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in Vivo
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
Katie M. Kilgour, Brendan L. Turner, Augustus Adams, Stefano Menegatti, Michael A. Daniele
Finally, synthetic peptides represent special building blocks for tissue scaffold engineering, being biocompatible, biodegradable, bioactive, and low-toxicity protein mimetics (Du, Zhou, Shi, & Xu, 2015; Liu, Zhang, Zhu, Liu, & Chen, 2019). Peptides can assemble into hydrogels either physically, by forming a network of hydrogen bonds and electrostatic and hydrophobic interactions, or chemically, via site-selective crosslinking (Liu et al., 2019). Lastly, they can be manufactured in high volumes, affordably, and with no variability. This makes peptides ideal biomaterials for tissue engineering and wound healing (Barbosa & Martins, 2017). In this context, elastin-like polypeptides are of particular interest, as they feature a thermo-responsive phase behaviour, wherein the sol–gel transition temperature and the mechanical properties of the resulting hydrogel depend on the ELP’s amino acid sequence (Urry, 1997). Engineered ELPs fused with cell-binding peptide domains or signalling proteins have been expressed and utilised as building blocks to construct different angiogenic substrates (e.g., gels, films, or fibres) with tuned ELP: water ratio, temperature, and composition of the growth medium. Crosslinked ELP hydrogels have been constructed to present cell-binding motifs such as fibronectin-derived REDV, VEGF-derived QK, laminin-derived IKVAV, and integrin-binding RGD to act as ECM mimetics. Cai et al. developed ELP-based hydrogels encapsulating HUVECs and functionalised with the cell-binding RGD sequence and the VEGF mimetic QK peptide; the hydrogels maintained nearly 100% of cell viability along with significantly enhanced cell proliferation and 3D outgrowth (Cai, Dinh, & Heilshorn, 2014). Another study, by Santos et al., focused on cell- and factor-free hybrid hydrogels constructed with ELPs, polyethylene glycol (PEG), and the self-assembling IKVAV peptide and evaluated their ability to induce angiogenesis and innervation in vivo (dos Santos et al., 2019); notably, the hydrogel hosted a larger density of vessels 26 days post-implantation when the IKVAV peptide was present, indicating that integration of bioactive peptides in natural biomaterials provides a route towards long-term stability in pro-angiogenic scaffolds.
The study of fatty acid mediated Mefp-1 adsorption by Quartz Crystal Microbalance with Dissipation
Published in The Journal of Adhesion, 2023
LinQing Xie, Wei Cao, ChengJun Sun
Considering the influence of QCM signal noise fluctuations, the change of the Δf of harmonic 5 is generally used for the rigid film fitting calculation analysis. This is a typical harmonic used by the Sauerbrey equation for adsorption mass calculation[24] (subsequent analysis of rigid film adsorption is all fitted with Δf5). After fitting the Δf5, the adsorption mass of Mefp-1 on the Au surface is calculated to be 218.56 ± 0.32 ng/cm2 (Figure 3b), and the thickness is 1.8 nm. The results show that a small amount of Mefp-1 can bind to the Au surface within a short time in the buffer environment, but the adsorption mass is very small. HööK[18] et al. used QCM-D to study the adsorption of Mefp-1 on modified with Au surface, and the results are shown in Table 1. They modified the Au surface to an electrically inert non-polar hydrophobic one and found that the adsorption mass of Mefp-1 was 1027 ± 20 ng/cm2 and the thickness was 9.9 nm. It can be found that the adsorption mass of Mep-1 on the modified non-polar Au surface is significantly higher than that of the unmodified Au. When we roughly calculate the adsorption rate of Mefp-1 on the non-polar Au and pure Au surface, the rates are 2 ng/cm2/s and 1.4 ng/cm2/s, respectively. This indicates that the non-polar environment conditions on the surface of the Au substrate is favorable for the adsorption and binding of Mefp-1. Meanwhile, our results suggest a small amount of Mefp-1 can quickly adsorb to the Au surface in acidic buffer environment, which may be due to the complex effect of the DOPA structure in Mefp-1. Dalsin[25] et al. used protein mimetic polymers containing DOPA similar to Mfp to study surface binding and found that DOPA can complexes with Au, thereby tightly binds to the Au surface. Waite[1] et al. believed that the DOPA structure in the mussel foot proteins might be bound to Au through a π bond. In order to explore the role of Dopa in this adhesion process, we used fully Fe3+-chelated Mefp-1 to conduct the same experiment and found that there was no Mefp-1 adsorbed on the Au surface. This indicates that the DOPA in Mefp-1 is involved in Au surface binding. But whether it is through the π bond interaction or other interactions remains to be further explored.