Mc lc A. M : 3 B. Ni dung: 4 I. Khi nim t bo gc v phn loi t bo gc: 4 1. Khi nim t bo gc: 4 2. Phn loi t bo gc: 4 a. Da trn tim nng bit ha: 4 b. Theo v tr thu nhn 5 II. Cc c tnh c bn ca t bo gc 6 III. Phng php xc nh t bo gc: 7 1. Xc nh da vo Alkaline phosphate 7 2. Xc nh t bo gc da vo vic s dng cc maker phn t: 9 Vi t bo gc phi: 9 i vi cc t bo gc tu sng 10 *Mt s k thut ph bin s dng maker phn t xc nh t bo gc: 10 IV. Liu php t bo gc 12 1. Liu php t bo gc l g 12 2. Cc ng dng ca liu php t bo gc 12 Ri ro liu php t bo gc: 22 IV. Kt lun 24 Ti liu tham kho 24

A.

M : T bo gc (stem cell) l khi nim dung ch cc t bo nguyn thy cha bit nh v hn nh (phn chia v hn).N c kh nng phn chia v to nn cc loi t bo khc trng thch hp. Nh vy,t t bo gc chng ta c th to ra hn 200 loi t bo khc nha hiu hng i mi cho cc ngnh sinh hc, y hc trong vic nghin cu cc ng dng tr liu hn cho ngi bnh, cng nh cc ng dng ca n trong vic bo tn cc loi ng vt. Hi hin cu c quan tm hng u ca cc nh khoa hc trn th gii. Trong khun kh bi chu t bo gc v mt s ng dng ca n trong thc tin.

B. Ni dung: I. Khi nim t bo gc v phn loi t bo gc: 1. Khi nim t bo gc: L nhng TB nguyn thy cha bit ha, c hai c tnh l tnh t lm mi v t Tnh t lm mi (self-renewal): l kh nng tin hnh mt s lng ln chu k phn g bit ha. Tnh tim nng khng gii hn (unlimited potency): t bo gc c kh nng bit ha thc t c tnh ny ch ng vi cc t bo gc ton nng, hoc vn nng, tuy nhin mt t 2. Phn loi t bo gc: Trong vic phn loi t bo gc i vi mi nh nghin cu khc nhau c th c cc cch ph loi c xut nhiu hn c l phn loi t bo gc da vo tim nng bit ha v phn l a. Da trn tim nng bit ha: Tn gi S t bo c bit ha Ngun gc c im Ton nng (Totipotent) -Tt c cc t bo c bit ha trong c th -Mi t bo c th pht trin thnh c th mi -Hp t (trng c th tinh) -T bo c to ra sau mt s ln phn ct ca hp t(phi t 1-3 ngy) -Bit ha k Vn nng (Pluripotent) -Tt c cc t bo bn trong c th sinh ra t ba lp phi(trn 200 -Khi t bo bn trong ca phi bo(Blastocyst) giai on 5-14 ngy -Bit ha khng gi a nng (Multipotent) -S t bo thuc cc m sinh dng -M bo thai,mu dy rn,c -Ch c th sn sinh ra cc t bo thuc cng mt h.VD:t bo c tim, c xng, t bo gan Vi tim nng (Oligopotent) Mt vi T bo ty 5 kiu t bo mu: hng cu, monocy osinophil, neutrophil Bn tim nng (Quadripotent) Bn T bo tin thn trung m T bo sn, t bo Ba tim nng (Tripotent) Ba T bo tin thn thn kinh m 2 kiu t bo thn thn kinh m t gai Hai tim nng (Bipotent) Hai T bo c cht hai tim nng t gan thai chut T ophage n nng (Unipotent) Mt C cht dng bo Dng bo b. Theo v tr thu nhn

