Efficacy of stem cells on bone consolidation of distraction osteogenesis in animal models: a systematic review

MORILLO, Carlos Manuel Rubio; SLONIAK, Mariane Cristina; GONÇALVES, Fernanda; VILLAR, Cristina Cunha

doi:10.1590/1807-3107bor-2018.vol32.0083

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Systematic Review, Mouth and Jaw Surgery • Braz. oral. res. 32 • 2018 • https://doi.org/10.1590/1807-3107bor-2018.vol32.0083 linkcopy

Efficacy of stem cells on bone consolidation of distraction osteogenesis in animal models: a systematic review

Authorship SCIMAGO INSTITUTIONS RANKINGS

Distraction osteogenesis (DO) relies on the recruitment and proliferation of mesenchymal stem cells (MSC) to the target site, where they differentiate into osteoblasts to promote bone formation. Nevertheless, MSC recruitment appears to be slow and limits bone formation in DO defects. Thus, this systematic review aims to evaluate the ability of locally applied MSC to enhance bone formation in DO preclinical models. Databases were searched for quantitative pre-clinical controlled studies that evaluated the effect of local administration of MSC on DO bone formation. Eligible studies were identified and data regarding study characteristics, outcome measures and quality were extracted. Nine studies met the inclusion criteria. Autogenous and xenogenous MSC were used to promote DO bone formation. These included bone marrow-derived MSC, adipose tissue-derived MSC and MSC derived from human exfoliated deciduous teeth. Meta-analysis was not possible due to heterogeneities in study designs. Local MSC implantation was not associated with adverse effects. In 4 out of the 5 studies, locally delivered undifferentiated bone-marrow MSC had a positive effect on DO bone formation. Few studies evaluated the therapeutic effects of MSC from other sources. The adjunct use of biologically active molecules or forced expression of key genes involved in osteogenesis further boosted the ability of bone-marrow MSC to promote DO bone formation. While risk of bias and heterogeneity limited the strength of this systematic review, our results suggest that the use of MSC is safe and may provide beneficial effects on DO bone formation.

Mesenchymal Stromal Cells; Osteogeneses, Distraction; Osteogenesis; Review

Study	Reason for exclusion
Zeng et al. (2016)¹⁹	Control group did not receive the scaffold used in MSC-based therapy.

