In vitro effects of meloxicam on metabolism in articular chondrocytes from dogs with naturally occurring osteoarthritis

Metabolic responses of meniscal tissue to focal collagenase degeneration

Purpose: The objective of this study was to determine the responses of normal meniscus to collagenase activity. It was hypothesized that meniscal explants exposed to collagenase would significantly increase release of pro-inflammatory cytokines and degradative enzymes, in a dose-dependent manner, compared to control.Methods: Menisci were harvested from adult dogs (n = 6) euthanized for reasons unrelated to this study. Meniscal explants were created from the central portion of lateral and medial meniscus. Explants were injected with 100 µl collagenase at a concentration of 50 µg/ml, 5 µg/ml, or 0 µg/ml of collagenase. Explants were cultured for 12 days, and media were changed and collected every 3 days for biomarker analyses. Differences among collagenase concentrations were determined by a three factor ANOVA with adjustment for multiple comparisons, with pre-adjustment statistical significance set at p < 0.05.Results: When data from all explants were compared, the 50 µg group released significantly higher IL-6 and PGE2, and the 5 µg group released significantly higher levels of MMP-3 and CTX-II compared to the 0 µg group. Explants from the medial meniscus released significantly more MMP-1, MMP-2, MMP-3, and MMP-13 in response to stimulation with 5 µg/ml of collagenase compared to explants from the lateral meniscus.Discussion: The data from this study indicate that in response to localized degradative enzyme activity, the meniscus increases the release of pro-inflammatory and degradative biomarkers in a dose-dependent manner. Further, these data indicate potential differences in metabolic responses of lateral versus medial menisci to collagenase insult.

Development and validation of ultra-performance liquid chromatography method for the determination of meloxicam and its impurities in active pharmaceutical ingredients

The main objective was to develop a suitable and rapid ultra-performance liquid chromatography (UPLC) method for the quantitative determination of meloxicam and its impurities. Starting from data in literature, we calculated the new parameters to translate a high performance liquid chromatography method used for the analysis of meloxicam with its major degradation products to UPLC method, and then we switched on many trials to optimize and improve its analytical performance. Chromatographic separation was achieved on ACQUITY UPLC HSS-T3 (2.1×100mm, 1.8μm). The eluted compounds were monitored at 260nm and 350nm. The flow rate was set at 0.4mL/min, injection volume at 0.8μl, and the column oven temperature was maintained at 45°C. The developed method was validated according to the International Conference on Harmonisation (ICH) guidelines for specificity, linearity, accuracy, precision, robustness, quantification limit, detection limit; and then applied to stability study of meloxicam subjected to different ICH prescribed stress conditions (hydrolysis, oxidation, heat and photolysis). The results show that the new UPLC method enables separation of meloxicam from its impurities in only 5min with a total mobile phase consumption of 1.8mL. All impurities get separated with good peak shapes and resolution factor greater than 2. The new method indicates stability and proved to be specific, precise accurate with linear correlation between concentrations and peak areas, allowing gain of more than six times analysis and more than twenty times solvent consumption, so in cost. Therefore, it can be beneficial for pharmaceutical industrial output.

A quicker degradation rate is yielded by a novel kind of transgenic silk fibroin consisting of shortened silk fibroin heavy chains fused with matrix metalloproteinase cleavage sites

Degradation performance of silk fibroin is an important property for its medical applications. Herein we constructed a shortened silk fibroin heavy chain protein fused with a matrix metalloproteinase cleavage site (SSFH-MMP) along with a glutathione S-transferase tag ahead. The digestion assay shows it can be cut by matrix metalloproteinase-2 (MMP-2) at its MMP cleavage site. Furthermore, we introduced the SSFH-MMP into silk fibroin by genetic modification of silkworms in order to increase the degradation rate of the silk fibroin. After acquisition of a race of transgenic silkworms with the coding sequence of the MMP cleavage site in their genomic DNA, we tested some properties of their silk fibroin designated TSF-MMP. The results show that the TSF-MMP has MMP cleavage sites and yields a quicker degradation rate during dilution in MMP-2 enzyme buffer or implantation into tumor tissues compared with that of normal silk fibroin. Moreover, the TSF-MMP is in vitro non-toxic to human bone marrow mesenchymal stem cells (hBM-MSCs) indicating that the TSF-MMP may become a biomaterial with a quicker degradation rate for its medical applications.