- T bo gc phi (Embryonic stem cell-ES) c thu nhn t giai on phi nang(4-7 ngy tu trong ca phi nang. T bo gc phi c kh nng phn chia v hn trong nui cy v bit h lp phi, tr t bo nhau thai v cung rn( t bo gc phi thuc loi t bo ton nng) - T bo gc thai (foetal stem cells): l cc t bo gc c phn lp t t chc tha vn tim nng hoc a tim nng, tc l chng c tim nng pht trin thnh nhiu loi t - T bo gc nh nhi (infant stem cells): l cc t bo a tim nng hoc vn tim inh, dy rn, v t nhau thai. - T bo gc trng thnh (adult stem cells): l cc t bo cha bit ho, c t rng thnh (ty xng, mu ngoi vi, m no, m da, m c...), c cho l c tnh a tim t bo chuyn bit -T bo gc ging t bo gc phi (embryonic like stem cell) hay t bo gc vn ti ced plutipotent stem cell) l nhng t bo c to ra bng cch cm ng cc t bo bit t bo gc phi - T bo gc mm (Embryonic germ cell-EG) c thu nhn t rnh sinh dc(tin inh dc),c kh nng bit ha thnh cc t bo thuc c quan sinh dc( thuc loi vn nng) - T bo gc ung th biu m phi (Embryonic carcinoma-EC) c bn cht ging nh cc t b tin t khi u trong tinh hon v bung trng mt s chng chut

II. Cc c tnh c bn ca t bo gc Theo nh nghin cu Phan Kim Ngc t bo gc c cc c im chnh l : Tnh cht t lm mi (self-renewal): kh nng i xuyn sut cc chu k sinh sn ca

khng bit ho. Tim nng (potency): kh nng bit ho thnh cc dng t bo chuyn bit. Trong n hi t bo gc phi l hoc totipotent hay pluripotent c kh nng to ra dng t bo tr ultipotent hay unipotent thnh thong vn c xem nh l t bo gc. III. Phng php xc nh t bo gc: Cc nh nghin cu bit rng nhiu loi t bo gc khc nhau lun tn ti trong c th nhn g c th ngi, trong mt s trng hp 1 t bo gc trong 100.000 t bo trong tun hon m xt cc t bo di knh hin vi, chng trng ging nh bt k t bo khc trong t bo, n nh t bo gc so vi cc t bo bnh thng khc. Nguyn tc chung ca cc phng php x t bo chuyn bit cng nh cc dng t bo gc khc. 1. S dng phng php y l mt phng php n gin pht hin nhanh chng t bo gc. Akaline phosphatase l v c hot ho trong iu kin kim. Enzyme ny c chng minh l hot ng mnh c i l mt ch th tin cy phn bit cc t bo gc v cc t bo bit ho. VD: Cc nh nghin cu xc nh aldehyde dehydrogenase l mt marker mi cho s hin di ty, mt pht hin em li tim nng trong pht trin phng php iu tr mc tiu. Ung th tuyn ty l mt loi ung th kh cng u i vi cc phng php iu tr Zeshaan Rasheed, M.D., Ph.D, mt nh nghin cu ti i hc Johns Hopkins: Cc t bo kh nng iu tr tn ch, nhng c c phng php iu tr hiu qu cn phi xc n Phn tch cc mu ung th tuyn ty ngi, Rasheed v ng nghip pht hin ra mt qun rogenase, v nhng t bo ny cho thy kh nng pht trin cao hn so vi nhng t bo khc dehydrogenase. Cc nghin cu trc y cho thy cc t bo CD24+ v CD44+ l cc t bo ung th t Rasheed v ng nghip pht hin ra rng cc t bo CD24+, CD44+ v biu hin aldeh se c kh nng tng sinh cao ng k so vi cc t bo khc v c th l gy di cn ung th jaldehyde dehydrogenase cng lin quan mt thit n kh nng sng st sau cng. C th l bo ny sng trung bnh 14 thng sau khi chn on so vi 18 thng nhng bnh nhn khng Nhng kt qu ny cho thy mi lin h trc tip gia t bo gc ung th v tnh t Johns Hopkins. (Bi bo co c trnh by Ti Hi Ngh thng nin 2008 ca AACR-Hip hi Cc thng tin c truyn nh th no trong t bo gc thng qua mt cch lin lc it nh t bo mu trong c th chng ta, khm ph ny do cc nh khoa hc thuc Vin the M Cancer Research. Kt qu ny c ng ti trn Cell Stem Cell s 06/03/2009, y l nghin cu hng kinh in Wnt trong qu trnh cm ng to t bo mu trong c th ngi v mt s ng t bo chng c th p ng vi tn hiu pht trin thnh t bo mu. Mick Bhatia (Gi d Cancer Research) cho bit s bit ha trc tip, phng php ny cho chng ta mt cch

