Micro-channel diffusion characteristics of an implantable drug delivery device for age-related macular degeneration

2014 ◽  
Vol 21 (9) ◽  
pp. 1967-1974 ◽  
Author(s):  
Ramana M. Pidaparti ◽  
Jae-Hwan Lee ◽  
Hu Yang
Author(s):  
Jae-Hwan Lee ◽  
Ramana M. Pidaparti

New drugs for curing eye diseases have been developing for a decade and are very unique for each eye diseases such as glaucoma, cataracts, and age-related macular degeneration (AMD). It is estimated that 1.6 million adults in the US over the age of 50 and above suffer from age-related macular degeneration and about 200,000 cases are diagnosed annually. Worldwide, about 500,000 cases are diagnosed annually [1]. Drugs currently utilized for AMD are delivered via repeated intravitreal injections of the drug into the eye. Risks of repeated intravitreal injections can include intraocular infections (endophthalmitis), intraocular hemorrhage, and retinal detachment. Also, reducing the frequency of dosing will clearly benefit the patient by reducing the need for risky intravitreal injections and improving the pharmacokinetics of the drug in the eye. The eye disease of posterior segment (Dry and Wet) has limits to deliver the drug to retina region using typical eye drop. The drug injection using a needle with syringe can deliver but it barely provide right amount of doses, or over doses that may cause more severe problem such as swelling, fatigue, and damaging photoreceptor molecules. Furthermore, most drugs run away in a month so that repeated injection is necessary. Developing an implantable drug delivery device will help reduce the costs and risks associated with frequent injections and facilitate delivering the drug in a controlled manner and in the required amounts, and improve therapeutic efficacy and safety of drugs. This study focuses on the design, simulation and development of the implantable ocular drug delivery device.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Jae-Hwan Lee ◽  
Ramana M. Pidaparti ◽  
Gary M. Atkinson ◽  
Ramana S. Moorthy

Ocular diseases, such as, glaucoma, age-related macular degeneration (AMD), diabetic retinopathy, and retinitis pigmentosa require drug management in order to prevent blindness and affecting million of adults in USA and worldwide. There is an increasing need to develop devices for drug delivery to address ocular diseases. This study focuses on the design, simulation, and development of an implantable ocular drug delivery device consisting of micro-/nanochannels embedded between top and bottom covers with a drug reservoir made from polydimethylsiloxane (PDMS) which is silicon-based organic and biodegradable polymer. Several simulations were carried out with six different micro-channel configurations in order to see the feasibility for ocular drug delivery applications. Based on the results obtained, channel design of osmotic I and osmotic II satisfied the diffusion rates required for ocular drug delivery. Finally, a prototype illustrating the three components of the drug delivery design is presented. In the future, the device will be tested for its functionality and diffusion characteristics.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2035
Author(s):  
Bo Yang ◽  
Ge Li ◽  
Jiaxin Liu ◽  
Xiangyu Li ◽  
Shixin Zhang ◽  
...  

Age-related macular degeneration (AMD) is a degenerative eye disease that is the leading cause of irreversible vision loss in people 50 years and older. Today, the most common treatment for AMD involves repeated intravitreal injections of anti-vascular endothelial growth factor (VEGF) drugs. However, the existing expensive therapies not only cannot cure this disease, they also produce a variety of side effects. For example, the number of injections increases the cumulative risk of endophthalmitis and other complications. Today, a single intravitreal injection of gene therapy products can greatly reduce the burden of treatment and improve visual effects. In addition, the latest innovations in nanotherapy provide the best drug delivery alternative for the treatment of AMD. In this review, we discuss the development of nano-drug delivery systems and gene therapy strategies for AMD in recent years. In addition, we discuss some novel targeting strategies and the potential application of these delivery methods in the treatment of AMD. Finally, we also propose that the combination of CRISPR/Cas9 technology with a new non-viral delivery system may be promising as a therapeutic strategy for the treatment of AMD.


2014 ◽  
Vol 8 (2) ◽  
Author(s):  
Jonathan Marsh ◽  
Ramana M. Pidaparti

This paper presents an implantable device concept with applications for treating ocular diseases such as glaucoma, age-related macular degeneration (AMD), diabetic retinopathy, and retinitis pigmentosa. The design of a biodegradable drug delivery device concept consisting of a polydimethylsiloxane (PDMS) shell with a fluid reservoir and micro/nanofluidic tubes that allow the drug to be stored and delivered at a specified rate is discussed. Computational fluid dynamics simulations were conducted through various tube configurations in order to obtain the drug diffusion characteristics. The results from the simulation studies revealed information related to drug transport under varying design parameters. The design simulations were conducted with a desired rate. Based on results from several simulations, an optimization study was conducted to achieve the required dosage for about 2 years. The results obtained from the optimization study shows that the device concept can be extended for different drugs to treat ocular diseases.


2013 ◽  
Vol 11 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Stephen G Schwartz ◽  
Ingrid U Scott ◽  
Harry W Flynn ◽  
Michael W Stewart

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