Sirolimus loaded chitosan functionalized poly (lactic-co-glycolic acid) (PLGA) nanoparticles for potential treatment of age-related macular degeneration

Int J Biol Macromol. 2021 Sep 15:S0141-8130(21)01991-7. doi: 10.1016/j.ijbiomac.2021.09.069. Online ahead of print.ABSTRACTThe usefulness of sirolimus (SIR) in the treatment of diseases that involve retinal degeneration like age-related macular degeneration (AMD) has been well documented. However, the problem still remains probably owing to the peculiar environment of the eye and/or unfavourable physiochemical profile of SIR. In the present work, we aimed to fabricate sirolimus loaded PLGA nanoparticles (SIR-PLGA-NP) and chitosan decorated PLGA nanoparticles (SIR-CH-PLGA-NP) to be administered via non-invasive subconjunctival route. Both the nanoparticles were characterized in terms of size, zeta potential, DSC, FTIR and XRD analysis. Quality by Design (QbD) approach was employed during the preparation of nanoparticles and the presence of chitosan coating was confirmed through thermogravimetric analysis and contact angle studies. Cationic polymer modification showed sustained in-vitro SIR release and enhanced ex-vivo scleral permeation and penetration. Further, SIR-CH-PLGA-NP revealed enhanced cellular uptake and thus, reduced lipopolysaccharide (LPS)-induced free-radicals generation by RAW 264.7 cells. The prepared nanoparticles were devoid of residual solvent and were found to be safe in HET-CAM analysis, RBCs damage analysis and histopathology studies. Moreover, high anti-angiogenic potential was observed in SIR-CH-PLGA-NP compared with SIR-PLGA-NP in chorioallantoic membr...
Source: International Journal of Biological Macromolecules - Category: Biochemistry Authors: Source Type: research

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For the first time, an implant for age-related macular degeneration won approval from the FDA.Medscape Medical News
Source: Medscape Medical News Headlines - Category: Consumer Health News Tags: Ophthalmology News Source Type: news
Conclusion: This review serves to strengthen the OCT nomenclature “bacillary layer detachment,” based on specific reflectance information obtained by OCT and previously published histologic observations.
Source: RETINA - Category: Opthalmology Tags: Review Source Type: research
Purpose: To investigate associations between residual subretinal fluid (rSRF) volumes, quantified using artificial intelligence and treatment outcomes in a subretinal fluid (SRF)–tolerant treat-and-extend (T&E) regimen in neovascular age-related macular degeneration. Methods: Patients enrolled in the prospective, multicenter FLUID study randomized in an SRF-tolerant T&E regimen were examined by spectral-domain optical coherence tomography and tested for best-corrected visual acuity (BCVA). Intraretinal fluid and SRF volumes were quantified using artificial intelligence tools. In total, 375 visits of 98 pat...
Source: RETINA - Category: Opthalmology Tags: Original Study Source Type: research
Purpose: To define injection index (II) and assess its impact on visual acuity (VA) in pigment epithelial detachment from age-related macular degeneration over 5 years. Methods: Injection index is defined as the mean anti–vascular endothelial growth factor injections per year from presentation. A retrospective study of 256 eyes in 213 patients was performed. Patients were stratified by II (high: ≥9, low:
Source: RETINA - Category: Opthalmology Tags: Original Study Source Type: research
Conclusion: We report the existence of massive advancing nonexudative Type 1 choroidal neovascularization in CTRP5 late-onset retinal degeneration. These findings have implications for age-related macular degeneration. They provide a monogenic model system for studying the mechanisms underlying the distinct events of choroidal neovascularization development, enlargement, progression to exudation, and atrophy in age-related macular degeneration. They suggest that choroidal hypoperfusion precedes neovascularization and that nonexudative neovascularization may protect against atrophy.
Source: RETINA - Category: Opthalmology Tags: Original Study Source Type: research
Conclusion: These novel observations suggest the pressure gradient for flow in the affected veins varied from low gradients when the filling was slow to high gradients when the filling was faster. The vessels violated the physiological watershed zone and seem to function as anastomoses between the ordinarily segmented venous drainage of the choroid. The dilated segments may result in pooling of venous blood as part of venous outflow abnormalities that may be operative in these diseases.
Source: RETINA - Category: Opthalmology Tags: Original Study Source Type: research
Exp Eye Res. 2021 Oct 22:108798. doi: 10.1016/j.exer.2021.108798. Online ahead of print.ABSTRACTAge-related macular degeneration (AMD) has been associated with protective genetic variants in the β1-3 glucosyltransferase (B3GLCT) locus through genome-wide association studies. B3GLCT mediates modification of proteins with thrombospondin type I repeats (TSR) that contain O-linked glucose β1-3 fucose and C-linked mannose glycosylation motifs. B3GLCT-mediated modification is required for proper secretion of TSR-containing proteins. We aimed to start understanding the role of B3GLCT in AMD by evaluating its effect on g...
Source: Experimental Eye Research - Category: Opthalmology Authors: Source Type: research
Age-related macular degeneration (AMD) is a leading cause of blindness. Late AMD can be classified into exudative (commonly known as wet AMD [wAMD]) or dry AMD, both of which may progress to macular atrophy (MA). MA causes irreversible vision loss and currently has no approved pharmacological treatment. The standard of care for wAMD is treatment with anti-vascular endothelial growth factors (VEGF). However, recent evidence suggests that anti-VEGF treatment may play a role in the development of MA. Therefore, it is important to identify risk factors for the development of MA in patients with wAMD. For example, excessive blo...
Source: Ophthalmologica - Category: Opthalmology Source Type: research
Source: Expert Opinion on Therapeutic Targets - Category: Drugs & Pharmacology Authors: Source Type: research
Exp Eye Res. 2021 Oct 21:108800. doi: 10.1016/j.exer.2021.108800. Online ahead of print.ABSTRACTAging is a predominant risk factor for various eye diseases. Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly, and its etiology remains unclear. Fragmented and dysfunctional mitochondria are associated with age-related diseases. The retinal pigment epithelium (RPE), a polarized cell layer that functions in visual pigment recycling and degeneration, is suspected as the primary region site of AMD. In the present study, we investigated the relationship between mitochondrial dysfunction and RPE...
Source: Experimental Eye Research - Category: Opthalmology Authors: Source Type: research
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