Amidic alginate hydrogel for nucleus pulposus replacement

Abstract

Degeneration of intervertebral discs is the most common cause of back pain. The first phase of this degenerative process involves the nucleus pulposus (NP). A rapid recovery of this structure can prevent further degradation of the annulus fibrosus. A new amidic derivative of alginate (AAA) was developed to obtain a polysaccharide possessing some of the physical-chemical properties of Hyal (i.e. viscosity) without losing the rigidity of the native alginate structure. The modified polysaccharide was crosslinked using 1.3 diaminopropane as crosslinking agent. The hydrogel obtained was characterized in terms of water uptake and rheological behavior. In particular, the viscoelastic behavior of the hydrogel was determined in shear stress under dynamic conditions and compared with the behavior of nondegenerated human lumbar NP. We then assessed the effect of the AAA hydrogel on NHC (Normal Human Chondrocyte) cell viability and on the production of important extracellular matrix factors, such as glycosaminoglycans and Type II collagen. In conclusion, the results achieved in this study demonstrated that the amidic alginate-based scaffold is a promising material to be utilized in the replacement of NP.

Scaffolding in tissue engineering: general approaches and tissue-specific considerations

“…A wide range of biomaterials dominated by natural biomaterials has been used for nucleus replacement. These materials include collagen [121], atellocollagen [98,99], alginate [70,76], gelatin [118], chitosan [33], collagen/ glycosaminoglycan [97], collagen/hyaluronan [2] and poly-L-lactic acid [94]. Reviews for nucleus replacements have been reported elsewhere [29,103].…”

“…In most if not all cases, freeze-drying has been employed as the fabrication method to create porous structures. In most nucleus and annulus replacement strategies, survival and growth of seeded cells, and enhanced synthesis of collagen II and proteoglycans by these cells are reported [2,23,70,76,94,97,118,120]. Nevertheless, almost all studies using the pre-made scaffold approach are in vitro while only a few are in vivo [76].…”

Biomaterials for intervertebral disc regeneration: past performance and possible future strategies

“…Bertolo et al, 2012;Cheng et al, 2010;Cheng et al, 2013;Dai et al, 2011;Iwasaki et al, 2004;Li et al, 2005b;Mao et al, 2004;Di Martino et al, 2005;Patel et al, 2010;Pusateri et al, 2003;Richardson et al, 2008;Roughley et al, 2006;Shao and Hunter, 2007;Sun et al, 2014;Zhang et al, 2014 Alginate Brown seaweed Delayed drug delivery systems Cells cultured in 3D constructs, tested in vivo in murine model. Bron et al, 2011;Chou et al, 2009;Chou and Nicoll, 2009;Guo et al, 1989;Larsen and Haug, 1971;Leone et al, 2008;Li et al, 2008;Lee and Mooney, 2012;…”

“…In vivo degradation is dependent on the process of removing links between chains (Lee and Mooney, 2012). In vivo, alginate induces negligible immunological reactions (Leone et al, 2008;Li et al, 2008;Nunamaker et al, 2007). Alginate hydrogel stiffness can be regulated by changing its alginate weight/volume (w/v) percentage (Bron et al, 2011).…”

Hydrogel-Based Platforms for the Regeneration of Osteochondral Tissue and Intervertebral Disc

“…With regard to synthetic hydrogels, physically crosslinked hydrogel based on polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) [114], and on NVP/HEMA (N-vinyl-2-pyrrolidone and 2-hydroxyethylmathacrylate) based hydrogel [115] have been studied. In any case, none of the above mentioned materials presented the desired biological cues and the required behavior [111,116].…”