Table 6.

Biomaterials used for inkjet printing.

Materials	Process	In Vivo/In Vitro Model	Key Findings	Ref.
Powders: hydroxyapatite + β-TCP); Binding liquid: (0.6 wt % PVA + 0.25 wt % Tween 80) and (8.75 wt % phosphoric acid + 0.25 wt % Tween 80)	Microporous cylindrical scaffolds (3 mm × 10 mm) were 3D printed using ZPrinter 250 printer at 0.1 mm powder thickness and 0.3 L/m3 binder spray velocity. Scaffolds were set to dry at 50 °C for 2 h.	Rabbit bone marrow stromal cells (BMSCs)	Constructs printed with phosphoric acid showed better fabrication accuracy and mechanical properties than constructs printed with PVA. Both binding liquids showed good cellular affinity with BMSCs.	[35]
Substrate: paper and polyethylene terephthalate (PET); Binding liquid: concentrated solution of paracetamol, theophylline, and caffeine	Concentrated drug solutions were selectively placed on the substrates at 30 °C, and at 10 µm dropping distance using dimatix materials printer (DMP) 2800 inkjet printer.		Active pharmaceutical ingredients were successfully 3D printed using inkjet technology. The accurate deposition and crystallization of the drugs can be highly controlled. Precise and personalized dosing of the drug substances is possible with this technology.	[36]
Powders: β-TCP + hydroxyapatite + dextrin; Binding liquid: water + glycerol	Powder bed thickness was maintained 100 µm at 0.006 m/s print head speed. Constructs were gradually heated up to 350 °C and sintered at 1200 °C for 4 h. Fibrin and BMP-2 were coated. Osteoblasts were seeded on the scaffolds.	Male Lewis rats	3D printed constructs with BMP-2 and osteoblast cells showed enhanced ectopic bone formation.	[38]
Powder: α-TCP; Binding liquid: 8.75 wt % phosphoric acid + 0.25 wt % Tween 80	Powder layer thickness 89 µm and binder liquid to powder ratio 0.46. Vancomycin and rifampin were added to the powder bed. Polylactic-co-glucolic acid (PLGA) was coated in some groups.	Female BALB/cJ mice	Unlike PMMA, co-delivery of drugs vancomycin and rifampin was possible with 3D printed constructs. Thus, significantly improving implant-associated osteomyelitis. Additional PLGA coating further prolonged the antibiotic release.	[39]
Binding liquid: Soluplus (co-polymer of PVC-PVA-PEG); Substrate: stainless steel microneedles	Drugs curcumin, 5-fluorouracil, cis-platin were added to the polymer and jetted as fine droplets (300 pL) on the needles at 1–5 m/s. Multiple coatings were given to acquire desired drug concentration.	Dermatomed porcine skin	Inkjet printing technology was proved effective in coating metallic microneedles for transdermal drug delivery.	[37]
Binding liquid: miconazole; Substrate: Gantrez AN 169 BF (poly (methyl vinyl ether-co-maleic anhydride)) microneedles	Miconazole in dimethyl sulfoxide was sprayed at a rate of 10 pL/droplet of solution. Drop spacing of 30 µm and 32.0 V jet voltage was used.	Candida albicans	Antifungal agents were successfully incorporated using inkjet printing technology and clear zone of inhibition was demonstrated. Fabricated constructs can be effectively used for transdermal treatment of cutaneous fungal infections.	[40]
Binding liquid: 2-pyrolidinone; Substrate: calcium sulfate hemihydrate	89 µm layer height	Osteoblast like sarcoma cells	Binder solution toxicity was assayed by sintering specimens at temperature ranging from 300–1100 °C. High temperature sintered samples were compatible	[41]
Binding liquid: 8.75% phosphoric acid + 0.25% Tween80 + 1%–2% collagen; Substrate: hydroxyapatite and α-TCP	89 µm layer height and binding liquid to powder ratio was 0.46 was used	In vitro cytocompatibility was tested on C3H/10T1/2 cells and in vivo evaluation was done on critical size femoral defects on female BLAB/cJ	Macroporosity up to 0.5 mm was achieved. Incorporation of collagen favored better cellular response and improved mechanical properties.	[42]
Binding liquid: aqueous solution of 2-pyrrolidone (zb63); Substrate: calcium sulfate (plaster), vinyl polymer and carbohydrate	Pore sizes of 0.4, 0.6, and 0.8 mm were designed and printed at binder to powder ratio of 0.24 (shell) and 0.12 (core)	Effect of layer thickness and orientation of printing were evaluated by measuring physical and mechanical properties	Layer thickness of 0.1125 mm and printing along X direction resulted in specimens with best mechanical strength and dimensional accuracy	[43]
Binder liquid: mesoporous silica nanoparticles, polyethyleneimine, furosemide, and propylene glycol; Substrate: hydroxypropyl methyl cellulose (HPMC), and polyester transparency films	Print speed at 200 mm/s, resolution of 150 and 500 dpi, and wet thickness of 500 µm	Drug release from inks, rheological properties, dynamic viscosity and other important properties were evaluated	Successfully demonstrated the feasibility of printing drug loaded nano particle suspension for poorly water-soluble drugs	[44]