Biopolymeric corneal lenticules by digital light processing based bioprinting: a dynamic substitute for corneal transplant.

Digital light processing (DLP) technology has gained significant attention for its ability to construct intricate structures for various applications in tissue modeling and regeneration. In this study, we aimed to design corneal lenticules using DLP bioprinting technology, utilizing dual network bioinks to mimic the characteristics of the human cornea. The bioink was prepared using methacrylated hyaluronic acid and methacrylated gelatin, where ruthenium salt and sodium persulfate were included for mediating photo-crosslinking while tartrazine was used as a photoabsorber. The bioprinted lenticules were optically transparent (85.45% ± 0.14%), exhibited adhesive strength (58.67 ± 17.5 kPa), and compressive modulus (535.42 ± 29.05 kPa) sufficient for supporting corneal tissue integration and regeneration. Puncture resistance tests and drag force analysis further confirmed the excellent mechanical performance of the lenticules enabling their application as potential corneal implants. Additionally, the lenticules demonstrated outstanding support for re-epithelialization and stromal regeneration when assessed with human corneal stromal cells. We generated implant ready corneal lenticules while optimizing bioink and bioprinting parameters, providing valuable solution for individuals suffering from various corneal defects and waiting for corneal transplants.

Instant gels from mixtures of amines and anhydrides at room temperature.

A series of novel two-component organogel systems comprising of amines and anhydrides was developed. These two-component systems in aromatic solvents exhibit instantaneous gelation during mixing at room temperature without the requirement of any external stimulus such as heat, sonication, etc. The corresponding alcohols, however, failed to produce gel under similar condition. The structure-property relationship was investigated. The effect of mixing ratio of the two components as well as the effect of solvents on gelation was studied. A detail characterization of the organogels using electron microscopy, FTIR, (1)H NMR and X-ray diffraction spectroscopy, differential scanning calorimetry and rheology suggested formation of a hydrogen-bonded complex that induces creation of three dimensional entangled network structures which immobilize the solvent showing macroscopic gelation. The packing of hydrocarbon chains of the amines and π-π stacking interaction in aromatic amines were observed to play a decisive role in altering the thermal and mechanical stability of the organogels. The organogels formed by mixing aromatic amines with the anhydride exhibit exceptional thermal and mechanical stability compared to the aliphatic amines.