Replica-mold nanopatterned PHEMA hydrogel surfaces for ophthalmic applications

Abstract

Biomimicking native tissues and organs require the development of advanced hydrogels. The patterning of hydrogel surfaces may enhance the cellular functionality and therapeutic efficacy of implants. For example, nanopatterning of the intraocular lens (IOL) surface can suppress the upregulation of cytoskeleton proteins (actin and actinin) within the cells in contact with the IOL surface and, hence, prevent secondary cataracts causing blurry or opaque vision. Here we introduce a fast and efficient method for fabricating arrays consisting of millions of individual nanostructures on the hydrogel surface. In particular, we have prepared the randomly distributed nanopillars on poly(2-hydroxyethyl methacrylate) hydrogel using replica molding and show that the number, shape, and arrangement of nanostructures are fully adjustable. Characterization by atomic force microscopy revealed that all nanopillars were of similar shape, narrow size distribution, and without significant defects. In imprint lithography, choosing the appropriate hydrogel composition is critical. As hydrogels with imprinted nanostructures mimic the natural cell environment, they can find applications in fundamental cell biology research, e.g., they can tune cell attachment and inhibit or promote cell clustering by a specific arrangement of protrusive nanostructures on the hydrogel surface.

Exploring the Potential of Nanoporous Materials for Advancing Ophthalmic Treatments

“…The nanopores, coined "nanopillars", are adjustable in number, shape, and arrangement, potentially allowing for a drug storage depot adjustable based on ocular drug needs. Given that pHEMA has a long history of use in ophthalmic applications, toxicity is not expected, and the study's preliminary in vitro cytotoxicity testing with fibroblasts corroborates this [80]. The challenge with pHEMA is the potential for calcification over time [81] and porosity may seed additional calcification.…”

Hydrogel-Based Therapy for Age-Related Macular Degeneration: Current Innovations, Impediments, and Future Perspectives

“…The versatility of synthetic hydrogels allows for the precise tuning of pore size and degradation rates, making them highly suitable for creating customized drug delivery platforms. pHEMA, for instance, has been utilized as a material for making soft contact lenses due to its unique transparency and satisfactory compatibility with ocular tissue [ 22 , 23 ]. Hybrid hydrogels represent an innovative fusion of both natural and synthetic materials, aiming to synergize the advantages of both categories.…”

Current State of the Art and Next Generation of Materials for a Customized IntraOcular Lens according to a Patient-Specific Eye Power

“…PHEMA is a transparent, biocompatible, nontoxic, non-degradable, non-adhesive, hydrophilic hydrogel material with high and tuneable mechanical strength, largely applied in ophthalmology. This polymer has been synthesized by Tomáš Krajňák et al [ 97 ] from the precursor monomer 2-hydroxyethyl methacrylate (HEMA) via thermally or radiatively (gamma, UV, blue-light) initiated free radical polymerization. XPS and FTIR analyses were employed to identify chemical bonds within the unmodified and patterned PHEMA surface, with results unchanged after the patterning.…”