Saturday, October 29, 2011
Hall 1-2 (San Jose Convention Center)
Celimar Valentin-Rodriguez, MSc
,
Biomedical Engineering, Purdue University, West Lafayette, IN
Tongalp Tezel, MD
,
School of Medicine, University of Louisville, Louisville, KY
Albena Ivanisevic, PhD
,
Biomedical Engineering, North Carolina State University, Raleigh, NC
Diabetic Retinopathy (DR) is the leading cause of blindness amongst adult Americans. Inadequate treatment results in an aggressive progression of DR to proliferative DR (PDR). In PDR, scar tissue forms (epiretinal membranes, ERM), causing further retinal damage. Careful and complete peeling of the inner limiting membrane (ILM) can facilitate removal of ERMs, reduce epiretinal tissue recurrence, and increase visual acuity. However, retinal trauma is a serious concern for patients undergoing ILM peeling. Our current research focuses on
the utilization of topographical and physico-chemical properties of ILM tissues extracted from diabetic patients to construct complex architectures composed of layer-by-layer films and nanoparticles to enhance adhesion of vitreoretinal instruments to these tissues. Atomic force microscopy imaging in air revealed the presence of globular structures in most of the ILM samples, coupled with fibrous structures in some of the samples. Modification of silicon nitride tips with oppositely charged functional groups showed changes in adhesion force at the membrane-tip interface. Nanoparticle-modified LbL films significantly increased the adhesion forces at the cantilever-ILM interface, compared to LbL films without particles.
Commercially available vitreoretinal surgical forceps were modified with the aforementioned LbL films. Surface topography analysis with scanning electron microscopy revealed that geometry of the instrument may affect the integrity of the film. Inductively-coupled plasma mass spectrometry analysis demonstrated that gold nanoparticles did not leach from the LbL film after 60 minutes. The final objective of this work will focus on characterizing the effect of vital dyes on the topographical characteristics of ILMs.
