SMILE-Derived Corneal Stromal Lenticule: Experimental Study as a Corneal Repair Material and Drug Carrier.

PURPOSE: A detailed study of the physicochemical properties of SMILE-derived lenticules and evaluation of their drug delivery after loading with silver nanoparticles (AgNPs).

METHODS

The lenticules were decellularized and modified with crosslinking concentrations of 0.01 (0.01E/L), 0.05 (0.05E/L), and 0.25 (0.25E/L) mmol N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) per mg lenticule at 5:1 carbodiimide/N-hydroxysuccinimide (EDC/NHS) ratios. The degree of swelling, light transmittance, biomechanical properties, and stability of the non-crosslinked decellularized lenticules (DLs), 0.01E/L, 0.05E/L, and 0.25E/L were measured and characterized using Fourier transform infrared spectroscopy and transmission electron microscopy with non-crosslinked non-decellularized lenticules as controls. DLs, 0.01E/L, 0.05E/L, and 0.25E/L were soaked in AgNPs for 24 hours, and the concentration of the drug released was measured.

RESULTS

There was no significant difference in the degree of swelling between the groups ( P > 0.05). The light transmittance of the lenticules did not change after decellularization and crosslinking and decreased after loading with AgNPs. Non-decellularized lenticules biodegraded within 108 to 120 hours, and the other groups biodegraded within 96 to 108 hours in vitro. The 0.01E/L had the highest tensile strength. The absorption peak intensity ratio of the amide I band and the amide II band decreased, and the arrangement of collagen fibers was more compact in crosslinked decellularized lenticules. The 0.01E/L had the highest cumulative drug release (3.4 ± 0.91 μg).

CONCLUSIONS

Crosslinking decellularization improved the biomechanical properties and resistance to water absorption of lenticules, increased covalent bonds between collagen fibers, and improved drug delivery. Crosslinked decellularized lenticules can be used as a new corneal patch material and drug delivery carrier for drug AgNPs.