Peptides in cancer nanomedicine: Drug carriers, targeting ligands and protease substrates

Abstract

Peptides are attracting increasing attention as therapeutic agents, as the technologies for peptide development and manufacture continue to mature. Concurrently, with booming researches in nanotechnology for biomedical applications, peptides have been studied as an important class of components in nanomedicine, and they have been used either alone or in combination with nanomaterials of every reported composition. Peptides possess many advantages, such as smallness, ease of synthesis and modification, and good biocompatibility. Their functions in cancer nanomedicine, discussed in this review, include serving as drug carriers; as targeting ligands; and as protease-responsive substrates for drug delivery.

Smart multifunctional nanoparticles in nanomedicine

“…Peptides are an attractive alternative as targeting molecule due to several advantages, including a smaller size, a lower immunogenicity, a higher tissue penetration capability, a higher stability and a relatively easy production process. Phagedisplayed peptide libraries are a valuable screening resource for identification of the peptides that target a specific receptor [54,55]. The most widely used peptide in targeted delivery is the integrin targeted arginineglycine-aspartic acid (RGD) peptide.…”

Toward a magic or imaginary bullet? Ligands for drug targeting to cancer cells: principles, hopes, and challenges

“…Peptides can be chemically synthesized at a large scale relatively inexpensively and, unlike in the case of recombinant expression technologies, the removal of endotoxins or cell culture-derived contaminants is not necessary. 67,68 Despite their small size, some peptides have binding affinities comparable to specific antibodies. 69 In vivo phage-display technology makes use of peptide libraries composed of short, random, amino acid sequences expressed on the surface of the phage particles.…”

“…67 The most widely used peptides in the targeted-delivery applications are integrin-targeting RGD-peptides -the first tumor-targeting peptides discovered. 68 Integrins α v β 3 and α v β 5 are overexpressed on tumor endothelium and some epithelial cells during tumor growth, angiogenesis, invasion, and metastasis. Therefore, they represent an interesting molecular target for a tumor-homing approach.…”

Nanotherapeutics in the EU: an overview on current state and future directions

“…In the development of nanotherapeutics, nanotechnology tools are used to improve drug solubility (eg, micelles 7 and nanocrystals 8 ), to guide drugs to the desired location of action with increased precision (ie, drug targeting 9,10 ), to control the drug's release (eg, nanoparticles 11 and liposomes 12 ), and/or to enhance the transport across biological barriers (eg, micelles 13 and nanoparticles 14 ). The main goal is to improve drug bioavailability, pharmacokinetics, efficacy, and safety to promote the treatment of diseases which currently cannot be achieved with conventional dosage forms.…”