Study	Animal model	Cell origin (n)/ characterization/ number of transplanted cells/ state of cell differentiation at application/ time of transplantation	Defect description/ location/ size	Scaffold
Ma et al. (2017)⁽⁸⁾	24 New Zealand white rabbits aged 3 months and weighing 2.5 - 3.0 kg.	BM-MSC, donor origin was not stated (n: not informed); ability to adhere; positive for CD29 and CD44 and negative or low expression of CD34 and CD45; ability to undergo osteogenic and adipogenic differentiation; aifferentiated into an osteogenic lineage at application; 5 x10⁶ cells/defect; injected into the distraction gap at the end of the DO period.	An osteotomy line was made between the first premolar and the mental foramen of the left mandible. An external distractor was fixed across both cortices. Left jaw underwent osteotomy by a fissured bur. After three days, the distractor was activated at a rate of 10 mm/twice a day, for five days, resulting in a 10 mm distraction gap	HA
Sun et al. (2014)⁽⁹⁾	54 OVX + 18 sham operated female New Zealand white rabbits, aged approximately 3 months and weighing approximately 2 kg.	Autogenous ADSC (n = 36); fibroblast-like cell morphology; 1 x10⁷ cells/defect; undifferentiated at application; injected into the distraction gap at the end of the DO period.	The corticotomy was performed immediately anterior to the first premolar. The distractor was fixed and distraction started after seven days, with an activation rate of 0.8 mm/day for ten days, resulting in 8 mm distraction gap.	None
Alkaisi et al. (2013)⁽¹⁰⁾	22 skeletally immature New Zealand white rabbits aged 3 to 5 months and weighing approximately 2.7 kg.	Xenogenous SHED (n = 4); fibroblast-like cell morphology; ability to adhere; colony forming efficacy; positive for CD105 and CD166; 6 x10⁶ cells/defect; undifferentiated at application; cells were transplanted at the surgical appointment.	A longitudinal incision was made on the inferior border of the right mandible. An incomplete osteotomy cut was placed between the first premolar and the mental foramen. A 12 X 12 mm distraction device was fixed to either side of the osteotomy cut.After four days, the distraction device was activated at a rate of 1.0 mm/day for six days, resulting in a 6 mm distraction gap.	None
Zhang et al. (2012)⁽¹¹⁾	12 New Zealand white rabbits aged approximately 4 months.	BM-MSC, donor origin was not stated (n= not informed); ability to undergo osteogenic, adipogenic, and chondrogenic differentiation; ability to adhere and colony forming efficiency; number of implanted cells was not informed; undifferentiated at application; applied into the distraction gap at the end of the DO period.	A straight unilateral osteotomy was performed from the first premolar to the mental foramen. A custom-made distractor was placed and fixed perpendicularly to the plane of the osteotomy. After one week, the distraction device was activated at a rate of 0.9 mm/day for 11 days, resulting in a 10 mm distraction gap.	None
Lai et al. (2011)⁽¹²⁾	54 skeletally mature male New Zealand white rabbits weighing 3.0 - 3.5 kg.	Autogenous BM-MSC; ability to adhere; 1 x10⁷ cells/defect; undifferentiated at application; injected into the distraction gap at the end of the DO period.	The osteotomy was performed on the bucal aspect of the left anterior mandible, anterior to the first molar. A custom-made distractor was fixed with 4 self-tapping screws. After six days, the distraction device was activated at a rate of 0.4 mm/12 hours for 6 days, resulting in a 4.8 mm distraction gap.	None
Jiang et al. (2010)⁽¹⁴⁾	42 skeletally mature male New Zealand white rabbits weighing 2.0 – 3.0 kg	Autogenous BM-MSC; ability to adhere; 1 x10⁷ cells/defect; undifferentiated at application; applied into the distraction gap at the end of the DO period.	An osteotomy line was made on the right mandibles, between the first premolar and the mental foramen. A custom-made titanium external distractor was fixed across both cortices. After three days, the distraction device was activated at a rate of 2.0 mm /day for 5 days, resulting in a 10 mm distraction gap.	None
Kinoshita et al. (2008)⁽¹⁵⁾	12 adult male Japanese white rabbits weighing 3.0 - 3.4 kg.	Autogenous BM-MSC Ability to adherence; ability to undergo osteogenic differentiation; 1 x10⁷ cells/defect; differentiated into osteogenic lineage at application; applied into the distraction gap at the end of the DO period.	Osteotomies were made bilaterally on the zygomatic process of the maxilla, and custom-made distractor devices were fixed. After five days, the distraction device was activated at a rate of 2.0 mm/day for 4 days, resulting in an 8 mm distraction gap.	PRP
Hu et al. (2007)⁽¹³⁾	54 adult male Sprague-Dawley rats weighing rats weighing 350–400 g.	Autogenous BM-MSC; Fibroblast-like cell morphology; ability to adhere; colony forming efficacy; 1 x10⁶ cells/defect; undifferentiated at application; applied into the distraction gap at the end of the DO period.	The osteotomy was performed to the middle of the anterior ramus to the inferior border of the right mandible; After five days, the distraction device was activated at a rate of 0.4 mm/day for 8 days, resulting in a 3.2 mm distraction gap.	None
Qi et al. (2006)⁽¹⁶⁾	40 adult male Sprague–Dawley rats weighing 350–400 g.	Autogenous BM-MSC; fibroblast-like cell morphology, ability to adhere, colony forming efficacy; 5 x10⁵ cells/defect undifferentiated at application; applied into the distraction gap at the end of the DO period.	Osteotomy was performed from the upper border of the anterior ramus to the inferior border of the mandible. A custom made distractor was fixed to osteotomy site. After five days, the distraction device was activated at a rate of 0.4 mm/day, for 8 days, resulting in a 3.2 mm distraction gap.	None

