scholarly journals Novel polymeric micelles for insect pest control: encapsulation of essential oil monoterpenes inside a triblock copolymer shell for head lice control

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3171 ◽  
Author(s):  
Alejandro Lucia ◽  
Ariel Ceferino Toloza ◽  
Eduardo Guzmán ◽  
Francisco Ortega ◽  
Ramón G. Rubio

BackgroundEssential oil components (EOCs) are molecules with interesting application in pest control, these have been evaluated against different insect pest from more than 100 years, but their practical use is rather limited. Thus, the enhancement of their bioavailability and manageability due to their dispersion in water can open new perspective for the preparation of formulations for the control of insect pest. In this work, we studied the encapsulation of different monoterpenes in a poloxamer shell in order to prepare aqueous formulations that can be used for the development of platforms used in pest control.MethodsMicellar systems containing a 5 wt% of poloxamer 407 and 1.25 wt% of the different monoterpenes were prepared. Dynamic Light Scattering (DLS) experiments were carried out to characterize the dispersion of the EOCs in water. The pediculicidal activity of these micellar systems was tested on head lice using anex vivoimmersion test.ResultsThe poloxamers allowed the dispersion of EOCs in water due to their encapsulation inside the hydrophobic core of the copolymer micelles. From this study, we concluded that it is possible to make stable micellar systems containing water (>90 wt%), 1.25 wt% of different monoterpenes and a highly safe polymer (5wt% Poloxamer 407). These formulations were effective against head lice with mortality ranging from 30 to 60%, being the most effective emulsions those containing linalool, 1,8-cineole,α-terpineol, thymol, eugenol, geraniol and nonyl alcohol which lead to mortalities above 50%.DiscussionSince these systems showed good pediculicidal activity and high physicochemical stability, they could be a new route for the green fabrication of biocompatible and biosustainable insecticide formulations.

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 476 ◽  
Author(s):  
Pescina ◽  
Lucca ◽  
Govoni ◽  
Padula ◽  
Favero ◽  
...  

This paper addresses the problem of ocular delivery of lipophilic drugs. The aim of the paper is the evaluation of polymeric micelles, prepared using TPGS (d-α-Tocopheryl polyethylene glycol 1000 succinate), a water-soluble derivative of Vitamin E and/or poloxamer 407, as a vehicle for the ocular delivery of dexamethasone, cyclosporine, and econazole nitrate. The research steps were: (1) characterize polymeric micelles by dynamic light scattering (DLS) and X-ray scattering; (2) evaluate the solubility increase of the three drugs; (3) measure the in vitro transport and conjunctiva retention, in comparison to conventional vehicles; (4) investigate the mechanisms of enhancement, by studying drug release from the micelles and transconjunctival permeation of TPGS; and (5) study the effect of micelles application on the histology of conjunctiva. The data obtained demonstrate the application potential of polymeric micelles in ocular delivery, due to their ability to increase the solubility of lipophilic drugs and enhance transport in and across the conjunctival epithelium. The best-performing formulation was the one made of TPGS alone (micelles size ≈ 12 nm), probably because of the higher mobility of these micelles, an enhanced interaction with the conjunctival epithelium, and, possibly, the penetration of intact micelles.


2002 ◽  
Vol 3 (2) ◽  
pp. 64-74 ◽  
Author(s):  
Mario D. L. Moretti ◽  
Giovanni Sanna-Passino ◽  
Stefania Demontis ◽  
Emanuela Bazzoni

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 855
Author(s):  
Silvia Pescina ◽  
Fabio Sonvico ◽  
Adryana Clementino ◽  
Cristina Padula ◽  
Patrizia Santi ◽  
...  

There is increasing consensus in considering statins beneficial for age-related macular degeneration and in general, for immune and inflammatory mediated diseases affecting the posterior segment of the eye. However, all available data relate to oral administration, and safety and effectiveness of statins directly administered to the eye are not yet known, despite their ophthalmic administration could be beneficial. The aim was the development and the characterization of polymeric micelles based on TPGS or TPGS/poloxamer 407 to increase simvastatin solubility and stability and to enhance the delivery of the drug to the posterior segment of the eye via trans-scleral permeation. Simvastatin was chosen as a model statin and its active hydroxy acid metabolite was investigated as well. Results demonstrated that polymeric micelles increased simvastatin solubility at least 30-fold and particularly TPGS/poloxamer 407 mixed micelles, successfully stabilized simvastatin over time, preventing the hydrolysis when stored for 1 month at 4 °C. Furthermore, both TPGS (1.3 mPas) and mixed micelles (33.2 mPas) showed low viscosity, suitable for periocular administration. TPGS micelles resulted the best performing in delivery simvastatin either across conjunctiva or sclera in ex vivo porcine models. The data pave the way for a future viable ocular administration of statins.


