Drug delivery systems for photodynamic therapy: the potentiality and versatility of electrospun nanofibers

Recently, photodynamic therapy (PDT) has become a promising approach for the treatment of a broad range of diseases, including oncological and infectious diseases. This minimally invasive and localized therapy is based on the production of reactive oxygen species able to destroy cancer cells and inactivate pathogens by combining the use of photosensitizers (PSs), light, and molecular oxygen. To overcome the drawbacks of drug systemic administration, drug delivery systems (DDS) can be used to carrier the PSs, allowing higher therapeutic efficacy and minimal toxicological effects. Polymeric nanofibers produced by electrospinning emerged as powerful platforms for drug delivery applications. Electrospun nanofibers exhibit outstanding characteristics, such as large surface-area-to-volume ratio associated with high drug loading, high porosity, flexibility, ability to incorporate and release a wide variety of therapeutic agents, biocompatibility, and biodegradability. Due to the versatility of this technique, fibers with different morphologies and functionalities, including drug release profile can be produced. The possibility of scalability makes electrospinning even more attractive for the development of DDS. This review aims to explore and show an up to date of the huge potential of electrospun nanofibers as DDS for different PDT applications and discuss the opportunities and challenges in this field.The authors are thankful to project UID/CTM/00264/2021 of 2C2T – Centro de Ciência e Tecnologia Têxtil, funded by National Founds through FCT/MCTES- Fundação para a Ciência e a Tecnologia. D.P.F. is thankful to CEECIND/02803/2017 and S.M.C. to the FCT PhD Scholarship (SFRH/BD/147517/2019), founded by National Founds through FCT/MCTES

Avaliação da resistência de cultivares de feijoeiro (Phaseolus spp.) a Meloidogyne javanica, para uso como porta-enxerto

Das diversas pragas e doenças que afetam o feijoeiro (Phaseolus spp.), encontram-se os nemátodes-das-galhas-radiculares (NGR), Meloidogyne spp., sendo amplamente conhecido o seu efeito devastador em culturas hortícolas. A principal estratégia de controlo assenta na aplicação de nematodicidas, que têm sido progressivamente restringidos. Têm sido consideradas técnicas de controlo alternativas, como a enxertia de hortícolas em porta-enxertos resistentes. Os objetivos do estudo foram: 1) conhecer a reação de cultivares de feijoeiro (Phaseolus vulgaris e P. coccineus) a Meloidogyne javanica, considerando o seu grau de suscetibilidade ou resistência; 2) avaliar a severidade dos danos causados nas raízes; e 3) inferir sobre a potencial utilização destas cultivares como porta-enxerto comercial de feijoeiro. Foi realizado um ensaio em vaso, com cinco repetições de cada uma de nove cultivares testadas, que decorreu numa sala de culturas com condições controladas. As plantas foram inoculadas com 5000 ovos e jovens de M. javanica; plantas não inoculadas serviram de testemunha negativa, sendo a testemunha positiva plantas de tomateiro cv. Tiny Tim reconhecidamente suscetível a M. javanica. Sessenta dias após a inoculação, procedeu-se à determinação do número de galhas e de massas de ovos nas raízes. Nenhuma das cultivares testadas foi completamente resistente ao nemátode. No entanto, através de uma análise comparativa, foi detetado um potencial de resistência nas cultivares Bencanta e Oriente, em que foram registados níveis do número de galhas, de massas de ovos e de reprodução dos nemátodes comparáveis aos de cultivares classificadas como resistentes. As cultivares Bencanta e Oriente revelaram resultados promissores relativamente à sua utilização como porta-enxertos resistentes a NGR, justificando-se uma investigação mais aprofundada para testar e avaliar a viabilidade da sua utilização na enxertia de feijoeiro, em condições controladas e no campo, e na presença de outras espécies de NGR.Evaluation of the resistance of common bean (Phaseolus spp.) to Meloidogyne javanica, for use as rootstocks. Among the numerous pests and diseases that affect common bean (Phaseolus spp.), root-knot nematodes (RKN), Meloidogyne spp., are the ones that stand out for their devastating effects on horticultural crops. The main control strategy is based on the application of nematicides, which have been 1 progressively restricted. Alternative nematode management methods have been considered, such as vegetable grafting using resistant cultivars. The objectives of this study were: 1) to know the reaction of nine cultivars of common bean (Phaseolus vulgaris and P. coccineus) to Meloidogyne javanica, considering their degree of susceptibility and resistance; 2) to assess the severity of damage to the roots; and 3) to infer on the potential use of these cultivars as commercial bean rootstocks. A pot experiment was done under controlled conditions in a culture room, and each treatment consisted of five replicates. Plants were inoculated with 5000 eggs and second stage juveniles of M. javanica, with uninoculated plants serving as negative control and susceptible tomato plants cv. Tiny Tim being used as positive control. Sixty days after inoculation, roots were observed to determine the number of galls and egg masses. None of the tested cultivars was completely resistant to the nematode. However, through a comparative analysis, a potential for resistance was detected in Bencanta and Oriente cultivars, with levels of nematode-induced galls and egg masses comparable to those of cultivars classified as resistant. The Bencanta and Oriente cultivars showed promising results regarding their use as resistant rootstocks to RKN, justifying further research to test and assess the feasibility of their use in bean grafting, under controlled conditions and in the field, and in the presence of other species of RKN.Programa Estratégico UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569), financiado por fundos nacionais através da Fundação para a Ciência e a Tecnologia, e pelo Fundo Europeu de Desenvolvimento Regional (FEDER), através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI)Empresa Alípio Dias & Irmão LdaEmpresa Tozer Iberica SLEscola Superior Agrária de Ponte de LimaLaboratório de Nematologia da Universidade de Coimbrainfo:eu-repo/semantics/publishedVersio

