Fabrication and characterization of an injectable reinforced composite scaffold for cartilage tissue engineering: an in vitro study.

There are limitations in current medications of articular cartilage injuries. Although injectable bioactive hydrogels are promising options, they have decreased biomechanical performance. Researchers should consider many factors when providing solutions to overcome these challenges. In this study, we created an injectable composite hydrogel from chitosan and human acellular cartilage extracellular matrix (ECM) particles. In order to enhance its mechanical properties, we reinforced this hydrogel with microporous microspheres composed of the same materials as the structural building blocks of the scaffold. Articular cartilage from human donors was decellularized by a combination of physical, chemical, and enzymatic methods. The decellularization efficiency was assessed by histological analysis and assessment of DNA content. We characterized the composite constructs in terms of storage modulus, gelation time, biocompatibility, and differentiation potential. The results showed that mechanical behavior increased with an increase in microsphere content. The sample that contained 10% microsphere had an enhanced storage modulus of up to 90 kPa. Biocompatibility and preliminary differentiation investigations revealed that this composite hydrogel might have potential benefits for cartilage tissue engineering.