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Design and synthesis of aptamer-cyclometalated iridium(III) complex conjugate targeting cancer cells
Weigang Chen1, Xianhong Cai1, Qiang Sun1
1Guangdong Key Laboratory for Research and Development of Natural Drugs, School of Pharmacy, Guangdong Medical University, Zhanjiang, Guangdong, 524023, China.
Abstract:
Targeted therapy showed broad application prospects in the treatment of various types of cancer. Through carriers such as aptamers, antibodies, proteins and peptides, targeted therapy can selectively deliver drugs into tumor cells. Compared with traditional treatment methods such as chemo- and radiotherapy, targeted drug delivery systems can reduce the toxic effects of drugs on normal cells and avoid adverse reactions. Herein, an aptamer-cyclometalated iridium(III) complex conjugate (ApIrC) has been designed and developed as a targeted anticancer agent. Owing to the targeting ability of aptamers, ApIrC specifically bound to nucleolin over-expressed on the surface of cancer cells and showed strong fluorescence signal for tumor imaging and diagnosis. ApIrC had more substantial cellular uptake in cancer cells than the iridium complex alone and exhibited favorable low toxicity to normal cells. After uptake by cells through endocytosis, ApIrC can selectively accumulated in mitochondria and induced caspase-3/7-dependent cell death. Remarkably, ApIrC can also specifically target 3D multicellular spheroids (MCSs) and show excellent tumor permeability. So, it can effectively reach the interior of MCSs and cause cell damage. To our knowledge, this is the first report of the aptamer-cyclometalated iridium(III) complex conjugate which studied for cancer targeted therapy. The developed conjugate has great potential to be developed as novel therapeutics for effective and low-toxic cancer treatment.
Insights
A novel aptamer-cyclometalated iridium(III) complex conjugate (ApIrC) offers targeted cancer therapy with reduced toxicity. This conjugate specifically targets cancer cells, enabling effective tumor imaging, diagnosis, and treatment with low adverse effects.
Area of Science:
- Biomedical Engineering
- Materials Science
- Oncology
Background:
- Targeted cancer therapy utilizes carriers like aptamers to selectively deliver drugs to tumor cells, minimizing damage to normal tissues.
- Traditional treatments like chemotherapy and radiotherapy often cause severe side effects due to their lack of specificity.
Purpose of the Study:
- To design and develop a novel aptamer-cyclometalated iridium(III) complex conjugate (ApIrC) for targeted cancer therapy and imaging.
- To evaluate the efficacy, specificity, and safety of ApIrC in cancer treatment models.
Main Methods:
- Conjugation of an aptamer with a cyclometalated iridium(III) complex to create ApIrC.
- Assessment of ApIrC's binding affinity to nucleolin-overexpressed cancer cells.
- Evaluation of cellular uptake, cytotoxicity in cancer and normal cells, and mechanism of cell death (caspase-3/7-dependent).
- Testing ApIrC's targeting ability and permeability in 3D multicellular spheroids (MCSs).
Main Results:
- ApIrC specifically targets cancer cells expressing nucleolin, showing strong fluorescence for imaging.
- ApIrC demonstrated enhanced cellular uptake in cancer cells compared to the iridium complex alone, with low toxicity to normal cells.
- ApIrC accumulated in mitochondria, inducing caspase-3/7-dependent apoptosis and effectively damaging cancer cells within 3D MCSs due to excellent tumor permeability.
Conclusions:
- The developed aptamer-cyclometalated iridium(III) complex conjugate (ApIrC) represents a promising targeted anticancer agent.
- ApIrC exhibits potential for effective and low-toxic cancer treatment, offering advantages in tumor imaging, diagnosis, and therapy.
- This study is the first to report on aptamer-iridium(III) complex conjugates for cancer targeted therapy, highlighting their significant therapeutic potential.