Three-Year Study From a Portuguese Tertiary Referral Center

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Evaluation of a novel fusion system for soluble protein overexpression in Escherichia coli

Proteins production requires a successful correlation between expression, solubility and purification steps. As an expression system, Escherichia coli combines its low cost and ease of use with rapid expression, being widely used for heterologous protein production. This host cell has however several drawbacks, namely at the expression of insoluble proteins aggregated into inclusion bodies. Many efforts have been made to overcome such problems, including the optimization of expression conditions and the use of solubility fusion tags. The use of fusion tags for protein production remains challenging since none of the available fusion systems work universally with every partner protein. A novel fusion system had been recently discovered and submitted to a patenting process by Hitag Biotechnology, Lda. This fusion system consists of low molecular weight peptides/proteins from recombinant antigens, which have demonstrated to increase soluble protein expression levels in E. coli. This work aims at the evaluation of the effects of two novel fusion tags on soluble protein expression in E. coli. Specific primers were designed to amplify and sub‐clone gene sequences that encodes for frutalin, Cryptosporidium parvum 12kDa protein and Giardia lamblia cyst wall protein. These target proteins present therapeutic and diagnostic interests and had shown to be difficult‐to‐express in E. coli. Proteins were first fused to novel tags and than expressed in E. coli. Proteins purification was carried out by affinity chromatography, using nickel‐NTA columns. Pooled fractions were dialysed against phosphate buffer pH 7.4 and latter analysed by SDS‐PAGE. Protein expression levels were determined by Bradford assay. When fused to novel tags, all target proteins were successfully expressed in E. coli. Comparing to the respective non‐fused proteins, both novel tags used in this work promoted an increase from three to nine folds on soluble proteins expression levels. The SDS‐PAGE analysis confirmed the purity of Ni‐NTA pooled fractions, corroborating also these results. Tag1‐fusions achieved higher production yields than fusions with Tag2. In this work, three different target proteins were used to evaluate two novel fusion tags. The soluble overexpression effect offered by this novel fusion system may provide an important advance in recombinant protein expression processes in E. coli

