Tackling complex diseases in the post genomic era: the case of the pine wilt disease

info:eu-repo/semantics/draf

E hoje, já comeu feijão? O papel das leguminosas em dietas mais sustentáveis

info:eu-repo/semantics/publishedVersio

Chitosan and chitooligosaccharide utilization in phytoremediation and biofortification programs: current knowledge and future perspectives

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Nanotechnological approaches for treating skin cancer : from drug delivery nanoformulations to 3D models of skin cancer

Basal cell carcinoma is the most common skin cancer in the world. Even though its mortality rates are low, the number of cases has been rising worldwide. Photodynamic therapy mediated by 5-aminolevulinic acid (5-ALA) is a possible treatment for this kind of cancer. However, the penetration capability of 5-ALA into the deeper layers of the skin is limited, constraining the potential of this therapy. To overcome this limitation, phosphocholine-based nanovesicles were developed, using a pH gradient active loading protocol, to serve as a drug delivery system and to improve the transdermal passage of 5-ALA. The vesicles were characterized by morphology, encapsulation efficiency, loading capacity, stability, and diffusion capacity using ex-vivo pig skin. Additionally, a 3D cellular model was developed to resemble skin cancer, using a collagen hydrogel as a scaffold. Cellular tests were conducted using this skin model, which evaluated the vesicles' toxicity and penetration capability. Furthermore, preliminary tests of the efficacy of this therapy were carried out with 2D melanoma cells. According to the results, with a feeding concentration of 833 μg/mL of 5-ALA, its encapsulation efficiency is 24%. The vesicles presented an average diameter of 154,8 ± 18,8 nm, which decreased slightly until day 15 of storage, from when the sample stabilized. The vesicles have good thermostability. The diffusion tests showed that the vesicles could penetrate the skin, therefore, have the potential as a transdermal drug delivery system. Though the tumor target of this project is basal cell carcinoma, cellular tests have been performed with melanoma cells. The results show the therapeutic potential of the vesicles upon application of the photodynamic stimulus. In addition, preliminary studies with 3D hydrogel models of skin cancer embedded with melanoma spheroids and overlayed with keratinocytes demonstrate the capability of the vesicles to penetrate the matrix and enter the spheroids.O carcinoma basocelular é o cancro de pele mais comum no mundo. Embora apresente baixas taxas de mortalidade, o número de casos tem vindo a aumentar em todo o mundo. A terapia fotodinâmica mediada por ácido 5-aminolevulínico (5-ALA) é um possível tratamento para este tipo de cancro. Porém, a capacidade de penetração do 5-ALA nas camadas mais profundas da pele é limitada, comprometendo o seu potencial. Para superar essa limitação, neste trabalho, nanovesículas à base de fosfocolina foram desenvolvidas, usando um protocolo de encapsulamento ativo por gradiente de pH, que servirão como um sistema de libertação controlada de fármacos, facilitando a passagem transdérmica de 5-ALA. Estas foram caracterizadas quanto à sua morfologia, eficiência do encapsulamento, capacidade de carga, estabilidade e capacidade de difusão. Adicionalmente, um modelo celular 3D foi desenvolvido para representar cancro da pele, utilizando um hidrogel de colagénio-agarose como scaffold. Através de testes celulares neste modelo, avaliaram-se a toxicidade e capacidade de penetração das nanoparticulas. Adicionalmente, testes preliminares da eficácia desta terapia foram realizados com culturas 2D de células de melanoma. De acordo com os resultados, para uma concentração inicial de 5-ALA de 833 μg/mL, a eficiência de encapsulamento obtida foi de 24%. As nanovesículas apresentaram diâmetro médio de 154,8 ± 18,8 nm, que diminuiu ligeiramente até o 15º dia de armazenamento, a partir do qual a amostra estabilizou. As vesículas apresentaram boa estabilidade térmica. Os testes de difusão mostraram que as vesículas foram capazes de penetrar a pele. Embora a patologia alvo deste projeto seja o carcinoma basocelular, os testes celulares foram realizados com células de melanoma. Os resultados mostraram o potencial terapêutico das vesículas mediante aplicação de estímulo fotodinâmico. Além disso, estudos preliminares com o modelo 3D desenvolvido demonstram a capacidade das vesículas de penetrar na matriz do hidrogel e entrar nos esferoides

Combined effect of elevated CO2 and Fe deficiency on common bean metabolism and mineral profile

Aims: Elevated atmospheric CO2 (eCO2) and restricted iron (Fe) supply are known to impact plant growth and nutritional quality of food crops. However, studies aimed at understanding how eCO2 will interact with Fe deficiency are scarce. Changes in the nutritional status of the common bean (Phaseolus vulgaris L.) may significantly impact the nutritional status of populations that rely heavily on this crop. Methods: To understand the combined effects of eCO2 and Fe deficiency on mechanisms relevant to plant nutrient uptake and accumulation, common bean plants were grown under Fe sufficiency (Fe+, 20 mM Fe-EDDHA) and Fe deficiency (Fe-, 0 mM Fe-EDDHA) combined with eCO2 (800 ppm) or ambient CO2 (aCO2, 400 ppm) in hydroponics until maturity. Results: Elevated CO2, besides stimulating photosynthesis and stomatal closure, highly affected plant Fe metabolism: stimulated root ferric chelate reductase (FCR) activity by 6-fold and downregulated the expression of root FRO1 and IRT1 expressions by about 4-fold. In leaves, citrate and oxalate increased, but ferritin expression decreased by 9-fold. Such changes may have determined the differences on mineral accumulation patterns particularly the lower levels of Fe in roots (62%), leaves (38%) and seeds (50%). The combination of Fe deficiency and eCO2 doubled the effect of a single factor on FCR up-regulation, balanced the internal pH of Fe deficient plants, and resulted in the lowest Fe accumulation in all plant parts. Conclusions: These results suggest that eCO2 directly affects the Fe uptake mechanism of common bean plants, decreasing plant Fe content.info:eu-repo/semantics/publishedVersio

TRUE - Transition Paths to Sustainable Legume Base Systems in Europe: European Countries and Kenya

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Evaluation of the susceptibility of Portuguese autochthonous flora to the pine wilt nematode (Bursaphelenchus xilophylus)

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