Stiffness‐Controlled Thermoresponsive Hydrogels for Cell Harvesting with Sustained Mechanical Memory

Abstract

Most mechanobiological investigations focused on in situ mechanical regulation of cells on stiffness-controlled substrates with few downstream applications, as it is still challenging to harvest and expand mechanically primed cells by enzymatic digestion (e.g., trypsin) without interrupting cellular mechanical memory between passages. This study develops thermoresponsive hydrogels with controllable stiffness to generate mechanically primed cells with intact mechanical memory for augmented wound healing. No significant cellular property alteration of the fibroblasts primed on thermoresponsive hydrogels with varied stiffness has been observed through thermoresponsive harvesting. When reseeding the harvested cells for further evaluation, softer hydrogels are proven to better sustain the mechanical priming effects compared to rigid tissue culture plate, which indicates that both the stiffness-controlled substrate and thermoresponsive harvesting are required to sustain cellular mechanical memory between passages. Moreover, epigenetics analysis reveals that thermoresponsive harvesting could reduce the rearrangement and loss of chromatin proteins compared to that of trypsinization. In vivo wound healing using mechanically primed fibroblasts shows featured epithelium and sebaceous glands, which indicates augmented skin recovery compared with trypsinized fibroblasts. Thus, the thermoresponsive hydrogel-based cell harvesting system offers a powerful tool to investigate mechanobiology between cell passages and produces abundant cells with tailored mechanical priming properties for cell-based applications.

Smart hydrogels with high tunability of stiffness as a biomimetic cell carrier

“…Cell viability experiment of bone marrow stromal cells (BMSCs) confirm the biocompatibility of the hydrogel. Integrating thermoresponsive components into mechanobiology, Fan et al () developed a novel stiffness‐controlled thermoresponsive hydrogels to generate mechanically primed cells with mechanical memory for wound healing. The hydrogel stiffness is increased from 112.4 to 1130.0 Pa by promoting PEG‐NIPAm concentration.…”

Photo‐Crosslinkable Unnatural Amino Acids Enable Facile Synthesis of Thermoresponsive Nano‐ to Microgels of Intrinsically Disordered Polypeptides

“…Thermoresponsive hydrogel particles are versatile materials used in a variety of applications, ranging from photonics to tissue engineering and drug delivery . These particles, made of crosslinked networks of polymers, proteins, or polypeptides, offer the ability to respond to local changes in temperature, which is manifested as reversible shrinking and swelling in solution due to changes in network solubility.…”

Soft Actuators with Stiffness and Shape Modulation Using 3D-Printed Conductive Polylactic Acid Material

“…2,3 Stiffness tuning can be used for adaptive vibration damping, 4 precise control of joints for manipulators, 5 and mechanical modulation of cell growth. 6 The change of stiffness can also be used for universal orthopedic casts, customized seatings, and adaptive aerodynamic surfaces. 7 There have been a number of approaches reported for stiffness tuning, several of which involve the change of pressure input in pneumatic or hydraulic actuation.…”