Biological Synthesis of Silver Nanoparticles from Lavandula mairei Humbert: Antibacterial and Antioxidant Activities

Hospital-acquired infections involving carbapenem-resistant Acinetobacter baumannii (A. baumannii) and extended spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae pose significant challenges in the intensive care units. The lack of novel antimicrobial drugs amplifies the urgency to explore innovative management strategies. Nanotechnology, with its ability to generate nanoparticles possessing specific properties beneficial in drug delivery and nanomedicine, stands as a pivotal research domain. The objective of this study was to synthesize, for the first time, biologically silver nanoparticles (Ag-NPs) from Lavandula mairei Humbert (L. mairei) plant. The biosynthesized Ag-NPs were characterized by UV-visible spectral analysis, X-Ray diffraction Analysis, Fourier transform infrared spectroscopy analysis, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy. Subsequently, the antibacterial and antioxidant activities of Ag-NPs were assessed using the micro-dilution method, DPPH test and FRAP assay, respectively. The green-synthesized Ag-NPs exhibited high antibacterial activity against ESBL-producing multidrug-resistant (MDR) strains and against carbapenem-resistant and non-carbapenem-resistant strains of A. baumannii, as well as a very interesting antioxidant activity. The present study suggests that these results hold very promising for the potential application of biologically synthesized Ag-NPs from L. mairei (Ag-LM-NPs) in the invention of novel antibacterial and antioxidant agents.

Application of Lavandula angustifolia Mill. Extracts for the Phytosynthesis of Silver Nanoparticles: Characterization and Biomedical Potential

Nanotechnology can offer a series of new "green" and eco-friendly methods for developing different types of nanoparticles, among which the development of nanomaterials using plant extracts (phytosynthesis) represents one of the most promising areas of research. This present study details the use of lavender flowers (Lavandula angustifolia Mill., well-known for their use in homeopathic applications) for the biosynthesis of silver nanoparticles with enhanced antioxidant and antibacterial properties. Several qualitative and quantitative assays were carried out in order to offer an image of the extracts' composition (the recorded total phenolics content varied between 21.0 to 40.9 mg GAE (gallic acid equivalents)/g dry weight (d.w.), while the total flavonoids content ranged between 3.57 and 16.8 mg CE (catechin equivalents)/g d.w.), alongside modern analytical methods (such as gas chromatography-mass spectrometry-GC-MS, quantifying 12 phytoconstituents present in the extracts). The formation of silver nanoparticles (AgNPs) using lavender extract was studied by UV-Vis spectroscopy, Fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and dynamic light scattering (DLS)/zeta potential, with the selected nanoparticles having crystallite sizes of approx. 14.55 nm (AgNP-L2) and 4.61 nm, respectively (for AgNP-L4), and hydrodynamic diameters of 392.4 nm (for AgNP-L2) and 391.6 nm (for AgNP-L4), determined by DLS. A zeta potential of around -6.4 mV was displayed for both samples while presenting as large aggregates, in which nanoparticle clusters with dimensions of around 130-200 nm can be observed. The biomedical applications of the extracts and the corresponding phytosynthesized nanoparticles were evaluated using antioxidant and antimicrobial assays. The obtained results confirmed the phytosynthesis of the silver nanoparticles using Lavandula angustifolia Mill. extracts, as well as their antioxidant and antimicrobial potential.

Lavandula stoechas extract incorporated polylactic acid nanofibrous mats as an antibacterial and cytocompatible wound dressing

In recent years, great efforts have been devoted to the design and production of bioactive wound dressings that promote skin regeneration and prevent infection. Many plant extracts and essential oils have been widely accepted in traditional medicine for a wide variety of medicinal purposes, especially wound healing. Over the past decade, many studies have focused on manufacturing and designing wound dressings containing plant compounds and extracts. In this study, Lavandula stoechas extract (LSE) (0.25 %, 0.5 %, and 1%wt) incorporated-polylactic acid (PLA) nanofibrous mats were successfully produced and characterized. Microstructural analysis by SEM revealed that the fiber diameter changed with the increase in the amount of LSE. Also, the nanofibrous mats were evaluated for their in vitro antibacterial, cytotoxicity, and wound healing properties for their use as a wound dressing material. According to the results of the disc diffusion test, PLA nanofibrous mats containing LSE %1 showed 9.65 ± 0.46 and 7.37 ± 0.03 inhibition zone (mm) against E. coli and S. aureus, respectively. According to the results of the in vitro wound healing assay, mats containing 0.5 % LSE showed better-wound closure activity compared to the control. Our results show that LSE-incorporated nanofibrous dressings can be an effective alternative with good antimicrobial activity.

