Browsing by Author "Gameiro, Paula"
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- Boosting cosmeceutical peptides: coupling imidazolium-based ionic liquids to pentapeptide-4 originates new leads with antimicrobial and collagenesis-inducing activitiesPublication . Gomes, Ana; Bessa, Lucinda J.; Fernandes, Iva; Aguiar, Luísa; Ferraz, Ricardo; Monteiro, Cláudia; Martins, M. Cristina L.; Mateus, Nuno; Gameiro, Paula; Teixeira, Cátia; Gomes, PaulaFollowing our previous reports on dual-action antibacterial and collagenesis-inducing hybrid peptide constructs based on “pentapeptide-4” (PP4, with amino acid sequence KTTKS), whose N-palmitoyl derivative is the well-known cosmeceutical ingredient Matrixyl, herein we disclose novel ionic liquid/PP4 conjugates (IL-KTTKS). These conjugates present potent activity against either antibiotic-susceptible strains or multidrug resistant clinical isolates of both Gram-positive and Gram-negative bacterial species belonging to the so-called “ESKAPE” group of pathogens. Noteworthy, their antibacterial activity is preserved in simulated wound fluid, which anticipates an effective action in the setting of a real wound bed. Moreover, their collagenesis-inducing effects in vitro are comparable to or stronger than those of Matrixyl. Altogether, IL-KTTKS exert a triple antibacterial, antifungal, and collagenesis-inducing action in vitro. These findings provide solid grounds for us to advance IL-KTTKS conjugates as promising leads for future development of topical treatments for complicated skin and soft tissue infections (cSSTI). Further studies are envisaged to incorporate IL-conjugates into suitable nanoformulations, to reduce toxicity and/or improve resistance to proteolytic degradation.
- “Clicking” an ionic liquid to a potent antimicrobial peptide: on the route towards improved stabilityPublication . Gomes, Ana; Bessa, Lucinda J.; Correia, Patrícia; Fernandes, Iva; Ferraz, Ricardo; Gameiro, Paula; Teixeira, Cátia; Gomes, PaulaA covalent conjugate between an antibacterial ionic liquid and an antimicrobial peptide was produced via “click” chemistry, and found to retain the parent peptide’s activity against multidrug-resistant clinical isolates of Gram-negative bacteria, and antibiofilm action on a resistant clinical isolate of Klebsiella pneumoniae, while exhibiting much improved stability towards tyrosinase-mediated modifications. This unprecedented communication is a prelude for the promise held by ionic liquids -based approaches as tools to improve the action of bioactive peptides.
- Disclosure of a promising lead to tackle complicated skin and skin structure infections: antimicrobial and antibiofilm actions of peptide PP4-3.1Publication . Gomes, Ana; Bessa, Lucinda J.; Fernandes, Iva; Ferraz, Ricardo; Monteiro, Cláudia; Martins, M. Cristina L.; Mateus, Nuno; Gameiro, Paula; Teixeira, Cátia; Gomes, PaulaEfficient antibiotics are being exhausted, which compromises the treatment of infections, including complicated skin and skin structure infections (cSSTI) often associated with multidrug resistant (MDR) bacteria, methicillin-resistant S. aureus (MRSA) being the most prevalent. Antimicrobial peptides (AMP) are being increasingly regarded as the new hope for the post-antibiotic era. Thus, future management of cSSTI may include use of peptides that, on the one hand, behave as AMP and, on the other, are able to promote fast and correct skin rebuilding. As such, we combined the well-known cosmeceutical pentapeptide-4 (PP4), devoid of antimicrobial action but possessing collagenesis-boosting properties, with the AMP 3.1, to afford the chimeric peptide PP4-3.1. We further produced its N-methyl imidazole derivative, MeIm-PP4-3.1. Both peptide-based constructs were evaluated in vitro against Gram-negative bacteria, Gram-positive bacteria, and Candida spp. fungi. Additionally, the antibiofilm activity, the toxicity to human keratinocytes, and the activity against S. aureus in simulated wound fluid (SWF) were assessed. The chimeric peptide PP4-3.1 stood out for its potent activity against Gram-positive and Gram-negative bacteria, including against MDR clinical isolates (0.8 ≤ MIC ≤ 5.7 µM), both in planktonic form and in biofilm matrix. The peptide was also active against three clinically relevant species of Candida fungi, with an overall performance superior to that of fluconazole. Altogether, data reveal that PP4-3.1 is as a promising lead for the future development of new topical treatments for severe skin infections.
