A suitable scaffold for nucleus pulposus regeneration

Introduction Nucleolus Pulposus (NP) of the Intervertebral disc (IVD) is the first tissue to initiate degeneration especailly from a younger age which eventually leads to low back pain. IVD degeneration happens due to unusual sitting, trauma, genetic inheritance and impaired nutrient exchange between nucleus pulposus and blood vessels. If the extracellular matrix of NP remains the same throughout life, the disc height will not collapse. Objectives To find a suitable scaffold – for IVD implantation To fabricate a tissue-engineered scaffold using MSCs Transplantation of the tissue-engineered construct to the defective IVD site in an animal model. Methods Alginate was selected as the material of choice to mimic the NP structure. Alginate hydrogel was made in different concentrations incorporating strontium and tested for the required compression strength to mimic the real NP which is always under constant pressure. The designed and fabricated Alginate/Strontium (Alg/Sr) hydrogel was tested for cytotoxicity to depict the safety of the material and further tested in-vitro by mimicking an in vivo 3 dimensional structure incorporating cells which was ultimately injected in situ at the physically damaged NP site of the lumbar vertebrae (L4/L5-L5/L6) of New Zealand White rabbits in situ. Results This study showed that Alg/Sr Hydrogel can encapsulate cells for secreting extra cellular matrix (ECM) to restore the collapsed disc height to a certain extent to enable temporary relief of low back pain. This preclinical study mainly focused on the stiffness and load bearing of hydrogel to permit cells to proliferate, expand and provide extra cellular matrix to increase the disc height by regeneration of the defected disc and revert to normal function. ConclusionIn the clinical perspective, Alg-Sr & cell combination product may be an interim relief to improve the quality of life of the younger generation affected by low back pain.

کلیدواژه ها:

Nucleus pulposus ، Alginate/strontium hydrogel ، Intervertebral disc lapine IVD model