Perceived barriers for healthy eating by university employees at the workplace

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Targeting Lipid Peroxidation for Cancer Treatment

grant number RTI2018-093864-B-I00Cancer is one of the highest prevalent diseases in humans. The chances of surviving cancer and its prognosis are very dependent on the affected tissue, body location, and stage at which the disease is diagnosed. Researchers and pharmaceutical companies worldwide are pursuing many attempts to look for compounds to treat this malignancy. Most of the current strategies to fight cancer implicate the use of compounds acting on DNA damage checkpoints, non-receptor tyrosine kinases activities, regulators of the hedgehog signaling pathways, and metabolic adaptations placed in cancer. In the last decade, the finding of a lipid peroxidation increase linked to 15-lipoxygenases isoform 1 (15-LOX-1) activity stimulation has been found in specific successful treatments against cancer. This discovery contrasts with the production of other lipid oxidation signatures generated by stimulation of other lipoxygenases such as 5-LOX and 12-LOX, and cyclooxygenase (COX-2) activities, which have been suggested as cancer biomarkers and which inhibitors present anti-tumoral and antiproliferative activities. These findings support the previously proposed role of lipid hydroperoxides and their metabolites as cancer cell mediators. Depletion or promotion of lipid peroxidation is generally related to a specific production source associated with a cancer stage or tissue in which cancer originates. This review highlights the potential therapeutical use of chemical derivatives to stimulate or block specific cellular routes to generate lipid hydroperoxides to treat this disease.publishersversionpublishe

Food consumption determinants and barriers for healthy eating at the workplace: a university setting

Background: A wide variety of social, cultural and economic factors may influence dietary patterns. This work aims to identify the main determinants of food consumption and barriers for healthy eating at the workplace, in a university setting. Methods: A cross-sectional observational study was conducted with 533 participants. Data were obtained through the application of a self-administered questionnaire that included socio-demographic information, food consumption determinants and the main perceived barriers for healthy eating at the workplace. Results: The respondents identified “price” (22.5%), “meal quality” (20.7%), and “location/distance” (16.5%). For women, the determinant “availability of healthy food options” was more important than for men (p < 0.001). The food consumption determinants at the workplace most referred to by respondents were related to the nutritional value. Smell, taste, appearance and texture, and good value for money, were also considered important for choosing food at the workplace. Respondents referred to work commitments and lack of time as the main barriers for healthy eating at the workplace. Conclusions: Identification of determinants involved in food consumption, and the barriers for healthy eating, may contribute to a better definition of health promotion initiatives at the workplace aiming to improve nutritional intake.info:eu-repo/semantics/publishedVersio

Development of chitosan-gelatin nanofibers with cellulose nanocrystals for skin protection applications

In this work, natural-based and biodegradable nanofibers were produced by electrospinning for drug delivery and wound dressing applications, using gelatin (Gel), chitosan (CS), cellulose nanocrystals (CNC) and natural propolis extract. The polymeric formulations and electrospinning parameters were optimized, resulting in the development of Gel/CS nanofibers with mean diameters of 97 nm. CNC were successfully introduced into the optimized Gel/CS solution and the viscosity and conductivity values were recorded. The developed nanofibers were characterized using FESEM, ATR-FTIR, TGA and WCA. The incorporation of different CNC concentrations improved the solutions’ electrospinnability and the membranes’ physical integrity. Defect-free and uniform Gel/CS/CNC nanofibers were observed by FESEM images, and the fibers’ diameters slight increased. The hydrophilic character was maintained after the CNC incorporation. Finally, Gel/CS/CNC/Propolis nanofibers demonstrated antibacterial activity against both Gram-negative (E. coli) and Gram-positive (S. aureus) bacteriaThe authors are thankful to TSSiPRO project, operation code NORTE01-0145-FEDER-000015. The authors are also grateful to FCT, Portugal for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020) and to 2C2T (UID/CTM/00264/2019). D. P. Ferreira thank the national funding by FCT through the individual scientific employment program-contract (CEECIND/02803/2017) and S. M. Costa thank the FCT PhD Scholarship (SFRH/BD/147517/2019)