• Biomaterials and Biomechanics in Bioengineering
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• 제2권1호
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• pp.47-59
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• 2015

A bioactive and multifunctional elastin-like polymer (ELP) was produced by genetic engineering techniques to develop new artificial matrices with the ability to mimic the extracellular matrix (ECM). The basic composition of this ELP is a thermo- and pH-sensitive elastin pentapeptide which has been enriched with RGD-containing domains, the RGD loop of fibronectin, for recognition by integrin receptors on their sequence to promote efficient cell attachment. Hydrogels of this RGD-containing polymer were obtained by crosslinking with hexamethylene diisocyanate, a lysine-targeted crosslinker. These materials retain the "smart" nature and temperature-responsive character, and the desired mechanical behavior of the elastin-like polymer family. The influence of the degree of crosslinking on the morphology and properties of the matrices were tested by calorimetric techniques and scanning electron microscopy (SEM). Their mechanical behavior was studied by dynamical mechanical analysis (DMA). These results show the potential of these materials in biomedical applications, especially in the development of smart systems for tissue engineering.

• 대한의생명과학회지
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• 제19권1호
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• pp.41-47
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• 2013

Pluripotent stem cells (PSCs) have lots of potential in biomedical sciences owing to its potential to differentiate into any kind of cells in the body. However, it is still a challenge to culture PSCs on a large scale for application to regenerative medicine. Herein, we introduce a synthetic polymer that enables large-scale suspension culture of human PSCs. By employing suspension culture, it became unnecessary to use conventional substrata such as mouse embryonic fibroblast (MEF) or Matrigel$^{TM}$, which are believed to be main causative sources of xenogeneic contamination in cultured human PSCs in vitro. Human PSCs were cultured in the medium in which elastin-like polypeptide (ELP) dissolved. The ELP in the medium became harden as temperature increases by transforming the medium into a semi-solid gel that supported growth of human PSCs in suspension. Gel-sol transition temperature of ELP can be adjusted by modifying the peptide sequence in which 5 amino acids, Val-Pro-Gly-Xaa-Gly, repeated sequentially. We constructed 3D suspension media having transition temperature around $33{\sim}35^{\circ}C$ using an ELP consisted of 40, 60, or 80 repeats of a monomer, which was Val-Pro-Gly-Val-Gly. Among the ELPs, ELP80 was chosen as the best ELP to support growth of human PSCs in suspension culture. This result suggests that the ELP80 can be a medium component for culturing human PSCs in large-scale.

• 폴리머
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• 제35권3호
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• pp.223-227
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• 2011

자극감응성 고분자는 다양한 응용에 중요한 역할을 하는 재료로 널리 연구되어오고 있다. 온도감응성을 가지는 히알루론산 공중합체를 카르복실기 고분자와 생체친화성 히알루론산의 아미드 결합을 통하여 연결시켜 합성하였다. 온도감응성 특징은 두 공중합체 모두에 구현되었으며, 탁도 측정과 rheolgical 결과는 일치하였다. 두 공중합체 중 elastin-like peptide(ELP)를 그래프트 사슬에 둔 공중합체의 경우가 N-ispropylacryamide(PNIPAAm) 경우에 비해 보다 완만한 LCST 변화과정을 보여주었다. PNIPAAm과 ELP의 그래프트 부분 함량이 증가함에 따라 점도가 증가하였고, 비슷한 그래프트 함량에서는 PNIPAAm 공중합체의 점도 증가가 컸다. 이러한 결과를 통해 생체친화성의 히알루론산에 그래프트 사슬을 붙임으로써 온도감응성을 부여할 수 있고, 그 특성을 설계할 수 있음을 알 수 있었다.