Table II.
Design strategies for ocular cancer therapy based on administration route and material selection
Adminstration route | Drug release venues | Carrier Materials | Advantage | Disadvantage |
---|---|---|---|---|
Systemic | Injection in to blood stream | Degradable and hydrogel nanoparticles. Eg: N isopropyl acrylamide (NIPAM) nanoparticles.47 | Less invasive to ocular tissue | Blood ocular barrier hinders drug delivery; potential systemic drug toxicity.34 |
Topical | via corneal diffusion | Nanocapsules, nanoparticles and mucoadhesive polymers Eg: Chitosan nanoparticles.48 | Easy access to iris and ciliary body.33,34 | Poor drug delivery efficiency and unsuitable for posterior eye diseases.28 |
Sub-conjunctiva | Released from conjunctiva tissue | Polymeric nanoparticles.37 eg:polystyrene nanoparticles various sizes & charge | Prolonged drug release with increased drug delivery to uveal tissue. | Small (<20nm) nanoparticles may be cleared by lymphatic.37,38 |
Sub-tenon | Released from void space between Tenon’s capsule and sclera | No studies on subtenon injection of nanodevices. Mainly used for injection of drugs.49,50 | Prolonged drug penetration and low clearance from vitreous tissue.35 | Requires skilled surgeon for implantation and retinal pigment epithelium poses a barrier.35 |
Intravitreal | Direct injection in to the vitreous | PLA/PLGA nanoparticles.43,51,52 | Deliver high molecular weight drugs. Accumulation in the retina for long time periods.51 | May cause retinal detachment & endophthalmitis |