Mohammed N. Al-anbr

Facile green synthesis of zinc oxide nanoparticles using Ulva lactuca seaweed extract and evaluation of their photocatalytic, antibiofilm and insecticidal activity

The bioactivity of semiconductor nanocomplexes has been poorly studied in the field of pesticide science. In this research, the synthesis of zinc nanoparticles was accomplished through new effortless green chemistry process, using the Ulva lactuca seaweed extract as a reducing and capping agent. The production of U. lactuca-fabricated ZnO nanoparticles (Ul-ZnO Nps) was characterized by powder X-ray diffraction (XRD), UV-visible, Fourier transform infrared (FTIR) spectroscopy, selected area electron diffraction (SAED) analysis and transmission electron microscopy (TEM). The U. lactuca-fabricated ZnO NPs were tested for their photodegradative action against organic dyes, as well as for antibiofilm and larvicidal activities. The UV visible absorbance spectrum of Ul-ZnO NPs exhibited the absorbance band at 325nm and TEM highlighted average crystallite sizes of nanoparticles of 10-50nm. Methylene blue (MB) dye was efficiently corrupted under sunlight in presence of Ul-ZnO NPs. Excellent bactericidal activity was shown by the Ul-ZnO Nps on Gram positive (Bacillus licheniformis and Bacillus pumilis) and Gram negative (Escherichia coliand Proteus vulgaris) bacteria. High antibiofilm potential was noted under both dark and sunlight conditions. The impact of a single treatment with Ul-ZnO NPs on biofilm architecture was also analyzed by confocal laser scanning microscopy (CLSM) on both Gram positive and Gram negative bacteria. Moreover, Ul-ZnO NPs led to 100% mortality of Aedes aegypti fourth instar larvae at the concentration of 50μg/ml within 24h. The effects of ZnO nanoparticle-based treatment on mosquito larval morphology and histology were monitored. Overall, based on our results, we believe that the synthesis of multifunctional Ul-ZnO Nps using widely available seaweed products can be promoted as a potential eco-friendly option to chemical methods currently used for nanosynthesis of antimicrobials and insecticides.

Synthesis of chitosan-alginate microspheres with high antimicrobial and antibiofilm activity against multi-drug resistant microbial pathogens

The successful treatment of multi-drug resistant microbial pathogens represents a major challenge for public health management. Here, chitosan-alginate (CS/ALG) microspheres with narrow size distribution were fabricated by ionically cross linking method using Ca2+ ions as agents for polymer solidification. The physicochemical properties of CS/ALG microspheres, such as surface morphology and size, were studied by SEM. The functional group interactions were confirmed by Fourier transform infrared (FTIR) spectroscopy. SEM revealed that the CS/ALG microspheres were spherical in shape with smooth surfaces, size was 50-100xa0μm. The synthesized CS/ALG microspheres showed antibacterial and antibiofilm activity on bacteria of public health relevance. CS/ALG microspheres exhibited antibacterial activity at the concentration of 5-20xa0μg, with significant inhibitory zones on multiple antibiotic resistant pathogens, including Gram positive Staphylococcus aureus, Enterococcus faecalis, and Gram negative Pseudomonas aeruginosa and Proteus vulgaris. Furthermore, in situ light microscopy and confocal laser scanning microscopy (CLSM) showed that CS/ALG microspheres inhibited the bacterial biofilm formation in S. aureus, E. faecalis P. aeruginosa and P. vulgaris after a single treatment with 40xa0μg. Overall, our findings underlined that chemically synthesized CS/ALG biomaterial has high antibacterial and antibiofilm activity against a number of microbial pathogens of interest for human health, thus this synthesis route can be further exploited for drug development in current biomedical science.

Structural characterization of Bacillus licheniformis Dahb1 exopolysaccharide—antimicrobial potential and larvicidal activity on malaria and Zika virus mosquito vectors