y cng l phng php mi to t bo mu t t bo gc, phng php ny c th g th bch cu hoc bnh nhn ang iu tr bng cc liu php tr ung th Thng qua qu t chc nng thnh t bo c nhiu chc nng hn, t bo gc c kh nng pht trin thnh bt , c v mu. Ngoi ra, cc nh khoa hc cng nhn thy mt con ng th cp khc, n khng bo mu. Tuy nhin, con ng th cp ny ng vai tr quan trng trong vic gia tng vic ian Cancer Society, Cannadian Institutes for Health Research v Stem Cell Network.

2. Xc nh t bo gc da vo vic s dng cc maker phn t: Bao gm cc maker DNA cng nh maker protein khng th nhm pht hin ra cc sn phm c t c c trng bi s hot ho ca mt s gene v to ra cc sn phm ca chng, trong cc k thut phn tch DNA nh cc k thut lai, microarray Ta c th pht hin ra cc t hi hn hp t bo. Trong , hin nay ph bin nht l cc k thut xc nh t bo gc b th c hiu. Vi t bo gc phi: i vi t bo gc phi, cc nh khoa hc tm ra gene Oct-4, m ho mt yu t phin m, t bo gc phi cng nh trong qu trnh bo qun t bo gc phi khng cho bit ho chng al,2000). Bn cnh Oct-4, mt loi maker khc cng c x dng nh mt ch th xc nh t bo g inh l xut hin t hn cc t bo c bit ho, c vai tr trong vic duy tr trng r I et al, Mitsui K et al, 2003). Tuy nhin, mc biu hin ca gene Nanog t hn so vi nh chc nng ca chng hin nay vn cha c lm r Bng cc bin php so snh gia cc dng t bo gc phi, cng nh gia t bo gc phi vi hi c pht hin v tr thnh cc maker. Bng phng php ny, gene Est-1 c pht

chut (Tanaka TS et al, 2002). Cng bng phng php ny, Sato v cc cng s pht hin ti cc t bo gc phi ngi, so vi cc loi t bo bit ho khc, phn ln trong s ch ra rng, ch c 92 gene, bao gm c Oct-4 v Nanog, c biu hin 6 dng t bo gc t bo gc chut. S khc bit ny c th do vic la chn cc dng t bo gc khc nhau nh to lp h s gene biu hin i vi cc t bo gc tu sng Trc y, cc t bo gc tu sng c pht hin nh vic xc nh kch thc, mt , cn drocacbon c ngun gc ch yu thc vt). Tuy nhin, ngy nay, bin php chnh pht hi g cc loi t bo gc ny ch yu da trn cc ch th protein b mt, nh l cc khng th khng nguyn nh: CD34, CD38, CD43, CD45RA, CD45RO, CD90 Bn cnh , cn c cc ch th t cht nhum mu khc c s dng nh Rhodamine 123 (thuc nhum ty th), Hoechst33342 (xc dng hot ng, c th bm ra cc phn t thuc, biu hin cao t bin cc t bo gc), (ch th cho nhm enzyme aldehide dehydrogenase hot ng). Vic kt hp mt vi maker ny g vic tch cc dng t bo gc tu sng, phc v cho vic nghin cu cc c tnh sinh ho Cc ch th ny c xy dng da trn mc biu hin ca cc protein ny trn mng t b (mc biu hin khng nguyn, hoc sn phm mRNA ca chng) gia cc dng t bo gc vi ho khc cho php xc nh cc ch th chn lc di dng m tnh, biu hin thp, hay dn -1 hay CD117 c coi l cc maker dng tnh (s xut hin ca n c coi l ch th tm ti cc t bo gc tu sng, cng nh cc t bo gc mu, tuy nhin, chng cn c biu hi vi maker CD90+ c chng minh l mt phng php ng tin cy xc nh cc t bo g *Mt s k thut ph bin s dng maker phn t xc nh t bo gc: K thut Realtime-PCR K thut lai Western Blot K thut lai Northern Blot K thut FACS . Trong k thut FACS hin nay ang c s dng ph bin xc nh v tch dng

