L. Moser (Krems, AT)
Danube University KremsPresenter Of 2 Presentations
P065 - Biotribological Tests of Inflammatory Osteochondral Plugs After Treatment with Hyaluronic Acid (HA), Glucocorticoids (GC) and HA/GC
Abstract
Purpose
The current study aimed to investigate the effects of hyaluronic acid (HA), glucocorticoids and (GC) and a co-administration (HA/GC) on cytokine-treated bovine osteochondral plugs under biomechanical stress via biotribological testing.
Methods and Materials
Osteochondral plugs were harvested from three bovine knee joints. The plugs were treated with (positive control) or without (negative control) pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) for 1 week to simulate an OA environment. After seven days, the inflammatory medium was replaced by therapeutic medium (GC, HA, or GC/HA) for additional seven days. On day 14, biotribological testing was performed using PBS as a test fluid. Testing was standardized accordingly: an initial load of 180N for 10 minutes is followed by a resting phase of 10 min. This is followed by 3 cycles of repetitive sliding tests (2 mm/s at 180 N) for 10 minutes with a resting phase of 10 minutes between each cycle. The coefficient of friction (COF) was measured constantly during testing. Gene expression analysis, metabolic activity and measurements of sGAGs were carried out.
Results
In cytokine-treated plugs, COF increased compared to the negative control. HA led to decreased COF compared to positive control. Co-administration of HA/GC maintained the decreased COF. In all inflammatory conditions anabolic genes (COL2A1 and ACAN) decreased and catabolic genes (MMP1 and MMP13) increased compared to the negative control. Metabolic activity was lower in all inflammatory conditions compared to the untested control group at day 0. sGAG were increased in the positive control group compared to the negative control. HA and HA/GC decreased sGAGs compared to the positive control group and only adding GC alone.
Conclusion
Treatment of osteochondral plugs with HA led to a reduced COF and a decreased sGAG amount. A co-administration of HA/GC does not impair this effect. Thus, combining HA/GC has positive biotribological effects on bovine osteochondral plugs cultivated under inflammatory conditions.
P070 - Hyaluronic Acid Supports the Effects of Cortison and Avoids Cytotoxic Effects of Local Anesthetics in Human Articular Chondrocytes in Vitro
Abstract
Purpose
The current study aimed to investigate the chondrotoxicity of co-administrating local anesthetics (LA) with glucocorticoids (GC) and hyaluronic acid (HA) in vitro.
Methods and Materials
Human articular cartilage was obtained from five patients undergoing total knee arthroplasty. Chondrocytes were isolated, expanded and seeded in 24-well plates for experimental testing. Local anesthetics (Lidocaine 1%, Bupivacaine 0,5%, Ropivacaine 2%) were used separately and co-administered with each of the following substances: GC (Triamcinolone Hexacetonide (TH) 4,5mg/ml), GC plus HA (TH: 4,5mg/ml, HA: 22 mg/ml), HA (22mg/ml). Cells were incubated with the various conditions for one hour, before substances were discarded followed by two washing steps. Culture medium was added, and cells were incubated for 24 hours. After 24 hours microscopic images were taken, and metabolic activity was measured. Also, a viability assay using flow cytometry was performed.
Results
The addition of HA and GC/HA resulted in enhanced attachment and branched appearance of the chondrocytes compared to LA and LA/GC. Metabolic activity was better in all LA co-administered with HA and GC/HA than with GC and only LA (Figure 1). Flow cytometry revealed the lowest cell viability in lidocaine and the highest cell viability in ropivacaine (Figure 2). This finding was also confirmed by the live/dead assay.
Conclusion
In conclusion, HA supports the effect of GC and reduces chondrotoxic effects of LA in vitro. Thereby the co-administration of HA to LA and GC offers an alternative less chondrotoxic approach for treating patients with symptomatic osteoarthritis of the knee.
Presenter Of 2 Presentations
P065 - Biotribological Tests of Inflammatory Osteochondral Plugs After Treatment with Hyaluronic Acid (HA), Glucocorticoids (GC) and HA/GC
Abstract
Purpose
The current study aimed to investigate the effects of hyaluronic acid (HA), glucocorticoids and (GC) and a co-administration (HA/GC) on cytokine-treated bovine osteochondral plugs under biomechanical stress via biotribological testing.
Methods and Materials
Osteochondral plugs were harvested from three bovine knee joints. The plugs were treated with (positive control) or without (negative control) pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) for 1 week to simulate an OA environment. After seven days, the inflammatory medium was replaced by therapeutic medium (GC, HA, or GC/HA) for additional seven days. On day 14, biotribological testing was performed using PBS as a test fluid. Testing was standardized accordingly: an initial load of 180N for 10 minutes is followed by a resting phase of 10 min. This is followed by 3 cycles of repetitive sliding tests (2 mm/s at 180 N) for 10 minutes with a resting phase of 10 minutes between each cycle. The coefficient of friction (COF) was measured constantly during testing. Gene expression analysis, metabolic activity and measurements of sGAGs were carried out.
Results
In cytokine-treated plugs, COF increased compared to the negative control. HA led to decreased COF compared to positive control. Co-administration of HA/GC maintained the decreased COF. In all inflammatory conditions anabolic genes (COL2A1 and ACAN) decreased and catabolic genes (MMP1 and MMP13) increased compared to the negative control. Metabolic activity was lower in all inflammatory conditions compared to the untested control group at day 0. sGAG were increased in the positive control group compared to the negative control. HA and HA/GC decreased sGAGs compared to the positive control group and only adding GC alone.
Conclusion
Treatment of osteochondral plugs with HA led to a reduced COF and a decreased sGAG amount. A co-administration of HA/GC does not impair this effect. Thus, combining HA/GC has positive biotribological effects on bovine osteochondral plugs cultivated under inflammatory conditions.
P070 - Hyaluronic Acid Supports the Effects of Cortison and Avoids Cytotoxic Effects of Local Anesthetics in Human Articular Chondrocytes in Vitro
Abstract
Purpose
The current study aimed to investigate the chondrotoxicity of co-administrating local anesthetics (LA) with glucocorticoids (GC) and hyaluronic acid (HA) in vitro.
Methods and Materials
Human articular cartilage was obtained from five patients undergoing total knee arthroplasty. Chondrocytes were isolated, expanded and seeded in 24-well plates for experimental testing. Local anesthetics (Lidocaine 1%, Bupivacaine 0,5%, Ropivacaine 2%) were used separately and co-administered with each of the following substances: GC (Triamcinolone Hexacetonide (TH) 4,5mg/ml), GC plus HA (TH: 4,5mg/ml, HA: 22 mg/ml), HA (22mg/ml). Cells were incubated with the various conditions for one hour, before substances were discarded followed by two washing steps. Culture medium was added, and cells were incubated for 24 hours. After 24 hours microscopic images were taken, and metabolic activity was measured. Also, a viability assay using flow cytometry was performed.
Results
The addition of HA and GC/HA resulted in enhanced attachment and branched appearance of the chondrocytes compared to LA and LA/GC. Metabolic activity was better in all LA co-administered with HA and GC/HA than with GC and only LA (Figure 1). Flow cytometry revealed the lowest cell viability in lidocaine and the highest cell viability in ropivacaine (Figure 2). This finding was also confirmed by the live/dead assay.
Conclusion
In conclusion, HA supports the effect of GC and reduces chondrotoxic effects of LA in vitro. Thereby the co-administration of HA to LA and GC offers an alternative less chondrotoxic approach for treating patients with symptomatic osteoarthritis of the knee.