scholarly journals Preliminary Investigation on Simvastatin-Loaded Polymeric Micelles in View of the Treatment of the Back of the Eye

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 855
Author(s):  
Silvia Pescina ◽  
Fabio Sonvico ◽  
Adryana Clementino ◽  
Cristina Padula ◽  
Patrizia Santi ◽  
...  
Keyword(s):  
Mixed Micelles ◽  
Polymeric Micelles ◽  
Ex Vivo ◽  
Preliminary Investigation ◽  
Posterior Segment ◽  
Age Related Macular Degeneration ◽  
Poloxamer 407 ◽  
Low Viscosity ◽  
Age Related ◽  
Ophthalmic Administration

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.

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
Keyword(s):  
Essential Oil ◽  
Pest Control ◽  
Polymeric Micelles ◽  
Ex Vivo ◽  
Insect Pest ◽  
Immersion Test ◽  
Poloxamer 407 ◽  
Head Lice ◽  
Hydrophobic Core ◽  
Micellar Systems

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.

scholarly journals Posterior segment eye diseases in Ijebu, Southwestern Nigeria

2018 ◽  
Vol 6 (1) ◽  
pp. 8
Author(s):  
Tayo Julius Bogunjoko ◽  
Adekunle O. Hassan ◽  
Adunola Ogunro ◽  
Toyin Akanbi ◽  
Bidemi Abudu
Keyword(s):  
Diabetic Retinopathy ◽  
Posterior Segment ◽  
Eye Diseases ◽  
Age Related Macular Degeneration ◽  
Systematic Sampling ◽  
Slit Lamp ◽  
Central Visual Field ◽  
Southwestern Nigeria ◽  
Ogun State ◽  
Age Related

Background: To review cases of posterior segment eye diseases (PSEDs) seen at the Eye Foundation Centre Ijebu, Nigeria in a 5 year period for planning purposes.Methods: Data was collected from patients’ case notes from January 2006 to December 2011. A systematic sampling of 468 patients from 1173 case notes of patient with (PSEDs) was done. Information retrieved was: age, sex, state of residence and diagnosis. All patients were examined by the glaucoma and the vitroretinal specialist as the case may be. They had visual acuity, refraction, slit lamp examination (including intraocular pressure (IOP) with Goldman applanation tonometer), and dilated fundoscopy with (bilateral indirect ophthalmoscopy) BIO, slit lamp using 20 D, 78 D and 90 D respectively. The glaucoma patients in addition had central visual field (CVF), Central cornea thickness (CCT), fundus photograph and in some cases optical coherence tomography (OCT) done in addition to the above.Results: The mean age was 59.98 years (SD 17.67) and the age range is 5-95 years. Males outnumbered females by 63% to 37%. The diseases were more common in age group 61 to 80. Patients’ attendances were mostly from Ijebu division of Ogun state (57%). Glaucoma is the commonest cause of attendance 262 (56%) followed by diabetic retinopathy 29 (6.2%) and age-related macular degeneration (ARMD) 28 (6.0%).Conclusions: Glaucoma, diabetic retinopathy and ARMD were noted as the commonest PSEDs in Ijebu division in Southwestern Nigeria.

scholarly journals Antioxidant Role of PRGF on RPE Cells after Blue Light Insult as a Therapy for Neurodegenerative Diseases

2020 ◽  
Vol 21 (3) ◽  
pp. 1021 ◽  
Author(s):  
Carlota Suárez-Barrio ◽  
Susana del Olmo-Aguado ◽  
Eva García-Pérez ◽  
María de la Fuente ◽  
Francisco Muruzabal ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Human Cell Line ◽  
Antioxidant Effect ◽  
Age Related Macular Degeneration ◽  
Strong Impact ◽  
Retinal Diseases ◽  
Age Related ◽  
Gene And Protein Expression

Oxidative stress has a strong impact on the development of retinal diseases such as age-related macular degeneration (AMD). Plasma rich in growth factors (PRGF) is a novel therapeutic approach in ophthalmological pathologies. The aim of this study was to analyze the antioxidant effect of PRGF in retinal epithelial cells (EPR) in in vitro and ex vivo retinal phototoxicity models. In vitro analyses were performed on ARPE19 human cell line. Viability and mitochondrial status were assessed in order to test the primary effects of PRGF. GSH level, and protein and gene expression of the main antioxidant pathway (Keap1, Nrf2, GCL, HO-1, and NQO1) were also studied. Ex vivo analyses were performed on rat RPE, and HO-1 and Nrf2 gene and protein expression were evaluated. The results show that PRGF reduces light insult by stimulating the cell response against oxidative damage and modulates the antioxidant pathway. We conclude that PRGF’s protective effect could prove useful as a new therapy for treating neurodegenerative disorders such as AMD.

scholarly journals Fructosamine-3-Kinase as a Potential Treatment Option for Age-Related Macular Degeneration

2020 ◽  
Vol 9 (9) ◽  
pp. 2869
Author(s):  
Sander De Bruyne ◽  
Caroline Van den Broecke ◽  
Henk Vrielinck ◽  
Samira Khelifi ◽  
Olivier De Wever ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Near Infrared ◽  
Ex Vivo ◽  
Pairwise Comparison ◽  
Age Related Macular Degeneration ◽  
Tissue Sections ◽  
Age Related ◽  
Human Eyes ◽  
Developed World ◽  
First Time

