June 2015
Volume 56, Issue 7
Free
ARVO Annual Meeting Abstract  |   June 2015
Mechanical Properties of Four Carboxymethylated Hyaluronic Acid Hydrogel Polymer Formulations
Author Affiliations & Notes
  • Brittany Coats
    Mechanical Engineering, University of Utah, Salt Lake City, UT
  • McKenna MARIE Drysdale
    Mechanical Engineering, University of Utah, Salt Lake City, UT
  • Hee-Kyoung Lee
    Jade Therapeutics, Inc., Salt Lake City, UT
    Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT
  • Barbara M Wirostko
    Jade Therapeutics, Inc., Salt Lake City, UT
    Ophthalmology, University of Utah, Salt Lake City, UT
  • Footnotes
    Commercial Relationships Brittany Coats, None; McKenna Drysdale, None; Hee-Kyoung Lee, Jade Therapeutics (E), Jade Therapeutics (I); Barbara Wirostko, Jade Therapeutics (E), Jade Therapeutics (I), Jade Therapeutics (P), Jade Therapeutics (S)
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2015, Vol.56, 4167. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Brittany Coats, McKenna MARIE Drysdale, Hee-Kyoung Lee, Barbara M Wirostko; Mechanical Properties of Four Carboxymethylated Hyaluronic Acid Hydrogel Polymer Formulations. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):4167.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract
 
Purpose
 

Bioerodable hydrogel polymers are a promising topical drug delivery system because they are biocompatible, diffuse drug easily, and improve retention time. Toward this end, Jade Therapeutics is developing a proprietary biodegradable cross-linked, thiolated carboxymethylated hyaluronic acid (CMHA)-based hydrogel film for topical ocular applications. To assess the structural integrity of the film and establish baselines for future degradation studies, four different cross-linked CMHA formulations were evaluated in uniaxial stress relaxation and pull-to-failure tests before and after ethylene oxide sterilization.

 
Methods
 

Films were fabricated by varying the HA-based polymers (thiolated CMHA with or without gelatin) and cross-linkers (Poly(ethyleneglycol) diacrylate (PEGDA) or glutathione disulfide (GSSG)). The polymerized gel was dried at room temperature overnight. Dried strips (6 x 10 mm) were hydrated in phosphate buffered saline (PBS) for 24 hrs and dimensioned using an optical stereomicroscope. Hydrated specimens were mounted in custom clamps located in a PBS chamber attached to a material test system (Model 5943, Instron) and a 500 gram submersible load cell (LSB210, Futek). The stress relaxation protocol was applied at a rate of 1.0 in/min up to 9% strain in increments of 0.5% strain (Fig. 1). Pull-to-failure tests were performed at 1.0 in/min. All measured load and displacement data were converted to stress and strain. Elastic modulus, relaxation modulus, and ultimate stress were extracted.

 
Results
 

All four films exhibited non-linear stress-strain behavior. The CMHA-PEGDA film had the largest hydrated thickness (0.281±0.092 mm), the lowest relaxation modulus (35.4±3.2 kPa, Fig. 2) and lowest ultimate stress (26.2±19.9 kPa). Sterilization significantly increased the relaxation modulus and ultimate stress in all formulations, but following sterilization CMHA-PEGDA was the only formulation that remained comparable to standard soft contact lens properties.

 
Conclusions
 

CMHA-PEGDA was the most promising formulation in terms of both its comfort as a topical ocular film (i.e., low relaxation modulus) and structural integrity.  

 
Fig 1. Sample of the strain protocol applied to the hydrogels (maroon) and a typical load response to that strain protocol (red).
 
Fig 1. Sample of the strain protocol applied to the hydrogels (maroon) and a typical load response to that strain protocol (red).
 
 
Fig 2. Comparison of the low strain (0.5-4.5%) and high strain (5.0-9.0%) relaxation moduli for each formulation before and after sterilization.
 
Fig 2. Comparison of the low strain (0.5-4.5%) and high strain (5.0-9.0%) relaxation moduli for each formulation before and after sterilization.

 
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×