Table 4.

Histopathology Outcome Data for Scaffolds Implanted in Tibia Defect Animals

Sacrifice timepoint	Treatment	Cumulative inflammation score	Necrosis	Osteoblast cells	Osteoclast remodeling	Neovascularization	Implant degradation	Osteogenic response
Iliac: 8 weeks	Iliac DCIA implantation + BMP-2	5.0	0.0	1.7	0.7	2.0	0.0	2.0
Iliac: 8 weeks	Iliac DCIA implantation + BMP-2	3.3	0.0	1.0	0.0	2.0	0.0	2.0
	Mean ± standard deviation	4.2 ± 1.2	0.0 ± 0.0	1.3 ± 0.5	0.3 ± 0.5	2.0 ± 0.0	0.0 ± 0.0	2.0 ± 0.0
Iliac: 8 weeks + tibia: 13 weeks	Iliac DCIA implantation, tibia implantation + BMP-2	4.3	0.0	1.0	0.7	2.3	0.0	1.0
Iliac: 8 weeks + tibia: 24 weeks	Iliac DCIA implantation, tibia implantation + BMP-2	3.3	0.0	0.0	0.0	2.0	0.0	0.3
Tibia: 24 weeks	Tibia implantation + BMP-2	2.0	0.0	1.3	1.3	1.0	0.0	2.0

Cumulative inflammation (the sum of scores assigned to PMN, lymphocyte, plasma cell, macrophages, and giant cell categories; maximum possible score = 20) was lowest in the scaffold dosed with BMP-2 and implanted directly in the tibia for 24 weeks. The osteogenic response was generally lower in scaffolds that underwent iliac DCIA implantation before tibia implantation. Despite increased bone formation around the scaffold periphery, the scaffold implanted directly into the tibia for 24 weeks demonstrated similar osteogenic growth in the scaffold ROI as scaffolds that were not implanted into the tibia. No signs of necrosis or implant degradation were observed within any scaffold.

ROI, region of interest.