## 3 Results
### Results of Individual Studies  
[PERSON] et al. (2013) [23] evaluated 32 male Wistar rats (250-300 g) divided in two groups (n = 16 each). In each rat, two critical-size defects of 5.3 mm in diameter were created in the dorsal part of the parietal bone. The defect on the right side was the experimental group, while the left side was the control (no treatment). In the first group, the right-side defect was filled with a PLGA scaffold, and the second group received a PLGA-based scaffold embedding SIM (20 ug/scaffold). According to the histological analysis, the PLGA-SIM group promoted the highest length of the bone formation, filling the defects on days 28 and 56 (0% and 96%, respectively, \(p\) < 0.05). The control group showed 38% and 52% of bone formation on days 28 and 56, respectively, while the PLGA group filled 71% of the defects on days 28 and 56. [PERSON] et al. (2016) [22] created two defects of 5 mm in diameter in the calvaria of 180 Wistar rats (180 g). Six groups were evaluated: Naive (incision and detachment of the periosteum); sham (negative control); vehicle (ethyl alcohol in phosphate-buffered saline); PLGA-HA-\(\beta\)TCP; PLGA-HA-\(\beta\)TCP-SIM (200 ug/scaffold); and 200 ug SIM only. Radiographs were carried out and bone densitometry was determined on days 1, 7, 15, 30, and 60. On day 60, according to the gray scale values, PLGA-HA-\(\beta\)TCP-SIM, PLGA-HA-\(\beta\)TCP, naive, sham, vehicle, and SIM groups showed approximately 85, 75, 105, 72, 80, and 72 of bone densitometry, respectively (_p_ > 0.05). Therefore, SIM alone or embedded into PLGA-HA-\(\beta\)TCP scaffolds failed to support bone formation. [PERSON] et al. (2013) [18] created critical-size defects in the calvaria bone of 34 female Wistar rats (6 weeks old), randomly divided into three groups: PLGA-HA; PLGA-HA-SIM (8 ug/scaffold); and a control group that did not receive any material. On days 28 and 56 post-implantation, _u_CT analyses were performed to quantify bone formation. The PLGA-HA-SIM group exhibited the highest bone formation (approximately 4% and 10% on days 28 and 56, respectively, \(p\) < 0.05). The control group showed an average of approximately 0.5% and 1.8% of bone formation on days 28 and 56, respectively, while PLGA-HA group demonstrated 0.5% and 3.9% on days 28 and 56, respectively. [PERSON] et al. (2014) [24] evaluated a 4-mm diameter critical-sized defect created at the left side of the calvarium of 32 ICR mice (4 weeks old), divided into four groups: PLGA scaffold; PLGA-SIM (35 ug/scaffold); PLGA-stromal cell-derived factor 1\(\alpha\) (SDF1\(\alpha\)); and PLGA-SIM-SDF1\(\alpha\). According to the _u_CT performed 42 days after the implantation, the PLGA-SIM-SDF1\(\alpha\) group promoted the highest volume of bone formation (1.1 mm\({}^{3}\), \(p\) < 0.05). Conversely, the PLGA group did not lead to bone formation. PLGA-SIM and PLGA-SDF1\(\alpha\) showed 0.18 mm\({}^{3}\) and 0.41 of bone formation, respectively. [PERSON] et al. (2017) [8] evaluated an 8-mm bone defect in the calvaria of 35 Wistar rats (three months old) divided into five groups: control (blank default); PLGA-based scaffold; PLGA-SIM (40 ug/scaffold); PLGA-mesenchymal stem cells (MSC); and PLGA-SIM-MSC. After 56 days, according to the histomorphometric analyses, the PLGA-SIM