Browsing by Keyword "Hydrogel"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Confocal and Histological Features After Poly(Ethylene Glycol) Diacrylate Corneal Inlay Implantation(2019-11) Bidaguren, Aritz; Mendicute, Javier; Madarieta, Iratxe; Garagorri, Nerea; Biomateriales; Tecnalia Research & InnovationPurpose: To evaluate the in vivo biocompatibility of photopolymerized poly(ethylene glycol) diacrylate (PEGDA) intrastromal inlays in rabbit corneas. Methods: Sixty-three eyes of 42 New Zealand rabbits were included. Manual intrastromal pockets were dissected in 42 eyes. PEGDA inlays were obtained using a specifically designed photomask and were inserted in the intrastromal pocket of 21 eyes (inlay group); the remaining 21 right eyes did not receive any implant (pocket-only group). Twenty-one eyes with no intervention were used as controls. In vivo confocal microscopy (IVCM) was performed at every visit. After 2 months, rabbits were sacrificed and corneas removed for histological analysis. Results: Corneas remained clear in all but two animals, and five cases of corneal neovascularization were seen (P = 0.2). Inlays remained stable without evidence of lateral or anterior migration, and no other complications were observed. No changes in anterior and posterior keratocyte density (P = 0.3 and P = 0.1, respectively) or endothelial cell density (P = 0.23) were observed between groups during the study time by IVCM. On pathology samples, thinning of the epithelium over the inlay area and epithelial hyperplasia over the edges were observed. A polygonal empty space with no evidence of PEGDA hydrogel within the midstroma was seen in the inlay group. Keratocytes were normal in shape and number in the vicinity of the PEGDA implant area. Conclusions: Photopolymerized PEGDA intrastromal inlays have shown relatively good safety and stability in rabbit corneas. Inlays were biostable in the corneal environment and remained transparent during follow up. Translational Relevance: The investigated PEGDA is promising for the development of biocompatible intrastromal implants.Item Integrated 3D Hydrogel Waveguide Out-Coupler by Step-and-Repeat Thermal Nanoimprint Lithography: A Promising Sensor Device for Water and pH: A promising sensor device for water and pH(2018-10) Francone, Achille; Kehoe, Timothy; Obieta, Isabel; Saez-Martinez, Virginia; Bilbao, Leire; Khokhar, Ali Z.; Gadegaard, Nikolaj; Delgado Simao, Claudia; Kehagias, Nikolaos; Sotomayor Torres, Clivia M.; Tecnalia Research & Innovation; PRINTEXHydrogel materials offer many advantages for chemical and biological sensoring due to their response to a small change in their environment with a related change in volume. Several designs have been outlined in the literature in the specific field of hydrogel-based optical sensors, reporting a large number of steps for their fabrication. In this work we present a three-dimensional, hydrogel-based sensor the structure of which is fabricated in a single step using thermal nanoimprint lithography. The sensor is based on a waveguide with a grating readout section. A specific hydrogel formulation, based on a combination of PEGDMA (Poly(Ethylene Glycol DiMethAcrylate)), NIPAAm (N-IsoPropylAcrylAmide), and AA (Acrylic Acid), was developed. This stimulus-responsive hydrogel is sensitive to pH and to water. Moreover, the hydrogel has been modified to be suitable for fabrication by thermal nanoimprint lithography. Once stimulated, the hydrogel-based sensor changes its topography, which is characterised physically by AFM and SEM, and optically using a specific optical set-up.