The development of novel biodegradable polymeric biomaterials for use in the repair of damaged intervertebral discs

PhD ceremony: Mr. S. Sharifi, 12.45 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: The development of novel biodegradable polymeric biomaterials for use in the repair of damaged intervertebral discs

Promotor(s): prof. D.W. Grijpma

Faculty: Medical Sciences

Low back pain (LBP) affects a considerable proportion of the population in Western industrialized countries. Intervertebral disc (IVD) injuries, either small fissures in the outer part of IVD (annulus fibrosus) or protrusions of the inner part of IVD (nucleus pulposus) through a failing annulus fibrosus, are the main causes of back pain. Current treatments for LBP include conservative therapy and surgery. These therapies are complicated, not functional and only alleviate symptoms. New therapies for LBP are based on regenerative medicine and tissue engineering. These therapies aim to restore disc function by reversing the degeneration process or engineering new healthy tissue. Novel strategies for annular repair are compulsory for the success of these treatments. This thesis addresses biomaterial-based strategies for securely sealing a herniated disc (torn annulus fibrosus) and integrating a tissue engineering construct to native annulus fibrosus tissue. Four different classes of resorbable biomaterials were developed and characterized, i.e., shape memory polymers, injectable and photo-crosslinkable macromers, reinforced nanocomposite hydrogels and polymeric tissue adhesives. In parallel, the potential of these biomaterials for closure of annulus fibrosus were investigated. Results of this work have highlighted the complexity and multifactorial aspect of LBP. We have shown some of the main challenges in developing strategies and materials for immediate restoration of IVD stability after herniation. These findings can help researchers to design more efficient biomaterials based systems for low back pain treatment.