Nanotherapies for the treatment of ocular diseases

Visual tracing of diffusion and biodistribution for amphiphilic cationic nanoparticles using photoacoustic imaging after ex vivo intravitreal injections

“…[8][9][10][11] A series of drug carriers based on poly(ethylene glycol)-poly(ε-caprolactone) (PEG-PCL) and poly(ethylene glycol)-poly(l-lactide-coglycolide) amphiphilic nanoparticles (NPs) have been exploited for more efficient drug delivery via intravitreal administration. [12][13][14][15] They are considered essential for overcoming the current limitations by facilitating frequent and sustained release of retinal medications.…”

Multifunctional organic–inorganic hybrid nanoparticles and nanosheets based on chitosan derivative and layered double hydroxide: cellular uptake mechanism and application for topical ocular drug delivery

“…It has been shown that nanotherapies for the treatment of ocular diseases can efficiently improve the bioavailability by prolonging drug residence time on the ocular surface, as well as the permeability across the corneal and conjunctival epithelium. 2 Layered double hydroxides (LDHs), a class of anionic clay materials, are found to be a potential inorganic nanocarrier for drug and gene delivery due to their large specific surface area (100-300 m unique properties. Organic-inorganic hybrid LDH nanocomposites consist mainly of three types, organic-coated inorganic hybrid LDH nanoparticles ( Figure 1A), organic-intercalated inorganic hybrid LDH nanoparticles ( Figure 1B) and organicinorganic hybrid LDH nanosheets ( Figure 1C).…”

Mucoadhesive polymers in ophthalmic therapy

“…The volume of a dispensed eye drop is [5][6] times greater than the tear fluid volume on the ocular surface. During eye drop instillation, the fluid may flow out of the eye, followed by reflex blinking and a possibly increase in tear secretion, especially if the eye drop contains an irritant Reimondez-Troitiño et al, 2015). Both the pH of the drug delivery system and the osmolality of the formulation must be similar to those of the natural tear film, as otherwise the formulation can cause increased tearing and irritation, resulting in poor therapeutic efficiency .…”

“…The corneal surface and conjunctiva are covered by a mucin coat, secreted by the goblet cells of the conjunctiva, with the functions of hydration, cleaning, lubrication and defence against pathogens. The corneal epithelium contains five cell layers, which are very well sealed, because the cells are joined by tight junctions and gap junctions, and they provide resistance against both hydrophilic and lipophilic active ingredients Reimondez-Troitiño et al, 2015). Another possibility for drug removal is absorption of the drug into the systemic circulation (Urtti, 2006).…”

“…The most common are eye ointments, prodrugs, penetration enhancers, liposomes, niosomes, nanoparticles, nanospheres, nanosuspensions, microemulsions and viscosity enhancers (mucoadhesive polymers, gels and in situ forming gels) Reimondez-Troitiño et al, 2015).…”