Study	Groups/ n of defects	Healing period	Outcomes
Ma et al. (2017)⁽⁸⁾	Group 1: BM-MSC+HA (n=8). Group 2: BM-MSC-CSF + HA (n=8). Group 3: oBM-MSC-CSF + HA (n=8).	6 weeks	Micro-CT
			New bone (mm3):
			BM-MSC + HA: ~ 360 (A)
			BM-MSC-CSF + HA: 445 ± 29.6 (B)
			oBM-MSC-CSF + HA: 510 ± 26.3 (C)
			oBM-MSC group exhibited a more mature cortical bone.
Sun et al. (2014)⁽⁹⁾	Group 1: OVX rabbits + saline solution (n=6 /time point). Group 2: OVX rabbits + Adv-GFP- ADSC (n=6 /time point). Group 3: OVX rabbits + Adv-Runx2-GFP-ADSC (n=6 /time point). Group 4: sham rabbits + saline solution (n=6 /time point).	3, 6, and 9 weeks	i) Micro-CT
			Bone mineral density (mg/cc) at:
			3 weeks:
			OVX control: ~ 70 (A)
			OVX + ADSC: ~ 85 (A)
			OVX + Runx2-ADSC: ~ 145 (B)
			Sham control: ~ 250 (C)
			6 weeks: (data restricted to 2 groups)
			OVX + Runx2-ADSC: ~ 610 (A)
			Sham control: ~ 460 (B)
			9 weeks: (data restricted to 2 groups)
			OVX + Runx2-ADSC: ~ 800 (A)
			Sham control: ~ 825 (A)
			Bone volume to total volume ratio (%) at:
			3 weeks:
			OVX control: ~ 6 (A)
			OVX + ADSC: ~ 6 (A)
			OVX + Runx2-ADSC: ~ 11 (B)
			Sham control: ~ 24 (C)
			6 weeks: (data restricted to 2 groups)
			OVX + Runx2-ADSC: ~ 55 (A)
			Sham control: ~ 42 (A)
			9 weeks: (data restricted to 2 groups)
			OVX + Runx2-ADSC: ~62 (A)
			Sham control: ~ 64 (A)
			Trabecular number (1/mm) at:
			3 weeks:
			OVX control: ~ 0.8 (A)
			OVX + ADSC: ~ 0.8 (A)
			OVX + Runx2-ADSC: ~1.6 (B)
			Sham control: ~ 0.9 (A)
			6 weeks: (data restricted to 2 groups)
			OVX + Runx2-ADSC: ~2.4 (A)
			Sham control: ~ 1.4 (B)
			9 weeks: (data restricted to 2 groups)
			OVX + Runx2-ADSC: ~3 (A)
			Sham control: ~ 2.2 (B)
			Trabecular thickness (um) at:
			3 weeks:
			OVX control: ~ 50 (A)
			OVX + ADSC: ~50 (A)
			OVX + Runx2-ADSC: ~70 (B)
			Sham control: ~ 80 (C)
			6 weeks: (data restricted to 2 groups)
			OVX + Runx2-ADSC: ~150 (A)
			Sham control: ~ 190 (B)
			9 weeks: (data restricted to 2 groups)
			OVX + Runx2-ADSC: ~240 (A)
			Sham control: ~ 240 (A)
			ii) Histological analysis: (data restricted to 2 groups)
			No differences between OVX + Runx2-ADSC and sham control.
Alkaisi et al. (2013)⁽¹⁰⁾	Group 1: negative control (n=9). Group 2: SHED (n=9).	2, 4, and 6 weeks	i) Radiographic analysis
			2 weeks: SHED group had more bone radiopacity bridging the DO gap.
			4 weeks: SHED group demonstrate bony continuity with greater radiodensity than control group.
			6 weeks: SHED group demonstrated greater radiodensity in the distraction gap than that the control group.
			ii) Histomorphometric analysis.
			New Bone (%) at:
			2 weeks:
			Control: 18.41 (A)
			SHED: 35.97 (B)
			4 weeks:
			Control: 31.45 (A)
			SHED: 56.69 (B)
			6 weeks:
			Control: 52.61 (A)
			SHED: 65.28 (B)
			Bone union at:
			2 weeks:
			Control: 0.96 (A)
			SHED: 1.75 (B)
			4 weeks:
			Control: 1.58 (A)
			SHED: 2.96 (B)
			6 weeks:
			Control: 2.5 (A)
			SHED: 3.25 (B)
			Stage of bone maturity at:
			2 weeks:
			Control: 2.25 (A)
			SHED: 3.16 (B)
			4 weeks:
			Control: 3.25 (A)
			SHED: 4.5 (B)
			6 weeks:
			Control: 3.5 (A)
			SHED: 4.66 (B)
