Table 1.
SWOT analysis of short peptides.
| Strengths | Weaknesses |
| essential bio-molecules with a broad range of activities & functionalities in vivo | instability in vivo (easy degradation in plasma, protease sensitivity) |
| bio-chemical diversity, easy availability | short half-life |
| structural simplicity | low (oral) bioavailability |
| easy design & cost-effective synthesis with high purity | difficult membrane permeability in the case of greater peptides * |
| easy modification, scaling up | low binding affinity * |
| mechanical stability | high conformational freedom * |
| high: modularity, flexibility *, selectivity, target specificity, affinity *, absorbability, potency, tolerability, efficacy, safety, biocompatibility, biodegradibility | |
| low toxicity, antigenicity, immunogenicity | |
| easy recognition by bio-systems | |
| ability to penetrate the cell membranes (but only very short peptides) *, high brain penetration in systematical administration | |
| versatility as both targeting moieties and therapeutic agents | |
| specific interactions with various bio-systems | |
| predictable metabolism: degradation products are amino acids (non-toxic, natural entities used as nutrients or cellular building blocks) | |
| lack or fewer secondary off-targets (side) effects (peptides do not accumulate in kidney or liver) | |
| low unspecific binding to the structures other than the desired target, minimisation of drug-drug interactions, less accumulation in tissues (low risk of complications due to intermediate metabolites) | |
| Opportunities | Threats |
| development of peptide-based delivery systems: - cell-penetrating peptides - nano-cyclic peptide-based micceles, vesicles as gene or drug carriers - conjugations with non-peptidic motifs |
oncogenicity of endogenous & synthetic peptides |
| supramolecular peptide-based biofunctional materials | immunogenicity (related to greater peptides) |
| formulations development (e.g., subcutaneous injections)various forms of using (drugs, vaccines, hormones, radioisotopes) | |
| development of the peptide-based safe & effective vaccines | |
| diveristy of well-ordered, robust, long-lived self-assembled nanostructures | |
| vital tool for neurodegenerative diseases studies & various applications in anticancer therapy | |
| peptoids or peptidomimetics |
* Bivalent property which may be either strength or weakness depending on particular species.