6.3.7 · HinglishBiotechnology Applications
Describe stem cells and regenerative medicine
6.3.7· Biology › Biotechnology Applications
Stem cells KIYA hain?
Dono properties kyun zaroori hain: agar ek cell sirf differentiate kar sakti, toh reserve ek repair ke baad khatam ho jaata. Agar yeh sirf self-renew kar sakti, toh tumhe undecided cells ka ek bekar dher milta. Magic yeh hai ki yeh dono karti hai, aksar asymmetric division ke zariye (ek daughter stem cell rehti hai, doosri commit karti hai).
Stem cells ke sources (WOH KAHAAN se aate hain)
| Type | Source | Potency | Note |
|---|---|---|---|
| Embryonic stem cells (ESCs) | Blastocyst ki inner cell mass | Pluripotent | Powerful lekin ethically debated (embryo destroy hota hai) |
| Adult / somatic stem cells | Bone marrow, gut lining, skin | Usually multipotent | Pehle se tumhare body mein hain, low ethical concern |
| Induced pluripotent stem cells (iPSCs) | Lab mein reprogrammed adult cell | Pluripotent | Embryo ki zaroorat nahi; patient-matched |
| Umbilical cord blood | Birth ke baad cord | Multipotent (mostly blood) | Bank karna aasaan |
Regenerative medicine KIYA hai?
Ek typical therapy kaise chalti hai (workflow):
- Isolate — stem cells nikalo (ya skin biopsy se iPSCs banao).
- Expand — unhe culture karo taaki woh self-renew karke badi tadaad mein ho jaayein.
- Differentiate — signalling molecules (growth factors) add karo taaki unhe zaroorat ke hisaab se cell type ki taraf steer kar sako.
- Deliver — inject karo, ya scaffold par seed karke implant karo.
- Integrate — cells ko host mein connect aur function karna hoga.
Common mistakes (Steel-man then fix)
Active recall
Recall Khud se test karo (answers cover karo)
- Stem cell ki do defining properties? → self-renewal + potency (differentiation)
- Kaunsi potency placenta bana sakti hai? → totipotent
- Chaar Yamanaka factors? → Oct4, Sox2, Klf4, c-Myc
- iPSCs immune rejection se kyun bachti hain? → yeh patient ki khud ki cells se bani hain
- Kaunsa stem cell source ethical concerns uthata hai aur kyun? → ESCs, kyunki harvesting blastocyst destroy karti hai
- Tissue engineering mein scaffold ka purpose? → growing cells ko shape aur support dene ke liye ek 3D frame
Recall Feynman: ek 12-saal ke bachche ko samjhao
Socho LEGO bricks jo abhi decide nahi kar paayi ki kya banna hai. Ek bana hua LEGO car ek "grown-up" cell hai — woh sirf ek kaam karti hai. Ek stem cell ek fresh brick hai: yeh wheel, door, ya window ban sakti hai, AUR khud copy kar sakti hai taaki fresh bricks kabhi khatam na hon. Regenerative medicine woh hai jab doctors yeh undecided bricks lete hain aur unhe dhire se kehte hain, "please skin ban jao," ya "please blood ban jao," taaki body ka ek toota hua hissa theek ho sake — sirf bandage lagaane ki jagah.
Connections
- Cell Differentiation — woh process jisse stem cells guzarti hain, aur iPSCs reverse karti hain.
- Gene Expression and Regulation — Yamanaka factors transcription factors hain.
- Tissue Culture — cells ko in vitro expand kaise kiya jaata hai.
- Cloning and Totipotency — plant totipotency (koi bhi cell → poora plant) vs animal.
- Cancer — uncontrolled self-renewal ek stem-cell property hai jo galat ho gayi.
- Gene Therapy — stem cells ke saath combine karke inherited disease correct karna.
Stem cell ki do defining properties kya hain?
Self-renewal (aur stem cells banana) aur potency (specialized cells mein differentiate hone ki ability).
Totipotent define karo.
Saare cell types BANA SAKTA HAI including extra-embryonic/placental tissue; jaise zygote.
Pluripotent define karo.
Teen germ layers ki koi bhi cell bana sakta hai lekin placental tissue NAHI; jaise embryonic stem cells.
Multipotent define karo, ek example ke saath.
Cells ki ek limited, related family mein differentiate kar sakta hai; jaise haematopoietic stem cells → saari blood cells.
iPSCs kya hain?
Induced pluripotent stem cells — adult somatic cells jo defined genes use karke pluripotency mein wapas reprogram ki gayi hain.
Chaar Yamanaka reprogramming factors batao.
Oct4, Sox2, Klf4, c-Myc (OSKM).
iPSCs ESCs se zyada advantageous kyun hain?
Patient-matched hain (koi immune rejection nahi) aur koi embryo destroy nahi hota (koi bada ethical objection nahi).
Regenerative medicine kya hai?
Ek field jo damaged tissue ki structure aur function restore karti hai cells replace/regenerate karke, na ki sirf symptoms treat karke.
Classic proven stem-cell therapy batao.
Bone-marrow (haematopoietic stem cell) transplant blood system rebuild karne ke liye, jaise leukaemia mein.
Tissue engineering mein scaffold kya hai?
Ek biodegradable 3D framework jo growing cells ko ek tissue/organ mein shape aur support deta hai.
Asymmetric division kya hai?
Ek stem cell division jisme ek stem cell banti hai (self-renewal) aur ek committed daughter (differentiation).
Stem cell therapies ke do main risks?
Uncontrolled division se tumour formation aur donor cells ka immune rejection.
Embryonic stem cells kahaan se milti hain?
Blastocyst ki inner cell mass se.