Tunable Sol-Gel Transition in Poloxamer Blends for Injectable Osteoarticular Applications.
TL;DR
The results show that careful selection and optimization of poloxamer blends allow tailoring material properties for specific biomedical functions, and make them practical for further development in injectable biomaterials and drug delivery systems for osteoarticular repair.
Abstract
Thermoresponsive poloxamers are commonly used in biomedical applications; however, their wider translational applicability depends on precisely controlling sol-gel transition behavior near body temperature while ensuring injectability and a favorable biocompatibility profile. In this study, blends of three clinically relevant poloxamers were evaluated to find formulations suitable for potential injectable meniscal and joint therapies. The rheological properties and temperature-dependent gelation of these formulations were characterized, followed by testing their injectability into meniscal defects and assessing biological responses in vitro. The gelation temperatures reported in this work were operationally defined from viscosity-based temperature sweep measurements. Biocompatibility, cell viability, and migration of outer fibrochondrocytes exposed to selected poloxamer hydrogels were examined to gauge their potential for orthopedic applications. Different material behaviors emerged based on polymer composition. Synperonic F-108 combined with Poloxamer 188 showed decreased adhesiveness and aggregation, along with maintained cell viability after prolonged incubation, indicating potential as a coating material or a general structural matrix. Conversely, blends of Kolliphor K 407 with Poloxamer 188 displayed temperature-dependent increases in viscosity. They formed stable gels at body temperature, maintaining a favorable biological response in direct-contact conditions, which supports their further evaluation in long-term injectable applications with controlled structural stability. These results show that careful selection and optimization of poloxamer blends allow tailoring material properties for specific biomedical functions. The adjustable thermoresponsive behavior, chemical inertness, and simple preparation of these triblock copolymers make them practical for further development in injectable biomaterials and drug delivery systems for osteoarticular repair.