導(dǎo)讀：華裔科學(xué)家Jeremy J.Mao教授繼利用干細(xì)胞成功造出人工牙齒后,，一項(xiàng)利用干細(xì)胞培育出骨骼的實(shí)驗(yàn)在兔身上首次獲得成功,，推動(dòng)了再生關(guān)節(jié)技術(shù)的進(jìn)一步發(fā)展。
7月29日,，著名學(xué)術(shù)雜志《柳葉刀》（The Lancet）在線發(fā)布了一美籍華裔科學(xué)家首次成功利用干細(xì)胞培植出骨骼和軟骨組織,，填補(bǔ)殘缺的腿關(guān)節(jié)。據(jù)香港《文匯報(bào)》報(bào)道稱,，再生關(guān)節(jié)完全在動(dòng)物體內(nèi)培植,，是該實(shí)驗(yàn)的另一大突破，為日后病人在自己體內(nèi)利用自身干細(xì)胞培植髖關(guān)節(jié)和膝關(guān)節(jié)奠下基礎(chǔ),。
美國(guó)哥倫比亞大學(xué)醫(yī)學(xué)中心的華裔科學(xué)家Jeremy J.Mao領(lǐng)導(dǎo)的研究小組在此次研究中,，先移除了10只兔子的大腿關(guān)節(jié)，再在相關(guān)部位植入一種已注入生長(zhǎng)激素的人造支架,。生長(zhǎng)激素會(huì)刺激干細(xì)胞生長(zhǎng),，并引導(dǎo)干細(xì)胞移向失去關(guān)節(jié)的部位，分兩層再生骨骼和軟骨,。在4周內(nèi),，兔子就可如常活動(dòng),。之前,，即年內(nèi)5月25日，Jeremy J.Mao領(lǐng)導(dǎo)的研究小組宣布牙齒再生技術(shù)獲得新突破,，研究人員成功在動(dòng)物口腔內(nèi)進(jìn)行了牙齒再生實(shí)驗(yàn),，這意味著未來(lái)人們就可將該技術(shù)應(yīng)用于臨床實(shí)驗(yàn)領(lǐng)域。新的技術(shù)只需在患者口腔內(nèi)植入一個(gè)托架,，并將患者體內(nèi)的干細(xì)胞引導(dǎo)至需要牙齒再生的地方,，就可以實(shí)現(xiàn)真正意義上的“牙齒再生”。
相關(guān)內(nèi)容：J.Dental Research：人體干細(xì)胞成功造出人工牙齒
目前要把這科技應(yīng)用在人類身上尚困難重重,。由于人類用雙腿來(lái)負(fù)重,，髖關(guān)節(jié)的再生過(guò)程會(huì)更漫長(zhǎng)；若本身患有某些疾病或正接受藥物療程,，或會(huì)對(duì)骨骼再生帶來(lái)不良影響,；長(zhǎng)者或糖尿病患者亦缺乏正常的再生能力。有專家預(yù)計(jì),，距技術(shù)發(fā)展成熟還需20至30年,。
杰里米·毛對(duì)新發(fā)現(xiàn)最終可造福人類，再生膝,、肩,、髖和手指關(guān)節(jié)和骨骼充滿信心。再生關(guān)節(jié)可發(fā)揮原本關(guān)節(jié)的運(yùn)動(dòng),、負(fù)重等作用,，而且比現(xiàn)有的人造組織更耐用，從而解決病人換上金屬代用關(guān)節(jié)后，還需在15至20年內(nèi)再進(jìn)行更換手術(shù)的煩惱,。(生物谷Bioon.com)
2010年干細(xì)胞技術(shù)與應(yīng)用講座
生物谷推薦原文出處：
The Lancet, doi:10.1016/S0140-6736(10)60668-X
Regeneration of the articular surface of the rabbit synovial joint by cell homing: a proof of concept study
Chang H Lee PhD a, James L Cook DVM b, Avital Mendelson MS a, Eduardo K Moioli PhD a, Hai Yao PhD c, Prof Jeremy J Mao PhD a
Background
A common approach for tissue regeneration is cell delivery, for example by direct transplantation of stem or progenitor cells. An alternative, by recruitment of endogenous cells, needs experimental evidence. We tested the hypothesis that the articular surface of the synovial joint can regenerate with a biological cue spatially embedded in an anatomically correct bioscaffold.
Methods
In this proof of concept study, the surface morphology of a rabbit proximal humeral joint was captured with laser scanning and reconstructed by computer-aided design. We fabricated an anatomically correct bioscaffold using a composite of poly-?-caprolactone and hydroxyapatite. The entire articular surface of unilateral proximal humeral condyles of skeletally mature rabbits was surgically excised and replaced with bioscaffolds spatially infused with transforming growth factor β3 (TGFβ3)-adsorbed or TGFβ3-free collagen hydrogel. Locomotion and weightbearing were assessed 1—2, 3—4, and 5—8 weeks after surgery. At 4 months, regenerated cartilage samples were retrieved from in vivo and assessed for surface fissure, thickness, density, chondrocyte numbers, collagen type II and aggrecan, and mechanical properties.
Findings
Ten rabbits received TGFβ3-infused bioscaffolds, ten received TGFβ3-free bioscaffolds, and three rabbits underwent humeral-head excision without bioscaffold replacement. All animals in the TGFβ3-delivery group fully resumed weightbearing and locomotion 3—4 weeks after surgery, more consistently than those in the TGFβ3-free group. Defect-only rabbits limped at all times. 4 months after surgery, TGFβ3-infused bioscaffolds were fully covered with hyaline cartilage in the articular surface. TGFβ3-free bioscaffolds had only isolated cartilage formation, and no cartilage formation occurred in defect-only rabbits. TGFβ3 delivery yielded uniformly distributed chondrocytes in a matrix with collagen type II and aggrecan and had significantly greater thickness (p=0·044) and density (p<0·0001) than did cartilage formed without TGFβ3. Compressive and shear properties of TGFβ3-mediated articular cartilage did not differ from those of native articular cartilage, and were significantly greater than those of cartilage formed without TGFβ3. Regenerated cartilage was avascular and integrated with regenerated subchondral bone that had well defined blood vessels. TGFβ3 delivery recruited roughly 130% more cells in the regenerated articular cartilage than did spontaneous cell migration without TGFβ3.
Interpretation
Our findings suggest that the entire articular surface of the synovial joint can regenerate without cell transplantation. Regeneration of complex tissues is probable by homing of endogenous cells, as exemplified by stratified avascular cartilage and vascularised bone. Whether cell homing acts as an adjunctive or alternative approach of cell delivery for regeneration of tissues with different organisational complexity warrants further investigation.
Funding
New York State Stem Cell Science; US National Institutes of Health.
