The aim of this study was to examine the bone augmentation properties of an injectable composite
consisting of PLGA microspheres/CaP cement (20/80), and the additional effect of loading
PLGA microspheres with TGF-β1 (200 ng). For this purpose, PLGA/CaP composites (control) and
PLGA/CaP composites loaded with TGF-β1 (test group) were injected on top of the skulls of 24
Wistar rats. Each rat received 2 materials from the same experimental group, and in total 48
implants were placed (n = 8). After 2, 4, and 8 weeks the results were evaluated histologically
and histomorphometrically. The contact length between the implants and newly formed bone
increased in time, and was significantly higher for the TGF-β1-loaded composites after 2 weeks.
Also, bone formation was significantly higher for the TGF-β1-loaded composites (18.5% ± 3)
compared to controls (7.21% ± 5) after 8 weeks of implantation. Immunohistochemical staining
demonstrated massive inflammatory infiltrates in both groups, particularly at 2 weeks, which
decreased substantially at 4 and 8 weeks. In conclusion, injectable PLGA/CaP composites stimulated
bone augmentation in a rat model. The addition of TGF-β1 to the composite significantly increased
bone contact at 2 weeks and enhanced new bone formation at 8 weeks