2014 ◽  
Vol 20 ◽  
pp. 25-32
Author(s):  
N Sapna Bai ◽  
OK Remadevi ◽  
TO Sasidharan ◽  
M Balachander ◽  
Priyadarsanan Dharmarajan

Context: Entomopathogenic fungi have been recognized as viable alternate options to chemicals in insect pest control. Unlike other potential biocontrol agents, fungi do not have to be ingested to infect their hosts but invade directly through the cuticle. Entry into the host involves both enzymic degradation of the cuticle barrier and mechanical pressure. Production of a range of cuticle degrading enzymes is an important event in the interaction of entomopathogenic fungi and host. Enzyme secretion is believed to be a key contributor for the virulence of a fungal isolate. Objectives: The potentiality of nine isolates of M. anisopliae were tested to produce to produce three important cuticle degrading enzymes, viz., chitinase, protease and lipase. Materials and Methods: Nine isolates of M. anisopliae were evaluated for chitinase, protease and lipase enzyme production by determining the enzyme index and activities. Results: Chitinase index of these isolates were ranged from 1.5 to 2.2 and chitinolytic activity from 0.525 to 1.560 U/ml. The isolates showed protease index in the range of 1.2 to 3.3 and the activity ranged from 0.020 to 0.114 U/ml. Lipase index ranged from 1.15 to 7.0 and the enzyme activity ranged from 0.153 to 0.500 U/ml. A strong relationship was observed between virulence of the isolates and cuticle degrading enzyme production as increased enzyme production was observed for virulent isolates. Conclusion: In the present study three isolates as (MIS2, MIS7 and MIS13) demonstrated cuticle degrading enzyme (CDE) that indicate higher virulence based on the bioassay conducted earlier by the authors as strongly substantiating the role of CDEs is considered the virulence of Metarhizium isolates. So, these isolates may be as ecofriendly insect-pest control agent in future. DOI: http://dx.doi.org/10.3329/jbs.v20i0.17648 J. bio-sci. 20: 25-32, 2012


2021 ◽  
Author(s):  
Isabelle Kurnik ◽  
Natália D’Angelo ◽  
Priscila Gava Mazzola ◽  
Marlus Chorilli ◽  
Daniel Kamei ◽  
...  

We generated stable amphiphilic copolymer-based polymeric micelles (PMs) with temperature-responsive properties utilizing Pluronic® L35 and a variety of ionic liquids (ILs) to generate different aqueous two-phase micellar systems (ATPMSs). The...


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2041
Author(s):  
Luiz Jardelino de Lacerda Neto ◽  
Andreza Guedes Barbosa Ramos ◽  
Renata Evaristo Rodrigues da Silva ◽  
Luís Pereira-de-Morais ◽  
Fernanda Maria Silva ◽  
...  

Purpose: Alternative methods for the use of animals in research have gained increasing importance, due to assessments evaluating the real need for their use and the development of legislation that regulates the subject. The principle of the 3R’s (replacement, reduction and refinement) has been an important reference, such that in vitro, ex vivo and cord replacement methods have achieved a prominent place in research. Methods: Therefore, due to successful results from studies developed with these methods, the present study aimed to evaluate the myorelaxant effect of the Dysphania ambrosioides essential oil (EODa) using a Sus scrofa domesticus coronary artery model, and the toxicity of both the Dysphania ambrosioides essential oil and its major constituent, α-terpinene, against Drosophila melanogaster in toxicity and negative geotaxis assays. Results: The EODa relaxed the smooth muscle of swine coronary arteries precontracted with K+ and 5-HT in assays using Sus scrofa domesticus coronary arteries. The toxicity results presented LC50 values of 1.546 mg/mL and 2.282 mg/mL for the EODa and α-terpinene, respectively, thus showing the EODa and α-terpinene presented toxicity to these dipterans, with the EODa being more toxic. Conclusions: Moreover, the results reveal the possibility of using the EODa in vascular disease studies since it promoted the relaxation of the Sus scrofa domesticus coronary smooth muscle.


2021 ◽  
Vol 70 ◽  
pp. 158-166
Author(s):  
Qiang Zhang ◽  
Wei Dou ◽  
Clauvis Nji Tizi Taning ◽  
Guy Smagghe ◽  
Jin-Jun Wang

2021 ◽  
Vol 901 ◽  
pp. 98-103
Author(s):  
Sunee Channarong ◽  
Parapat Sobharaksha ◽  
Chanchai Sardseangjun ◽  
Panipak Vasvid

Abstract The aim of this study was to fabricate curcumin-loaded polymeric mixed micelle which was a new nanocarrier of therpeutic agent for skin uses. Curcumin was extracted from dried turmeric rhizomes using ethanol and recrystallized. The purity of curcumin was 79±3.6 %w/w. Six curcumin-loaded polymeric micelles (PM1-PM6) were prepared by simple dissolution method using poloxamer 407 (5% and 10%) as a main core structure. PEG-40 hydrogenated castor oil (PEG-40HCO) was incorporated at two percentages (2.5% and 5.0%) to study the effect on the nanoparticle characteristics. The average particle sizes of PM1-PM6 were in the range of 33.3±6.6 nm to 171.3±52.8 nm. The entrapment efficiency and the loading capacity of curcumin were in the range of 47.45%-77.35% and 0.048%w/w-0.078%w/w, respectively. When PEG-40HCO was incorporated in to the polymeric micelles, the particle size decreased and the entrapment efficiency increased. Thus, PM4 and PM5 were selected for further study. Moisturizing antioxidant creams containing 0.005%w/w of curcumin loaded in PM4, PM5 and curcumin simply dissolved in propylene glycol (PG) were formulated. The resulted formulations showed good spreadability and good characteristics. After being subjected to accelerated test, all of the formulations remained with characteristic color, pH and showed no phase separation. The stability data showed that the moisturizing antioxidant creams were stable for the whole 3 months after storage at accelerated temperature (45°C/75%RH). The study demonstrated that polymeric mixed micelle spontaneously encapsulated a poorly water-soluble curcumin and increased the solubility up to 250 folds. The developed moisturizing cream containing 0.005%w/w of curcumin resulted a greenish-yellow color preparation. It had tolerable physicochemical properties based on curcumin content, pH and viscosity under the harsh condition. The cream also had satisfactory antioxidant activity, which can be regarded as an effective and acceptable therapeutic or skincare products for topical uses.


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