Table 1.

Summary about the classification of the core in SNA and its advantages and disadvantages.

Classification	Core	Advantages	Disadvantages	Ref.
Metal-SNA	Au; Ag	Diverse physicochemical properties that give SNA systems functional versatility.	Difficult to attach DNA by covalent linkage; potentially toxic to humans	[50,[55], [56], [57],62]
Polymers-SNA	PLGA; poloxamer F127	The use of polymers allows for controllability and greatly improves drug delivery efficiency	Polymeric carriers are generally ineffective on their own and are prone to cause toxic side effects on organs.	[73,74]
Protein-SNA	Cas9 protein; glucose oxidase	The nucleic acid shell of SNA is able to reduce the degradation of proteins by proteases, while being able to improve the uptake of proteins by cells.	Requires proteins with sites that allow nucleic acids to attach; the protein needs to be kept active	[36,95]
Liposomes-SNA	Lipids	High biocompatibility and wide range of drug delivery.	Does not have a long-term effect in the body; easy to leak drugs; low encapsulation rates	[83,85]
Nucleic acid-SNA	DNA Nanoclew; peptide nucleic acid; PSDNA	Capable of self-delivery, avoiding toxicity or immunogenicity of the carrier	Complex preparation; inherent instability	[89,91,93]