Recent achievements in nano-based technologies for ocular disease diagnosis and treatment, review and update

Abstract

Ocular drug delivery is one of the most challenging endeavors among the various available drug delivery systems. Despite having suitable drugs for the treatment of ophthalmic disease, we have not yet succeeded in achieving a proper drug delivery approach with the least adverse effects. Nanotechnology offers great opportunities to overwhelm the restrictions of common ocular delivery systems, including low therapeutic effects and adverse effects because of invasive surgery or systemic exposure. The present review is dedicated to highlighting and updating the recent achievements of nano-based technologies for ocular disease diagnosis and treatment. While further effort remains, the progress illustrated here might pave the way to new and very useful ocular nanomedicines.

Keywords: Diagnosis; Nanotechnology; Ocular diseases; Treatment.

Fig. 1

Schematic representation of ocular nanomedicine for various biomedical uses in ophthalmology [15]

Fig. 2

Graphical representation of the various delivery routes for ocular administration [26]

Fig. 3

Ocular barriers to drug delivery: (a) the tear film is consist of the mucin, aqueous, and lipid layers; (b) the corneal layer is composed of the endothelium, Descemet’s membrane, stroma, Bowman’s membrane, and epithelium; (c) the conjunctival barrier; (d) the blood-aqueous barrier begins at the ciliary body stroma and is formed by the basement membrane, pigmented and non-pigmented cells and is specified with the basement membrane; (e) the blood-retinal barrier is composed of Bowman’s membrane, RPE, photoreceptors, horizontal cells, bipolar cells, amacrine cells, and the retinal ganglion cells [26]

Fig. 4

Chain-like clusters of gold nanoparticles (CGNP) increased molecular imaging for optical coherence tomography and multimodal photoacoustic microscopy (PAM). Experimental setup of OCT/PAM systems. a Schematic representation of the imaging technique. b Physical setup. In the PAM method, nanosecond excitation laser is concentrated on the retina. For multidimensional imaging, the excitation laser beam employed to induce photoacoustic signal was coaxially aligned with OCT multispectral luminescence with a center wavelength (805 and 905 nm). Using a needle-shaped hydrophone ultrasonic transducer, the produced acoustic signal was detected and the recorded data was utilized to reproduce PAM images. It employed a spectrometer for detecting the reflected OCT light that interfered with the interference intensity spectra and the reference light. By using a galvanometer, the retina was scanned. c Demonstration of in vivo multidimensional imaging following intravenous administration of CGNP clusters-RGD into the rabbit model. By using nanosecond-pulsed laser light at 578/650 nm, photoacoustic signals from the rabbit's retina were produced [57]

Fig. 5

Targeting capability of various nanocarrier platforms. The penetration of nanodrugs through the ophthalmic barrier on topical administration for ocular disease therapy. The symbols next to the nanocarriers show the penetration or targeting ability of the related nanocarriers [3]

Fig. 6

Designing Fe3O4–Avastin nanocomposite as a potential drug for AMD therapy. a Preparation and dextran coating of iron oxide NPs b Thiolation of Avastin c, d Avastin loading on the surface of Fe3O4 NPs e Intravitreal injection of Fe3O4–Avastin nanocomposite for AMD Therapy [87]

Fig. 7

Production of AuNPs using green synthesis for diabetic retinopathy therapy [100]

Fig. 8

The graphical representation of Nano-IOLs to prevent PCO; a The digital figure; b Nano-IOLs with nanostructured Au@SiO2 external rim; c The mechanism of action of Nano-IOLs for PCO prevention. The Nano-IOLs implanted in the cataract rabbit eyes prevent the lens fibrosis via area-confined photothermal therapy under the Near-infrared irradiation. Adapted with permission from [110]

Fig. 9

a Different lipid-based nanocarriers b The procedure followed by lipid-based nanocarriers overwhelming the ocular barrier [70]. NLCs: Nanostructured lipid carriers; CSNs: Core/shell nanoparticles

Fig. 10

Preparation of nano eye drops and their use for the treatment of glaucoma. Production of hollow ceria NPs and then their dual functionalization with ZM241385/chitosan and also loading with pilocarpine for usage as nano eye drops. Topical delivery of the nano eye drops and their pharmacological/biological functions for opening the tight junctions of corneal epithelium, targeting drug molecules toward the ciliary body tissue, and attenuation of inflammation and oxidative stress for successful treatment of glaucoma [158]

Fig. 11

Diagram illustrating how MIONs might be beneficial in the tissue regeneration area. Adapted with permission from [166]