- Dual-action peptides as potential novel topical agents for treatment of skin and soft tissue infectionsPublication . Gomes, Ana; Bessa, Lucinda; Ferraz, Ricardo; Prudêncio, Cristina; Gameiro, Paula; Teixeira, Cátia; Gomes, PaulaChronic skin and soft-tissue infections (SSTI) such as diabetic foot ulcers (DFU) exhibit signs and symptoms that are consistent with localized bacterial biofilms that contribute to tissue destruction, delayed woundhealing and other serious complications. As such, most current approaches for advanced wound care aim at providing antimicrobial protection to the open wound together with a matrix scaffold (often collagenbased) to boost reestablishment of the skin tissue. While efficient production of recombinant human collagen remains an unmet goal, an alternative sensible option may be the design of formulations containing collagen-boosting instead of collagen-like components. Actually, collagen-boosting peptides, e.g., Matrikines®, are already used in cosmetics to promote extracellular matrix production, rebuilding structure and restoring all functions of healthy skin. Additionally, many antimicrobial peptides (AMP) can also act as wound-healing peptides, thus displaying the dual antimicrobial and tissue-regenerating properties highly desired in novel topical agents for treatment of SSTI. With the increasing prevalence of multi-drug resistant bacteria, and considering the burden that DFU alone represents to human health and healthcare facilities, the development of novel topical agents for effective treatment for this and other severe SSTI is an urgent need.
- Ocellatin-PT antimicrobial peptides: High-resolution microscopy studies in antileishmania models and interactions with mimetic membrane systemsPublication . Oliveira, Mayara; Gomes-Alves, Ana Georgina; Sousa, Carla; Marani, Mariela Mirta; Plácido, Alexandra; Vale, Nuno; Delerue-Matos, Cristina; Gameiro, Paula; Kuckelhaus, Selma A. S.; Tomás, Ana M.; Leite, José Roberto S. A.; Eaton, PeterAlthough the mechanism of action of antimicrobial peptides (AMPs) is not clear, they can interact electrostatically with the cell membranes of microorganisms. New ocellatin-PT peptides were recently isolated from the skin secretion of Leptodactylus pustulatus. The secondary structure of these AMPs and their effect on Leishmania infantum cells, and on different lipid surface models was characterized in this work. The results showed that all ocellatin-PT peptides have an a-helix structure and five of them (PT3, PT4, PT6 to PT8) have leishmanicidal activity; PT1 and PT2 affected the cellular morphology of the parasites and showed greater affinity for leishmania and bacteria-mimicking lipid membranes than for those of mammals. The results show selectivity of ocellatin-PTs to the membranes of microorganisms and the applicability of biophysical methods to clarify the interaction of AMPs with cell membranes.
- Peptide conjugates for the topical treatment of infected woundsPublication . Gomes, Ana; Fernandes, Iva; Bessa, Lucinda; Ferreira, Mariana; Maciel, Joana; Plácido, Alexandra; Teixeira, Cátia; Leal, Ermelindo; Ferraz, Ricardo; Gameiro, Paula; Carvalho, Eugénia; Gomes, PaulaDue to widespread multidrug-resistant (MDR) microbes, efficient treatments for infected wounds are being exhausted.1 The symptoms of wound infection are consistent with local polymicrobial biofilms, which are difficult to eliminate and delay the healing process. The current standard of care requires oral antibiotics and other measures, often complex and distressing (e.g., amputations). A perfect treatment should promote both antimicrobial protection and fast tissue regeneration, to improve the inefficient healing in elderly people affected with, e.g., diabetes or venous/arterial insufficiency. 2 Considering the above, we advance peptide conjugates as potential active pharmaceutical ingredients for topical formulations to tackle skin infections. Such conjugates are anticipated to concomitantly display antimicrobial and anti-biofilm action along with fast healing through, e.g., collagenesis-inducing effects. Promising results were obtained with chimeric peptides combining a de novo designed antimicrobial peptide sequence 3 with a cosmetic peptide, used as anti-aging, with ability to induce collagen production.4 The best constructs exhibited: (i) antibacterial and anti-biofilm activity against Gram-positive and Gram-negative bacteria, including MDR clinical isolates; (iii) improved action against S. aureus (prevalent pathogen in chronically-infected wounds) in simulated wound fluid; and (v) antifungal activity. 5 The replacement of the antimicrobial peptide by an ionic liquid afforded a new conjugate, a peptide-ionic liquid construct, with broadspectrum antibacterial activity, antifungal action, and collagen-inducing effect. These results will be shown alongside the most recent findings that provide deeper insight into the mode of action of the best conjugates.
