β‑Amino Acid and Amino-Alcohol Conjugation of a Nonsteroidal Anti-Inflammatory Drug (NSAID) Imparts Hydrogelation Displaying Remarkable Biostability, Biocompatibility, and Anti-Inflammatory Properties

A well-known nonsteroidal anti-inflammatory
drug (NSAID), namely,
naproxen (Np), was conjugated with β-alanine and various combinations
of amino alcohols and l-alanine. Quite a few bioconjugates,
thus synthesized, were capable of gelling pure water, NaCl solution
(0.9 wt %), and phosphate-buffered saline (PBS) (pH 7.4). The hydrogels
were characterized by rheology and electron microscopy. Hydrogelation
was probed by FT-IR and temperature-variable 1H NMR studies.
Single-crystal X-ray diffraction (SXRD) of a nonhydrogelator and a
hydrogelator in the series established a useful structure–property
(gelation) correlation. MTT assay of the hydrogelators in the mouse
macrophage RAW 264.7 cell line showed excellent biocompatibility.
The prostaglandin E2 (PGE2) assay of the hydrogelators
revealed their anti-inflammatory response, which was comparable to
that of the parent NSAID naproxen sodium (Ns).