Table 4.
Summary of unique oxysterols investigated for in vivo bone tissue engineering in animal models
| Oxysterol name | Change from cholesterol1 | Effect on in vivo bone formation (defect model) | Ref. |
| 20(S)-OHC | OH group at C20(S) | Increase2 (alveolar and calvarial) | Aghaloo et al[17], 2007; Hokugo et al[30], 2014; Lee et al[35], 2017; Cui et al[34], 2017; Bakshi et al[37], 2019; Huang et al[38], 2019 |
| 22(R)-OHC | OH group at C22(R) | Increase2 ,3 (alveolar) | Bakshi et al[37], 2019 |
| 22(S)-OHC | OH group at C22(S) | Increase2 ,3 (calvarial) | Aghaloo et al[17], 2007 |
| Oxy4/Oxy34 | OH group at C20(S), single bond between C5 and C6, OH group at C6(S) | Increase2 (spinal fusion) | Johnson et al[21], 2011; Stappenbeck et al[20], 2012 |
| Oxy18 | OH group at C20(S), single bond between C5 and C6, OH group at C6(S), deuterated carbons at C22 and C23 | Increase4 (spinal fusion) | Stappenbeck et al[20], 2012 |
| Oxy21/Oxy133 | OH group at C20(S), single bond between C5 and C6, OH group at C6(S), n-hexane at C20(S) | Increase2 (spinal fusion, calvarial) | Stappenbeck et al[20], 2012; Montgomery et al[19], 2014; Scott et al[31], 2015; Li et al[36], 2015; Buser et al[33], 2017 |
| Oxy49 | OH group at C20(S), single bond between C5 and C6, OH group at C6(S), double bond between C25 and C27 | Increase2 (spinal fusion, calvarial) | Johnson et al[21], 2011; Hokugo et al[32], 2016 |
1
(S) and (R) denote stereoisomerism. Refer to Figure 3 for molecular structures.
2
Statistically significant relative to control.
3
Used in combination with 20(S)-OHC.
4
Significantly greater bone formation relative to Oxy4/Oxy34 (internal positive control). OHC: Hydroxycholesterol.