Novel Contact Lenses Embedded with Drug-Loaded Zwitterionic Nanogels for Extended Ophthalmic Drug Delivery

Abstract

Therapeutic ophthalmic contact lenses with prolonged drug release and improved bioavailability have been developed to circumvent tedious eye drop instillation. In this work, zwitterionic nanogels based on poly(sulfobetaine methacrylate) (PSBMA) were easily fabricated by one-step reflux-precipitation polymerization, with the advantages of being surfactant-free and morphology controlled. Then, the ophthalmic drug levofloxacin (LEV) was encapsulated into the nanogels. A set of contact lenses with varied nanogel-loading content was fabricated by the cast molding method, with the drug-loaded nanogels dispersed in pre-monomer solutions composed of 2-hydroxyethyl methacrylate (HEMA) and N-vinyl-2-pyrrolidone (NVP). The structure, surface morphology, water contact angle (WCA), equilibrium water content (EWC), transmittance, and mechanical properties of the contact lenses were subsequently investigated, and in vitro drug release and biocompatibility were further evaluated. As a result, the optimized contact lens with nanogel-loading content of 8 wt% could sustainably deliver LEV for ten days, with critical lens properties within the range of recommended values for commercial contact lenses. Moreover, cell viability assays revealed that the prepared contact lenses were cytocompatible, suggesting their significant potential as an alternative to traditional eye drops or ointment formulations for long-term oculopathy treatment.

Recent advances in various stimuli-responsive hydrogels: from synthetic designs to emerging healthcare applications

“…10 Nanogels are well defined as small-sized nanoparticles of hydrogels with sizes ranging from 1 to 1000 nm. 11 The nanogel networks generally consist of hydrophilic polyionic or amphiphilic polymers. These systems are also considered to be smart nanocarriers due to their exclusive characteristics.…”

Synthesis and Characterization of a Novel Dual-Responsive Nanogel for Anticancer Drug Delivery

“…Oxidative Medicine and Cellular Longevity feature of P(VCL-co-AA) and Dox@P(VCL-co-AA) in an aqueous solution [50]. Moreover, they have significantly been shrunk under dry conditions [50].…”

“…In summary, after Dox loading by P(VCL-co-AA), the diameter of the polymeric nanogels becomes smaller, and their aggregation increases. It is noteworthy that the hydrodynamic size calculated from DLS was larger than that observed by SEM, due to the highly swollen feature of P(VCL-co-AA) and Dox@P(VCL-co-AA) in an aqueous solution [ 50 ]. Moreover, they have significantly been shrunk under dry conditions [ 50 ].…”

“…It is noteworthy that the hydrodynamic size calculated from DLS was larger than that observed by SEM, due to the highly swollen feature of P(VCL-co-AA) and Dox@P(VCL-co-AA) in an aqueous solution [ 50 ]. Moreover, they have significantly been shrunk under dry conditions [ 50 ]. The particle size distribution of P(VCL-co-AA) and Dox@P(VCL-co-AA) is illustrated in Figure 6 .…”

Surface Self-Assembly Construction of Therapeutic Contact Lens with Bacterial “Kill-Releasing” and Drug-Reloading Capabilities for Efficient Bacterial Keratitis Treatment

“…Contact lenses, originally used for vision correction, recently have been adopted for ocular delivery of antimicrobial agents to treat infectious keratitis due to extended corneal contact, drug retention time in ocular surface, improved corneal permeation, and biosafety. , In particular, various drug delivery strategies have been extensively applied in contact lenses (CLs), including soaking, molecular imprinting, embedding, and surface coating. − For example, Liu et al prepared a multilayer-silver nanoparticle (AgNP)-loaded contact lens through a mussel-inspired facile method for early treatment of bacterial keratitis . However, poor biosafety and biocompatibility caused by the release of metal ions may restrict their applications .…”