Recent Advances – Vaccines, CRISPR, mRNA Technology, Artificial Organs.

Sol –

CRISPR-Cas9 is a revolutionary gene-editing technology that allows scientists to precisely modify genes lr an organism’s DNA. 

• CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) are segments of DNA containing repetitive sequences, while Cas9 is an enzyme that acts as a pair of molecular scissors.
• CRISPR-Cas9 was adapted from a naturally occurring genome editing system that bacteria use as an immune defense. 

It involves two essential components: 

1. a guide RNA to match a desired target gene, and 
2. Cas9 (CRISPR-associated protein 9)—an endonuclease that causes a double-stranded DNA break, allowing modifications to the genome 

• The Cas9 follows the guide RNA to the same location in the DNA sequence and makes a cut across both strands of the DNA. 
• At this stage, the cell recognises that the DNA is damaged and tries to repair it.
• The DNA repair machinery is used to introduce changes to one or more genes in the genome of a cell of interest. → Mutation/ delete/ insertion new segment

CRISPR-Cas9 has revolutionized genome editing by offering unprecedented precision, versatility, efficiency, and accessibility, opening up new possibilities for understanding and manipulating the genetic code of organisms.

1. Correction of genetic disorders: Casgevy and Lyfgenia, the two cell-based gene therapies approved by the Food and Drug Administration (FDA) for the treatment of sickle cell anemia and beta-thalassemia, utilise the Nobel-winning CRISPR/Cas9 genome-editing technology.
   • India has approved a 5-year project to develop CRISPR to cure sickle cell anaemia,
2. Treatment of infectious diseases, such as HIV :  It was shown in mice.
3. CSIR-IGIB developed a COVID-19 testing kit named ‘Feluda’ based on the CRISPR/Cas9 system.
4. Agriculture: to optimize the shape and size of the crops according to consumer preferences. It also opens new opportunities to engineer disease resistance traits.
   • Japan has already approved the commercial cultivation of a tomato variety that has been improved using CRISPR-based intervention.
   • In India, several research groups are working on CRISPR-based enhancements for various crops, including rice and banana.
5. Bio-hacking: There are commercial CRISPR-based home kits that allow amateur researchers to develop their own biotechnology applications, triggering a subculture called ‘bio-hacking’.

Issues involved with it

1. Ethical dilemma: The 2018 ‘designer baby’ revelation highlighted ethical worries over CRISPR’s potential misuse for human enhancement.
2. Biological concerns: CRISPR’s imprecise nature poses risks like mutations and antibiotic resistance, challenging its safety.
3. Genetic drive: Transferred manipulated genes may persist across generations, impacting the environment.

Thus, CRISPR/Cas9 technology has the potential to revolutionize the treatment of many paediatric conditions. A number of practical and ethical challenges must be overcome before this potential can be realized at the bedside