Smart scaffolds in bone tissue engineering: A systematic review of literature

Table 3 Description of included studies which modified the scaffolds by addition of nanoparticles

Ref.	Scaffold	Fabrication	Type of modification	Cell type	Tests and results
Kim et al[54], 2006	PLGA + nHA	SC/PL and GF/PL	New composition fabrication	RCOCs	Average cell density: GF/PL = 2.4 × 106 cells/scaffold (86.5% increase) SC/PL = 2.1 × 106 cells/scaffold (69.7% increase) ALP activity: GF/PL= 0.6 mol/min per 106 SC/PL= 0.5 mol/min per 106
Wang et al[55], 2007	PA + nHA	Thermally induced phase inversion	Surface coating	BMMSCs	MTT assay and ALP activity: No negative effects on the BMMSCs in vitroIn vivo: Good biocompatibility and extensive osteoconductivity with host bone in vivo
Lv et al[56], 2009	PLGA + nHA	Microsphere sintering method (modification of the emulsion and solvent evaporation method)	New composition fabrication	BMMSCs	MTS assay: (cell number) PLGA + nHA : 1.2 million/mm2 PLAGA: 0.06 million/mm2 ALP activity: PLGA + nHA: 0.10 mL/μg PLAGA: 0 mL/μg
Roohani- Esfahani et al[57], 2010	BCP/PCL + nHA	Sonication	Surface coating	PHOLCs	ALP activity: BCP/PCL + nHA: 2 mmol/h per mg BCP: 0.5 mmol/h per mg RT-PCR: (relative) BSP: BCP/PCL + nHA: 0.4, PCL: 0 Runx2: BCP/PCL + nHA: 8, PCL: 5 OCN: BCP/PCL + nHA: 1.2, PCL: 0.8 Col I: BCP/PCL + nHA: 4.5, PCL: 2.5
Ye et al[58], 2010	PCL + nAP	Freeze-dried	Scaffold architecture	MG63Cs	Cell proliferation on composite scaffolds porosity of 76% > porosity of 53%
Phipps et al[52], 2011	PCL+ Col I + nHA	Electrospun	Bone-mimetic electrospun matrices	BMMSCs	Activation of focal adhesion kinase: Cells seeded onto PCL + col I + nHA scaffolds were better spread, and exhibited greater amounts MTS assay: (relative) PCL + Col + nHA: 5 PCL + nHA: 2.5 PCL: 1
Zhang et al[59], 2011	PLLA + ODA-nD	Sonication	Surface coating	7F2CS	Alamar Blue assay: A slight reduction in cell viability compared to control RT-PCR: (relative) ALP: PLLA + ND-ODA: 1, PLLA: 1 OCN: PLLA + ND-ODA: 3, PLLA: 2.8
Zeng et al[31], 2012	HA + MNPs	Tuning	New composition fabrication	MC3T3-E1Cs ROS 17/1.8Cs	MTT assay: HA + MNPs: MC3T3-E1: 0.2 OD value, ROS 17/1.8: 1.8 OD value HA: MC3T3-E1: 0.9, ROS 17/1.8: 0.25 ALP activity: HA + MNPs: MC3T3-E1: 0.75 U/mg, ROS 17/1.8: 4.5 U/mg HA: MC3T3-E1: 0.5 U/mg, ROS 17/1.8: 3.5 U/mg BGP activity: HA + MNPs: MC3T3-E1: 350 ng/L, ROS 17/1.8: 4000 ng/L HA: MC3T3-E1: 300 ng/L, ROS 17/1.8: 3500 ng/L
Hafezi et al[60], 2012	G + nBG	Homogenization through stirring	New composition fabrication	hAFCs	MTT assay: No difference compared to control In vivo: Radiographic evaluation: Improved the speed of the bone healing process
Buschmann et al[61], 2012	PLGA + n-aCaP	Electrospun	Electrospun PLGA/a-CaP scaffold architecture	ADSCs	MGTS: Extracellular matrix production was significantly higher FACS: CD13, CD29, CD44 and CD105 were expressed on PLGA + n-aCaP
Ganesh et al[62], 2012	nfPCL + nS	Electrospun	New composition fabrication	BMMSCs	FACS: CD29 = 3.3%, CD44 = 77.1%, CD73 = 94%, CD31, 34, 45 = 0% Cell viability: No difference compared to control BCA assay: NS + PCLN: 250 Ug/mg, PCLN: 100
Im et al[63], 2012	SWCNT + C + nHA	Lyophilization procedure	Scaffold architecture + new composition	BMMSCs	Cell adhesion and proliferation: SWCNT + C + nHA > SWCNT + C
Rodrigues et al[64], 2012	TCP + nfPCL	Electrospun + dynamic culturing environment	Scaffold architecture + new composition	BMMSCs	ELISA: TCP + nfPCL: 0.8 μg/mL TCP: 0.2 μg/mL ALP assay: TCP + nfPCL: 100 mol/h TCP: 20 mol/h
Panzavolta et al[65], 2013	G + nHA	Foaming + freeze-drying method	Surface coating+ scaffold architecture	BMMSCs	ALP activity: No difference compared to control RT-PCR: (Relative) ALP: G + nHA: 3.2, G: 1.8 Col I: G + nHA: 0.25, G: 0.25 Runx2: G + nHA: 0.5, G: 0.4 TGF-b1: G + nHA: 0.6, G: 0.55
Xing et al[66], 2013	PLLA + OTND	Manual perfusion technique under pressure	New composition fabrication	BMMSCs	BCA assay: No difference compared to control RT-PCR: (relative) OPN: PLLA + OTND: 3.5, PLL: 1 BSP: PLLA + OTND: 3, PLL: 1 BMP-2: PLLA + OTND: 4, PLL: 1 In vivo: New bone formation: PLLA + OTND: 50%, PLL: 10%
Liu et al[67], 2013	C + nHA	Electrospun	New composition fabrication	BMMSCs	Cell attachment: C + nHA: 1100 μm2 C: 250 RT-PCR: (Relative) BMP-2: C + nHA: 1.5, C: 1 BMP-4: C + nHA: 25, C: 0 Smad1: C + nHA: 9, C: 1 ALP: C + nHA: 1.2, C: 1 Runx2: C + nHA: 22, C: 1 Itga1: C + nHA: 17, C: 1 Itgb1: C + nHA: 7, C: 1 Itgb3: C + nHA: 8, C: 1 Myh9: C + nHA: 7, C: 1 Myh10: C + nHA: 3.5, C: 1 Col 1: C + nHA: 4.5, C: 1 In vivo: Superior ability of bone reconstruction
Wang et al[68], 2014	C + nHA	Lyophilization procedure + cold atmospheric plasma (CAP) treatment	Scaffold architecture + surface coating	BMMSCs	SEM: MSCs adhesion and infiltration were enhanced ELISA: (Relative) Fibronectin: C + nHA 0.8 compared to control (C) Vitronectin: C + nHA 1.1 compared to control