Zhang et al. (2012)⁽¹¹⁾	Group 1: Sham-RT (n=3). Group 2: RT (n=3). Group 3: RT + BM-MSC (n=3). Group 4: RT +BMP2/7_BM-MSC (n=3).	4 weeks	i) Radiographic analysis
			RT + MSC and RT + MSC_BMP-2/7_BM-MSC groups showed more cortical bone formation compared with sham-RT and RT control groups.
			ii) Micro-CT
			Trabecular separation (mm):
			Sham-RT: 0.99 ± 0.16 (A)
			RT: 1.00 ± 0.07 (A)
			RT + BM-MSC: 0.99 ± 0.17 (A)
			RT + BMP2/7_BM-MSC: 1.32 ± 0.17 (B)
			Trabecular thickness (mm):
			Sham-RT: 0.12 ± 0.01 (A)
			RT: 0.12 ± 0.03 (A)
			RT + BM-MSC: 0.15 ± 0.01 (A)
			RT + BMP2/7_BM-MSC: 0.22 ± 0.02 (A)
			Number of trabeculae (1/mm):
			Sham-RT: 0.91 ± 0.12 (A)
			RT: 0.90 ± 0.04 (A)
			RT + BM-MSC: 0.83 ± 0.04 (A)
			RT + BMP2/7_BM-MSC: 1.08 ± 0.1 (A)
			Bone volume fraction:
			Sham-RT: 0.12 ± 0.03 (A)
			RT: 0.11 ± 0.03 (A)
			RT + BM-MSC: 0.08 ± 0.02 (A)
			RT + BMP2/7_BM-MSC: 0.12 ± 0.04 (A)
			iii) Histological analysis
			BM-MSC and BMP2/7_BM-MSC exhibited more mature medullary and cortical bones than the control groups.
Lai et al. (2011)⁽¹²⁾	Group 1: Saline solution (n = 9 /time point). Group 2: BM-MSC (n = 9 /time point). Group 3: OSX_BM-MSC (n = 9 /time point).	2 and 6 weeks	i) Radiographic analysis
			Radiodensity at:
			2 weeks:
			Control: ~54 (A)
			BM-MSC: ~75 (B)
			OSX_BM-MSC: ~95 (C)
			6 weeks:
			Control: ~105 (A)
			BM-MSC: ~121 (B)
			OSX_BM-MSC: ~143 (C)
			ii) Histological analysis.
			Trabecular thickness (mm) at:
			2 weeks:
			Control: 22.89 ± 1.96 (A)
			BM-MSC: 26.96 ± 3.23 (B)
			OSX_BM-MSC: 39.39 ± 3.54 (C)
			6 weeks:
			Control: 34.69 ±3.73 (A)
			BM-MSC: 42.41 ± 2.34 (B)
			OSX_BM-MSC: 54.21 ± 2.38 (C)
			Newly formed cortical bone area (%)at:
			2 weeks:
			Control: 44.53 ± 5.43 (A)
			BM-MSC: 52.43 ± 2.74 (B)
			OSX_BM-MSC: 61.62 ± 3.10 (C)
			6 weeks:
			Control: 84.42 ±3.06 (A)
			BM-MSC: 90.26 ± 2.12 (B)
			OSX_BM-MSC: 97.32 ± 2.65 (C)
			Cancellous bone area (%) at:
			2 weeks:
			Control: 24.54 ± 3.22 (A)
			BM-MSC: 33.85 ± 3.49 (B)
			OSX_BM-MSC: 42.45 ± 2.98 (C)
			6 weeks:
			Control: 42.05 ±3.58 (A)
			BM-MSC: 53.80 ± 2.91 (B)
			OSX_BM-MSC: 67.75 ± 4.04 (C)
Jiang et al. (2010)⁽¹⁴⁾	Group 1: Saline solution (n = 14). Group 2: Ad5_BM-MSC (n = 14). Group 3: Ad5_bFGF BM-MSC (n =1 4).	8 weeks	i) DXA analysis
			Bone mineral density (g/cm2):
			Control: ~0.23 (A)
			Ad5_BM-MSC: ~0.25 (B)
			Ad5_bFGF BM-MSC: ~ 0.27 (C)
			Bone mineral content (g):
			Control: ~0.21 (A)
			Adv5_BM-MSC: ~0.23 (B)
			Ad5_bFGF BM-MSC: ~0.25 (C)
			ii) Micro-CT
			Bone volume to total volume ratio (%):
			Control: 56.00 ± 3.72 (A)
			Adv5_BM-MSC: ~ 61.6 (B)
			Ad5_bFGF BM-MSC: ~67.2 (C)
			Connectivity density (mm3):
			Control: 11.05 ± 1.73 (A)
			Adv5_BM-MSC: ~ 13.26 (B)
			Ad5_bFGF BM-MSC: ~ 21.00 (C)
			Trabecular thickness (mm):
			Control: 0.21 ± 0.04 (A)
			Adv5 BM-MSC: ~ 0.30 (B)
			Ad5-bFGF BM-MSC: ~ 0,38 (C)
			Trabecular separation (mm):
			Control: 0.32 ± 0.03 (A)
			Adv5_BM-MSC: ~ 0.32 (AB)
			Ad5_bFGF BM-MSC: ~ 0,36 (B)
			Trabecular number:
			Control: 2.01 ± 0.39 (A)
			Adv5_BM-MSC: ~ 2.60 (B)
			Ad5_bFGF BM-MSC: 3.28 (C)
			iii) Histological analysis (data restricted to half of the samples).
