title: The effects of cross-linked thermo-responsive PNIPAAm-based hydrogel injection on retinal function.
abstract: There is significant interest in biomaterials that provide sustained release of therapeutic molecules to the retina. Poly(N-isopropylacrylamide) (PNIPAAm)-based materials have received significant attention as injectable drug delivery platforms due to PNIPAAm's thermo-responsive properties at approximately 32 °C. While the drug delivery properties of PNIPAAm materials have been studied extensively, there is a need to evaluate the safety effects of hydrogel injection on retinal function. The purpose of this study was to examine the effect of poly(ethylene glycol) diacrylate (PEG-DA) crosslinked PNIPAAm hydrogel injection on retinal function. Utilizing scanning laser ophthalmoscopy (SLO), optical coherent tomography (OCT), and electroretinography (ERG), retinal function was assessed following hydrogel injection. In region near the hydrogel, there was a significant decrease in arterial and venous diameters (∼4%) and an increase in venous blood velocity (∼8%) 1 week post-injection. Retinal thickness decreased (∼6%) at 1 week and the maximum a- and b-wave amplitudes of ERG decreased (∼15%). All data returned to baseline values after week 1. These data suggest that the injection of PEG-DA crosslinked PNIPAAm hydrogel results in a small transient effect on retinal function without any long-term effects. These results further support the potential of PNIPAAm-based materials as an ocular drug delivery platform.
authors.affiliation: Department of Biomedical Engineering, Illinois Institute of Technology, 3255 South Dearborn Street, Wishnick Hall Room 314, Chicago, IL 60616, USA.
authors.forename: Sanja B
authors.initials: SB
authors.lastname: Turturro
authors.forename: Micah J
authors.initials: MJ
authors.lastname: Guthrie
authors.forename: Alyssa A
authors.initials: AA
authors.lastname: Appel
authors.forename: Pawel W
authors.initials: PW
authors.lastname: Drapala
authors.forename: Eric M
authors.initials: EM
authors.lastname: Brey
authors.forename: Victor H
authors.initials: VH
authors.lastname: Pérez-Luna
authors.forename: William F
authors.initials: WF
authors.lastname: Mieler
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Kang-Mieler
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D000180:Acrylic Resins; D000818:Animals; D004596:Electroretinography; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D009887:Ophthalmoscopy; D011108:Polymers / Q000737:chemistry*; D051381:Rats; D012160:Retina / Q000502:physiology*; D041623:Tomography, Optical Coherence
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate