. 2021 Sep 1;79(4):711–718. doi: 10.1007/s12013-021-01019-3

Table 2.

The advantage and disadvantage of different targeting agents

Name	Advantages	Disavantages
Nucleic acid aptamers	1. Can be screened out to target many types of elements, including inorganic and organic small molecules biological macromolecules, and even cells 2. Easy to produce and cheap	1. Challenging to obtain nucleic acid aptamers with high specificity and high affinity for individual targets 2. Binding affinity for electronegative target wanes 3. Requires certain ionic strength, pH 4. Easily degraded
Antibodies	1. Good performance in good specificity	1. limited tissue penetration 2. high production cost
Peptides	1. Smaller in size and penetrate more efficiently into tissue compared to antibodies. 2. Synthesized by automated techniques with low production costs.	1. Have low stability in plasma, are sensitive to proteases and can be cleared from the circulation in a few minutes.

Name

Advantages

Disavantages

Nucleic acid aptamers

1. Can be screened out to target many types of elements, including inorganic and organic small molecules biological macromolecules, and even cells

2. Easy to produce and cheap

1. Challenging to obtain nucleic acid aptamers with high specificity and high affinity for individual targets

2. Binding affinity for electronegative target wanes

3. Requires certain ionic strength, pH

4. Easily degraded

Antibodies

1. Good performance in good specificity

1. limited tissue penetration

2. high production cost

Peptides

1. Smaller in size and penetrate more efficiently into tissue compared to antibodies.

2. Synthesized by automated techniques with low production costs.

1. Have low stability in plasma, are sensitive to proteases and can be cleared from the circulation in a few minutes.