Table 1.

Polymeric nanoparticle distribution within the eye

Significant areas of distribution	Administration route	Polymer	Coating	Size (nm), Zeta Potential (mV)	Additional features	Suggested clinical use	Ref
Cornea	Topical	PCL	PVA	250, − 20*	Benzalkonium chloride	Controlled release of antibiotic drugs to treat corneal infection	[14]
	Subconjunctival	pRNA	None	10	PLGA-PEG-PLGA thermosensitive hydrogel	Delivery of anti-VEGF aptamer to reduce corneal neovascularization and graft rejection	[18]
Iris, Conjunctiva	Topical	PCL	PF68	165, − 20*	Benzalkonium chloride	Delivery of anti-inflammatory medications to treat iritis Controlled release of NSAIDs, antibiotics, or steroidal drugs to treat conjunctivitis	[14]
Ciliary body	Suprachoroidal injection	Polystyrene†	None	20–10,000	Carboxylmethylcellulose (700 kDa) and methylcellulose (90 kDa) solution	Delivery of β-blockers or carbonic anhydrase inhibitors for the treatment of glaucoma	[30]
Lens	Topical	PLGA	Gelatin	170, − 12*	None	Delivery of antioxidants for cataract prevention or chaperone proteins to reverse congenital cataracts and stabilize misfolded crystallin proteins Delivery of anti-VEGF for treatment of CNV	[26]
Choroid, Retina	Topical	PCL	PF68	165, − 20*	None	Delivery of anti-VEGF or corticosteroids for treatment of CNV or diabetic retinopathy Delivery of antioxidants to slow progression of dry AMD	[14]
	Topical	PLGA	Chitosan	170, 35*	None	Delivery of antioxidants to slow progression of dry AMD Delivery of anti-VEGF and/or corticosteroids to treat diabetic retinopathy or CNV	[26]
	Suprachoroidal injection	Polystyrene†	None	20–10,000	Hyaluronic acid solution	Delivery of anti-VEGF or corticosteroids for treatment of CNV or diabetic retinopathy Delivery of antioxidants to slow progression of dry AMD	[30]
Retina	Subconjunctival injection	pRNA	None	10	PLGA-PEG-PLGA thermosensitive hydrogel	Delivery of anti-VEGF aptamer to treat diabetic retinopathy	[18]
	Intravitreal injection	PLGA	PVA	227 ± 15, − 2 ± 1	None	Delivery of anti-VEGF and/or corticosteroids to treat diabetic retinopathy	[67]
	Intravitreal injection	Glycosylated chitosan	None	229.1 ± 8.7, 16.4 3.2	None	Delivery of neuroprotective agents to ganglion cells to treat glaucoma	[63]
	Intravitreal injection	CK/PEG-DNA polyplex	None	60 ± 6, − 1 ± 4	None	Gene delivery to the retina to treat inherited retinal degeneration VEGF silencing to treat exudative AMD	[67]
Inner Retina	Intravitreal injection	Hyaluronic acid	None	213.4 ± 10.3, − 26.2 ± 4.0	None	Delivery of anti-VEGF, kinase inhibitors, or gene delivery to silence VEGF for treating diabetic retinopathy	[63]
	Intravitreal injection	Human serum albumin	None	326.3 ± 9.7, − 20.9 ± 2.0	None	Delivery of anti-VEGF, kinase inhibitors, or gene delivery to silence VEGF for treating diabetic retinopathy	[63]

*Data extracted from bar graph. ^†Polymer used as a proof of concept and is not necessarily intended for drug delivery