Targeted long-term noninvasive treatment of choroidal neovascularization by biodegradable nanoparticles

ROS-responsive drug delivery system with enhanced anti-angiogenic and anti-inflammatory properties for neovascular age-related macular degeneration therapy

Neovascular age-related macular degeneration (nAMD) has become the leading cause of vision loss in people over 60 years old. Anti-vascular endothelial growth factor (anti-VEGF), the current first-line drug for the treatment of nAMD, suffers from poor patient compliance and fundus fibrosis scar formation. In addition to VEGF, oxidative stress and inflammation also play key roles in the pathological process of choroidal neovascularization (CNV). Therefore, combinational therapeutics with anti-angiogenic, reactive oxygen species (ROS)-scavenging and anti-inflammatory functions will broaden therapeutic effects and reduce side effects. The Yes-associated protein-1 (YAP) has proven to inhibit angiogenesis, inflammation, and subretinal fibrosis in CNV. Herein, verteporfin (VP), the inhibitor of YAP, was encapsulated into a polydopamine modified mesoporous silica nanoparticle (PMSN-VP NPs) and then conjugated with PLGA-PEG-PBA decorated cerium oxide nanoparticles (PPCeO2 NPs) to develop an integrated nano-drug delivery system. The PMSN-VP@PPCeO2 NPs exhibited ROS-responsive degradation and VP release behaviors, and our in vitro data revealed that the PMSN-VP@PPCeO2 NPs downregulated angiogenic-related and fibrosis-related gene expressions in human umbilical vein endothelial cells (HUVECs) and further showed excellent anti-oxidative and anti-inflammatory capacities in BV2 cells. More importantly, the PMSN-VP@PPCeO2 NPs significantly suppressed vascular leakage and macrophage infiltration in the laser-induced CNV lesions of mice. Overall, our findings demonstrated that the PMSN-VP@PPCeO2 NPs provided an effective therapeutic strategy for nAMD.

Topical application of insulin encapsulated by chitosan-modified PLGA nanoparticles to alleviate alkali burn-induced corneal neovascularization

Corneal neovascularization (CRNV) severely impairs corneal transparency and is one of the leading causes of vision loss worldwide. Drug therapy is the main approach to inhibit CRNV. Insulin (INS) has been reported to facilitate the healing of corneal injuries and suppress inflammation. However, but due to the unique physiological barriers of the eye, its bioavailability is low, limiting its therapeutic effect. In this study, we developed a chitosan-poly(lactic-co-glycolic acid)-INS nanoparticles (CPI NPs) system for INS delivery. The characterization of CPI NPs was satisfactory. Experimental results demonstrated that CPI NPs effectively inhibited the migration of vascular endothelial cells and the formation of tubular structures. Furthermore, CPI NPs markedly suppressed the neovascularization in a CRNV model without any observable side effects. Quantitative proteomics analysis indicated that INS treatment led to a reduction in FTO levels within the neovascularized cornea. Both in vitro and in vivo experiments substantiated the impact of CPI NPs on FTO protein expression and the N6-methyladenosine modification. In conclusion, this study successfully developed an effective ocular drug delivery system for the treatment of CRNV induced by alkali burns, thereby offering a novel therapeutic option for this condition.

Utilization of Nanoparticles for Treating Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a predominant cause of vision loss, posing significant challenges in its management despite advancements such as anti-vascular endothelial growth factor (anti-VEGF) therapy. Nanomedicine, with its novel properties and capabilities, offers promising potential to transform the treatment paradigm for AMD. This review reports the significant advancements in the use of diverse nanoparticles (NPs) for AMD in vitro, in vivo, and ex vivo, including liposomes, lipid nanoparticles, nanoceria, nanofibers, magnetic nanoparticles, quantum dots, dendrimers, and polymer nanoparticles delivered in forms such as gels, eye drops, intravitreally, or intravenously. Drug delivery was the most common use of NPs for AMD, followed by photodynamic therapy dose enhancement, antioxidant function for nanoceria, biomimetic activity, and immune modulation. Innovative approaches arising included nanotechnology-based photodynamic therapy and light-responsive nanoparticles for controlled drug release, as well as gene therapy transfer. Nanomedicine offers a transformative approach to the treatment and management of AMD, with diverse applications. The integration of nanotechnology in AMD management not only provides innovative solutions to overcome current therapeutic limitations but also shows potential in enhancing outcomes and patient quality of life.

