Lumbar Interbody Fusion Conducted on a Porcine Model with a Bioresorbable Ceramic/Biopolymer Hybrid Implant Enriched with Hyperstable Fibroblast Growth Factor 2

Abstract

Many growth factors have been studied as additives accelerating lumbar fusion rates in different animal models. However, their low hydrolytic and thermal stability both in vitro and in vivo limits their workability and use. In the proposed work, a stabilized vasculogenic and prohealing fibroblast growth factor-2 (FGF2-STAB®) exhibiting a functional half-life in vitro at 37 °C more than 20 days was applied for lumbar fusion in combination with a bioresorbable scaffold on porcine models. An experimental animal study was designed to investigate the intervertebral fusion efficiency and safety of a bioresorbable ceramic/biopolymer hybrid implant enriched with FGF2-STAB® in comparison with a tricortical bone autograft used as a gold standard. Twenty-four experimental pigs underwent L2/3 discectomy with implantation of either the tricortical iliac crest bone autograft or the bioresorbable hybrid implant (BHI) followed by lateral intervertebral fixation. The quality of spinal fusion was assessed by micro-computed tomography (micro-CT), biomechanical testing, and histological examination at both 8 and 16 weeks after the surgery. While 8 weeks after implantation, micro-CT analysis demonstrated similar fusion quality in both groups, in contrast, spines with BHI involving inorganic hydroxyapatite and tricalcium phosphate along with organic collagen, oxidized cellulose, and FGF2- STAB® showed a significant increase in a fusion quality in comparison to the autograft group 16 weeks post-surgery (p = 0.023). Biomechanical testing revealed significantly higher stiffness of spines treated with the bioresorbable hybrid implant group compared to the autograft group (p < 0.05). Whilst histomorphological evaluation showed significant progression of new bone formation in the BHI group besides non-union and fibrocartilage tissue formed in the autograft group. Significant osteoinductive effects of BHI based on bioceramics, collagen, oxidized cellulose, and FGF2-STAB® could improve outcomes in spinal fusion surgery and bone tissue regeneration.

A Biological Study of Composites Based on the Blends of Nanohydroxyapatite, Silk Fibroin and Chitosan

“…Additionally, focusing on the mechanism for the formation of crystallinity centers, during bone mineralization, the distance between individual crystallinity centers is given as 0.362 nm according to Pawlikowski [ 36 ], which is consistent with the distances between amino acids alternately arranged in the beta-sheet structures, in silk fibroin according to Sashina [ 37 ]. Additionally, the amino acid composition of silk fibroin rich in sericin is similar to the composition of growth factors, commonly added to increase the biocompatibility of materials in tissue engineering [ 38 ].…”

Speed and quality of interbody fusion in porous bioceramic Al 2 O 3 and polyetheretherketone cages for anterior cervical discectomy and fusion: a comparative study

“…The rst evidence of bony fusion was de ned as the sign of new bone tissue formation in the area of a cage, or incipient trabecular bridging. Subsequently, fusion was assessed and graded qualitatively according to a modi ed fusion quality scale (Table 1) [14,15,16].…”