Scalable diclofenac lauryl ester prodrug nanoparticles: a promising strategy for reducing inflammation associated with intervertebral disc degeneration

As the most frequent clinical problem, intervertebral disc degeneration (IVDD) and associated inflammatory pain are still a big challenge, thus there is a need for improved and more lasting therapeutic approaches. In this study, a lipidic prodrug of diclofenac, Diclofenac Lauryl Ester (L-DCF), was synthesized and formulated into nanoparticles (Nanofenac-L) using the ethanol injection method followed by microfluidization. The encapsulation efficiency of Nanofenac-L was > 97% with sustained drug release, releasing around 65% of the diclofenac in 48 h. The therapeutic potential of Nanofenac-L was evaluated in rat intervertebral disc-derived nucleus pulposus cells. Nanofenac-L was found to be more effective than free Diclofenac Sodium (DCF-Na) in terms of anti-inflammatory activity, which was confirmed with significant suppression of COX-2 and Substance P. Furthermore, Nanofenac-L increased the expression of antioxidant genes in cells, such as SOD1, GPX1 and PRDX1. Preventive treatment was found to have shown therapeutic value whereas the curative treatment yielded a significant therapeutic effect indicating the possibility of Nanofenac-L to alleviate inflammation as well as to slow down disease progression. Altogether, these results suggest that Nanofenac-L could represent a promising long-lasting anti-inflammatory, pain relieving and antioxidant nanotherapeutic. Comprehensive preclinical and clinical evaluation is essential to translate these findings into viable therapies.