Age-Related Macular Degeneration (AMD): Pathophysiology, Drug Targeting Approaches, and Recent Developments in Nanotherapeutics

The most prevalent reason for vision impairment in aging inhabitants is age-related macular degeneration (AMD), a posterior ocular disease with a poor understanding of the anatomic, genetic, and pathophysiological progression of the disease. Recently, new insights exploring the role of atrophic changes in the retinal pigment epithelium, extracellular drusen deposits, lysosomal lipofuscin, and various genes have been investigated in the progression of AMD. Hence, this review explores the incidence and risk factors for AMD, such as oxidative stress, inflammation, the complement system, and the involvement of bioactive lipids and their role in angiogenesis. In addition to intravitreal anti-vascular endothelial growth factor (VEGF) therapy and other therapeutic interventions such as oral kinase inhibitors, photodynamic, gene, and antioxidant therapy, as well as their benefits and drawbacks as AMD treatment options, strategic drug delivery methods, including drug delivery routes with a focus on intravitreal pharmacokinetics, are investigated. Further, the recent advancements in nanoformulations such as polymeric and lipid nanocarriers, liposomes, etc., intended for ocular drug delivery with pros and cons are too summarized. Therefore, the purpose of this review is to give new researchers an understanding of AMD pathophysiology, with an emphasis on angiogenesis, inflammation, the function of bioactive lipids, and therapy options. Additionally, drug delivery options that focus on the development of drug delivery system(s) via several routes of delivery can aid in the advancement of therapeutic choices.

Recent Advances in Nanomedicine for Ocular Fundus Neovascularization Disease Management

As an indispensable part of the human sensory system, visual acuity may be impaired and even develop into irreversible blindness due to various ocular pathologies. Among ocular diseases, fundus neovascularization diseases (FNDs) are prominent etiologies of visual impairment worldwide. Intravitreal injection of anti-vascular endothelial growth factor drugs remains the primary therapy but is hurdled by common complications and incomplete potency. To renovate the current therapeutic modalities, nanomedicine emerged as the times required, which is endowed with advanced capabilities, able to fulfill the effective ocular fundus drug delivery and achieve precise drug release control, thus further improving the therapeutic effect. This review provides a comprehensive summary of advances in nanomedicine for FND management from state-of-the-art studies. First, the current therapeutic modalities for FNDs are thoroughly introduced, focusing on the key challenges of ocular fundus drug delivery. Second, nanocarriers are comprehensively reviewed for ocular posterior drug delivery based on the nanostructures: polymer-based nanocarriers, lipid-based nanocarriers, and inorganic nanoparticles. Thirdly, the characteristics of the fundus microenvironment, their pathological changes during FNDs, and corresponding strategies for constructing smart nanocarriers are elaborated. Furthermore, the challenges and prospects of nanomedicine for FND management are thoroughly discussed.

Multifunctional nano-in-micro delivery systems for targeted therapy in fundus neovascularization diseases

Fundus neovascularization diseases are a series of blinding eye diseases that seriously impair vision worldwide. Currently, the means of treating these diseases in clinical practice are continuously evolving and have rapidly revolutionized treatment opinions. However, key issues such as inadequate treatment effectiveness, high rates of recurrence, and poor patient compliance still need to be urgently addressed. Multifunctional nanomedicine can specifically respond to both endogenous and exogenous microenvironments, effectively deliver drugs to specific targets and participate in activities such as biological imaging and the detection of small molecules. Nano-in-micro (NIM) delivery systems such as metal, metal oxide and up-conversion nanoparticles (NPs), quantum dots, and carbon materials, have shown certain advantages in overcoming the presence of physiological barriers within the eyeball and are widely used in the treatment of ophthalmic diseases. Few studies, however, have evaluated the efficacy of NIM delivery systems in treating fundus neovascular diseases (FNDs). The present study describes the main clinical treatment strategies and the adverse events associated with the treatment of FNDs with NIM delivery systems and summarizes the anatomical obstacles that must be overcome. In this review, we wish to highlight the principle of intraocular microenvironment normalization, aiming to provide a more rational approach for designing new NIM delivery systems to treat specific FNDs.

