RAD16-I, free acid TFA is a derivative of RADA16, with no Ac and NH2 modifications at both ends, and it has the same function as RADA16. RAD16-I, free acid TFA is a non-directed self-assembling peptide hydrogel. Under physiological conditions, RAD16-I, free acid TFA spontaneously forms a three-dimensional nanofiber network that mimics the extracellular matrix, and possesses excellent properties such as high water content, biocompatibility and degradability. RAD16-I, free acid TFA serves as an ideal scaffold for three-dimensional cell culture. RAD16-I, free acid TFA not only maintains cell viability and induces self-organization, but also supports cell adhesion, proliferation, differentiation and insulin secretion, effectively stabilizes islet clusters and promotes directed differentiation of the cardiac lineage. RAD16-I, free acid TFA can construct a cell-friendly nano-microenvironment for research related to diseases such as myocardial infarction and diabetes [1] [2] [3] [4].
In Vivo, RAD16-I (surgical implantation) free base TFA enables real-time monitoring of myocardial infarct scar formation via electrical impedance spectroscopy, with impedance magnitude changes corresponding to distinct stages of scar development when used to rehydrate a decellularized human pericardium scaffold for implantation[2].
In Vitro, The self-assembling peptide hydrogel RAD16-I (0.1-0.3% w/v; up to 21 days) free acid TFA maintains high viability of subATDPCs for up to 21 days, supports basal upregulation of cardiac markers in control medium, enhances the upregulation of cardiac markers when combined with cardiac induction medium, and regulates the viscoelasticity of the scaffold over time[1]. Modified RAD16-I, free acid TFA self-assembling peptide hydrogels (0.15-0.3% w/v) bearing the RGD motif, heparin, or both maintain high viability of subATDPCs, promote cell elongation and orderly arrangement; compared with unmodified RAD16-I, free acid TFA hydrogels, they do not significantly alter the expression of myocardial markers; while under cardiomyogenic induction conditions, RAD16-I, free acid TFA/RADRGD hydrogels with enhanced initial stiffness downregulate the expression of myocardial proteins in subATDPCs[1]. RAD16-I, free acid TFA self-assembles into β-sheet-containing nanofibers under physiological conditions, with a diameter of 19.58 nm[3]. The 3D sandwich culture system with RAD16-I, free acid TFA maintains the long-term viability of dedifferentiated human ICCs (with a cell survival rate of approximately 85% on day 18 of culture) and also promotes the aggregation of ICCs into larger cell clusters within 18 days, but does not significantly upregulate the expression of β-cell-specific genes compared with the non-adherent control group[3]. RAD16-I, free acid TFA can adsorb onto poly (ethyl acrylate), 90/10 ethyl acrylate-acrylic acid copolymer (mass ratio), and glass coverslip substrates, forming β-sheet structures detectable by Congo Red staining, while unremoved excess peptides form a three-dimensional gel layer with weak adhesion[4]. RAD16-I (0.025%; 1 h at 37°C) free acid TFA can adsorb and form unique structures on the surfaces of polyethyl acrylate, 90/10 wt% ethyl acrylate-acrylic acid copolymer, and glass coverslip substrates under the conditions of Protocol 2 (no induced self-assembly); among them, the coating supported by 90/10 wt% ethyl acrylate-acrylic acid copolymer is more uniform than that supported by polyethyl acrylate, and the root-mean-square roughness values of the three at a concentration of 0.025% are 0.54 nm, 0.15 nm, and 1.24 nm, respectively[4]. Adsorption of RAD16-I (0.025-0.1%; 1 h at 37°C, 4 h self-assembly) free acid TFA alters the surface wettability of polyethyl acrylate, ethyl acrylate-acrylic acid copolymer with a mass ratio of 90/10, and glass coverslip substrates, while inducing substrate-specific changes in contact angles and polar components of surface tension; in addition, pre-swelled substrates show a better correlation between wettability and peptide coating uniformity observed by AFM[4].
References:
[1]. Castells-Sala C, et al. Three-Dimensional Cultures of Human Subcutaneous Adipose Tissue-Derived Progenitor Cells Based on RAD16-I Self-Assembling Peptide. Tissue Eng Part C Methods. 2016;22(2):113-124.
[2]. Sanchez B, et al. Towards on line monitoring the evolution of the myocardium infarction scar with an implantable electrical impedance spectrum monitoring system. Annu Int Conf IEEE Eng Med Biol Soc. 2012;2012:3223-3226.