y l phng php da trn vic nh du cc dng t bo gc bi cc cht mang mu khc nh bo khng phi t bo gc s khng c gn vi maker). Sau khi tin hnh php lai gia cc gc, hn hp s c i qua mt h thng trong dng t bo thot ra theo tng t bo mt ang mu khc nhau, ng thi phn loi chng v mt ng thu kt qu. T ta c th tch r chn lc khc nhau phc v cho cc nghin cu sau ny. u im ca phng php l c th phn tch nhanh cc dng t bo gc v loi b cc t bo

Tuy nhin, nhc im ca phng php ny vi ch mt maker ch th chn lc l ch c th t bo T hoc t bo ung th. Kt qu s c ci thin ng k nu s dng 2 maker chn l 50000 t bo c tch mt giy) v i hi thit b t tin hn.

IV. Liu php t bo gc 1. Liu php t bo gc l g - L liu php nhm thay th cc t bo b bnh bng cc t bo khe mnh,tng t qu trn ch khng phi l c quan. 2. Cc ng dng ca liu php t bo gc Ngy nay cc nh khoa hc c nhiu cng trnh nghin cu v thc hin cy ghp h,vi d nh: S dng t bo gc phi thai:iu tr bnh i tho ng,bnh l tim mch. S dng t bo gc to mu: iu tr bnh ca c quan to mu v cc c quan khc. thay th t bo gc to mu.T bo gc to mu c tc dng iu tr nhiu bnh ung th kh h nng chng khi u, t bo bnh l. S dng t bo gc bo thai: iu tr cc bnh ca cc t chc khc nhau: t bo g inson, i ng, bnh tim mch, bnh sng khp. Bnh i tho ng: t bo gc c th sinh ra t bo beta sn xut insulin. Parkinson: t bo gc bit ho thnh t bo sn xut dopamin, cc t bo ny c th Tim mch: Thay th t bo c tim tn thng: t bo gc s pht trin thnh t bo ai loi t bo quan trng cu trc ln c tim. a. Liu php t bo gc trong iu tr bnh tim mch: Bnh tim mch, trong suy tim v nhi mu c tim l nguyn nhn hng u gy nn khong 16,7 triu ngi cht hng nm. Con s l 900 000 ngi mi nm. Nhiu liu php

mi s dng cc cng c t bo hay gene, hoc kt hp c 2 cho thy kh nng trc tip .