Mediterranean Lavenders from Section Stoechas: An Undervalued Source of Secondary Metabolites with Pharmacological Potential

Globally, climate change and wildfires are disrupting natural ecosystems, thus setting several endemic species at risk. The genus Lavandula is widely present in the Mediterranean region and its species, namely, those included in the section Stoechas, are valuable resources of active compounds with several biological assets. Since ancient times lavenders have been used in traditional medicine and for domestic purposes. These species are melliferous, decorative, and essential oil-producing plants with a high economic interest in the pharmaceutical, flavor, fragrance, and food industries. The essential oils of Lavandula section Stoechas are characterized by high amounts of 1,8-cineole, camphor, fenchone, and specifically for L. stoechas subsp. luisieri one of the major compounds is trans-α-necrodyl acetate. On the other hand, the diversity of non-volatile components like phenolic compounds, such as phenolic acids and flavonoids, make these species an important source of phytochemicals with pharmacological interest. Rosmarinic, caffeic, and salvianolic B acids are the major phenolic acids, and luteolin and eriodictyol-O-glucuronide are the main reported flavonoids. However, the concentration of these secondary metabolites is strongly affected by the plant’s phenological phase and varies in Lavandula sp. from different areas of origin. Indeed, lavender extracts have shown promising antioxidant, antimicrobial, anti-inflammatory, and anticancer properties as well as several other beneficial actions with potential for commercial applications. Despite several studies on the bioactive potential of lavenders from the section Stoechas, a systematized and updated review of their chemical profile is lacking. Therefore, we carried out the present review that gathers relevant information on the different types of secondary metabolites found in these species as well as their bioactive potential.

Exploring Iberian Peninsula Lamiaceae as Potential Therapeutic Approaches in Wound Healing

Skin tissue has a crucial role in protecting the human body from external harmful agents, preventing wounds that frequently demand proper healing approaches. The ethnobotanical knowledge of specific regions with further investigation on their medicinal plants has been paramount to create new and effective therapeutical agents, including for dermatological purposes. This review attempts, for the first time, to investigate the traditional applications of Lamiaceae medicinal plants that are already used by local communities in the Iberian Peninsula in wound healing. Henceforward, Iberian ethnobotanical surveys were reviewed, and the information about the traditional wound healing practices of Lamiaceae was comprehensively summarized. Afterwards, the scientific validation of each Lamiaceae species was exhaustively checked. From this, eight out of twenty-nine Lamiaceae medicinal plants were highlighted by their wound-related pharmacological evidence and are in-depth presented in this review. We suggest that future studies should focus on the isolation and identification of the active molecules of these Lamiaceae, followed by robust clinical trials that may confirm the security and effectiveness of such natural-based approaches. This will in turn pave the way for more reliable wound healing treatments.

Antioxidant Activity Enhancement Effect of Silver-Ionized Water: Silver Cation Prepared by Electrolysis

In the present study, tap water, alkaline electrolyzed water (AlEW) and tourmaline water (TMW) were used as the electrolytes to generated the silver-ionized water (SIW), AlEW-SIW and TMW-SIW, respectively. The antioxidant properties of the samples containing ascorbic acid (AsA) were investigated by WST-kit method. The results showed that the SOD activity of AsA (2 mmol/L) dissolved in SIW (66.0%) was enhanced by about 8% compared to that of the tap water (57.9%). The SOD activity of the AlEW-SIW solution (77.3%), which was higher than that of the SIW solution, and lower than that of the AlEW solution (83.6%). The SOD activity of the TMW-SIW solution (83.0%) was similar to that of the TMW solution (82.5%). Furthermore, to classify the sample solutions, discriminant analyses were performed based on near infrared (NIR) spectral data, which was consistent with the results of the WST-kit method. The SOD activity of the AlEW-SIW and TMW-SIW solutions decreased slowly with storage time, and their SOD activities were higher than that of AlEW, TMW and the tap water solutions at storage time of 14 days. In summary, AlEW-SIW and TMW-SIW showed similar antioxidant activity enhancement as AlEW and TMW, and they also maintained the stability of the antioxidant activity of AsA during storage.

