Table 2.

Bioengineering methods of growth factor delivery, examples, advantages, and disadvantages.

Method	Examples	Advantages	Disadvantages	Ref.
Scaffolds	Polymers: synthetic, natural, mixed, plasma coated	Mechanical stability Easy to fabricate	Natural polymers: low mechanical stability.	[46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70]
	Ceramic Bioinert: zirconia and alumina, Bioactive: Bioactive glass, Hydroxyapatite, glass	Biodegradable Biocompatible	Bioinert ceramics exhibit Hydrothermal aging Brittle	[43,44,45]
	Metal-based scaffolds Titanium, Zirconium, Platinum, stainless steel	High Young’s modulus Enhanced compressive strength	Ion release Non-degradable	[41,42]
Encapsulation	Physical encapsulation: Phase emulsion, freeze-drying solvent casting, gas foaming	Maintained bioactivity	Rapid burst release	[62,63]
	Microparticles Synthetic polymers MPs: PLGA	High surface to volume ratio High drug loading ability	Difficult to control the degradation rate	[64,65,66]
	Nanoparticles: BMP-7 loaded NPs	Controlled release Enhance mechanical strength	Unstable in nature	[67,68,69,70]
Layer-by-layer Assembly	3-D bioprinting	Retains growth factor functions High tensile strength	Low loading capacity Bone overgrowth	[71,72,73,74]
Hydrogel	HA hydrogel, Collagen, Chitosan, Alginate	Site-specific release	Low tensile strength	[75,76,77,78,79]