Microbial polysaccharides produced by marine species play a key role in food and cosmetic industry, as they are nontoxic and biodegradable polymers. This investigation reports the isolation of exopolysaccharide from Bacillus licheniformis Dahb1 and its biomedical applications. Bacillus licheniformis Dahb1xa0exopolysaccharide (Bl-EPS) was extracted using the ethanol precipitation method and structurally characterized. FTIR and 1H-NMR pointed out the presence of various functional groups and primary aromatic compounds, respectively. Bl-EPS exhibited strong antioxidant potential confirmed via DPPH radical, reducing power and superoxide anion scavenging assays. Microscopic analysis revealed that the antibiofilm activity of Bl-EPS (75xa0μg/ml) was higher against Gram-negative (Pseudomonas aeruginosa and Proteus vulgaris) bacteria over Gram-positive species (Bacillus subtilis and Bacillus pumilus). Bl-EPS led to biofilm inhibition against Candida albicans when tested at 75xa0μg/ml. The hemolytic assay showed low cytotoxicity of Bl-EPS at 5xa0mg/ml. Besides, Bl-EPS achieved LC50 values <u200980xa0μg/ml against larvae of mosquito vectors Anopheles stephensi and Aedes aegypti. Overall, our findings pointed out the multipurpose bioactivity of Bl-EPS, which deserves further consideration for pharmaceutical, environmental and entomological applications.

Green Synthesis of Ag Nanoparticles with Anti-bacterial Activity Using the Leaf Extract of an African Medicinal Plant, Ipomoea asarifolia (Convolvulaceae)

Herbal drugs prepared with the plant Ipomoea asarifolia has many medicinal uses throughout West Africa, including its employ as diuretic, emmenagogue and purgative. This species is a good source of acylated anthocyanins, and the methanol and ethylxa0acetate extracts of I. asarifolia are known for their strong acetylcholinesterase inhibitory effects. Here, green synthesis of Ag nanoparticles (Ag NPs) was performed at room temperature using the I. asarifolia leaf extract. The Ag NPs were characterized by UV–visible spectroscopy, FT-IR, XRD, AFM, SEM with EDX and TEM. AFM and SEM analyses showed that spherical morphology of I. asarifolia-synthesized Ag NPs with a size range of 20 to 60xa0nm. TEM revealed that I. asarifolia-synthesizedxa0Ag NPs had a mean particle size of 40xa0nm. The I. asarifolia-synthesized Ag NPs was tested against four bacterial pathogens using the disk diffusion method. The zone of inhibition varied xa0significantly in a dose-dependent manner. Overall, our results underlined the potential of cheap aqueous extracts from this African medicinal plant species for the synthesis of silver nanocomplexes with wide efficacy against human pathogenic bacteria.

Biocompatible properties of nano-drug carriers using TiO 2 -Au embedded on multiwall carbon nanotubes for targeted drug delivery

Nanomaterial-based drug carriers have become a hot spot of research at the interface of nanotechnology and biomedicine because they allow efficient loading, targeted delivery, controlled release of drugs, and therefore are promising for biomedical applications. The current study made an attempt to decorate the multiwalled carbon nanotubes (MWCNT) with titanium dioxide‑gold nanoparticles in order to enhance the biocompatibility for doxorubicin (DOX) delivery. The successful synthesis of nano drug carrier (NDC) was confirmed by XRD, XPS and UV-Visible spectroscopy. FESEM and TEM revealed that the morphology of NDC can be controlled by manipulating the reaction duration, MWCNT concentration and TiO2-Au source concentration. Results showed that TiO2 and Au nanoparticles were well coated on MWCNT. NDC had finely tuned biocompatible properties, as elucidated by hemolytic and antimicrobial assays. NDC also showed a high antioxidant potential, 80.7% expressed as ascorbic acid equivalents. Commercial DOX drug was utilized to treat A549 and MCF7 cancer cell lines showing improved efficiency by formulating it with NDC, which selectively delivered at the pHu202f5.5 with drug loading capacity of 0.45u202fmg/mL. The drug releasing capacity achieved by NDC was 90.66% for 10u202fh, a performance that far encompasses a wide number of current literature reports.

Sargassum wightii -synthesized ZnO nanoparticles – from antibacterial and insecticidal activity to immunostimulatory effects on the green tiger shrimp Penaeus semisulcatus

The green synthesis of metal nanoparticles using phytochemical from marine seaweeds is a fast-growing research field in nanotechnology. Here, the biosynthesis of zinc oxide nanoparticles was achieved using the hot water extract of Sargassum wightii. The hot water extract prepared from S. wightii (H Sw) and ZnO NPs were studied by UV-visible and FTIR spectroscopy, SEM and XRD. Then, both products were evaluated for antibiofilm activity towards aquatic pathogens. The nanoparticles immunostimulating potential on green tiger prawns, Penaeus semisulcatus was studied through immersion and dietary administration. Shrimp immune parameters (i.e., total hemocytes count (THC), respiratory bursts (RBs), phenoloxidase (PO) and superoxide dismutase (SOD) activity) were significantly affected by exposure or ingestion of ZnO nanoparticles. In addition, the hot water extract and ZnO nanoparticles had high antibiofilm activity against Gram-positive (B. subtilis, S. aureus) and Gram-negative (S. sonnei, P. aeruginosa) microbial pathogens. It was accomplished that the ZnO nanoparticles can be used as the bacteriostatic and immunostimulant agents through immersion and dietary administration enhancing immunity of green tiger shrimp. Furthermore, the toxicity effects of ZnO nanoparticles were 100% at 24u202fh on Aedes aegypti 3 rd instar larvae at the concentration of 100u202fμg/mL and the greatest efficacy was accomplished by H Sw ZnO NPs against the Ae. aegypti after 24u202fh (LC50 49.22; LC90 86.96u202fmg/mL), if compared to the seaweed extract alone. Morphological and histological damages triggered by nanoexposure were investigated.

