In vitro investigation and biomechanical modeling of the effects of PLF-68 on osteoarthritis in a three-dimensional model.
In this study, it was hypothesized that Pluronic F-68 (PLF-68) increases matrix synthesis of osteoarthritis (OA) chondrocytes in addition to its well-documented cell survival effect. To test this hypothesis, rat articular chondrocytes were embedded in agarose discs and were exposed to 5-azacytidine (Aza-C) to induce OA-like alterations. Chondrocytes were then treated with PLF-68 (8 and 12 mg/ml) for 10 days. Aza-C-exposed and PLF-68-untreated chondrocytes and Aza-C-unexposed and PLF-68-untreated chondrocytes were used as negative and positive control groups, respectively. Dynamic hydrostatic pressure (max 0.2 MPa, 0.1 Hz) was applied to discs for 30 min/day (5 days/week). Cell viability, collagen and proteoglycan deposition in discs were determined. Unconfined compression stress relaxation tests were performed to determine peak stress and material parameters of discs--namely spring constants (k (1) and k (2)), damping coefficient (η), instantaneous modulus (E (0)) and relaxed modulus (E (∞)) using Kelvin model to evaluate the functional coherence of the matrix. PLF-68 treatment significantly increased the collagen deposition in discs and viability of OA-like chondrocytes. A dose-dependent increase was also observed for elastic stiffness parameters (k (1), k (2), E (0) and E (∞)). Same positive effect of PLF-68 was not observed for proteoglycan deposition. However, dose-dependent increase in η suggests that PLF-68 treatment resulted with the deposition of functional matrix. This is the first study which reports that PLF-68 has also positive effect on collagen synthesis of OA cells. As a conclusion, our results suggest that PLF-68 has a potential for recovery from OA-like alterations, which should be further analyzed.
Department of Engineering Sciences, Middle East Technical University, 06531, Ankara, Turkey.
Ayşegül
A
Kavas
Mustafa
M
Ozdemir
Senih
S
Gürses
Dilek
D
Keskin
Ayşen
A
Tezcaner
D000818:Animals; D001374:Azacitidine / Q000494:pharmacology; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000166:cytology / Q000187:drug effects; D019902:Chondrocytes / Q000187:drug effects; D066298:In Vitro Techniques; D008962:Models, Theoretical; D010003:Osteoarthritis / Q000188:drug therapy* / Q000503:physiopathology; D020442:Poloxamer / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley
D020442:Poloxamer; D001374:Azacitidine