Antibacterial Peptides in Dermatology–Strategies for Evaluation of Allergic Potential

During recent decades, the market for peptide-based drugs, including antimicrobial peptides, has vastly extended and evolved. These drugs can be useful in treatment of various types of disorders, e.g., cancer, autoimmune diseases, infections, and non-healing wounds. Although peptides are less immunogenic than other biologic therapeutics, they can still induce immune responses and cause allergies. It is important to evaluate the immunogenic and allergic potential of peptides before they are forwarded to the expensive stages of clinical trials. The process of the evaluation of immunogenicity and cytotoxicity is complicated, as in vitro models and bioinformatics tools cannot fully simulate situations in the clinic. Nevertheless, several potentially promising tests for the preclinical evaluation of peptide drugs have been implemented (e.g., cytotoxicity assays, the basophil activation test, and lymphocyte activation assays). In this review, we focus on strategies for evaluation of the allergic potential of peptide-based therapeutics

Release systems based on self-assembling RADA16-I hydrogels with a signal sequence which improves wound healing processes

Self-assembling peptides can be used for the regeneration of severely damaged skin. They can act as scaffolds for skin cells and as a reservoir of active compounds, to accelerate scarless wound healing. To overcome repeated administration of peptides which accelerate healing, we report development of three new peptide biomaterials based on the RADA16-I hydrogel functionalized with a sequence (AAPV) cleaved by human neutrophil elastase and short biologically active peptide motifs, namely GHK, KGHK and RDKVYR. The peptide hybrids were investigated for their structural aspects using circular dichroism, thioflavin T assay, transmission electron microscopy, and atomic force microscopy, as well as their rheological properties and stability in different fluids such as water or plasma, and their susceptibility to digestion by enzymes present in the wound environment. In addition, the morphology of the RADA-peptide hydrogels was examined with a unique technique called scanning electron cryomicroscopy. These experiments enabled us to verify if the designed peptides increased the bioactivity of the gel without disturbing its gelling processes. We demonstrate that the physicochemical properties of the designed hybrids were similar to those of the original RADA16-I. The materials behaved as expected, leaving the active motif free when treated with elastase. XTT and LDH tests on fibroblasts and keratinocytes were performed to assess the cytotoxicity of the RADA16-I hybrids, while the viability of cells treated with RADA16-I hybrids was evaluated in a model of human dermal fibroblasts. The hybrid peptides revealed no cytotoxicity; the cells grew and proliferated better than after treatment with RADA16-I alone. Improved wound healing following topical delivery of RADA-GHK and RADA-KGHK was demonstrated using a model of dorsal skin injury in mice and histological analyses. The presented results indicate further research is warranted into the engineered peptides as scaffolds for wound healing and tissue engineering

Amino acids, glycans, peptides and proteins in the diagnostic and therapeutic pathways of the 21st century civilization diseases : design, physicochemical and structural characterisation

The civilization diseases of the 21st century are non-infectious disorders, affecting a large part of modern society. They are associated with the significant development of industry and technology, and hence with environmental pollution and an unhealthy lifestyle. These factors have led to the development of many civilization diseases, which currently include: cardiovascular diseases, respiratory diseases, diabetes, obesity, malignant tumors, gastrointestinal diseases, mental disorders and allergic diseases. The development of technologies, including modern therapies and new drugs, resulted in increase in life expectancy. This creates a global problem of an aging population with an increasing number of diseases of the old age, i.e. dementias. In addition, sedentary lifestyles and changing diets are the reasons why more and more people develop metabolic diseases, as well as neurological and cognitive disorders characterized by progressive damage to nerve cells and dementia. Currently, problem on a global scale is also the growing resistance to existing antimicrobial drugs. Therefore, the scientists face many challenges related to searching for the causes of these diseases, their diagnosis and treatment. Scientific research conducted at the Department of Biomedical Chemistry at the Faculty of Chemistry of the University of Gdańsk is part of this research trend. In this publication, we discuss various research topics with the long-term aim of solving the problems associated with the diseases mentioned above. The following chapters are dedicated to (i) looking for new effective fluorophores with diagnostic and anti-cancer activity; (ii) designing of new compounds with antibacterial and antiviral activity and their synthesis; (iii) investigating the mechanisms of amyloid deposit formation by human cystatin C and possibilities of inhibition of this process; (iv) designing and studies of compounds activating the proteasome with the potential to suppress the development of neurodegenerative diseases; (v) designing peptide fibrils and hydrogels as drug carriers; (vi) searching for peptide inhibitors of immune checkpoint as potential drugs for immunotherapy; (vii) studying the mechanism of action of selected herpesviruses by determining the structure of viral proteins and (viii) studying the composition of natural glycans and glycoconjugates in order to better understand the mechanisms of interaction of bacteria with the environment or with the host