Comprehensive Ocular and Systemic Safety Evaluation of Polysialic Acid-Decorated Immune Modulating Therapeutic Nanoparticles (PolySia-NPs) to Support Entry into First-in-Human Clinical Trials

An inflammation-resolving polysialic acid-decorated PLGA nanoparticle (PolySia-NP) has been developed to treat geographic atrophy/age-related macular degeneration and other conditions caused by macrophage and complement over-activation. While PolySia-NPs have demonstrated pre-clinical efficacy, this study evaluated its systemic and intraocular safety. PolySia-NPs were evaluated in vitro for mutagenic activity using Salmonella strains and E. coli, with and without metabolic activation; cytotoxicity was evaluated based on its interference with normal mitosis. PolySia-NPs were administered intravenously in CD-1 mice and Sprague Dawley rats and assessed for survival and toxicity. Intravitreal (IVT) administration in Dutch Belted rabbits and non-human primates was assessed for ocular or systemic toxicity. In vitro results indicate that PolySia-NPs did not induce mutagenicity or cytotoxicity. Intravenous administration did not show clastogenic activity, effects on survival, or toxicity. A single intravitreal (IVT) injection and two elevated repeat IVT doses of PolySia-NPs separated by 7 days in rabbits showed no signs of systemic or ocular toxicity. A single IVT inoculation of PolySia-NPs in non-human primates demonstrated no adverse clinical or ophthalmological effects. The demonstration of systemic and ocular safety of PolySia-NPs supports its advancement into human clinical trials as a promising therapeutic approach for systemic and retinal degenerative diseases caused by chronic immune activation.

The Effect of Different Factors on Poly(lactic-co-glycolic acid) Nanoparticle Properties and Drug Release Behaviors When Co-Loaded with Hydrophilic and Hydrophobic Drugs

Poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) are versatile drug nanocarriers with a wide spectrum of applications owing to their extensive advantages, including biodegradability, non-toxic side effects, and low immunogenicity. Among the numerous nanoparticle preparation methods available for PLGA NPs (the hydrophobic polymer), one of the most extensively utilized preparations is the sonicated-emulsified solvent evaporation method, owing to its simplicity, speed, convenience, and cost-effectiveness. Nevertheless, several factors can influence the outcomes, such as the types of concentration of the surfactants and organic solvents, as well as the volume of the aqueous phase. The objective of this article is to explore the influence of these factors on the properties of PLGA NPs and their drug release behavior following encapsulation. Herein, PLGA NPs were fabricated using bovine serum albumin (BSA) as a surfactant to investigate the impact of influencing factors, including different water-soluble organic solvents such as propylene carbonate (PC), ethyl acetate (PA), and dichloromethane (DCM). Notably, the size of PLGA NPs was smaller in the EA group compared to that in the DCM group. Moreover, PLGA NPs showed excellent stability, ascribed to the presence of the BSA surfactant. Furthermore, PLGA NPs were co-loaded with varying concentrations of hydrophilic drugs (doxorubicin hydrochloride) and hydrophobic drugs (celecoxib), and exhibited pH-sensitive drug release behavior in PBS with pH 7.4 and pH 5.5.

A review on PLGA particles as a sustained drug-delivery system and its effect on the retina

In this review, the designs and recent developments of polymer-based drug delivery of Poly(lactic-co-glycolic acid) (PLGA) will be discussed for the possible treatment of age-related macular degeneration (AMD). PLGA is a versatile co-polymer that consists of synthetic lactic acid and glycolic acid monomers that are constructed to produce nanoparticles, microparticles, and scaffolds for the intraocular delivery of various drugs. As an FDA-approved polymer, PLGA has historically been well-suited for systemic slow-sustained release therapies due to its performance in biodegradability and biocompatibility. This review will examine recent in vitro and in vivo studies that provide evidence for PLGA-based particles as a therapeutic drug carrier for the treatment of AMD. Anti-angiogenic and antiproliferative effects of small peptides, small molecules, RNA molecules, and proteins within PLGA particles are briefly discussed. AMD is a leading cause of central vision loss in people over 55 years and the number of those afflicted will rise as the aging population increases. AMD has two forms that are often sequential. Dry AMD and wet AMD account for 85-90% and 10-15% of cases, respectively. The distinct categories of PLGA-based drug delivery vehicles are important for dispensing novel small molecules, RNA molecules, peptides, and proteins as a long-term effective treatment of AMD.