Energetic electron assisted synthesis of highly tunable temperature-responsive collagen/elastin gels for cyclic actuation: macroscopic switching and molecular origins

Abstract

Thermoresponsive bio-only gels that yield sufficiently large strokes reversibly and without large hysteresis at a well-defined temperature in the physiological range, promise to be of value in biomedical application. Within the present work we demonstrate that electron beam modification of a blend of natural collagen and elastin gels is a route to achieve this goal, viz. to synthesize a bioresorbable gel with largely reversible volume contractions as large as 90% upon traversing a transition temperature that can be preadjusted between 36 °C and 43 °C by the applied electron dose. Employing circular dichroism and temperature depending confocal laser scanning microscopy measurements, we furthermore unravel the mechanisms underlying this macroscopic behavior on a molecular and network level, respectively and suggest a stringent picture to account for the experimental observations.

From Strain Stiffening to Softening—Rheological Characterization of Keratins 8 and 18 Networks Crosslinked via Electron Irradiation

“…Therefore, it seems that neither the network percolation nor the bundling is the main effector for the nonlinear response but that it is most likely EBI-related chemical changes. In previous work, electron beam-treated keratin and elastin–collagen gels exhibited a reduction in the α-helical content with a concomitant increase in β-sheet and random coil, respectively [ 30 , 34 ]. This unfolding was conceptualized before as the origin of strain stiffening; furthermore, studies on hard keratin, keratin-like bundles, and vimentin (another IF protein) have confirmed the loss of the α-helical structure and the creation of an extended β-sheet upon stretching [ 56 , 57 , 58 ].…”

“…This method is reagent-free, with no potentially toxic residual reagents, making it very useful for cell studies. Additionally, it has been shown to be a convenient tool for a systematic tuning of the material properties in biopolymer networks [ 28 , 29 , 30 , 31 , 32 ]. The formation of stable covalent crosslinks between polymer chains through irradiation gives rise to a significant increase in the storage modulus of irradiated gels.…”

Mechanical properties of the premature lung: From tissue deformation under load to mechanosensitivity of alveolar cells

“…Altered elastin content, as well as crosslinking differences of the lungs in preterm infants compared to adults may serve as a key role in the observed mechanical differences (Chrzanowski et al, 1980;Mižíková and Morty, 2015). Moreover, as shown by Wilharm et al (2019), buckling instabilities such as Euler buckling in elastin networks, can enforce structural failure (Han et al, 2013;Nelson, 2016), and the network collapses irreversibly under a certain load. Such behavior is not seen in our experiments since the tissue is most likely stabilized by incompressible cells, which, in case of tissue compression, impede a network collapse.…”

Stimuli‐Responsive Natural Proteins and Their Applications

“…[1,37] Therefore, ELPs, RLPs, and SLPs show promising potential in drug delivery, incremental expression and purification of engineered proteins, ameliorating biosecurity and usage as protein-based medicines. [38][39][40][41] Transient receptor potential vanilloid 1 (TRPV1) is the founding member of thermosensitive transient receptor potential (TRP) channels in mammals to respond to ambient temperature by changing Ca 2 + permeability, which was first reported by Caterina et al in 1997. [42,43] TRPV1 consists of tetrad monomeric subunits arrayed in a four-fold symmetry around the ion path center.…”

“…By tuning the LCST, the polypeptides will be phase‐separated or self‐assemble into nanoparticles or micelles [1,37] . Therefore, ELPs, RLPs, and SLPs show promising potential in drug delivery, incremental expression and purification of engineered proteins, ameliorating biosecurity and usage as protein‐based medicines [38–41] …”