Human cancer is one of the most important causes of death in the western countries. In advanced stages of the disease, the therapeutic opportunities are still limited due to the difficulty to target specifically only cancer cells sparing healthy ones. Cancer cells have on their surface antigens that are expressed at higher levels than their normal counterparts. Often these antigens (also called tumour-associated antigens) have receptor activity and bind to specific proteins or peptides. The latter can be used for the specific delivery of anticancer drugs to cancer cells through retargeting strategies and/or for the direct modulation of cancer cell proliferation and survival interacting with cell-surface-specific receptors.

These bioactive peptides can be raised against either tumour cells themselves or to the tumour microenvironment cell components (tumour vessels, tumour-associated macrophages, and fibroblasts). However, the feasibility of pharmacological application of peptides depends on absorption and bioavailability in intact forms in target tissues. Moreover, their correct biodistribution is sometimes hampered by biopharmaceutical drawbacks, that is, protection by circulating protease-mediated degradation or specific accumulation in tumour tissues. Chemical modification of peptide backbone can increase the stability of peptides in biological fluids. Moreover, the use of delivery systems, and in particular the use of nanotechnologies, not only protects peptides from enzymatic degradation but also improves the delivery of the bioactive peptide in the target tissue. Moreover, peptide conjugation on the surface of nanovectors can be useful for selective delivery of conventional chemotherapeutic agents in tumour tissues.

Therefore, we invite investigators to contribute original research articles as well as review articles in the following potential topics. Potential topics include, but are not limited to:

• Biopharmaceutical issues for peptide administration (enzymatic degradation, nonspecific distribution in the body, and physical and chemical instability)
• Chemical modification of the peptides (modified amino acids and polymeric conjugation)
• Drug delivery systems for peptides
• Peptides as targeting moieties

Before submission authors should carefully read over the journal's Author Guidelines, which are located at http://www.hindawi.com/journals/jaa/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/submit/journals/jaa/bioapp/ according to the following timetable: