Fig. 9From: Systematic review on the application of 3D-bioprinting technology in orthoregeneration: current achievements and open challengesPCL/hydroxyapatite prevascularized femoral defect studya Porous PCL scaffold design. Two PCL scaffolds were bioprinted; both were 4 mm in diameter and 5 mm high and coated with nano-hydroxyapatite. One scaffold was left empty whilst the other was filled with prevascularized scaffold bioink. b SEM images depicting nHA coating and confocal image of microvessels within scaffolds. Scale bar in images i, ii, iii and iv 100 μm, 2 μm, 200 nm and 50 μm, respectively. c Images highlighting rat femoral defect location and X-ray and μCT images showing defect dimensions. d Schematic outlining surgical procedure. Reprinted with permission from [141]Back to article page