The fabrication of cryogel scaffolds incorporated with poloxamer 407 for potential use in the regeneration of the nucleus pulposus

Degeneration of the nucleus pulposus (NP) is the primary cause of back pain in almost 80% of the world population. The current gold standard treatment for a degenerated NP is a spinal fusion surgery which is costly, temporary, and extremely invasive. Research has been moving towards minimally invasive methods to lessen the collateral damage created during surgery. The use of a tissue-engineered scaffold has the potential to promote a healthy and hydrated environment to regenerate the NP. Cryogels are unique polymeric scaffolds composed of a highly connected, macroporous structure, and are capable of maintaining stability under high deformations. For this study, cryogels have been developed using gelatin and poloxamer 407 (P407) at varying ratios to determine the ideal combination of stability, water retention, and pore size. For the application of NP regeneration, a gelatin-P407 cryogel should be both stable and a well hydrated carrier. The cryogels created varied from a 1:1 gelatin to P407 ratio to a 10:1 ratio. The inclusion of P407 in the cryogels resulted in a significant increase in hydrophilicity, ideal pore size for cell infiltration, mechanical stability over 28 days, and cell infiltration after just 21 days. This novel gelatin-P407 composite cryogel has the potential to be a practical alternative to the spinal fusion procedure, saving patients hundreds of thousands of dollars and, ideally, leading to improved patient outcome.