TABLE 2.

Summary of advantages and disadvantages of various biological materials.

Materials	Advantages	Disadvantages
Viral vectors	High transfection characteristics	Potential genotoxicity and immune inflammatory response
Exosomes	Protect miRNAs from extracellular environmental pollution or degradation and does not cause immune rejection	Different subtypes of exosomes may lead to different outcomes
Plasmid	High transfection efficiency and cell innocuity	Unstable structure and low lysosome escape rate
CS	Biocompatibility and antibacterial property	Transshipment capacity is limited, and metabolism is difficult
PEG	Excellent softness and water solubility	Excessive degradation and lacks of pharmacokinetic stability
PLGA	Strong biological binding ability and structural controllability	Degradation of products easily affects cell activity
PEI	Enhancement of cell adhesion, aggregation, and osteogenic activity	Effect of osteogenesis is not significant at low concentrations and has strong biotoxicity at high concentrations
Metallic materials	Good mechanical and antibacterial properties	Lack of sufficient carrying capacity
Calcium orthophosphate	Good biocompatibility and osteogenic induction	Mechanical brittleness
Silicon-based materials	Degradation nontoxic	Lack of sufficient nucleic acid-binding ability