Receptor-Targeted Dual pH-Triggered Intracellular Protein Transfer

Abstract

Protein therapeutics, including monoclonal antibodies, cytokines, transcription factors, enzymes, and peptides, play an essential role against cancer, infectious diseases, cardiovascular disorders, immunological diseases, and metabolic disorders, resulting in brilliant successes. [9][10][11] Compared with chemotherapy, the critical function of protein therapeutics in treating diseases that lack effective therapeutic options relies on the unique advantages of (i) abundant species; (ii) complex set of biological functions; (iii) high specificity; (iv) fewer adverse effects; (v) excellent biocompatibility and biodegradability; and (vi) inherent amino, carboxyl, and hydroxyl groups for chemical conjugations. 12 Proteins, in contrast to genetic drugs, act on their targets in a way that is both more direct and more specific. This allows them to regulate biological processes in a way that eliminates the risk of permanent gene mutation, off-target effects brought on by persistent gene expression, and the possibility of cancer development. 11 Major challenges of protein therapeuticsThe progress path toward clinical application of proteins is neither straightforward nor uncomplicated, for example, due to the limited administration routes, low bioavailability of proteins in circulation, and host immune responses that may result in the inactivation of proteins before reaching their sites of action. 13 Therefore, biotechnologists have employed tremendous efforts to overcome the delivery drawbacks 2, 14, 15 to protect them from denaturation and degradation, facilitate tumor-targeted delivery, and control the protein release/activity in targeted sites. 16,17 Most protein medicines now available on the market were created based on extracellular targets. These extracellular targets include cell membrane proteins (PD1, HER2, CD20, etc.) and secretory proteins (TNFα, IL12, VEGF, etc.). 11,18 Despite the success of current protein products that mostly address extracellular targets, efficient cytosolic delivery of Ju, E. et al. 36 first reported that gold nanoclusters (AuNCs) can self-assemble with Streptococcus pyogenes Cas9 (SpCas9) protein under physiological conditions, and the complexes (SpCas9-AuNCs) efficiently deliver SpCas9 protein into the cell nucleus.SpCas9-AuNCs could be disassembled at a lower pH 4.5 but are stable at a higher pH 7.4. SpCas9 is delivered into cells and the cell nucleus, where it performs its cleavage function, through the assembly disassembly process. Furthermore, the E6 oncogene was effectively knockout by self-assembled SpCas9-AuNCs nanoparticles after the HPV18 E6 sgRNA transfected into cervical cancer cells. Consequently, this causes the tumorsuppressing protein p53 to resume its normal activity and induces apoptosis in cervical cancer cells but had little effect on the normal cells. Because of their unique characteristics, SpCas9-AuNCs are an intriguing biomaterial for the treatment of cancer.Nanogels are water-rich nanoscale three-dimensional polymer networks. Because of this, it is simple for nan...

Polymerizable 2-Propionic-3-methylmaleic Anhydrides as a Macromolecular Carrier Platform for pH-Responsive Immunodrug Delivery

“…Polymeric maleic anhydride structures have mostly been applied as linkers 46 or conjugated to polylysine 44 as pH-sensitive carriers. To the best of our knowledge, polymerizable monomers with pendant 2-propionic-3-methylmaleic anhydride groups have not been reported.…”