2015 Journal of tissue engineering and regenerative medicine
* Poly-ε-caprolactone scaffold and reduced in vitro cell culture: beneficial effect on compaction and improved valvular tissue formation.
- Tissue-engineered heart valves (TEHVs), based on polyglycolic acid (PGA) scaffolds coated with poly-4-hydroxybutyrate (P4HB), have shown promising in vivo results in terms of tissue formation. However, a major drawback of these TEHVs is compaction and retraction of the leaflets, causing regurgitation. To overcome this problem, the aim of this study was to investigate: (a) the use of the slowly degrading poly-ε-caprolactone (PCL) scaffold for prolonged mechanical integrity; and (b) the use of lower passage cells for enhanced tissue formation. Passage 3, 5 and 7 (P3, P5 and P7) human and ovine vascular-derived cells were seeded onto both PGA-P4HB and PCL scaffold strips. After 4 weeks of culture, compaction, tissue formation, mechanical properties and cell phenotypes were compared. TEHVs were cultured to observe retraction of the leaflets in the native-like geometry. After culture, tissues based on PGA-P4HB scaffold showed 50-60% compaction, while PCL-based tissues showed compaction of 0-10%. Tissue formation, stiffness and strength were increased with decreasing passage number; however, this did not influence compaction. Ovine PCL-based tissues did render less strong tissues compared to PGA-P4HB-based tissues. No differences in cell phenotype between the scaffold materials, species or cell passage numbers were observed. This study shows that PCL scaffolds may serve as alternative scaffold materials for human TEHVs with minimal compaction and without compromising tissue composition and properties, while further optimization of ovine TEHVs is needed. Reducing cell expansion time will result in faster generation of TEHVs, providing more rapid treatment for patients.
=>1.時代, 季節, 歳月, 当時, 現代, 一生, 年季, 就業時間, 期間, 時刻, 時点, 機会, 拍子, 速度, 何度, 何回,
時, 時間, 回, 2.時間[速度]を測定する, 時間を決める, (装置などの)タイミングを調節する
Overview of noun time
The noun time has 10 senses (first 9 from tagged texts)
1. (219) time, clip -- (an instance or single occasion for some event; "this time he succeeded"; "he
called four times"; "he could do ten at a clip")
2. (160) time -- (a period of time considered as a resource under your control and sufficient to
accomplish something; "take time to smell the roses"; "I didn't have time to finish"; "it took more
than half my time")
3. (114) time -- (an indefinite period (usually marked by specific attributes or activities); "he
waited a long time"; "the time of year for planting"; "he was a great actor in his time")
4. (43) time -- (a suitable moment; "it is time to go")
5. (36) time -- (the continuum of experience in which events pass from the future through the
present to the past)
6. (10) time -- (a person's experience on a particular occasion; "he had a time holding back the
tears"; "they had a good time together")
7. (7) clock time, time -- (a reading of a point in time as given by a clock; "do you know what time
it is?"; "the time is 10 o'clock")
8. (5) fourth dimension, time -- (the fourth coordinate that is required (along with three spatial
dimensions) to specify a physical event)
9. (1) meter, metre, time -- (rhythm as given by division into parts of equal duration)
10. prison term, sentence, time -- (the period of time a prisoner is imprisoned; "he served a prison
term of 15 months"; "his sentence was 5 to 10 years"; "he is doing time in the county jail")
Overview of verb time
The verb time has 5 senses (first 3 from tagged texts)
1. (4) clock, time -- (measure the time or duration of an event or action or the person who performs
an action in a certain period of time; "he clocked the runners")
2. (3) time -- (assign a time for an activity or event; "The candidate carefully timed his
appearance at the disaster scene")
3. (1) time -- (set the speed, duration, or execution of; "we time the process to manufacture our
cars very precisely")
4. time -- (regulate or set the time of; "time the clock")
5. time -- (adjust so that a force is applied and an action occurs at the desired time; "The good
player times his swing so as to hit the ball squarely")
--- WordNet end ---