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You searched for +publisher:"Georgia Tech" +contributor:("Nickerson, John"). Showing records 1 – 3 of 3 total matches.

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Georgia Tech

1. Kim, Yoo C. Targeted drug delivery within the eye.

Degree: PhD, Chemical and Biomolecular Engineering, 2013, Georgia Tech

This work introduces novel approaches to enhance targeting of pharmacotherapies to cornea, ciliary body, choroid, and posterior segment of the eye using microneedles as a drug delivery platform. The first part of the work determines the ability to deliver protein therapeutics into the cornea using coated microneedles to suppress corneal neovascularization in a rabbit model. The data show that highly targeted delivery of the anti-vascular endothelial growth factor protein therapeutic gave a better biological response of suppressing neovascularization with 11,900 times less dosage compared to topical administration. The second part of the research aims to develop novel formulations to target ciliary body and choroid via suprachoroidal delivery. The results show that a strongly non-Newtonian fluid can be used to slow down the spreading of the particles at the injection site up to 2 months. The results also show that a high molecular weight formulation with weakly non-Newtonian fluid can be used to reach 100% coverage of the choroidal surface with a single injection. The third part of the research aims to determine the biological response of targeting anti-glaucoma therapeutics to the ciliary body in a rabbit model. The results show we can achieve 500- to 1000-fold dose sparing by targeted delivery via supraciliary delivery. The fourth and last part of the research aims to develop novel emulsion droplets to target different locations within the eye using a gravity-mediated delivery technique via suprachoroidal space injection. The results show that we can deliver up to 73% of injected polymeric particles posterior to the equator of the eye. Overall this work demonstrates that microneedles have the capability to deliver pharmacotherapies to cornea, ciliary body, choroid, and posterior of the eye in a highly targeted manner and provide significant dose sparing in the rabbit model. Advisors/Committee Members: Prausnitz, Mark (advisor), Hess, Dannis (committee member), Champion, Julie (committee member), Edelhauser, Henry (committee member), Nickerson, John (committee member).

Subjects/Keywords: Drug delivery; Eye

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APA (6th Edition):

Kim, Y. C. (2013). Targeted drug delivery within the eye. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/52971

Chicago Manual of Style (16th Edition):

Kim, Yoo C. “Targeted drug delivery within the eye.” 2013. Doctoral Dissertation, Georgia Tech. Accessed March 25, 2019. http://hdl.handle.net/1853/52971.

MLA Handbook (7th Edition):

Kim, Yoo C. “Targeted drug delivery within the eye.” 2013. Web. 25 Mar 2019.

Vancouver:

Kim YC. Targeted drug delivery within the eye. [Internet] [Doctoral dissertation]. Georgia Tech; 2013. [cited 2019 Mar 25]. Available from: http://hdl.handle.net/1853/52971.

Council of Science Editors:

Kim YC. Targeted drug delivery within the eye. [Doctoral Dissertation]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/52971

2. Patel, Samikumar R. Suprachoroidal drug delivery to the eye using hollow microneedles.

Degree: PhD, Chemical Engineering, 2011, Georgia Tech

Delivering drugs to effectively treat diseases of the back of the eye can be a challenging task. Although pharmacological therapies exist, drug delivery devices and techniques are not very effective at targeting delivery of drugs to the diseased tissues. This work introduces a novel approach to effectively deliver drugs to target tissues such as the choroid and retina. The approach involves a device, a hollow microneedle, to administer the drug formulation into a unique location in the eye, the suprachoroidal space. This new route of administration and a device to accomplish the delivery may provide an effective way to treat diseases of the choroid and retina. The first part of the work determines the ex-vivo feasibility of delivering materials within the suprachoroidal space. The results show that fluids and particles can be delivered into the suprachoroidal space of rabbit, pig and human eyes using a hollow microneedle. It further examines the important parameters for injection of the particles within the suprachoroidal space. The data shows that injection pressure and microneedle length are important parameters for effective delivery of particles. The results lead to a theory on the mechanism by which the particles are delivered into the suprachoroidal space. The second part of the research aims to develop a reliable in vivo delivery device and study the surface area coverage of materials injected into the suprachoroidal space. A hollow glass microneedle device is developed and for the first time shown to be effective in delivering a fluid into the suprachoroidal space in vivo. Up to 100 µL of India ink could be delivered into rabbit eyes in vivo and the spread within the suprachoroidal space is characterized. The results show that a single microneedle injection can cover a significant percentage of the available suprachoroidal space. This is the first study to examine the spread of a material injected into the suprachoroidal space of a live animal. A hollow metal microneedle device is also developed and shown to be effective. The device was able to inject up to 150 µL of latex into suprachoroidal space of fresh human cadaver eyes. The spread of latex is characterized and the results also show that a significant portion of the suprachoroidal space can be covered. The final part of the study examines the clearance of materials injected into the suprachoroidal space of rabbit eyes in vivo. First a comparison of a suprachoroidal injection to a conventional intravitreal injection shows that a suprachoroidal injection is more targeted to the chorioretinal tissues. In addition hollow microneedles are shown to effectively target macromolecules and a therapeutic antibody to the chorioretinal tissues. A study of the clearance kinetics show half lives within the suprachoroidal space on the order of several hours. Nano- and microparticles were also injected into the suprachoroidal space and showed very effective targeting. These non-degradable particles are shown to be present in the suprachoroidal space for months. Basic… Advisors/Committee Members: Prausnitz, Mark - Committee Chair, Edelhauser, Henry - Committee Co-Chair, Bommarius, Andreas - Committee Member, Nenes, Athanasios - Committee Member, Nickerson, John - Committee Member.