Trong vi nm gn y, nhiu cng trnh cho thy cc t bo t ty xng c th cm tin thn ni m, cc t bo n nhn ty xng v cc t bo CD34+ khi b nhi mu cp t ho kt qu ng tin cy, a ra tim nng ln vi mt liu php an ton v hiu qu iu Cc t bo gc tn ti trong tim trng thnh, iu ny gi ra mt kh nng s dng Cc nghin cu ti cu trc c tim b hng (do nhi mu) trn ng vt, cn c th hu t ty xng c-kit+, cc t bo MSC, ES v cc t bo tin thn c tim (CPC) c-kit+. Son th kt hp huy ng ngun t bo gc ty xng v hot ha cc b, huy ng cc CPC, vi s . Trong tt c cc trng hp ng dng trn ngi, kt qu cho thy c s ti to hc nng tim, v s gim hoi t. Ngoi ra s ti to c tim thng qua hot ha v bit ha thnh cng bc u ngi. Ngun t bo gc: Huy ng t bo gc d tr: Vic khan him tng i ca cc t bo tin thn st li trong c tim trng thnh ng cc t bo tin thn dinh dng tun hon di chuyn n tim, vi hy vng chng p l Trong mt nghin cu, mt qun th t bo biu hin c-kit c thu nhn t ty xn mu. Sau th nghim, quan st thy chng c th di c vo vng thiu mu, hi phc mt Tim nng s dng cc t bo tin thn tim mch, t nht l ng vt c v cho th v tr nhi mu. Nhiu tn hiu ha hc kt hp vi cc nhn t vng vim (nh cc cytokine , v c th kch thch s v nh cho cc t bo. Tht vy, cc phn t chemokine gi vai gc t ty xng dn vng m b nhi mu. T bo gc c: T bo gc c xng Cc t bo gc t m c biu hin cc Maker ca s bit ho c, nhng cng c th t n chu ca nhng t bo ny, nguyn bo c xng, hay k c t bo v tinh, cho kt qu b. T bo gc c tim Mt gi thuyt c chp nhn trong thi gian di l cc t bo c tim trng thnh i vo qu trnh phn chia p ng li cc tn hi tim, nh s cht cp tnh v mn tn thiu mu c tim). Hn th k qua, iu ny tr thnh mt nghi vn. Nm 1998, kajstura v bo c, chng c kh nng phn chia sau khi tim b h. Nhng t bo ny rt him, iu ny thiu mu. Tuy nhin qua nhiu nghin cu, cc nh khoa hc nhn thy rng protein maker b gc trong nhiu m khc cng c pht hin qun th ph trong tim trng thnh. Cc t bo tim trng thnh c tch bng maker t bo gc khng ch biu hin cc in vitro ging vi cc t bo tin thn, chng c kh nng to ra cc dng t bo biu hi v t bo ni m. Ngi ta cng thy rng, cc t bo ny c mi quan h vi mt qun th t t lm mi bng cch to ra t bo ging t bo gc, nh l mt chc nng bnh thng ca S tn ti ca cc t bo gc c tim gn y r rng hn, khi t bo Lin-/c-kit+ h gc. nhng t bo ny c kh nng t lm mi, to tp on, a nng in vitro, in vivo, v m. Khi tim cc t bo ny vo tim nhi mu, cc th h con chu ca chng ti to c p mi ny cn c cc c im sinh ha ging t bo c cn non. Nhng kt qu ny cho thy, s t lm mi t bo c trong tim ng vt c v trng h cc t bo c tim ni sinh di c t ca chng n vng tim tn thng h tr ti t T bo gc to mu: T bo gc trung m T bo tin thn ni m T bo gc t m m T bo gc phi v t bo ging t bo phi. Liu php t bo gc cho bnh tim: Huy ng t bo gc: ngi, vic huy ng t bo gc tin thn t ty xng di c tch cc n tim v cp tnh (AMI) cho thy mt n lc t nhin sa cha tim. Vic huy ng cc t bo tin thn ny l mt chin lc hp dn bi v n n gin ln gy hi cho c theertrong qu trnh thu nhn, cng nh phn phi t bo gc. SDF-1 c l l nhn t quan trng iu ha s huy ng cc t bo gc v cc t bo rung m ti m tn thng (thiu mu hay vim). Theo , SDF-1 c th kch thch s triu t h trong cc m tn thng.

