As a leading service provider focused on drug development, BOC Sciences has been supporting customers at the forefront of drug conjugation. Building drug conjugates facilitates the selective delivery of toxic therapeutic cargos to diseased cells. Among them, nucleic acid aptamers are one of the scaffolds that have received the most attention. We provide aptamer-drug conjugation services to meet your unique project needs. Our scientific team will work with you to create a scope of work to complete the project on time and within specifications.
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Nucleic acid aptamers are short, single-stranded oligonucleotides (DNA or RNA molecules) with a stable 3D structure, also known as “chemical antibodies”, which could be used as potential drug-delivery vehicles and are able to bind to a molecular target through secondary or tertiary conformation. The targets of aptamers range from small molecules and proteins to intact cells.
Advantages of aptamers served as targeting ligands:
- Small size
- High chemical stability
- Facile chemical modification
- Low immunogenicity
- Rapid tissue penetration
|Aptamer Name||Targets||Application||Aptamer Name||Targets||Application|
|CD4||RORγt||Gene therapy||aptPD-L1||PD-L1||Mammary cancer, immunotherapy|
|Zy1||SMMC-7721||Liver cancer||MUC-1||MCF-7||Mammary cancer|
|SL₂-B||Hep G2||Liver cancer||CL4||EGFR||Mammary cancer|
|G12msi||GPC3||Liver cancer||GL44||U-87 MG||Radiotherapy|
|CD28Apt7||B16||Skin cancer||AS1411||Nucleolin||Mammary cancer, skin cancer, photothermal therapy|
|AP-1||CD133||Anaplastic thyroid carcinoma||TIM3Apt||TIM-3||Immunotherapy|
|AptABCG2||ABCG2||Mammary cancer||Apt1, Apt2, Apt4, Apt5||LAG3||Immunotherapy|
|APTA12||Nucleolin||Mammary cancer||RCA II||CD40||Immunotherapy|
Table 1. Examples of aptamers selected with potential for targeted therapy (Liu, 2022)
Aptamer-drug conjugates (ApDCs) have been developed for targeted therapy. An ApDC typically consists of three molecular parts: a ligand (aptamer), a linker, and a warhead (drug). In these conjugates, aptamers specifically recognize diseases-associated biomarkers to deliver conjugated drugs to target cells or/and tissues. The chemical stability and simplicity of chemical modification of aptamers allow these to be easily combined with many warheads, such as chemotherapeutics, nucleic acids, proteins, photosensitizers, etc.
Fig 1. Aptamer binding to targets (Liu, 2022)
- Exponential enrichment (SELEX) method for screening aptamers.
- Chemical modification or insertion of drug molecules into DNA structures for aptamer drug conjugation.
- Adjustment for payload/drug load (proportion of drug part carried by a single ApDC unit).
- Increasement of the number of aptamer units on a single ApDC structure for improving aptamer targeting efficiency.
|Aptamer-Drug Conjugates||Aptamers||Therapeutic Cargoes|
|Aptamer-chemotherapeutic conjugates||sgc8, AS1411, A10, APT||Chemotherapeutics|
|Aptamer-nucleic acid conjugates||A10, CH6, Anti-gp120||siRNA|
|Aptamer-photosensitizer conjugates||AIR-3A, sgc8, TD05, AS1411||Photosensitizers|
|Aptamer-photothermal agent conjugates||sgc8||photothermal agents|
Table 2. Examples of aptamer-drug conjugates
Applications of ApDC
ApDCs can be used in the treatment of various diseases. Combined with aptamer, the diagnosis and treatment of diseases can effectively avoid the problems of low diagnostic sensitivity in vivo, large side effects of drugs, difficult tumor monitoring and so on. With the continuous development of aptamers, ApDC with different target sites are more and more widely used.
ApDCs are used for targeting drug delivery in chemotherapy, gene therapy, immunotherapy, photodynamic therapy and photothermal therapy for the treatment of various cancers such as liver, ovarian, skin, prostate, breast, pancreatic and anaplastic thyroid cancers, as well as acquired immunodeficiency syndrome. In addition, aptamer conjugates can be extended to other types of metal-organic framework (MOF) nanomaterials, and conjugates with targeted therapeutic and imaging capabilities can be developed for cancer cell detection and imaging.
- Different ApDC structures and batch development experience
- Various conjugation methods through chemical modification or molecular engineering
- A wide range of characteristic analysis
- People and suites that specialize in ApDC development, manufacturing, and testing
- Data analysis, detailed report with results and discussion
- Cost-effective and high-quality products
- Zhu, G., Niu, G., and Chen, X., Aptamer–Drug Conjugates, Bioconjug Chem., 2015, 26(11): 2186-2197.
- Liu, P., et al., Aptamer-drug conjugates: New probes for imaging and targeted therapy, Biosens. Bioelectron., 2022, 10, 100126.