Question 47 from UPSC CSE 2020 - S&T

Question

With reference to carbon nanotubes, consider the following statements:
1. They can be used as carriers of drugs and antigens in the human body.
2. They can be made into artificial blood capillaries for an injured part of the human body.
3. They can be used in biochemical sensors.
4. Carbon nanotubes are biodegradable.
Which of the statements given above are correct?

Accepted Answer

Correct Option: D. 1, 2, 3, and 4

Strategy: Acknowledge carbon nanotubes' widespread applications in biomedical and nanotechnology fields, including drug delivery, artificial blood vessels, and biochemical sensing. Incorporate the updated understanding of their biodegradability under enzymatic conditions, thus supporting all four identified uses/properties based on current evidence.

Key Info: Carbon nanotubes (CNTs) are cylindrical nanostructures composed of graphene sheets rolled into single (SWCNTs) or multiple (MWCNTs) layers. Their remarkable mechanical strength, electrical properties, and high surface area facilitate a range of advanced applications.

- **Drug and Antigen Carriers** -- CNTs serve as effective vectors for delivering drugs, nucleic acids, and antigens to targeted cells and tissues, improving bioavailability and specificity.
- **Artificial Blood Capillaries** -- Due to their flexibility, strength, and compatibility, CNTs can form tubular structures that mimic blood vessels, supporting tissue engineering and regeneration.
- **Biochemical Sensors** -- Leveraging their electrical conductivity and environmental sensitivity, CNTs' extensive use in nanosensors allows for detecting biomolecules, proteins, and toxins at low concentrations.
- **Biodegradability** -- While previously considered non-biodegradable, recent studies confirm that enzymes like peroxidase can mediate CNT biodegradation, enhancing their biocompatibility and safety.
- **Additional Context** -- CNTs are actively researched for tissue engineering, drug delivery systems, diagnostic probes, and as building blocks in nanomedicine, with institutions like the Indian Institute of Science, MIT, and NASA leading efforts.
- **Safety and Toxicity** -- Research into biocompatibility and long-term effects drives innovative approaches for safe functionalization and clearance of CNTs from biological systems.

Answer

Option A: 1 and 2 only

Answer

Option B: 2, 3, and 4 only

Answer

Option C: 1, 3, and 4 only