C quan tn thng gii phng SDF-1, sau n c h mch chuyn v t vng m tn thng hin cm ng t bo nn ty xng v t bo ni m huy ng cc t bo gc v t bo tin -

Cy ghp t bo gc vo tim: C nhiu phng php phn phi t bo c kho st, bao gm tim trc tip vo c gc, nhng cha th nh gi c phng php no l tt nht. Trong phng php truyn hp t xm ln trong vic phn phi t bo gc.

Tuy phng php huy ng t bo gc t thn c thun li, song chin lc ny i h v tr m khng di chuyn n cc vng khc (c th gy nn khi u). iu ny c khc ph thut.

1. T bo gc c tuyn la t ty xng chu ca bnh nhn. 2. Cc t bo gc trng thnh c tim vo tim bnh nhn ni b h hi. 3. Cc t bo t n bm cht v sn xut protein (cht m) cung cp tn hiu cho vic Rejuvenated heart tissue: Tr ha m tim (lm cho cc m ca tim tr li). Cc kt qu nghin cu cn lm sang v lm sng: Sau khi xut hin cc bo co v bnh nhn nhn tim t bo vi cc nghin cu trn cng sm c trin khai. T cc kt qu u tin (Menasche v cng s, 2001) v liu php t bo ngi c sng trn 170 ngi bnh. Ging vi vic th nghim trn ng vt, nhiu phng php phn hi bnh v phng php nh gi chc nng tim c s dng. Sau khi theo d i th hu ht cc th nghim u ng h tnh d dng ca liu php t chc nng tim sau khi cy ghp, cho d cha r nt. Liu php t bo gc trong iu tr bnh tiu ng:

Ngun t bo gc: T bo gc s dng trong vic iu tr c ly t cc t bo gc ty xng ca bnh nhn t

Ghp t bo gc iu tr bnh tiu ng s dng phng thc t ghp (autogreffe hn b bnh tiu ng ph thuc insuline (loi 1) cho php nhng bnh nhn ny ti sn tr ca bnh tiu ng loi 1. Nh mt phng thc t ghp nhng t bo gc (autogreffe de cellules souches), ly trong t 23 bnh nhn tiu ng t nguyn, c th khng cn phi nhn cc mi tim insuline mi Mt trong nhng bnh nhn tiu ng ng vng trong hn 4 nm khng cn tim insuline, 3 bnh nhn khc trong hai nm. 15 bnh nhn mi c tuyn m nht, c hng nhng c hard Burt, Northwestern University de Chicago, Illinois, lun lun khng cn n insuli thng sau khi can thip. Sau cc phng thc ghp nhng t bo ty tng (greffe de cellule ) sn xut insuline, c th nghim vo u nhng nm 2000, cc k thut ghp t bo gc t hes de la moelle osseuse) nh du mt bc ngot mi. Richart Burt cng b trong Journ rican Medical Association (JAMA) cng trnh nghin cu, c theo d i trong 3 nm, trn mt hn tiu ng, tt c u nhn mt k thut ghp nhng t bo gc.u im u tin c g cn phi theo ui mt iu tr nhm hy b min dch (traitement immunosuppresseur), tr ghp nhng t bo ty tng, iu ny cho php trnh mi tc dng ph. Cng trnh nghin c cha c tr li. Th d, ngi ta khng bit nhng t bo no ca ty xng c th c ine. C th l nhng t bo gc sinh huyt (cellule souche hmatopoitique) ca ty xn . Mt ng vin khc l mt t bo va mi c khm ph, MAPC (cellule prognitrice adulte th cho nhng t bo con ca hu ht tt c cc m v c quan ca c th. Ngi ta cng kh h nhn b bnh tiu ng loi 1 (s bnh nhn ln n khong 150.000 ngi Php), bnh hormone ng mt vai tr quan trng trong vic qun l cc cht sinh nng lng, trong hung, chnh s ph hy ca cc t bo bta ca ty tng (trong cc o nh Langerhans) gi ne, i khi ngay t tui u th. Nhng bnh tiu ng cng c th do s khng ca cc iu ng loi 2. Cc cht ch du c hiu Ty tng phi lun lun gi s lng t bo bt h yu l s i mi nhng t bo ny. Th m, ngay nm 2003, Markus Stoffel (Rockfeller Un k) trong Journal of Clinical Investigation a ra kh nng rng trong ty xng c mt ca nhng o nh Langerhans. Tht vy, mt vi trong nhng t bo pht xut t ty xng queurs spcifiques) ca cc t bo Langerhans: mt gne vn chuyn (Glut-2) v nhiu proti bo ty tng ny (gip sao chp li ADN thnh ARN trong t bo). Kt qu ca th nghim l Burt c th lm o ln hon ton vic nghin cu trong lnh vc ny. Tht vy, t nm 198