Untargeted Metabolomic Approach of Curcuma longa to Neurodegenerative Phytocarrier System Based on Silver Nanoparticles

Curcuma is one of the most famous medicinal and tropical aromatic plants. Its health benefits have been appreciated and exploited in traditional Asian medicine since ancient times. Various studies have investigated its complex chemical composition and demonstrated the remarkable therapeutic properties of curcuma's phytoconstituents. Oxidative stress is a decisive driving factor triggering numerous pathologies (neurodegenerative, psychiatric and cardiovascular diseases; diabetes; tumors, etc.). Numerous recent studies have focused on the use of natural compounds and nanomaterials as innovative molecular targeting agents as effective therapeutic strategies. In this study, we report, for the first time, the development of a simple target phytocarrier system that capitalizes on the bioactive properties of curcuma and AgNPs. The complete metabolic profile of curcuma was determined based on gas chromatography-mass spectrometry (GC-MS) and electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOF-MS). A total of 80 metabolites were identified under mass spectra (MS)-positive mode from 10 secondary metabolite categories: terpenoids, amino acids, diarylheptanoids, flavonoids, phenolic acids, steroids, fatty acids, coumarins, alkaloids and miscellaneous. In addition, the biological activity of each class of metabolites was discussed. A comprehensive characterization (FT-IR, UV-Vis, DLS, SEM, TEM, EDS, zeta potential and XRD) was performed to study the morphostructural properties of this new phytocarrier system. Antioxidant activity of the new phytocarrier system was evaluated using a combination of in vitro methods (total phenolic assay, 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and cyclic voltammetric method (Trolox equivalent antioxidant capacity (TEAC) electrochemical assay)). Antioxidants assays showed that the phytocarrier system exhibits superior antioxidant properties to those of its components, i.e., curcuma or citrate-coated-AgNPs. These data confirm the potential to enhance relevant theoretical knowledge in the area of innovative antioxidant agents, with potential application in neurodegenerative therapeutic strategies.

Investigation on wound healing effect of Mediterranean medicinal plants and some related phenolic compounds: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The human skin constitutes a biological barrier against external stress and wounds can reduce the role of its physiological structure. In medical sciences, wounds are considered a major problem that requires urgent intervention. For centuries, medicinal plants have been used in the Mediterranean countries for many purposes and against wounds.

AIM OF THIS REVIEW

Provides an outlook on the Mediterranean medicinal plants used in wound healing. Furthermore, the wound healing effect of polyphenolic compounds and their chemical structures are also summarized. Moreover, we discussed the wound healing process, the structure of the skin, and the current therapies in wound healing.

MATERIALS AND METHODS

The search was performed in several databases such as ScienceDirect, PubMed, Google Scholar, Scopus, and Web of Science. The following Keywords were used individually and/or in combination: the Mediterranean, wound healing, medicinal plants, phenolic compounds, composition, flavonoid, tannin.

RESULTS

The wound healing process is distinguished by four phases, which are respectively, hemostasis, inflammation, proliferation, and remodeling. The Mediterranean medicinal plants are widely used in the treatment of wounds. The finding showed that eighty-nine species belonging to forty families were evaluated for their wound-healing effect in this area. The Asteraceae family was the most reported family with 12 species followed by Lamiaceae (11 species). Tunisia, Egypt, Morocco, and Algeria were the countries where these plants are frequently used in wound healing. In addition to medicinal plants, results showed that nineteen phenolic compounds from different classes are used in wound treatment. Tyrosol, hydroxytyrosol, curcumin, luteolin, chrysin, rutin, kaempferol, quercetin, icariin, morin, epigallocatechin gallate, taxifolin, silymarin, hesperidin, naringin, isoliquiritin, puerarin, genistein, and daidzein were the main compounds that showed wound-healing effect.

CONCLUSION

In conclusion, medicinal plants and polyphenolic compounds provide therapeutic evidence in wound healing and for the development of new drugs in this field.

