Percorrer por autor "Gomes, 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.
- 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.
- Necessary skills and knowledge and challenges of the mathematics lesson study facilitator: aliterature reviewPublication . Quaresma, Marisa; Martins, Micaela; Gomes, Paula; Rodrigues, Bruna; Ponte, João Pedro daIn lesson studies carried out in Western countries, a key role is played by the facilitator, who organizes and leads the entire process. Despite the contributions regarding this issue provided in the literature, the knowledge about the preparation that facilitators need and the challenges that they face in their activity is still fragmented. Thus, the aim of this communication is to present a systematic literature review on the role of the facilitator in lesson studies in mathematics, identifying and synthesizing the necessary skills and knowledge and the challenges faced by facilitators and suggesting directions for future research.
- Neuroprotective effects on microglia and insights into the structure–activity relationship of an antioxidant peptide isolated from Pelophylax pereziPublication . Plácido, Alexandra; Amaral, Constança do Pais do; Teixeira, Cátia; Nogueira, Ariane; Brango-Vanegas, José; Barbosa, Eder Alves; Moreira, Daniel C.; Silva-Carvalho, Amanda É.; Silva, Maria da Gloria da; Dias, Jhones do Nascimento; Albuquerque, Patrícia; Saldanha-Araújo, Felipe; Lima, Filipe C. D. A.; Batagin-Neto, Augusto; Kuckelhaus, Selma; Bessa, Lucinda J.; Freitas, Jaime; Brand, Guilherme Dotto; Santos, Nuno C.; Relvas, João B.; Gomes, Paula; Leite, José Roberto S. A.; Eaton, PeterTryptophyllins constitute a heterogeneous group of peptides that are one of the first classes of peptides identified from amphibian’s skin secretions. Here, we report the structural characterization and antioxidant properties of a novel tryptophyllin-like peptide, named PpT-2, isolated from the Iberian green frog Pelophylax perezi. The skin secretion of P. perezi was obtained by electrical stimulation and fractionated using RP-HPLC. De novo peptide sequencing was conducted using MALDI MS/MS. The primary structure of PpT-2 (FPWLLS-NH2) was confirmed by Edman degradation and subsequently investigated using in silico tools. PpT-2 shared physicochemical properties with other well-known antioxidants. To test PpT-2 for antioxidant activity in vitro, the peptide was synthesized by solid phase and assessed in the chemical-based ABTS and DPPH scavenging assays. Then, a flow cytometry experiment was conducted to assess PpT-2 antioxidant activity in oxidatively challenged murine microglial cells. As predicted by the in silico analyses, PpT-2 scavenged free radicals in vitro and suppressed the generation of reactive species in PMA-stimulated BV-2 microglia cells. We further explored possible bioactivities of PpT-2 against prostate cancer cells and bacteria, against which the peptide exerted a moderate antiproliferative effect and negligible antimicrobial activity. The biocompatibility of PpT-2 was evaluated in cytotoxicity assays and in vivo toxicity with Galleria mellonella. No toxicity was detected in cells treated with up to 512 µg/ml and in G. mellonella treated with up to 40 mg/kg PpT-2. This novel peptide, PpT-2, stands as a promising peptide with potential therapeutic and biotechnological applications, mainly for the treatment/prevention of neurodegenerative disorders.
- Stepping up from an experienced teacher to a lesson study facilitatorPublication . Gomes, Paula; Martins, Micaela; Quaresma, Marisa; Rodrigues, Bruna; Ponte, João Pedro daIn this paper, we aim to understand how an experienced teacher, Vanda, who had already participated in two LS, has an initial experience as a lesson study facilitator. She was challenged to facilitate LS by a more experienced facilitator, who was alongside with her all the LS sessions. The two facilitators worked collaboratively to prepare the LS. Data collection included participant observation, with audio recordings of the preparation and LS sessions, and audio recordings of semistructured interviews before and after the LS and included document collection. The results show how the dimensions of resources, orientations, goals and identity (ROGI framework) interplay in framing Vanda's concerns and practices as a novice facilitator.