Fig. 4
From: Biomimetic delivery of signals for bone tissue engineering
Preprogrammed PTH delivery system for local bone defect repair. a Schematic illustration of PTH delivery device (pulsatile and continuous). Two types of devices made with the same biodegradable materials and loaded with the same amount of PTH but delivered PTH in distinct manners, pulsatile or continuous, for 21 days. b Representative µCT characterization of mouse calvarial defect (top panel) and intact tibiae (bottom panel) in response to the different PTH delivery systems in vivo. PTH delivery device (pulsatile or continuous) was implanted in the calvarial defect locally. A subset of control mice received standard PTH subcutaneous injection (40 µg/kg/day) for 21 days. The PTH pulsatile device significantly enhanced the PTH anabolic effects in regenerating bone compared to the standard PTH injection, whereas the PTH continuous device resulted in bone resorption; PTH local delivery (pulsatile or continuous) resulted in negligible systemic effect compared to the PTH injection treatment. Copyright © 2016 by Elsevier, reprinted with permission of Elsevier, from Dang et al.47