Biomedical and catalytic applications of agri-based biosynthesized silver nanoparticles

Nanotechnology has been recognized as the emerging field for the synthesis, designing, and manipulation of particle structure at the nanoscale. Its rapid development is also expected to revolutionize industries such as applied physics, mechanics, chemistry, and electronics engineering with suitably tailoring various nanomaterials. Inorganic nanoparticles such as silver nanoparticles (Ag-NPs) have garnered more interest with their diverse applications. In correspondence to green chemistry, researchers prioritize green synthetic techniques over conventional ones due to their eco-friendly and sustainable potential. Green-synthesized NPs have proven more beneficial than those synthesized by conventional methods because of capping by secondary metabolites. The present study reviews the various means being used by the researchers for the green synthesis of Ag-NPs. The morphological characteristics of these NPs as obtained from numerous characterization techniques have been explored. The potential applications of bio-synthesized Ag-NPs viz. Antimicrobial, antioxidant, catalytic, and water remediation along with the plausible mechanisms have been discussed. In addition, toxicity analysis and biomedical applications of these NPs have also been reviewed to provide a detailed overview. The study signifies that biosynthesized Ag-NPs can be efficiently used for various applications in the biomedical and industrial sectors as an environment-friendly and efficient tool.

Catalytic potential of endophytes facilitates synthesis of biometallic zinc oxide nanoparticles for agricultural application

Recent advances fascinated the use of biological resources in combination with metals to obtain high quality biometals and apply its advantages in different fields. Endophytic mediated Zinc oxide nanoparticles (ZnO-NPs) is an economical and ecofriendly way for farmers to avoid Zn deficiency in rice crop and obtain high yield. Here we synthesized ZnO-NPs utilizing endophytic bacterial strain of Enterobacter hormaechei (E. hormaechei). The physiochemical properties of the prepared NPs were determined through UV-Vis spectroscopy, XRD, FT-IR, SEM and TEM. The prepared NPs revealed surface plasmon resonance (SPR) at 320 nm (nm) and crystalline structure with 21 nm average crystalline size. FT-IR spectra showed the presence of carboxylic, alcohol and amine functional groups, which confirm the biometallic assembling of the ZnO and endophytic bacterial functional groups. SEM showed pyramidal symmetry whereas TEM revealed poly dispersed spherical shape with particle size distribution 18-48 nm. Our results showed that prepared NPs possess significant antifungal, antibacterial and antioxidant potential at 25, 50 and 100 µg/mL concentrations. Moreover, Cytotoxic and hemolytic assay showed significant results (less % viability and hemolysis activity) at 50 and 100 µg/mL (ZnO-NP's) concentrations as compared to control. The prepared ZnO-NPs were used as bio fertilizer in various concentrations as a foliar spray, which showed significant enhancement of the rice plant growth, along with chlorophyll, proteins and carotenoid contents. These results recommend that endophytic mediated ZnO-NPs are biocompatible and possess significant potential for agricultural applications.

Influence of Polyvinylpyrrolidone Concentration on Properties and Anti-Bacterial Activity of Green Synthesized Silver Nanoparticles

Environmentally green synthesis of stable polyvinyl pyrrolidone (PVP)-capped silver nanoparticles (PVP-AgNPs) was successfully carried out. The present study focused on investigating the influence of adding PVP during the synthesis process on the size, optical properties and antibacterial effect of silver nanoparticles produced. An aqueous extract of Eucalyptus camaldulensis leaves was used as a reducing agent. The effects of different PVP concentrations and reducing time on the synthesis of nanoparticles (NPs) were characterized by UV–Vis spectrophotometry, scanning electron microscopy (SEM), energy dispersive spectrum (EDX), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and nano tracker analysis (NTA). The addition of PVP was studied. The prepared PVP-AgNPs were spherical with an average size of 13 nm. FTIR analysis confirmed that PVP protects AgNPs by a coordination bond between silver nanoparticles and both N and O of PVP. DLS results indicated the good dispersion of silver nanoparticles. PVP-AgNPs were found to be stable for nearly 5 months. Antibacterial studies through the agar well diffusion method confirmed that silver nanoparticles synthesized using PVP had no inhibitor activity toward Gram-positive and Gram-negative bacteria as opposed to silver nanoparticles prepared without adding PVP, which showed a significant antibacterial activity towards some of the tested pathogens.