[3]. Aloy-Reverté C, et al. Use of RGD-Functionalized Sandwich Cultures to Promote Redifferentiation of Human Pancreatic Beta Cells After In Vitro Expansion. Tissue Eng Part A. 2018;24(5-6):394-406.
[4]. Arnal-Pastor M, et al. Interaction between acrylic substrates and RAD16-I peptide in its self-assembling[J]. Journal of Polymer Research, 2016, 23(9): 173.
In Vivo, RAD16-I (surgical implantation) free base TFA enables real-time monitoring of myocardial infarct scar formation via electrical impedance spectroscopy, with impedance magnitude changes corresponding to distinct stages of scar development when used to rehydrate a decellularized human pericardium scaffold for implantation[2].
In Vitro, The self-assembling peptide hydrogel RAD16-I (0.1-0.3% w/v; up to 21 days) free acid TFA maintains high viability of subATDPCs for up to 21 days, supports basal upregulation of cardiac markers in control medium, enhances the upregulation of cardiac markers when combined with cardiac induction medium, and regulates the viscoelasticity of the scaffold over time[1]. Modified RAD16-I, free acid TFA self-assembling peptide hydrogels (0.15-0.3% w/v) bearing the RGD motif, heparin, or both maintain high viability of subATDPCs, promote cell elongation and orderly arrangement; compared with unmodified RAD16-I, free acid TFA hydrogels, they do not significantly alter the expression of myocardial markers; while under cardiomyogenic induction conditions, RAD16-I, free acid TFA/RADRGD hydrogels with enhanced initial stiffness downregulate the expression of myocardial proteins in subATDPCs[1]. RAD16-I, free acid TFA self-assembles into β-sheet-containing nanofibers under physiological conditions, with a diameter of 19.58 nm[3]. The 3D sandwich culture system with RAD16-I, free acid TFA maintains the long-term viability of dedifferentiated human ICCs (with a cell survival rate of approximately 85% on day 18 of culture) and also promotes the aggregation of ICCs into larger cell clusters within 18 days, but does not significantly upregulate the expression of β-cell-specific genes compared with the non-adherent control group[3]. RAD16-I, free acid TFA can adsorb onto poly (ethyl acrylate), 90/10 ethyl acrylate-acrylic acid copolymer (mass ratio), and glass coverslip substrates, forming β-sheet structures detectable by Congo Red staining, while unremoved excess peptides form a three-dimensional gel layer with weak adhesion[4]. RAD16-I (0.025%; 1 h at 37°C) free acid TFA can adsorb and form unique structures on the surfaces of polyethyl acrylate, 90/10 wt% ethyl acrylate-acrylic acid copolymer, and glass coverslip substrates under the conditions of Protocol 2 (no induced self-assembly); among them, the coating supported by 90/10 wt% ethyl acrylate-acrylic acid copolymer is more uniform than that supported by polyethyl acrylate, and the root-mean-square roughness values of the three at a concentration of 0.025% are 0.54 nm, 0.15 nm, and 1.24 nm, respectively[4]. Adsorption of RAD16-I (0.025-0.1%; 1 h at 37°C, 4 h self-assembly) free acid TFA alters the surface wettability of polyethyl acrylate, ethyl acrylate-acrylic acid copolymer with a mass ratio of 90/10, and glass coverslip substrates, while inducing substrate-specific changes in contact angles and polar components of surface tension; in addition, pre-swelled substrates show a better correlation between wettability and peptide coating uniformity observed by AFM[4].
References:
[1]. Castells-Sala C, et al. Three-Dimensional Cultures of Human Subcutaneous Adipose Tissue-Derived Progenitor Cells Based on RAD16-I Self-Assembling Peptide. Tissue Eng Part C Methods. 2016;22(2):113-124.
[2]. Sanchez B, et al. Towards on line monitoring the evolution of the myocardium infarction scar with an implantable electrical impedance spectrum monitoring system. Annu Int Conf IEEE Eng Med Biol Soc. 2012;2012:3223-3226.
[3]. Aloy-Reverté C, et al. Use of RGD-Functionalized Sandwich Cultures to Promote Redifferentiation of Human Pancreatic Beta Cells After In Vitro Expansion. Tissue Eng Part A. 2018;24(5-6):394-406.
[4]. Arnal-Pastor M, et al. Interaction between acrylic substrates and RAD16-I peptide in its self-assembling[J]. Journal of Polymer Research, 2016, 23(9): 173.