Sulfated polysaccharide mediated TGF-β1 presentation in pre-formed injectable scaffolds for cartilage tissue engineering

In this work, a plant-derived polysaccharide carboxymethylcellulose (CMC) was chemically modified to incorporate sulfate groups to facilitate binding of cationic growth factors. The sulfated CMC (heparin mimic) was then used with CMC (glycosaminoglycan mimic) and gelatin (collagen mimic) to fabricate injectable pre-formed, macroporous scaffolds for cartilage tissue engineering. These scaffolds demonstrated high resilience and shape memory, thereby making them injectable through a 14G needle for up to 4-6 aspiration and injection cycles. Further, the scaffolds could sequester cationic proteins and growth factors (TGF-beta 1) through affinity-based interactions. When seeded with infrapatellar fat pad derived MSCs, the scaffolds demonstrated enhanced chondrogenesis after 28 days of in vitro culture when compared to controls. Taken together; these results demonstrate a polysaccharide-based minimally-invasive and translatable pre-formed injectable scaffold-based cell and growth factor delivery system for cartilage regeneration.