Age-related macular degeneration is the leading cause of blindness in the developed world. Since advanced glycation end products (AGEs) are implicated in the pathogenesis of AMD through various lines of evidence, we investigated the potential of fructosamine-3-kinase (FN3K) in the disruption of retinal AGEs, drusenoid material and drusenoid lesions in patients with AMD. AGE-type autofluorescence was measured to evaluate the effects of FN3K on glycolaldehyde-induced AGE-modified neural porcine retinas and unmodified human neural retinas. Eye pairs from cigarette-smoke- and air-exposed mice were treated and evaluated histologically. Automated optical image analysis of human tissue sections was performed to compare control- and FN3K-treated drusen and near-infrared (NIR) microspectroscopy was performed to examine biochemical differences. Optical coherence tomography (OCT) was used to evaluate the effect of FN3K on drusenoid deposits after treatment of post-mortem human eyes. FN3K treatment provoked a significant decrease (41%) of AGE-related autofluorescence in the AGE-modified porcine retinas. Furthermore, treatment of human neural retinas resulted in significant decreases of autofluorescence (−24%). FN3K-treated murine eyes showed less drusenoid material. Pairwise comparison of drusen on tissue sections revealed significant changes in color intensity after FN3K treatment. NIR microspectroscopy uncovered clear spectral differences in drusenoid material (Bruch’s membrane) and drusen after FN3K treatment. Ex vivo treatment strongly reduced size of subretinal drusenoid lesions on OCT imaging (up to 83%). In conclusion, our study demonstrated for the first time a potential role of FN3K in the disruption of AGE-related retinal autofluorescence, drusenoid material and drusenoid lesions in patients with AMD.

scholarly journals Age-related Macular Degeneration—Disease, Risk Factors, and Treatments

2014 ◽  
Vol 07 (02) ◽  
pp. 154
Author(s):  
Clyde Schultz ◽  
Keyword(s):  
Risk Factors ◽  
Macular Degeneration ◽  
Genetic Factors ◽  
Progressive Disease ◽  
Disease Risk ◽  
Treatment Options ◽  
Current Treatment ◽  
Posterior Segment ◽  
Age Related Macular Degeneration ◽  
Age Related

Age-related macular degeneration (AMD) is a progressive disease of the posterior segment of the eye. It is has been diagnosed worldwide and primarily affects individuals over 50 years of age. The incidence of the disease increases with age and with the presence of certain genetic factors, which may indicate a disposition for disease progression. In addition to genetic factors and age, other factors may be involved in developing AMD. These include obesity and smoking, which are also linked to various cardiovascular conditions. There are two forms of AMD: wet and dry. Both forms may involve the build-up of drusen deposits in the posterior segment of the eye, but the wet form tends to be more severe due to the proliferation of blood vessels into the macula and retinal areas of the back of the eye, thus causing an individual’s vision to become ‘blocked’ or ‘shaded’ usually beginning at the center of the visual field. There are a variety of treatment options for AMD including surgery in the form of laser or photo therapy. The most current treatment options involve the injection of a biologic into the posterior segment of the eye. There are some severe adverse events with this approach but they tend to be rare.

scholarly journals Ex Vivo Conjunctival Retention and Transconjunctival Transport of Poorly Soluble Drugs Using Polymeric Micelles

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 476 ◽  
Author(s):  
Pescina ◽  
Lucca ◽  
Govoni ◽  
Padula ◽  
Favero ◽  
...  
Keyword(s):  
Polymeric Micelles ◽  
Ex Vivo ◽  
Water Soluble ◽  
Poloxamer 407 ◽  
Conjunctival Epithelium ◽  
Ocular Delivery ◽  
Lipophilic Drugs ◽  
Polyethylene Glycol 1000 ◽  
The One

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.

scholarly journals Sunitinib-Loaded MPEG-PCL Micelles for the Treatment of Age-Related Macular Degeneration

2020 ◽  
Vol 88 (3) ◽  
pp. 30 ◽  
Author(s):  
Jarriaun Streets ◽  
Priyanka Bhatt ◽  
Deepak Bhatia ◽  
Vijaykumar Sutariya
Keyword(s):  
Macular Degeneration ◽  
Polymeric Micelles ◽  
Retinal Pigment Epithelial Cell ◽  
Retinal Pigment ◽  
Current Treatment ◽  
Age Related Macular Degeneration ◽  
Intravitreal Injections ◽  
Epithelial Cell Line ◽  
Anti Vegf ◽  
Age Related

Age-related macular degeneration (AMD) will be responsible for the vision impairment of more than five million late-aged adults in the next 30 years. Current treatment includes frequent intravitreal injections of anti-vascular endothelial growth factor (VEGF) agents. However, there are methods of drug delivery that can decrease the frequency of intravitreal injections by sustaining drug release. MPEG-PCL ((methoxypoly(ethylene glycol) poly(caprolactone)) has been reported as biocompatible and biodegradable. Polymeric micelles of MPEG-PCL can be useful in efficiently delivering anti-VEGF drugs such as sunitinib to the posterior segment of the eye. In this study, the novel micellar formulation exhibited an average dynamic light scattering (DLS) particle size of 134.2 ± 2.3 nm with a zeta potential of −0.159 ± 0.07 mV. TEM imaging further confirmed the nanoscopic size of the micelles. A sunitinib malate (SM)-MPEG-PCL formulation exhibited a sustained release profile for up to seven days with an overall release percentage of 95.56 ± 2.7%. In addition to their miniscule size, the SM-MPEG-PCL formulation showed minimal cytotoxicity onto the ARPE-19 human retinal pigment epithelial cell line, reporting a percent viability of more than 88% for all concentrations tested at time intervals of 24 h. The SM-MPEG-PCL micelles also exhibited exceptional performance during an anti-VEGF ELISA that decreased the overall VEGF protein expression in the cells across a 24–72 h period. Furthermore, it can be concluded that this type of polymeric vehicle is a promising solution to symptoms caused by AMD and improving the management of those suffering from AMD.

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