Swift fabrication of Ag nanostructures using a colloidal solution of Holostemma ada-kodien (Apocynaceae) – Antibiofilm potential, insecticidal activity against mosquitoes and non-target impact on water bugs

Recent research in entomology and parasitology focused on the efficacy of green fabricated nanomaterials as novel insecticides. In this study, we synthesized poly-dispersed and stable silver nanoparticles (AgNPs) using the leaf extract of Holostemma ada-kodien. The nanostructures were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray, and X-ray diffraction analysis. The efficacy of H. ada-kodien leaf extract and AgNPs in vector control was evaluated against the mosquitoes Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus, which act as major vectors of important parasitic and arboviral diseases. AgNPs showed higher toxicity if compared to the H. ada-kodien leaf aqueous extract, LC50 towards larvae of A. stephensi, A. aegypti, and C. quinquefasciatus were 12.18, 13.30, and 14.70u202fμg/mL, respectively. When the AgNPs were tested on non-target water bugs, Diplonychus indicus, the LC50 value was 623.48u202fμg/mL. Furthermore, 100u202fμl/mL of AgNPs achieved significant antimicrobial activity against Bacillus pumilus, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus vulgaris, and Candida albicans. Light and confocal laser scanning microscopy highlighted a major impact of the H. ada-kodien-synthesized AgNPs on the external topography and architecture of microbial biofilms, both on Gram-positive and Gram-negative bacteria. Overall, this study sheds light on the insecticidal and antibiofilm potential of H. ada-kodien-synthesized AgNPs, a potential green resource for the rapid synthesis of polydispersed and highly stable AgNPs.

High efficacy of (Z)-γ-bisabolene from the essential oil of Galinsoga parviflora (Asteraceae) as larvicide and oviposition deterrent against six mosquito vectors

The eco-friendly management of mosquitoes with novel and effective larvicides and oviposition deterrents is a crucial challenge to prevent outbreaks of mosquito-borne diseases. However, most of the herbal formulations tested in these years showed LC50 values higher of 40xa0ppm, and significantxa0oviposition deterrent activity only when tested at relatively higher doses (>u200950xa0μg/ml). Herein,xa0we studied the chemical composition of the Galinsoga parviflora essential oil (EO). This plant is an annual herb native to South America naturalized all over the world. We tested the EO larvicidal and oviposition deterrent action on 6 mosquito species. Totally 37 compounds were identified in the EO of G. parviflora by GC and GC-MS analyses. The major constituent was (Z)-γ-bisabolene (38.9%). The G. parviflora EO and (Z)-γ-bisabolene showed acute toxicity on An. stephensi (LC50u2009=u200931.04 and 2.04xa0μg/ml, respectively), Ae. aegypti (LC50u2009=u200934.22 and 2.26xa0μg/ml, respectively), Cx. quinquefasciatus (LC50u2009=u200937.10 and 2.47xa0μg/ml, respectively), An. subpictus (LC50u2009=u200940.97 and 4.09xa0μg/ml, respectively), Ae. albopictus (LC50u2009=u200945.55 and 4.50xa0μg/ml, respectively) and Cx. tritaeniorhynchus (LC50u2009=u200949.56 and 4.87xa0μg/ml, respectively) larvae. Furthermore, the oviposition deterrent potential of the G. parviflora EO and (Z)-γ-bisabolene was studied on six mosquito vectors, showing that 25xa0μg/ml of (Z)-γ-bisabolene led to anxa0Oviposition Activity Index lower of −u20090.79 in all tested mosquito vectors. Overall, all larvicidal LC50 values estimated for (Z)-γ-bisabolene were lower than 5xa0μg/ml. This result far encompasses current evidences of toxicity reported for the large majority of botanical products currently tested against mosquito young instars, allowing us to propose this compound as an highly effectivexa0mosquito larvicide and oviposition deterrent.

