Drug delivery strategies to improve the treatment of corneal disorders

Abstract

Anterior eye disorders including dry eye syndrome, keratitis, chemical burns, and trauma have varying prevalence rates in the world. Classical dosage forms based-topical ophthalmic drugs are popular treatments for managing corneal diseases. However, current dosage forms of ocular drugs can be associated with major challenges such as the short retention time in the presence of ocular barriers. Developing alternative therapeutic methods is required to overcome drug bioavailability from ocular barriers. Nanocarriers are major platforms and promising candidates for the administration of ophthalmic drugs in an adjustable manner. This paper briefly introduces the advantages, disadvantages, and characteristics of delivery systems for the treatment of corneal diseases. Additionally, advanced technologies such as 3D printing are being considered to fabricate ocular drug carriers and determine drug dosages for personalized treatment. This comprehensive review is gathered through multiple databases such as Google Scholar, PubMed, and Web of Science. It explores information around "ocular drug delivery systems'', "nano-based drug delivery systems'', "engineered nanocarriers'', and "advanced technologies to fabricate personalized drug delivery systems''.

Keywords: 3D printing; Corneal disorders; Drug delivery systems; Personalized medicine.

Graphical abstract

Fig. 1

Key bio-barriers of the anterior segment of the eye (Reprinted with some modifications from Ref. [70]).

Fig. 2

Administration of drug delivery carriers to be used as the corneal segments and provide suitable therapeutic approaches for corneal disorders. (www.vecteezy.com).

Fig. 3

The chemical structures of drug carriers.

Fig. 4

(I) Schematic representation of the Gel/Alg-CDH inks used to 3D-printed hydrogel bilayer scaffolds loaded with rhEGF/TSA for rabbits with corneal ALK models. (II) The evaluation of 3D-printed hydrogel scaffolds containing rhEGF/TSA in rabbit ALK model. (A) The ALK procedure involves the removal of the corneal epithelium and partial of the corneal stroma, followed by hydrogel scaffold implantation and suturing. (B–E) The slit lamp images (left) and the AS-OCT images (right) show the normal cornea, the defected cornea (control group), the implantation of hydrogel group, and the implantation of rhEGF/TSA bilayer hydrogel group, respectively.