Robust Reversible Cross-Linking Strategy for Intracellular Protein Delivery with Excellent Serum Tolerance

Abstract

Intracellular protein delivery has attracted increasing attentions in biomedical applications. However, current delivery systems usually have poor serum stability due to the competitive binding of serum proteins to the polymers during delivery. Here, we report a reversible cross-linking strategy to improve the serum stability of polymers for robust intracellular protein delivery. In the proposed delivery system, nanoparticles are assembled by cargo proteins and cationic polymers and further stabilized by a glutathione-cleavable and traceless cross-linker. The cross-linked nanoparticles show high stability and efficient cell internalization in serum containing medium and can release the cargo proteins in response to intracellular glutathione and acidic pH in a traceless manner. The generality and versatility of the proposed strategy were demonstrated on different types of cationic polymers, cargo proteins, as well as cell lines. The study provides a facile and efficient method for improving the serum tolerance of cationic polymers in intracellular protein delivery.

Role of Driving Force on Engineering Layer-by-Layer Protein/Polyphenol Coating with Flexible Structures and Properties

“…Protein coatings are widely used in biomedical applications, such as tissue engineering, wound repair scaffolds, antimicrobial coatings, sensing, and diagnostic devices . Chemical cross-linking is a common means of preparing protein coatings, in which irradiation, sulfation, and chemical reagents can induce covalent bonds between proteins to form coatings . The properties of protein coatings, such as mechanical strength, flexibility, and degradation rate, can be precisely manipulated by chemical cross-linking, but the cross-linking agents used are generally cytotoxic and detrimental to the biocompatibility of protein coatings .…”

“…4 Chemical cross-linking is a common means of preparing protein coatings, in which irradiation, sulfation, and chemical reagents can induce covalent bonds between proteins to form coatings. 5 The properties of protein coatings, such as mechanical strength, flexibility, and degradation rate, can be precisely manipulated by chemical cross-linking, but the cross-linking agents used are generally cytotoxic and detrimental to the biocompatibility of protein coatings. 6 Heat treatment of proteins is a promising method for producing physiologically stable protein coatings without additives.…”

A light-activated polymer with excellent serum tolerance for intracellular protein delivery

“…39 It is highly desired to develop carriers that can deliver proteins inside cells in the presence of abundant serum proteins. 40,41 Here, we propose a light-activated crosslinking (LAC) strategy to prepare polymers with excellent serum tolerance for intracellular protein delivery (Fig. 1).…”

“…39 It is highly desired to develop carriers that can deliver proteins inside cells in the presence of abundant serum proteins. 40,41…”

A Cu+/Thiourea Dendrimer Achieves Excellent Cytosolic Protein Delivery via Enhanced Cell Uptake and Endosome Escape

“…Although the proteins could be released from the carrier upon external or internal stimuli, the approaches involving chemical modification of proteins might affect protein activity. On the other hand, introducing protein binding ligands onto polymers to strengthen the interactions with proteins were extensively investigated and have emerged as a potential strategy for cytosolic delivery of native proteins [7,14–16] . For example, taking advantages of the salt bridge interactions between guanidinium and anionic amino acids, [8,15,17] and nitrogen‐boron coordination between phenylboronic acid and lysine/histidine residues, [16,18,19] and hydrogen bonding and hydrophobic interactions between catechol and multiple amino acids, [20] the functionalized polymers showed dramatically improved performance in cytosolic protein delivery with robust and unprecedented efficiency.…”