tng ca nhng ngi cho trn nhng bnh nhn tiu ng ph thuc insuline, c thc g t bo c ghp vn rt l t nh, v cc kt qu lm sng vn mc tm thng: khong mt nm sau khi c ghp. V tt c bnh nhn phi c iu tr hy b min dch sut rt c xng. Ri ro liu php t bo gc: Hnh thnh khi u: Kh nng ny cn phi ngn chn bng vic nh gi tim nng hnh thnh khi u, qua phng hn t marker b mt t bo vi kiu hnh cha bit ha. Cc market ny bao gm cc khng n & 4, glycoprotein TRA-1-60 v TRA-1-81 v hot ng ca cc enzyme c bit nh alkaline ph telomerase. Cc marker Oct4 v Rex1 c biu hin trong s pht trin sm v sau nhanh it ha. Phng php in vitro gip xc nh kh nng tim n ri ro gy khi u khi cy ghp, nhng dng tnh vi cc xt nghim trn (nh dng tnh vi Oct-4), nhng chng li khng h g ra in vivo cho kt qu thuyt phc hn. Sau khi t bo c cy ghp, s hnh thnh khi u hi u t bo mm, bao gm -fetoprotein, kch thch t mng m ngi (hCG) v lactate dehy d i ny s cung cp thng tin quan trng cho nh gi ri ro liu php t bo gc, trc kh Cc t bin di truyn: Kiu t bo gc c th nh hng ti kh nng t bin di truyn. Cc t bo ES l ng vin bo thay th c kh nng khuych i. Hu ht cc t bo gc sinh dng c v l m tnh v v thi gian phn chia ch chng 50 ln, gii hn trong kh nng tng sinh. Cc t bo gc hnh cng, mt phn l v kh nng ca chng d dng to dng, thao tc v khuych i. Vn ca t bo gc phi sinh dng cho s pht trin mt liu php an ton, gip ng dng cho h h nin. Bt k t bo phi hay cc t bo gc khc u cn phi c sng lc di truyn. Cc c tnh t nui cy ex vivo: Cy ghp m ngoi lai thng tim n nguy c truyn nhim tim n t ng vcaatj cho sang C th nhn sau khi c cy ghp Thi loi min dch: T bo cy ghp c th b ph hy t bo p ng thi loi min dch ca c th ch.

IV. Kt lun Trong lnh vc nguyn cu t bo gc cc nh khoa hc thu c rt nhiu kt qu ong lnh vc y hc, sinh hc. Bn cnh nhng thnh tu t c vn cn rt nhiu kh khn v vn cng ngh tm nghin cu hng u ca cc nh khoa hc trn th gii, bi nhng ng dng y trin v

Ti liu tham kho 1.Phan Kim Ngc, 2007. Cng ngh sinh hc trn ngi v ng vt, Nh xut bn Gio dc 2.Phm Thnh H, 2006. Nhp mn Cng ngh sinh hc, Nh xut bn Gio dc 3.Ti liu internet.