pH-sensitive Cyclic Peptide Discovery Service

Bicyclic peptides have improved proteolytic stability and high affinity compared to macrocyclic peptides, and pH-sensitive bicyclic peptides have been developed as potential therapeutics against cancers. In the field of phage display technology, Creative Biolabs has accumulated extensive expertise through our extensive experience. Creative Biolabs is able to offer high-quality pH-sensitive cyclic peptide discovery service at the most competitive cost.

Tumor progression is associated with acidosis. Tissue acidity is linked to various pathological states, including tumor, ischemia, inflammation, infection, atherosclerosis, and others. As tumor continues to grow, acidosis is increasing due to the poor blood perfusion and the switch of cancer cells to the glycolytic mechanism. pH is especially lower in the vicinity of the membrane of cancer cells. The most effective pH-sensitive tumor targeting agents should sense pH at the surface of cancer cells, where the pH is the lowest. A number of approaches have been developed for imaging and delivering therapeutic agents to diseased tissue in a pH-dependent manner. These approaches are based on the use of pH-sensitive polymers, liposomes, nanoparticles and small molecules. pH-sensitive bicyclic peptides are one of these small molecules. Cyclic peptides have become a subject of major interest in biological sciences because of their enhanced enzymatic stability versus linear peptides. Cyclic peptides show lots of advantages, including nuclear delivery of doxorubicin, low cytotoxicity, biocompatibility, and drug delivery through conjugation. Bicyclic peptides have been developed as potential therapeutics against a wide range of diseases, drug targeting agents, diagnostic probes, and research tools.

pH-sensitive Cyclic Peptide Discovery ServiceFig.1 The cyclic peptide molecules distribution between outer and inner leaflets of the lipid bilayer of plasma membrane (Weerakkody et al. 2016).

With the advent of phage display, it has become possible to generate pH-sensitive cyclic peptide binders to diverse protein targets. Phage display is a high-throughput and highly sensitive method which enables the identification of bicyclic peptides. Creative Biolabs has developed diverse strategies for discovery of pH-sensitive cyclic peptide on our advanced phage display platform. Different formats (e.g., CX6CX6C or XCX4CX4CX, C=cysteine, X=any random amino acid) of large combinatorial peptide libraries (up to 1011) can be constructed to meet every different demand. Also, combined with our Magic™ platform, pH-sensitive cyclic peptides in the enriched sublibrary can be identified efficiently and effectively.

Key advantages including but not limited to:

Creative Biolabs is pleased to share our cutting-edge technology and extensive expertise in pH-sensitive cyclic peptide discovery to facilitate our clients’ research and project development. We can offer the best customized pH-sensitive cyclic peptide discovery services by tailoring protocols to meet the most specific requirements.

For more detailed information, please feel free to contact us or directly send us an inquiry.


  1. Weerakkody, D.; et al. Novel pH-Sensitive Cyclic Peptides. Sci Rep. 2016, 6:31322.

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