Rational Design of Soft–Hard Interfaces through Bioinspired Engineering

Abstract

Soft–hard tissue interfaces in nature present a diversity of hierarchical transitions in composition and structure to address the challenge of stress concentrations that would otherwise arise at their interface. The translation of these into engineered materials holds promise for improved function of biomedical interfaces. Here, soft–hard tissue interfaces found in the body in health and disease, and the application of the diverse, functionally graded, and hierarchical structures that they present to bioinspired engineering materials are reviewed. A range of such bioinspired engineering materials and associated manufacturing technologies that are on the horizon in interfacial tissue engineering, hydrogel bioadhesion at the interfaces, and healthcare and medical devices are described.

Effect of Hydrogel Matrix and Fluid Shear Stress on the Behavioral Regulation of Mesenchymal Stem Cells

“…[15,16] The recent studies also show the design of the adjustable viscoelastic hydrogels to mimic soft-hard tissue interfaces has facilitated in vitro studies of cellmatrix interactions and boosted potential biomedical applications. [17,18] These mechanical cues can initiate signal perception based on integrin transmembrane proteins, induce focal adhesion formation, cytoskeleton assembly, and transmit signals from the cytoplasm to the nucleus by the linker of nucleoskeleton and cytoskeleton complex, thereby affecting the expression of genes related to cell behaviors. [19,20] For example, the nonlinear viscoelastic mechanical signal perception and response of myoblasts to extracellular matrix (ECM) during myogenesis are related to integrin-focal adhesion kinase signaling, actin polymerizationmediated myocardin-related transcription factor nuclear localization, and nuclear mechanotransduction.…”

Polymer Membrane Hydrolysis Diffusion-Induced Anisotropic Hydrogel Actuator with Fast Response and Programmable Actuation

“…In particular, among various smart materials, stimulus-responsive smart hydrogel materials hold great value in the fabrication of intelligent actuators. 17,18 Recent research has successfully demonstrated the diverse applications of these materials in soft robots, 19−21 microfluidic valves, 22,23 drug delivery systems, 24,25 multifunctional sensors, 26−30 and intelligent actuators. 31−33 However, traditional hydrogel actuators are limited as they can only produce isotropic macroscopic expansion or contraction in response to external stimuli, thereby lacking the capability for complex deformations.…”

Substrate Stiffness Regulates the Proliferation and Apoptosis of Periodontal Ligament Cells through Integrin-Linked Kinase ILK

“…7,8 ECM stiffness in native tissue is changed in physiology, which leads to the alteration of cell fate. 9,10 Moreover, studies in vitro show that substrate stiffness regulates the morphology, growth, and apoptosis of rat annulus fibrosus cells. 11 Increasing substrate stiffness promotes the proliferation of hepatocellular carcinoma cells and improves clinical chemotherapeutic resistance.…”

“…The movement of the orthodontic tooth (OTM) is accompanied by remodeling (i.e., bone resorption on the pressure side, and bone formation on the tension side) and adaptation of the periodontium. , Periodontium homeostasis plays an important role in OTM by incorporating various cells and molecular mechanisms. , Both cellular proliferation and apoptosis can occur in the periodontal ligament (PDL) during OTM to adapt to dynamic changes in mechanical properties (e.g., mechanical force and extracellular matrix (ECM) stiffness). − It has been reported that orthodontic force-induced cellular proliferation and apoptosis become more prompt on the tension side than the pressure side in a rat model . While the interaction between ECM stiffness and cellular behaviors is still unknown, recent evidence has demonstrated that the ECM stiffness of PDL is about 150 kPa. , ECM stiffness in native tissue is changed in physiology, which leads to the alteration of cell fate. , Moreover, studies in vitro show that substrate stiffness regulates the morphology, growth, and apoptosis of rat annulus fibrosus cells . Increasing substrate stiffness promotes the proliferation of hepatocellular carcinoma cells and improves clinical chemotherapeutic resistance .…”