Searching for crab-borne antimicrobial peptides: Crustin from Portunus pelagicus triggers biofilm inhibition and immune responses of Artemia salina against GFP tagged Vibrio parahaemolyticus Dahv2

Graphical abstract Figure. No caption available. HighlightsPurification of crustin (Pp‐Cru) from Portunus pelagicus was characterized by HPLC, CD, XRD, and FTIR analyses.We reported an enhancement of the immune system by Pp‐Cru through in vivo and in vitro analysis.Synergic antibacterial and antibiofilm properties of Pp‐Cru were observed against key bacterial pathogens.Live and dead assay showed ultra‐low bacterial cell viability post‐treatment with Pp‐Cru.In vivo study of crustin was assessed with Artemia salina as a model crustacean. &NA; Marine organisms represent a huge source of novel compounds for the development of effective antimicrobial drugs. The present study focus on the purification of the antimicrobial peptide crustin from the haemolymph of the blue swimmer crab, Portunus pelagicus, by blue Sepharose CL‐6B matrix assisted affinity column chromatography. Crustin showed a single band with a molecular mass of 17 kDa in SDS‐PAGE analysis. The XRD analysis exhibited peaks at 32° and 45° while a distinct peak with a retention time of 1.8 min resulted in high performance liquid chromatography (HPLC) pointing out the crystalline nature and purity of crustin, respectively. Crustin purified from P. pelagicus (Pp‐Cru) showed immunological activities, triggering encapsulation, phagocytosis on Sepharose beads and yeast (Saccharomyces cerevisiae) respectively. Furthermore, encapsulation of GFP tagged V. parahaemolyticus in Artemia salina and challenging study were assessed under CLSM and the potential of Pp‐Cru was examined in vivo. In addition, the growth reduction and biofilm inhibition potential of Pp‐Cru on Staphylococcus aureus, Enterococcus faecalis (Gram‐ positive bacteria) and Pseudomonas aeruginosa, Escherichia coli (Gram‐negative bacteria) was evidenced by inverted and confocal laser scanning microscopic analysis, revealing that 100 &mgr;g/ml of Pp‐Cru can disrupt the biofilm matrix thereby the thickness of biofilm was significantly reduced. Overall, the present investigation might provide a sensitive platform to realize the significant function of Pp‐Cru in crustacean immune mechanism as well as its potential to bacterial growth inhibitor. The functional properties of purified Pp‐Cru antimicrobial peptide may lead to a superior understanding of innate immune response in P. pelagicus species, which suggest the promising application for drug development in aquaculture.

Nanosilver crystals capped with Bauhinia acuminata phytochemicals as new antimicrobials and mosquito larvicides

To develop novel nanoformulated insecticides and antimicrobials, herein we produced Ag nanoparticles (AgNPs) using the Bauhinia acuminata leaf extract. This unexpensive aqueous extract acted as a capping and reducing agent for the formation of AgNPs. We characterized B. acuminata-synthesized AgNPs by UV-vis and FTIR spectroscopy, XRD and TEM analyses. UV-vis spectroscopy analysis of B. acuminata-synthesized AgNPs showed a peak at 441.5u202fnm. FTIR shed light on functional groups from the phytoconstituents involved in nanosynthesis. XRD of B. acuminata-synthesized AgNPs suggested a face-centered cubic structure, with a highly crystalline nature. TEM of B. acuminata-synthesized AgNPs revealed mean size of 25u202fnm, with round shape. AgNPs tested at 60u202fμg/mL inhibited the growth of 5 bacteria and 3 fungal pathogens. In the insecticidal assays on important mosquito species, LC50 of the aqueous extract of B. acuminata leaves on the larvae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus were 204.07, 226.02, and 249.24u202fμg/mL, respectively. The B. acuminata-synthesized AgNPs exhibited higher larvicidal efficacy, with LC50 values of 24.59, 27.19, and 30.19u202fμg/mL, respectively. Therefore, herein we developed a single-step, reliable, inexpensive, and environmentally non-toxic synthesis process to obtain AgNPs with high bioactivity against pathogens and vectors. Given the effective antimicrobial and larvicidal activity, nanoparticles fabricated using plant extracts and extremely low concentrations of trace elements, such as silver, can be exploited for multipurpose activities. Our results pointed out that B. acuminata-synthesized AgNPs have a promising potential in antimicrobial food packaging, as well as a foliar spray to control plant pathogens in the field, and to synergize the efficacy of fungicidal and larvicidal formulations.