TCP: Tricalcium phosphate; PLLA: Poly(l-lactic acid); Col: Collagen; C: Chitosan; PCL: Poly(e-caprolactone); HA: Hydroxy apatite; G: Gelatin; PLGA: Poly(D,L-lactic-co-glycolic acid); GF/PL: Gas forming and particulate leaching; SC/PL: Solvent casting and particulate leaching; BCP: Biphasic calcium phosphate; SWNT: Single-walled carbon nanotubes; PA: Polyamide; nf: Nano fibrous; NHA: Hydroxy apatite nano particles; nAP: Nano apatite; OTND: Oxygen-terminated nanodiamond particles; nS: Nanoparticles of silica; n-aCaP: Amorphous calcium phosphate nanoparticles; MNPs: Magnetic nanoparticles; ODA-ND: Octadecylamine-functionalized nanodiamond; nBG: Nano-sized bioactive glass; BMMSCs: Bone marrow mesenchymal stem cells; MG63Cs: Human osteosarcoma cell line; MC3T3-E1: Osteoblast precursor cells; ADSCs: Adipose-derived stem cells; RCOCs: Rat calvarial osteoblasts cells; hAFCs: Human airway fibroblast cells; ROS 17/1.8 Cs: Osteoblastic cells; 7F2CS: Mouse bone marrow cells; PHOLCs: Primary human osteoblasts-like cells; ALP: Alkaline phosphatase; MTT: 2-(4,5-dimethyl-2 thiazolyl)-3,5-diphenyl-2H-tetrazolium bromide; MTS: 5-[3-(carboxymethoxy)phenyl]-3-(4,5 dimethyl-2-thiazolyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt; FACS: Fluorescent activated cell scan; RT-PCR: Reverse transcriptase polymerase chain reaction; ELISA: Enzyme-linked immunosorbent assay; SEM: Scanning electron microscope; BGP: Bone Gla protein; BCA: Bicinchoninic acid; MGTS: Masson Goldner Trichrome staining; CD: Cluster of differentiation; Itga1: Integrin a1; Itgb1: Integrin b1; Itgb3: Integrin b3; Myh9: Non-muscle myosin 9; Myh10: Myosin 10.