			While only disordered tiny trabeculae were sporadically found in the distraction gaps of group 1, the distraction gaps in group 3 were completely bridged with mature and regular trabecular bone. Bone trabeculae only partially filled distracted gaps in group 2.
Kinoshita et al. (2008)⁽¹⁵⁾	Group 1: PRP (n = 6 defects). Group 2: Saline solution -contralateral internal control for group 1 (n = 6 defects). Group 3: oBM-MSC + PRP (n = 6 defects). Group 4: Saline solution - contralateral internal control for group 3 (n = 6 defects).	2,3 and 4 weeks	i) Radiographic analysis
			Radiodensity (mm AI) at:
			2 weeks:
			Ratio PRP/saline control: ~ 0.8 (A)
			Ratio BM-MSC + PRP/saline control: ~ 1.07 (B)
			3 weeks:
			Ratio PRP/saline control: ~0.7 (A)
			Ratio BM-MSC + PRP/saline control: ~1.09 (B)
			4 weeks:
			Ratio PRP/saline control: ~0.6 (A)
			Ratio BM-MSC + PRP/saline control ~1.1 (B)
			ii) Histological analysis (data restricted to week 4)
			New bone (%):
			Ratio PRP/saline control: ~1.2 (A)
			Ratio BM-MSC + PRP/saline control: ~1.6 (B)
			Bony content in the newly formed bone (%):
			Ratio PRP/saline control: ~0.95 (A)
			Ratio BM-MSC + PRP/saline control: ~1.2 (B)
Hu et al. (2007)⁽¹³⁾	Group 1: Saline solution (n = 9 /time point). Group 2: pEGFP-BM-MSC (n = 9 /time point). Group 3: pEGFP-BMP-2_BM-MSC (n = 9 /time point).	2 and 6 weeks	i) Radiographic analysis
			Radiodensity
			2 weeks:
			Control: ~52 (A)
			BM-MSC: ~58 (B)
			BMP-7 BM-MSC: ~70 (C)
			6 weeks:
			Control: ~99 (A)
			BM-MSC: ~113 (B)
			BMP-2_BM-MSC: ~135 (C)
			ii) Histomorphometric analysis
			Newly formed cortical bone area (%) at:
			2 weeks
			Control: 43.52 ± 6.11 (A)
			BM-MSC: 51.28 ± 3.85 (B)
			BMP-2_BM-MSC: 60.59 ± 4.00 (C)
			6 weeks
			Control: 82.66 ± 2.06 (A)
			BM-MSC: 89.30 ± 1.95 (B)
			BMP-2: 95.54 ± 2.07 (C)
			Cancellous bone area (%) at:
			2 weeks
			Control: 23.69 ± 2.60 (A)
			BM-MSC: 32.22 ± 4.22 (B)
			BMP-2_BM-MSC: 41.54 ± 3.01 (C)
			6 weeks
			Control: 41.46 ± 4.01 (A)
			BM-MSC: 52.47 ± 1.93 (B)
			BMP-2_BM-MSC: 66.33 ± 4.00 (C)
			Trabecular thickness (mm) at:
			2 weeks:
			Control: 21.13 ± 1.05 (A)
			BM-MSC: 25.43 ± 2.10 (B)
			BMP-2_BM-MSC: 37.32 ± 3.39 (C)
			6 weeks:
			Control: 32.45 ± 4.33 (A)
			BM-MSC: 40.97 ± 2.52 (B)
			BMP-2_BM-MSC: 52.32 ± 3.12 (C)
Qi et al. (2006)⁽¹⁶⁾	Group 1: Saline solution (n = 10/time point). Group 2: BM-MSC (n = 10/time point).	Day 27 and 55	i) Radiographic analysis
			Radiodensity at:
			Day 27:
			Control: 169 (A)
			BM-MSC: 203 (B)
			Day 55:
			Control: 221 (A)
			BM-MSC: 255 (B)
			ii) Histomorphometric analysis
			Newly formed bone volume in the cortical bone area (%) at:
			Day 27:
			Control: 38.52 ± 3.25 (A)
			BM-MSC: 54.28 ± 3.50 (B)
			Day 55:
			Control: 85.48 ± 4.69 (A)
			BM-MSC: 92.30 ± 1.95 (B)
			Newly formed bone volume at the cancelous bone area (%) at:
			Day 27:
			Control: 23.29 ± 3.60 (A)
			BM-MSC: 34.02 ± 3.21 (B)
			Day 55:
			Control: 41.46 ±4.01 (A)
			BM-MSC: 53.47 ± 1.83 (B)
			Trabecular thickness (mm) at:
			Day 27:
			Control: 23.13 ± 4.31 (A)
			BM-MSC: 30.40 ± 2.17 (B)
			Day 55:
			Control: 33.31 ± 3.55 (A)
			BM-MSC: 45.97 ± 3.52 (B)