Subjects/Keywords: Eye diseases; Medical device; Nanoparticles; Microparticles; Drug delivery devices; Eye Diseases; Choroid; Retina

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Patel, S. R. (2011). Suprachoroidal drug delivery to the eye using hollow microneedles. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/47816

Chicago Manual of Style (16th Edition):

Patel, Samikumar R. “Suprachoroidal drug delivery to the eye using hollow microneedles.” 2011. Doctoral Dissertation, Georgia Tech. Accessed March 25, 2019. http://hdl.handle.net/1853/47816.

MLA Handbook (7th Edition):

Patel, Samikumar R. “Suprachoroidal drug delivery to the eye using hollow microneedles.” 2011. Web. 25 Mar 2019.

Vancouver:

Patel SR. Suprachoroidal drug delivery to the eye using hollow microneedles. [Internet] [Doctoral dissertation]. Georgia Tech; 2011. [cited 2019 Mar 25]. Available from: http://hdl.handle.net/1853/47816.

Council of Science Editors:

Patel SR. Suprachoroidal drug delivery to the eye using hollow microneedles. [Doctoral Dissertation]. Georgia Tech; 2011. Available from: http://hdl.handle.net/1853/47816


Georgia Tech

3. Jiang, Ninghao. Ocular drug delivery using microneedles.

Degree: PhD, Chemical Engineering, 2006, Georgia Tech

Traditional methods of drug delivery to the eye include topical application, intraocular injection and systemic administration; however, each method has its limitation to efficiently delivery drugs to the back of the eye. In this study, microneedles were tested to provide targeted drug delivery into the eye in a minimally invasive way. To better interpret subsequent microneedle studies, we first quantified lateral drug diffusion profile within the sclera, by carrying out a diffusion study of a model compound, sulforhodamine, through human cadaver sclera, and developing a theoretical model for prediction of drug delivery kinetics and distribution. The results showed that measurable amounts of sulforhodamine were detected at distances of 5 and 10 mm from the sulforhodamine donor reservoir at 4 h and 3 days, respectively. The effective lateral diffusivity of sulforhodamine was determined to be 3.82 x 10-6 cm2/s, which is similar in magnitude to the transverse diffusivity. We next assessed the capability of using coated solid metal microneedles to deliver drugs into the ocular tissue in both in vitro and in vivo scenarios. The in vitro insertion tests showed that these microneedles were mechanically strong enough to penetrate into human cadaver sclera, and the coating solution rapidly dissolved off the needles after insertion and had been deposited within the tissue. In the in vivo experiments, microneedle delivery exhibited elevated fluorescein levels in the rabbit eye 60 times greater than that delivered by topical application of the equivalent dose. Similarly, microneedle delivery of pilocarpine caused rapid and extensive pupil constriction. Safety exams reported no inflammatory responses in the eye after microneedle administrations. We also used hollow glass microneedles to infuse solutions into the sclera tissue in vitro and examined the physiological barriers for flow. On average, 18 microliters of sulforhodamine solution and a solution containing nanoparticles was delivered into the sclera upon retraction of the microneedle. Successful delivery of micron-sized particles into the sclera could be improved by breaking down tightly packed collagen and GAG fibers using either collagenase or hyaluronidase. Advisors/Committee Members: Prausnitz, Mark R. (Committee Chair), Allen, Mark (Committee Member), Edelhauser, Henry (Committee Member), Geroski, Dayle (Committee Member), Nickerson, John (Committee Member), Sambanis, Athanassios (Committee Member).

Subjects/Keywords: Drug delivery; Eye; Microneedles; Drug delivery devices; Eye; Hypodermic needles; Sclera

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Jiang, N. (2006). Ocular drug delivery using microneedles. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/19796

Chicago Manual of Style (16th Edition):

Jiang, Ninghao. “Ocular drug delivery using microneedles.” 2006. Doctoral Dissertation, Georgia Tech. Accessed March 25, 2019. http://hdl.handle.net/1853/19796.

MLA Handbook (7th Edition):

Jiang, Ninghao. “Ocular drug delivery using microneedles.” 2006. Web. 25 Mar 2019.

Vancouver:

Jiang N. Ocular drug delivery using microneedles. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2019 Mar 25]. Available from: http://hdl.handle.net/1853/19796.

Council of Science Editors:

Jiang N. Ocular drug delivery using microneedles. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/19796

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