Catheter Injectable Scaffolds for Tissue Engineering Applications

Background: Injectable scaffolds, a unique therapeutic method used for tissues that are difficult to reach, are needed in various biomedical applications. Catheter delivery of hydrogel based scaffolds is novel and provides unique challenges and design parameters for the biomaterial. The main goal of this research is to develop and study new hydrogel formulations based on gelatin and alginate, crosslinked by carbodiimide, which can be mixed with air and injected through delicate long catheters, and used as porous scaffolds for treating a variety of internal ailments.

Methods: The polymer`s mechanical and physical properties, including tensile strength, Young`s modulus, gelation time, viscosity, porosity, and weight loss and degradation rate were determined, as well as the influence of injection via catheters of different lengths.

Results: It was found that gels with 200mg/ml gelatin, 10mg/ml alginate, and 20 mg/ml carbodiimide concentrations are ideal. Using this formulation, foamed polymers with various ratios of 1.25:1 and 1:1 (polymer-to-air) displayed optimal mechanical properties. It was also concluded that injection via catheters have no significant effect on any mechanical or physical properties, proving the great potential of this therapy.

Conclusion: This study presents proof of the concept of using hydrogels as catheter-injectable scaffolds, and may comprise the basis for future animal studies.