# Binary Polymeric System Based on Fish Collagen and Poloxamer 407: Mechanical and Rheological Analysis for Pharmaceutical and Biomedical Applications

## TL;DR

This paper develops a collagen and Poloxamer 407 hydrogel system optimized for pharmaceutical and biomedical uses, including 3D printing.

## Contribution

A novel binary polymer system using tilapia collagen and Poloxamer 407 is developed and optimized for biomedical applications.

## Key findings

- The CP12 system showed optimal pseudoplastic behavior and viscoelastic properties for topical use.
- SEM analysis confirmed microstructural features suitable for 3D printing.
- The hydrogels demonstrated structural recovery after shearing, important for extrusion-based printing.

## Abstract

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.