Evaluation of the Antioxidant and Anticancer Activities of Hydroalcoholic Extracts of Thymus daenensis Čelak and Stachys pilifera Benth

Herein, the effects of hydroalcoholic extracts of Thymus daenensis Celak (TDC) and Stachys pilifera Benth (SPB) plants on HepG2 cell line were investigated by using different analyses. Cytotoxicity and apoptosis of extracts were investigated by MTT method, AnnV/PI apoptosis assay, and their antioxidant capacity was evaluated by total thiol and glutathione peroxidase (GPX) assay. The results revealed that the SBP extract was more cytotoxic compared with the TDC extract and increased over time (128.49 µg/mL vs 107.11 µg/mL IC₅₀ values for 24 and 72 h, respectively). Although, AnnV/PI apoptosis assay showed apoptosis induction for both extracts, but the caspase-3 activity assay revealed that TDC extract significantly increased caspase-3 activity compared with the control and SPB extract. Increasing the activity of GPX by SPB extract revealed that it has high antioxidant capacity. In conclusion, the TDC and SPB with high antioxidant capacity have high cytotoxicity against HepG2 cancer cells and have high capability as a medicinal plant.

Facile green synthesis of silver nanoparticles using Mangifera indica seed aqueous extract and its antimicrobial, antioxidant and cytotoxic potential (3-in-1 system)

A novel approach for the utilisation of fruit waste is attempted in the present investigation. Mangifera indica seed aqueous extract was utilised for green synthesis of silver nanoparticles (AgNPs). The phytoconstituents in the seed acted as reducing and stabilising agent for AgNP formation. UV-Vis, Zeta potential, FT-IR, XRD, TEM, SAED, EDX analysis were used to characterise the green synthesised AgNPs. UV-vis spectra showed characteristic spectra at 450 nm; XRD and SAED confirmed the crystalline nature while TEM revealed the shape to be round and average size was 26.85 nm. FT-IR revealed functional groups like alcohol or phenols, carboxylic acids, ketones, amines, aromatic amines, aliphatic amines, alkyl halides and alkynes which were responsible for AgNP formation. The nanoparticles showed more antibacterial activity than antifungal activity and antibacterial activity towards Gram-negative bacteria was more than Gram-positive bacteria. Dose dependent antioxidant activity (DPPH, SO and ABTS) and dose dependent cytotoxic effect against HeLa, MCF-7 and normal fibroblast cell lines was envisaged. The green synthesised AgNPs exhibited three different bioactivities (3-in-1 system) i.e. dose dependent antimicrobial, antioxidant and cytotoxic activity. Fruit waste can be successfully utilised for silver nanoparticles formation which can be therapeutically useful and effective.[Figure: see text]HighlightsSilver nanoparticles were synthesised from M. indica fruit waste i.e. seedCharacterisation by spectroscopic techniques: UV-Vis, Zeta, FTIR, XRD, SAED, EDX and TEM analysis.Silver nanoparticles were 26.85 nm in size and round in shapeAntimicrobial activity against 14 microorganismsAntioxidant activity in terms of DPPH, SO and ABTSCytotoxic activity against HeLa, MCF-7 and Fibroblast normal cell lines.

Phytoantioxidant Functionalized Nanoparticles: A Green Approach to Combat Nanoparticle-Induced Oxidative Stress

Nanotechnology is gaining significant attention, with numerous biomedical applications. Silver in wound dressings, copper oxide and silver in antibacterial preparations, and zinc oxide nanoparticles as a food and cosmetic ingredient are common examples. However, adverse effects of nanoparticles in humans and the environment from extended exposure at varied concentrations have yet to be established. One of the drawbacks of employing nanoparticles is their tendency to cause oxidative stress, a significant public health concern with life-threatening consequences. Cardiovascular, renal, and respiratory problems and diabetes are among the oxidative stress-related disorders. In this context, phytoantioxidant functionalized nanoparticles could be a novel and effective alternative. In addition to performing their intended function, they can protect against oxidative damage. This review was designed by searching through various websites, books, and articles found in PubMed, Science Direct, and Google Scholar. To begin with, oxidative stress, its related diseases, and the mechanistic basis of oxidative damage caused by nanoparticles are discussed. One of the main mechanisms of action of nanoparticles was unearthed to be oxidative stress, which limits their use in humans. Secondly, the role of phytoantioxidant functionalized nanoparticles in oxidative damage prevention is critically discussed. The parameters for the characterization of nanoparticles were also discussed. The majority of silver, gold, iron, zinc oxide, and copper nanoparticles produced utilizing various plant extracts were active free radical scavengers. This potential is linked to several surface fabricated phytoconstituents, such as flavonoids and phenols. These phytoantioxidant functionalized nanoparticles could be a better alternative to nanoparticles prepared by other existing approaches.

