Suzana BV Mello,1 Elaine R Tavares,2 Adriana Bulgarelli,2 Eloisa Bonfá,1 Raul C Maranhão2,31Rheumatology Division, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil; 2Lipid Metabolism Laboratory, the Heart Institute (INCOR) of the Medical School Hospital, São Paulo, Brazil; 3Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, BrazilObjective: Commercial methotrexate formulations (MTX) have poor anti-inflammatory action for intra-articular treatment of rheumatoid arthritis.Our aim was to investigate whether an association between methotrexate and lipidic nanoemulsions (LDE) could improve MTX intra-articular action.Methods: For its association to LDE, MTX was previously esterified with dodecyl bromide.LDE-MTX was prepared by high pressure homogenization.
Antigen-induced arthritis (AIA) was achieved in rabbits sensitized with methylated bovine serum albumin, and the rabbits were subsequently intra-articularly injected with the antigen.Twenty-four hours illumivein after AIA induction, groups of four to nine rabbits were intra-articularly injected with increasing doses (0.0625–0.5 µmol/kg) of LDE-MTX, and were compared to treatment with 0.
5 µmol/kg commercial MTX, LDE alone, and saline (controls).Synovial fluid was collected 48 hours after AIA induction for analysis of protein leakage five finger death punch a decade of destruction and cell content.Synovial membranes were collected for histopathology.Uptake of LDE labeled with 3H-cholesteryl ether by the synovial tissue was also determined.
Results: Uptake of radioactive LDE by arthritic joints was 2.5-fold greater than by normal joints.Treatment with intra-articular LDE-MTX elicited a clear dose response pattern by reducing the synovial leukocyte infiltrate (P = 0.004) and protein leakage (P = 0.
032) when compared with arthritic non-treated joints.In contrast, the intra-articular injection of commercial MTX and LDE did not reduce leukocyte infiltrate or protein leakage.Toxicity to treatment was not observed in any of the animals.Conclusion: The association between LDE and MTX presented a marked anti-inflammatory effect that was absent after intra-articular commercial MTX treatment.
Therefore, the new formulation is a candidate for future clinical studies.Keywords: nanoparticles, cholesterol, methotrexate, arthritis, antigen-induced arthritis.