マックス・プランク研究所、カイコの糸から心臓組織再生用の足場材を作製
http://www.mpg.de/5000944/heart_of_silk?filter_order=L
Heart of silk
Max Planck scientists use silk from the tasar silkworm as a scaffold for heart tissue
January 27, 2012
Damaged human heart muscle cannot be regenerated.
Scar tissue grows in place of the damaged muscle cells.
Scientists from the Max Planck Institute for Heart and Lung Research in Bad Nauheim are seeking to restore complete cardiac function with the help of artificial cardiac tissue.
They have succeeded in loading cardiac muscle cells onto a three-dimensional scaffold, created using the silk produced by a tropical silkworm.
Zoom image
Disks cut from the cocoon of the tasar silkworm grub provide a basic scaffold for heart muscle cells. The disks are around the same size as cent coins.
© MPI for Heart and Lung Research
Of all the body’s organs, the human heart is probably the one most primed for performance and efficiency.
Decade after decade, it continues to pump blood around our bodies. However, this performance optimisation comes at a high price: over the course of evolution, almost all of the body’s own regeneration mechanisms in the heart have become deactivated.
As a result, a heart attack is a very serious event for patients; dead cardiac cells are irretrievably lost.
The consequence of this is a permanent deterioration in the heart’s pumping power and in the patient’s quality of life.
In their attempt to develop a treatment for the repair of cardiac tissue, scientists are pursuing the aim of growing replacement tissue in the laboratory, which could then be used to produce replacement patches for the repair of damaged cardiac muscle.
The reconstruction of a three-dimensional structure poses a challenge here.
Experiments have already been carried out with many different materials that could provide a scaffold substance for the loading of cardiac muscle cells.
“Whether natural or artificial in origin, all of the tested fibres had serious disadvantages,” says Felix Engel, Research Group Leader at the Max Planck Institute for Heart and Lung Research in Bad Nauheim.
“They were either too brittle, were attacked by the immune system or did not enable the heart muscle cells to adhere correctly to the fibres.
” However, the scientists have now found a possible solution in Kharagpur, India.
At the university there, coin-sized disks are being produced from the cocoon of the tasar silkworm (Antheraea mylitta).
According to Chinmoy Patra, an Indian scientist who now works in Engel’s laboratory, the fibre produced by the tasar silkworm displays several advantages over the other substances tested.
“The surface has protein structures that facilitate the adhesion of heart muscle cells.
It’s also coarser than other silk fibres.” This is the reason why the muscle cells grow well on it and can form a three-dimensional tissue structure.
“The communication between the cells was intact and they beat synchronously over a period of 20 days, just like real heart muscle,” says Engel.
Despite these promising results, clinical application of the fibre is not currently on the agenda.
“Unlike in our study, which we carried out using rat cells, the problem of obtaining sufficient human cardiac cells as starting material has not yet been solved,” says Engel.
It is thought that the patient’s own stem cells could be used as starting material to avoid triggering an immune reaction.
However, exactly how the conversion of the stem cells into cardiac muscle cells works remains a mystery.
絹の高機能化による再生医療材料創製システムの構築
http://brain.naro.affrc.go.jp/tokyo/marumoto/inv_up/press080829/29asakura.htm
研究課題名
絹の高機能化による再生医療材料創製システムの構築
研究代表者氏名及び所属
朝倉 哲郎
（国立大学法人東京農工大学）
研究実施期間
平成２０年度～２２年度（３年間）
研究の趣旨・概要
遺伝子組換えカイコならびに大腸菌が生産する絹を原料として、ヒトへの適用を目的とした再生医療材料を創製するため、絹の一次構造を改変する遺伝子操作技術、絹の形状を微細加工する技術、改変絹の構造と物性を解析する技術、および試作した再生医療材料の評価技術を開発し、システム化を図る。
この技術システムを利用してヒト用の小口径絹人工血管を試作し、ブタ、サルへの移植による生体親和性、開存率等の評価を行い、実用化を図る。また、本システムを活用して人口皮膚用絹フィルムと絹不織布の開発を行う。
研究項目及び実施体制（（）は研究担当者）
①再生医療材料開発のための絹基盤技術のシステム化とヒト用絹人工血管の開発
(国立大学法人東京農工大学 朝倉哲郎)
②ヒト用絹人工血管の動物実験による評価
(国立大学法人徳島大学 佐田政隆)
期待される効果
絹をベースに再生医療材料を創製するための独創的技術システムが開発され、実用性の高いヒト用小口径絹人工血管および人口皮膚用絹フィルム等が創出される。
本システムの活用により、新たな再生医療分野が切り開かれ、国民の医療に貢献する。また、カイコによる高付加価値の絹の生産は、養蚕と関連産業の活性化に寄与する。
研究のイメージ
