Binary Polymeric System Based on Fish Collagen and Poloxamer 407: Mechanical and Rheological Analysis for...

Tilapia skin collagen is recognized for its regenerative properties and biocompatibility. Poloxamer 407 (P407) is a copolymer considerate ideal for stabilization and emulsification. The objective of this study was to develop a binary polymer system composed of tilapia skin collagen and P407, seeking to optimize its properties for pharmaceutical and biomedical applications. Using the two-block Box-Behnken 3³ factorial design, the mechanical and rheological analysis of the binary polymer systems was evaluated, varying the temperature, polymer concentration and the combination of components. The binary polymer systems demonstrated pseudoplastic behavior (shear thinning). The results indicate that the combination of tilapia collagen with P407 provides synergistic behavior, promoting desirable characteristics for pharmaceutical and biomedical applications, especially for topical use and 3D printing. The CP12 system (0.75/17.5/7%COL/P407/Gly) stood out as the most efficient for topical application, presenting pseudoplastic behavior, significant thixotropic hysteresis area at 34 °C and viscoelastic properties. Furthermore, it exhibited adequate mechanical strength, which indicates good ability to maintain the integrity of the formulation after application. In addition, the combination of collagen and P407 offers a structural network capable of creating innovative drug delivery systems, such as 3D printing of biomedical constructs. Based on the mechanical and rheological data, the CP2, CP8, pCP2 and pCP8 systems showed pseudoplastic behavior and structural recovery capacity after shearing, essential characteristics for extrusion 3D printing. SEM analysis of the four best-performing systems revealed distinct microstructural features that correlate with mechanical and rheological properties, supporting their suitability for 3D printing. These results suggest that the hydrogels can flow through the needle and recover their original shape after deposition, which can favor the stability and fidelity of the printed structures, reinforcing their potential for biomedical applications.