pH-Responsive Self-Assembling Peptide-Based Biomaterials: Designs and Applications

Abstract

Stimuli-responsive peptide-based biomaterials are increasingly gaining interest for various specific and targeted treatments, including drug delivery and tissue engineering. Among all stimuli, pH can be especially useful because endogenous pH changes are often associated with abnormal microenvironments. pH-Responsive amino acids and organic linkers can be easily incorporated into peptides that self-assemble into various nanostructures. Thus, these largely biocompatible and easily tunable platforms are ideal candidates for drug release and as fibrous materials capable of mimicking the native extracellular matrix. In this review, we highlight common design motifs and mechanisms of pH-responsiveness in self-assembling peptide-based biomaterials, focusing on recent advances of these biomaterials applied in drug delivery and tissue engineering. Finally, we suggest future challenges and areas for potential development in pH-responsive self-assembling peptide-based biomaterials.

Emerging Role of Injectable Dipeptide Hydrogels in Biomedical Applications

“…Peptides containing acidic or basic amino acids undergo protonation or deprotonation when exposed to a switch in pH. This pH trigger provides a control over the self-assembling mechanism of the peptides and has been utilized in the generation of peptide-based materials . One such example is the peptide-functionalized nanoparticle designed by Stevens et al containing an acidic leucine zipper.…”

“…This pH trigger provides a control over the self-assembling mechanism of the peptides and has been utilized in the generation of peptide-based materials. 42 One such example is the peptide-functionalized nanoparticle designed by Stevens et al containing an acidic leucine zipper. The leucine zipper includes the repeated sequence of SGDLENEVAQLEREVRSLEDEAAELEQKVSRLKNEIEDLKAE which is used in biosensing as it is pH sensitive.…”

An Amino Acid‐Based Thixotropic Hydrogel: Tuning of Gel Recovery Time by Mechanical Shaking

“…[11][12][13][14] These stimuli are the key ingredients for controlling the self-assembly behavior of the hydrogelator. [15][16][17] The stimuli responsive property of hydrogel structure [18][19][20][21] is frequently installed into artificial hydrogel system to carry out sol-gel transition for various potential applications including targeted drug release, self-healing, shape memory, and supramolecular adhesion purposes. [22][23][24][25][26][27] Among these supramolecular hydrogels, amino acid and peptide-based [1][2][3][4][5][6][7][8][9][10] hydrogels attract special attention due to their ease of synthesis, amino acids mutation, purifications and characterizations, structure-function relationship, building blocks for supramolecular architectonics, biocompatible and biodegradable properties.…”

Naphthyl-Poly(S-((2-carboxyethyl)thio)-l-cysteine) Peptide Amphiphiles with Different Degrees of Polymerization: Synthesis, Self-Assembly, pH/Reduction-Triggered Drug Release, and Cytotoxicity

“…Rationally designed polypeptides can self-assemble into nanocarriers of different sizes and morphologies, including liposomes, nanotubes, nanofibers, nanomicelles, nanohydrogels, and so forth. Meanwhile, adding functional accessories according to the self-assembly principle can endow the nanocarriers with available properties such as light, electricity, and catalysis. − Response characteristics such as pH, redox, enzymes, temperature, light, and magnetism can be realized under the target or microenvironment. In recent years, the application of assembled peptides in tissue engineering, gene therapy, and drug delivery is still very important. , …”

“…Then, we carried out the research on PAs as drug carriers. In the tumor environment, the drug-loaded nanomaterials are endocytosed by cancer cells and then enter the acidic (pH about 4.5–6.5) endolysosome/lysosome, which is different from the typical physiological environment (pH about 7.4), and nanocarriers pH responsiveness is critical. , Meanwhile, the content of glutathione (GSH) in the tumor environment is more than that in normal tissues. GSH is a reductant that can achieve redox release of drugs by combining with drug carrier materials containing oxidant (−SS−). , Finally, in vitro cytotoxicity experiments were also carried out.…”