Stem Cells from Human Fat as Cellular Delivery Vehicles in an Athymic Rat Posterolateral Spine Fusion Model

Abstract

Adipose-derived stem cells show promise as gene transduction targets for inducing bone formation to enhance spinal fusion in biologically stringent environments.

Nanocomposite therapy as a more efficacious and less inflammatory alternative to bone morphogenetic protein‐2 in a rodent arthrodesis model

“…It is notable that animals in the rhBMP-2, Grafton 1 , and DBX 1 groups performed similarly to other studies utilizing the same doses of these products. 18,21,22,24 Because critics of rhBMP-2 use are concerned about the host inflammatory response demonstrated clinically in the cervical spine and lumbar interbody fusions, 10,11,16,17,34 TrioMatrix 1 was qualitatively and quantitatively evaluated in comparison to rhBMP-2 in a novel MR imaging protocol. Assessment 7 days after surgery demonstrated that the formation of an inflammatory response/fluid collection consistent with that described clinically after the use of rhBMP-2 was avoided with the use of TrioMatrix 1 .…”

“…These findings are supported by other studies that suggest that a local BMP threshold exists, below which no bone formation is seen. 24,49 The delivery of growth factors on a nanocrystalline scaffold, such as that which TrioMatrix 1 provides, may lead to the consistent and robust bone fusion that is not seen with conventional products.…”

“…Athymic rats (Harlan, Indianapolis, IN) were maintained under continuous anesthesia with an isoflurane inhalational anesthetic delivery system, and animals were monitored by an assistant for cardiac or respiratory anomalies during the entire procedure. Utilizing a previously-described surgical technique, 24 a posterior midline incision was made over the lumbar spinous processes, after which two separate fascial incisions were made 4 mm from the midline. The L4 and L5 transverse processes were exposed with a muscle-splitting approach via sharp dissection using a scalpel blade.…”

“…All harvested spines were manually palpated for evidence of successful fusion by three independent observers using a previously published scoring system in which ''0'' indicated no fusion, ''1'' indicated fusion unilaterally with evidence of bridging bone, and ''2'' indicated fusion bilaterally with abundant bridging bone. 24 Fusion scores for each specimen were then added to give a maximum score of 6. A total score of !3 was considered to be a successful fusion.…”

“…In a modification of a previously published protocol, two spines were placed in a plastic holder and scanned simultaneously with the spines' axes parallel to the scanner's rotation axis. 24,26 The X-ray tube was operated at 70 kVp and 114 mA, and the integration time for each projection was 0.200 s. Reconstruction was performed with 37 mm isotropic volume elements (voxels), and the 540 contiguous slice data sets encompassed the L4 and L5 transverse processes.…”