Evaluation of Intra-Articular Delivery Of The Internal Phase of A Sodium Hyaluronate and Indomethacin-Based Nanoemulsion in Primary Articular Chondrocytes

Abstract

In this study, we aimed to investigate the internalisation of the internal phase of a sodium hyaluronate (HNa) and indomethacin (Indo)-based nanoemulsion (NE) in murine articular chondrocytes, cells that secrete cartilage matrix. Immunofluorescence with antibodies against collagen II (Col2a1) and aggrecan (Acan) was used to assess collagen type II and aggrecan expression. RNA was extracted for analysing the expression of (metalloprotease 3) Mmp3, (metalloprotease 13) Mmp13, Acan, Col2a1, and Sox9 using polymerase chain reaction (PCR). Hyalgan was used as reference and a solution of each of the active substances (HNa and Indo) were used as controls. The chondrocytes reached confluence in a few hours, and 1% of the internal phase of the nanoemulsion exhibited a chondroprotective effect. Immunofluorescence using anti-Col II antibody showed expression of collagen, whereas that with anti-aggrecan antibody confirmed the expression of the matrix proteoglycan aggrecan, confirming the functional differentiation of the chondrocytes. Gene expression profiles showed that the expression of Col2a1 and Acan increased with the internal phase of the nanoemulsion (1% HNa-Indo), and that of Mmp13 and Mmp3 started decreasing after 24 h to almost undetectable after 4 days, indicating that the cells had completely differentiated and maintained a chondrocyte phenotype and protected the catabolic phenotype. Thus, our nanoemulsion can be used as a potential vehicle for improving the transdermal delivery of Indo and HNa.