Table 3.

Results of individual studies: CCK-8 assay and MTT assay, OD values.

Studies	Type of Study	Biomaterials	Bone Regeneration Measurement	Results
[19]	In vitro	a)2% (w/v) CS combined with 2% (w/v) gelatine, fabricated using 0.1% of glutaraldehyde b)2% (w/v) CS combined with 2% (w/v) gelatine, fabricated using 1% of glutaraldehyde	MTT assay of DPSCs at day 7	a)OD value = 1.6 b)OD value = 1.3
[23]	In vitro/in vivo (calvarial bone defects of rats)	a)electrospun 5 wt% bovine tendon collagen membrane b)electrospun 5 wt% bovine tendon collagen-5 wt% chitosan membrane c)BLANK GROUP (no material applied at the cranial defect)	CCK-8 assay (Dojindo Ltd., Tokyo, Japan) of PDLCs	a)OD value = 0.4 b)OD value = 0.7 c)OD value = 0.22
[26]	In vitro	a)CS (Qingdao Boyite Biomaterials Co. Ltd., Shandong, China) combined with CSn (pDNA-BMP2)-GP(*) b)CS (Qingdao Boyite Biomaterials Co. Ltd., Shandong, China) combined with CSn-GP(*)	CCK-8 assay (Dojindo Ltd., Tokyo, Japan) of PDLCs	a)OD value = 0.7 b)OD value = 0.6

CCK-8 = cell counting kit-8; CSn(pDNA-BMP2)-GP = chitosan nanoparticles loaded with bome morphogenetic protein-2 plasmid DNA into a chitosan-based hydrogel with α, β–glycerophosphate; DPSCs = dental pulp stem cells; tudies: CCK-8 assay and MTT assay, OD values. DPSCs = dental pulp stem cells; MTT = 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide; OD = optical density; PDLCs = periodontal ligament stem cells. (*) CS for nanoparticles: Hengtai Jinhu Crust Product Co. Ltd. (Shandong, China); αβ-GP: Sinopharm Chemical Reagent Co. Ltd.; Plasmid BMP2: Central Laboratory of the Affiliated Hospital of Qingdao University.