Prospective Application of Nanoparticles Green Synthesized Using Medicinal Plant Extracts as Novel Nanomedicines

The use of medicinal plants in green synthesis of metal nanoparticles is increasing day by day. A simple search for the keywords "green synthesis" and "nanoparticles" yields more than 33,000 articles in Scopus. As of August 10, 2021, more than 4000 articles have been published in 2021 alone. Besides demonstrating the ease and environmental-friendly route of synthesizing nanomaterials, many studies report the superior pharmacological properties of green synthesized nanoparticles compared to those synthesized by other methods. This is probably due to the fact that bioactive molecules are entrapped on the surface of these nanoparticles. On the other hand, recent studies have confirmed the nano-dimension and biocompatibility of metal ash (Bhasma) preparations, which are commonly macerated with biological products and administered for the treatment of various diseases in Indian medicine since ancient times. This perspective article argues for the prospective medical application of green nanoparticles in the light of Bhasma.

Biosynthesis of Silver Nanoparticles Mediated by Entomopathogenic Fungi: Antimicrobial Resistance, Nanopesticides, and Toxicity

Silver nanoparticles are widely used in the biomedical and agri-food fields due to their versatility. The use of biological methods for the synthesis of silver nanoparticles has increased considerably due to their feasibility and high biocompatibility. In general, microorganisms have been widely explored for the production of silver nanoparticles for several applications. The objective of this work was to evaluate the use of entomopathogenic fungi for the biological synthesis of silver nanoparticles, in comparison to the use of other filamentous fungi, and the possibility of using these nanoparticles as antimicrobial agents and for the control of insect pests. In addition, the in vitro methods commonly used to assess the toxicity of these materials are discussed. Several species of filamentous fungi are known to have the ability to form silver nanoparticles, but few studies have been conducted on the potential of entomopathogenic fungi to produce these materials. The investigation of the toxicity of silver nanoparticles is usually carried out in vitro through cytotoxicity/genotoxicity analyses, using well-established methodologies, such as MTT and comet assays, respectively. The use of silver nanoparticles obtained through entomopathogenic fungi against insects is mainly focused on mosquitoes that transmit diseases to humans, with satisfactory results regarding mortality estimates. Entomopathogenic fungi can be employed in the synthesis of silver nanoparticles for potential use in insect control, but there is a need to expand studies on toxicity so to enable their use also in insect control in agriculture.

Effect of Jasmonic Acid and Salicylic Acid on Growth and Biochemical Composition of In-Vitro-Propagated Lavandula angustifolia Mill

This study assessed the effect of jasmonic acid (JA) and salicylic acid (SA) on the in vitro development and production of Lavandula angustifolia Mill. plant material, and the accumulation of polyphenols, chlorophylls, and carotenoids in explants. Results were compared with explants grown in control media and with in-vivo-grown mature and young L. angustifolia plants. After 21 days of incubation, all explants propagated on low-SA-concentration or elicitor-free media produced a greater number of shoots than explants cultivated on media with higher elicitor concentrations. Shoots grew taller when activated charcoal (AC) was added to the elicitor-supplemented media, while AC negatively affected or had no effect on the phytochemical composition of plants. Explants grown in the presence of elicitors had higher polyphenolic and chlorophyll content than the controls, demonstrating the beneficial impact of elicitors on the secretion of secondary metabolites. Lutein and β-carotene were the dominating carotenoids in all samples. Culture media supplemented with 0.5 mg/L JA and 1.5 mg/L SA + AC proved the most suitable to produce plant material with high polyphenol and carotenoid content, comparable with in-vivo-grown plants.

