation and bacterial motility. In order to investigate the potential antibacterial mechanism of action of dehydrocorydaline against L. monocytogenes, label-free quantitative proteomics was used, demonstrating that dehydrocorydaline has multiple targets for combating L. monocytogenes including dysregulation of carbohydrate metabolism, suppression of cell wall synthesis, and inhibition of bacterial motility. Overall, this study demonstrated that dehydrocorydaline has potential as a natural and effective antibacterial agent with multi-target sites in pathogenic bacteria, and provides the basis for development of a new class of antibacterial agent.

Coaxial electrospinning preparation and antibacterial property of polylactic acid/tea polyphenol nanofiber membrane

The polylactic acid (PLA)/tea polyphenol (TP) nanofiber membranes were prepared by coaxial electrospinning. The physical properties, antibacterial agent release, degradation, and antibacterial properties were investigated. Results demonstrated that stepwise and controlled antibacterial agent release profiles were achieved based on the core-shell configuration and disparate degradation rate of PLA and TP. The mechanical performance decreased with the increase of the TP content in the shell layer. The cumulative antibacterial agent release rate of nanofiber membranes with different TP content was different, while the antibacterial agent release trend was the same. The antibacterial agent release rate of the sample was the fastest at the initial stage from 2 h to 8 h, and then gradually slowed down after 24 h. In addition, the antibacterial activity of the PLA/TP nanofiber membranes was confirmed by the inhibition zone method against both Gram-positive ( Staphylococcus aureus) and Gram-negative ( Escherichia coli). Results showed that the antibacterial performance of PLA/TP nanofiber was intensified with the increasing content of TP, especially had better antibacterial performance against S. aureus.

Antimicrobial Applications of Nanoparticles

Human mortality due to drug-resistant infections is becoming more prevalent in our society. Antibiotics are impotent due to abuse and/or misuse, leading to new, more expensive, and more effective medicines and treatments. Therefore, it causes many short-term and long-term side effects in the patient. On the other hand, nanoparticles have exhibited antibacterial activity against various pathogens due to their small size and ability to destroy cells by various mechanisms. Unlike antibiotics for the treatment of patients' diseases and infections, nanomaterials provide an exciting way to limit the growth of microorganisms due to infections in humans. This has led to the development of a number of nanoparticles as active antibacterial agents. Therefore, the authors have carefully reviewed the recent developments in the use of nanomaterials for antibacterial applications and the mechanisms that make them an effective alternate antibacterial agent.

Pengaruh Waktu Perendaman Perasan Jeruk Nipis (Citrus aurantium) Terhadap Penurunan Kadar Formalin pada Udang Rebon

Formalin sebagai antibacterial agent pada makanan yang mengandung banyak protein. Salah satu makanan yang dicurigai mengandung formalin yaitu udang rebon karena memiliki kandungan protein yang tinggi. Senyawa alami yang dapat menurunkan kadar formalin pada udang seperti senyawa saponin dapat ditemukan dalam jeruk nipis (Citrus aurantium). Tujuan penelitian yaitu menentukan kadar formalin pada udang rebon sebelum dan setelah perendaman dengan perasan jeruk nipis berdasarkan lama perendaman 80, 100, dan 120 menit dan mengetahui pengaruh waktu perendaman untuk menurunkan kadar formalin pada udang rebon. Metode penelitian yaitu metode semi kuantitatif (Strip Formaldehid) dan metode kuantitatif (Spektrofotometri UV-Vis). Hasil dari penelitian ini yaitu pada sampel A1 (80 menit) = 0,0321% b/v, sampel A2 (100 menit) = 0,0308% b/v dan sampel A3 (120 menit) = 0,0298% b/v. Penurunan kadar formalin paling tinggi yaitu pada perendaman selama 120 menit dengan konsentrasi awal yaitu 0,0826% b/v turun menjadi 0,0298% b/v setelah perendaman dengan perasan jeruk nipis 6% dengan penurunan kadar formalin sebanyak 0,0528% b/v. Semakin lama waktu perendaman maka semakin menurun kadar formalin pada udang rebon karena senyawa saponin yang terkandung di dalam jeruk nipis mampu berikatan dengan air dan formalin.

A Study on the Manufacture and Physical Properties of Liquid Adhesive for Wood Preservation - Focusing on the Synthesis of Gelatin and Carrageenan -

In order to improve the usability of glue, a traditional adhesive material, and the gelation process of seaweed extract carrageenan, a liquid adhesive for wood preservation was prepared by mixing the two materials. The prepared wood adhesive was mixed with a 15 wt% aqueous solution of glue, λ-carrageenan, an antibacterial agent, an antifoaming agent, and the maximum adhesive strength of 1.80 Mpa was confirmed. As a result of comparison, the adhesive strength was superior to that of 5 different types of traditional natural adhesive ingredients (aqueous solution) and 1 type of polyvinyl acetate-based adhesive.

Fenugreek Seed

Fenugreek (Trigonella foenum graecum), native to southern Europe and Asia, is anannual herb with white flowers and hard, yellowish brown and angular seeds,known from ancient times, for nutritional value beside of it medicinal effects. Fenugreek seeds are rich source of gum, fiber, alkaloid, flavonoids, saponin and volatile content. Due to it's high content of fiber, fenugreek could be used as food stabilizer, adhesive and emulsifying agent to change food texture for some special purposes. Some evidences suggest that fenugreek may also be regarded as antidiabetic, anticarcinogenic, remedy for hypocholesterolemia and hypoglycemia, antioxidant, antibacterial agent, gastric stimulant, and anti-anorexia agent. The present article is aimed to review the potential applications of fenugreek as a functional food and nutraceutical. Keywords: Chemical composition, Fenugreek gum, Fenugreek, Health benefits