Study	1	2	3	4	5	6	7	8	9	10

	Selection bias 1	Selection bias 2	Selection bias 3	Performance bias 1	Performance bias 2	Detection bias 1	Detection bias 2	Attrition bias	Reporting bias	Other bias
Ma et al. (2017)⁸	?	✓	x	?	x	x	x	✓	✓	✓
Sun et al. (2014)⁹	x	✓	x	?	x	x	x	x	✓	✓
Alkaisi et al. (2013)¹⁰	?	✓	x	?	x	x	x	x	✓	✓
Zhang et al. (2012)¹¹	?	✓	x	?	x	x	✓	x	✓	✓
Lai et al. (2011)¹²	?	✓	x	?	x	x	x	x	✓	✓
Jiang et al. (2010)¹⁴	?	✓	x	?	x	x	x	x	✓	✓
Kinoshita et al. (2008)¹⁵	?	✓	x	?	x	x	x	x	✓	✓
Hu et al. (2007)¹³	?	✓	x	?	x	x	x	✓	✓	?
Qi et al. (2006)¹⁶	?	✓	x	?	x	x	x	✓	✓	✓

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[TFN1] IRB, institutional review board; 1 ✓ = Adequate randomization; ? = randomized but no details; x = no evidence of randomization; 2 ✓ = Baseline characteristics given; x = baseline characteristics not given; 3 ✓ = Evidence of adequate concealment of groups; x = no evidence of adequate concealment of groups; 4 ✓ = Evidence of random housing of animals; ? = unknown housing arrangement; 5 ✓ = Evidence of examiners blinded to intervention; x = no evidence of examiners blinded to intervention; 6 ✓ = Evidence of random selection for assessment; x = no evidence of random selection for assessment; 7 ✓ = Evidence of researchers blinded; x = no evidence of assessor blinded; 8 ✓ = Explanation of missing animal data; x = no explanation of missing animal data; 9 ✓ = Free of selective reporting based on methods/results; x = selective reporting; 10 ✓ = Evidence of random housing of animals; ? = unknown housing arrangement.