Development and fabrication of disease resistance protein in recombinant Escherichia coli

Cyanobacteria and Spirulina produce C-phycocyanin (CPC), a water soluble protein associated pigment, which is extensively used in food and pharmaceutical industries. Other therapeutic proteins might exist in microalgal cells, of which there is limited knowledge. Such proteins/peptides with antibiotic properties are crucial due to the emergence of multi-drug resistant pathogens. In addition, the native expression levels of such disease resistant proteins are low, hindering further investigation. Thus, screening and overexpression of such novel proteins is urgent and important. In this study, a protein which was identified as a putative disease resistance protein (DRP) in the mixture of Spirulina product has been explored for the first time. To improve protein expression, DRP was cloned in the pET system, co-transformed with pRARE plasmid for codon optimization and was significantly overexpressed in E. coli BL21(DE3) under induction with isopropyl-β-d-1-thiogalactopyranoside (IPTG). Furthermore, soluble DRP exhibited intense antimicrobial activity against predominant pathogens, and an inhibition zone of 1.59 to 1.74 cm was obtained for E. coli. At a concentration 4 mg/mL, DRP significantly elevated the growth of L. rhamnosus ZY up to twofold showing probable prebiotic activities. Moreover, DRP showed potential as an effective antioxidant, and the scavenging ability for ROS was in the order of hydroxyl > DPPH > superoxide radicals. A putative disease resistance protein (DRP) has been identified, sequenced, cloned and over-expressed in E. coli as a functional protein. Thus expressed DRP showed potential anti-microbial and antioxidant properties, with promising therapeutic applications.

Fluorescence Emission Triggered by Radioactive β decay in Optimized Hyperbolic Cavities

Luminescence arising from β -decay of radiotracers has garnered much interest recently as a viable in-vivo imaging technique. The emitted Cerenkov radiation can be directly detected by high sensitivity cameras or used to excite highly efficient fluorescent dyes. Here, we investigate the enhancement of visible and infrared emission driven by β -decay of radioisotopes in the presence of a hyperbolic nanocavity. By means of a transfer matrix approach, we obtain quasi-analytic expressions for the fluorescence enhancement factor at the dielectric core of the metalodielectric cavity, reporting a hundred-fold amplification in periodic structures. A particle swarm optimization of the layered shell geometry reveals that up to a ten-thousand-fold enhancement is possible thanks to the hybridization and spectral overlapping of whispering-gallery and localized-plasmon modes. Our findings may find application in nuclear-optical medical imaging, as they provide a strategy for the exploitation of highly energetic gamma rays, Cerenkov luminescence, and visible and near-infrared fluorescence through the same nanotracer.

Facile preparation of a novel biogenic silver-loaded Nanofilm with intrinsic anti-bacterial and oxidant scavenging activities for wound healing

To eliminate the microbial infection from an injury site, various modalities have been developed such as dressings and human skin substitutes. However, the high amount of reactive oxygen species, microbial infection, and damaging extracellular matrix remain as the main challenges for the wound healing process. In this study, for the first time, green synthesized silver nanoparticles (AgNPs) using Teucrium polium extract were embedded in poly lactic acid/poly ethylene glycol (PLA/PEG) film to provide absorbable wound dressing, with antioxidant and antibacterial features. The physicochemical analysis demonstrated, production of AgNPs with size approximately 32.2 nm and confirmed the presence of phytoconstituents on their surface. The antibacterial assessments exhibited a concentration-dependent sensitivity of Staphylococcus aureus and Pseudomonas aeruginosa toward biosynthesized AgNPs, which showed a suitable safety profile in human macrophage cells. Furthermore, oxidant scavenging assays demonstrated exploitation of plant extract as a reducing agent, endows antioxidant activity to biogenic AgNPs. The formation of PLA/PEG nanofilm and entrapment of AgNPs into their matrix were clearly confirmed by scanning electron microscopy. More importantly, antibacterial examination demonstrated that the introduction of biogenic AgNPs into PLA/PEG nanofibers led to complete growth inhibition of P. aeruginosa and S. aureus. In summary, the simultaneous antioxidant activity and antimicrobial activity of the novel biogenic AgNPs/PLA/PEG nanofilm showed its potential for application as wound dressing.