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Massive coral bleachingepisodes induced by thermal stress areone of the first causes of coral death worldwide. Overproduction ofreactive oxygen species (ROS) has been identified as one of the potentialcauses of symbiosis breakdown between polyps and algae in corals duringextreme heat wave events. Here, we propose a new strategy for mitigatingheat effects by delivering underwater an antioxidant to the corals.We fabricated zein/polyvinylpyrrolidone (PVP)-based biocomposite filmsladen with the strong and natural antioxidant curcumin as an advancedcoral bleaching remediation tool. Biocomposites' mechanical,water contact angle (WCA), swelling, and release properties can betuned thanks to different supramolecular rearrangements that occurby varying the zein/PVP weight ratio. Following immersion in seawater,the biocomposites became soft hydrogels that did not affect the coral'shealth in the short (24 h) and long periods (15 days). Laboratorybleaching experiments at 29 and 33 & DEG;C showed that coral coloniesof Stylophora pistillata coated withthe biocomposites had ameliorated conditions in terms of morphologicalaspects, chlorophyll content, and enzymatic activity compared to untreatedcolonies and did not bleach. Finally, biochemical oxygen demand (BOD)confirmed the full biodegradability of the biocomposites, showinga low potential environmental impact in the case of open-field application.These insights may pave the way for new frontiers in mitigating extremecoral bleaching events by combining natural antioxidants and biocomposites.

A vinyl laurate-based elastomeric copolymer, developed as chewing gum base, was used to produce functional coatings with the antioxidant curcumin. Both the polymer and curcumin were dissolved in MIBK, methyl isobutyl ketone. Coatings were applied on glass but also on natural alginate and gelatin film surfaces by dip-coating. Microscopy analysis indicated that coatings had very homogenous surface and curcumin was effectively encapsulated within the polymeric matrix. In addition, curcumin-laden coatings (10 wt%) remained transparent with excellent UV filtering properties. The flexibility of alginate and gelatin films was maintained after coating, whereas their hydrophobicity and water vapor barrier properties improved. Furthermore, coating biocompatibility and low bacterial adhesion properties were confirmed by cell proliferation and bacterial surface contamination experiments, respectively. The radical scavenging activity of the coating was assessed with both DPPH and ABTS assay, revealing effective antioxidant properties. In addition, in weak acetic acid solutions, curcumin could be released in a sustained manner from the coatings. This coating can be used as a suitable option for improving the antioxidant and bacterial resistance properties of natural polymer films including food packaging or other relevant applications.

Polyvinylpyrrolidone (PVP) is probably one of the most utilized pharmaceutical polymers with applications ranging from blood plasma substitute to nanoparticle drug delivery since its synthesis in 1938. It is a highly biocompatible, non-toxic and transparent film-forming polymer. Although high solubility of PVP in an aqueous environment is advantageous, it still poses several problems for some applications in which sustained targeting and release are needed, or hydrophobic drug inclusion and delivery systems are to be designed. For this reason, in the field of controlled drug release, it is often used as an additive and not as a protagonist. On the other hand, in case of wound treatment, PVP can be a suitable biopolymer for the design of wound dressings due to its capacity to inhibit the crystallinity of several drugs, opening to their topical application, and its adhesive properties to the skin. Therefore, the main goal of this Ph.D. was to demonstrate that this underestimated synthetic polymer can be a proper based material for the design, the fabrication and the formulation of new smart wound dressings for the delivery of antibiotic and antioxidant compounds. In the first part of this Ph.D. study, PVP and acetic acid (AcOH) were used to inhibit the crystallization of the antibiotic Ciprofloxacin (Cipro) and to prepare transparent PVP foils as well as nanofiber mats. The presence of the antibiotic and the acid inside of the PVP matrix caused a plasticizer effect of these ingredients in the final mechanical properties of the films. Both films and nanofibers were able to release the Cipro, and an antibacterial synergism between acetic acid and the antibiotic were highlighted in vitro antibacterial assay. The PVP/Cipro/AcOH materials showed biocompatibility and a different rate of resorption in an in vivo wound mice model. In the second part of the Ph.D., a multifunctional polyvinylpyrrolidone/hyaluronic acid-based bilayer construct for sequential delivery of cutaneous antiseptic and antibiotic was designed and fabricated by using two scalable methodologies. The bilayer material showed strong adhesion to skin, effective antibacterial activity against three strains, biocompatibility, hemocompatibility, anti-inflammatory properties both in vitro and in vivo, resorption by the skin and accelerate the wound closure in mice model. Then, the PVP/Cipro/AcOH films and nanofibers were further characterized on an infected wound model based on ex-vivo human skin. The materials resulted non-toxic and with suitable profiles of the release of Cipro inside of the skin. Moreover, they highlighted a strong antibacterial activity against biofilms infection of Pseudomonas aeruginosa and, especially, in case of the films they were able to eradicate completely the biofilms from the skin. Finally, PVP was combined with the dietary phenolic compounds, p-coumaric acid (PCA). The introduction of the PCA in transparent films led to an increase of the hydrophobicity of the PVP-based matrix. Indeed, changes in water contact angles, water uptake and the rate of dissolution in water were found. Furthermore, the new biocomposites were investigated as drug delivery system of two model drugs and their antioxidant and anti-inflammatory activity were analyzed in vitro and in vivo, respectively. In conclusions, several PVP-based wound dressings were designed and fabricated, demonstrating their potential efficacy for the treatment of infected wounds, burns, and chronic wounds.

