Different hyaluronan concentration determinate distinctive physicochemical and biological properties of the intra-articular gel but does not affect satisfactory clinical outcome

Intra-articular injection of hyaluronic acid (HA) has been established as a suitable treatment for osteoarthritic (OA) joints, able to effectively relieve the disease symptoms. However, HA-based medical devices available on the market differ in their key properties that finally might radically influence their clinical effectiveness. This study aimed to evaluate and compare the physicochemical and biological properties of two different hyaluronic acid-based gels intended for intra-articular injection into large synovial joints and subsequently determine if observed differences have reflection in clinical outcome related to their use. Samples of Biolevox HA and Biolevox HA ONE (Biovico, Poland) provided from standard production batches were included in the analysis. The HA-based products were analyzed in order to assess their physicochemical properties, cytotoxicity, and the ability to rescue a negative impact of the pro-inflammatory-inducing agent on chondrocyte gene expression levels. Additionally, the clinical recognition of the HA products included in this study was evaluated. HA gels tested in this study differ from each other in terms of their physicochemical characteristics, with a higher product viscosity as a result of higher molecular weight, and higher concentration of hyaluronan in Biolevox HA ONE. Tested HA gels were not able to negatively affect the cell viability-regardless gel concentration used, what excluded any cytotoxic properties. Analysis of the gene expression showed that tested HA gels were able to effectively restore the down-regulated expression rate of bCol2a1 and bAcan in chondrocytes stimulated with rBoIL-1. Finally, the use of both Biolevox HA and Biolevox HA ONE gels was evaluated by the majority of physicians as very well-tolerated and painless by the patients. We show here that precisely tailored physicochemical properties of the HA products can provide desired biological properties of the gel and guarantee beneficial outcome related to the product.