Ocular Therapeutix Internship

Ocular Internship, Summer 2021

Summer of 2021 I worked at Ocular Theraputix in their Research and Development Department, on hydrogel technologies. These hydrogels are formed from water-soluble polymers that are crosslinked using reactive esters and amines end groups. I learned a number of analytical techniques, such as spectrophotometry, solution formulation, and hydrogel-specific techniques such as gel time, persistence, swelling, and other characterization. I also got to work with rabbit eyes and understood the structure and spaces we were targeting for drug delivery.

Experimental Set Up

Testing different pH levels, molecular weights, and the number of arms on ester and amine molecules, to see the impact on gel time.

Gel Time

To test gel time, the gel is cast into vials suspended in a water bath at body temperature. A stir bar is placed inside. Initially, the bar spins smoothly and uniformly at the bottom of the vial. When the stir bar starts to wobble, as pictured, this is the signal that the solutions have gelled. I would measure how long it would take each concentration to gel.

Gel Casts

Gels cast into the teflon block, then set to incubate at body temperature. These gels were ultimately used for persistence and swell testing.

Gel Film and Tube Casts

Cast gels into the film box, as well as in teflon tubes. These gels were used for persistence and swell studies as well. The film box attempts to simulate the thickness of the gel in the suprachoroidal space in the eye. The films were very difficult to handle and cut out, and often ripped. After the swell studies, they were even more liable to breakage. Removing gels from tubes was also very difficult, as you had to slit the tube down one side, without cutting the gel, then peel the stiff tube back.

Eye Dissection

Dissecting the eyes of New Zealand White Rabbits to understand where the suprachoroidal space is.

Casting Microspheres

Casting drug microspheres using the overhead stirrer.

Observing Microspheres

Observing the microspheres using the starret microscope. Also used the starret for characterizing gel inserts.