Topical treatment of wound infections is often a challenge due to limited drug availability at the site of infection. Topical drug delivery is an attractive option for reducing systemic side effects, provided that a more selective and sustained local drug delivery is achieved. In this study, a poorly water-soluble antibiotic, ciprofloxacin, was loaded on polyvinylpyrrolidone (PVP)-based foils and nanofiber mats using acetic acid as a solubilizer. Drug delivery kinetics, local toxicity, and antimicrobial activity were tested on an ex vivo wound model based on full-thickness human skin. Wounds of 5 mm in diameter were created on 1.5 × 1.5 cm skin blocks and treated with the investigated materials. While nanofiber mats reached the highest amount of delivered drug after 6 h, foils rapidly achieved a maximum drug concentration and maintained it over 24 h. The treatment had no effect on the overall skin metabolic activity but influenced the wound healing process, as observed using histological analysis. Both delivery systems were efficient in preventing the growth of Pseudomonas aeruginosa biofilms in ex vivo human skin. Interestingly, foils loaded with 500 µg of ciprofloxacin accomplished the complete eradication of biofilm infections with 1 × 109 bacteria/wound. We conclude that antimicrobial-loaded resorbable PVP foils and nanofiber mats are promising delivery systems for the prevention or topical treatment of infected wounds.

Em versão bilíngue, esta edição do Cadernos FGV Projetos aborda o tema Cidades Sustentáveis. A publicação traz uma entrevista com Simone Raskob, conselheira para a área de Meio Ambiente e Construção de Essen, na Alemanha, e líder do projeto que levou a cidade a conquistar o título de Capital Verde da Europa 2017. A edição tem também depoimentos de Elizabeth Yee, vice-presidente de Soluções para Cidades do programa 100 Resilient Cities, e de Marilene Ramos, diretora do BNDES e professora da Ebape/FGV, que falam sobre como suas instituições têm trabalhado para fomentar práticas mais sustentáveis e resilientes no Brasil e no mundo. O caderno apresenta artigos de especialistas e gestores urbanos, como a pesquisadora e líder de projetos do Instituto de Desenvolvimento Alemão (DIE) Clara Brandi (“O papel das cidades: implementação da Agenda 2030 e do Acordo de Paris”), o subsecretário de Urbanismo e Mobilidade Urbana da Prefeitura Municipal de Niterói, Rogério Gutierrez (“Sustentabilidade e resiliência urbana: dados, informações e tecnologia como ferramentas para gestão territorial”), os integrantes do ITS Rio Ronaldo Lemos, Fabro Steibel e Victor Vicente (“Participação cidadã e a crise ambiental nas cidades”), além de textos da professora da FGV Rossana Pavanelli (“Modelos de negócio em economia colaborativa”), dos coordenadores da FGV Projetos Carlos Augusto Costa (“Cidades inteligentes: o desafio do planejamento sustentável”), Marco Contardi e Marco Saverio Ristuccia (“Cidades inteligentes e sustentáveis: inovações para transformação urbana no Brasil”) e de outros importantes profissionais da área de planejamento e desenvolvimento urbano.

Esta edição do Cadernos FGV Projetos apresenta os inúmeros benefícios que o conceito de cidade inteligente vem trazendo para a mobilidade e outras áreas da gestão urbana, além de discutir os desafios a serem superados para gerar sistemas sustentáveis que atendam às demandas da população. Gestores urbanos, como o ex-prefeito de Bogotá e o diretor do Centro de Operações do Rio de Janeiro, apresentam-nos alguns dos esforços que vêm sendo realizados para tornar suas cidades mais inteligentes.