- Peptide-ionic liquid conjugates towards the treatment of skin infectionsPublication . Gomes, Ana; Bessa, Lucinda; Fernandes, Iva; Teixeira, Cátia; Aguiar, Luísa; Ferraz, Ricardo; Monteiro, Cláudia; Martins, Cristina; Mateus, Nuno; Gameiro, Paula; Gomes, PaulaThe treatment of complicated skin infections, like diabetic foot ulcers and other chronic wounds, are often associated with persistent polymicrobial biofilms that delay and difficult the healing process. The most severe cases culminate in inpatient hospital admission, where infections can be exacerbated by hospital-acquired pathogens, in particular, if caused by the so-called ESKAPE pathogens, for which few efficient antibiotics are available. The current biomedical approaches to chronic wounds aim at providing both protection against multidrug-resistant (MDR) bacteria and a matrix scaffold, often collagen-based, to boost the reestablishment of healthy skin. Therefore, new options and new antibiotics are urgently needed and having that in mind our strategy is to use: i) antimicrobial peptides (AMP) to prevent or treat infection in the open wound; ii) collagen-inducing peptides (CBP) to induce fast healing; iii) and ionic liquids (IL) with intrinsic antimicrobial chemical permeation enhancement properties for an improved skin permeation. Through different combinations of these three types of building blocks, we aim to find a new class of active pharmaceutical ingredients suitable for topical application in the treatment of complicated skin infections. All the different conjugates designed and tested in vitro thus far will be presented. The most promising ones result from conjugation of CBP with IL, delivering a new type of conjugate with potent antibacterial, antifungal, and collagen-inducing effects on human dermal fibroblasts. Hence, these peptide-ionic liquid conjugates are promising leads towards the development of a topical formulation for the treatment of complicated skin infections.
- Peptide/ionic liquid conjugates to tackle complicated skin infections: antimicrobial, antibiofilmand collagen-boosting effectsPublication . Gomes, Ana; Bessa, Lucinda; Fernandes, Iva; Aguiar, Luisa; Ferraz, Ricardo; Monteiro, Cláudia; Martins, Cristina; Mateus, Nuno; Gameiro, Paula; Teixeira, Cátia; Gomes, PaulaComplicated skin and soft tissue infections (cSSTI) like, e.g., diabeticfoot ulcers (DFU), are severe cases of cutaneous and deeper soft tis-sue infections. Their symptoms are consistent with local polymicro-bial biofilms, which are difficult to eliminate and delay the healing process. The standard-of-care for cSSTI requires oral antibiotics andother measures, often complex and distressing (e.g., amputations). Due to widespread multidrug resistant (MDR) microbes, efficient treatments for cSSTI are being exhausted. These should promote both antimicrobial protection and fast tissue regeneration, to at one the inefficient healing in elderly people afflicted with, e.g., diabetes orvenous/arterial insufficiency.
- Synergistic and antibiofilm properties of ocellatin peptides against multidrug-resistant Pseudomonas aeruginosaPublication . Bessa, Lucinda J; Eaton, Peter; Dematei, Anderson; Plácido, Alexandra; Vale, Nuno; Gomes, Paula; Delerue-Matos, Cristina; Leite, José Roberto Sá; Gameiro, PaulaAim:To test ocellatin peptides (ocellatins-PT2-PT6) for antibacterial and antibiofilm activities and synergy with antibiotics against Pseudomonas aeruginosa. Materials & methods: Normal- and checkerboard-broth microdilution methods were used. Biofilm studies included microtiter plate-based assays and microscopic analysis by confocal laser scanning microscopy and atomic force microscopy. Results: Ocellatins were more active against multidrug-resistant isolates of P. aeruginosa than against susceptible strains. Ocellatin-PT3 showed synergy with ciprofloxacin and ceftazidime against multidrug-resistant isolates and was capable of preventing the proliferation of 48-h mature biofilms at concentrations ranging from 4 to 8× the MIC. Treated biofilms had low viability and were slightly more disaggregated. Conclusion: Ocellatin-PT3 may be promising as a template for the development of novel antimicrobial peptides against P. aeruginosa.
- Thaulin-1: The first antimicrobial peptide isolated from the skin of a Patagonian frog Pleurodema thaul (Anura: Leptodactylidae: Leiuperinae) with activity against Escherichia coliPublication . Marani, Mariela M.; Perez, Luis O.; de Araujo, Alyne Rodrigues; Plácido, Alexandra; Sousa, Carla F.; Quelemes, Patrick Veras; Oliveira, Mayara; Gomes-Alves, Ana G.; Pueta, Mariana; Gameiro, Paula; Tomás, Ana M.; Delerue-Matos, Cristina; Eaton, Peter; Camperi, Silvia A.; Basso, Néstor G.; Leite, José Roberto de Souza de AlmeidaPatagonia's biodiversity has been explored from many points of view, however, skin secretions of native amphibians have not been evaluated for antimicrobial peptide research until now. In this sense, Pleurodema thaul is the first amphibian specie to be studied from this large region of South America. Analysis of cDNA-encoding peptide in skin samples allowed identification of four new antimicrobial peptides. The predicted mature peptides were synthesized and all of them showed weak or null antimicrobial activity against Klebsiella pneumoniae, Staphylococcus aureus and Escherichia coli with the exception of thaulin-1, a cationic 26-residue linear, amphipathic, Gly- and Leu-rich peptide with moderate antimicrobial activity against E. coli (MIC of 24.7μM). AFM and SPR studies suggested a preferential interaction between these peptides and bacterial membranes. Cytotoxicity assays showed that thaulin peptides had minimal effects at MIC concentrations towards human and animal cells. These are the first peptides described for amphibians of the Pleurodema genus. These findings highlight the potential of the Patagonian region's unexplored biodiversity as a source for new molecule discovery.