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- Total antioxidant activity and trace elements in human milk: the first 4 months of breast-feedingPublication . Matos, Carla; Moutinho, Carla; Balcão, Victor; Almeida, Cristina; Ribeiro, Marta; Marques, Agostinho Franklim; Guerra, AntónioThe content of many nutrients in breast milk are dependent on the nutritional status of the lactating woman. This is particularly true for fat and water-soluble vitamins, some of which have antioxidant properties. The aim of the study entertained herein was to evaluate the changes in total antioxidant status of human milk during the first 4 months of lactation, and to correlate such changes with the contents in specific antioxidant oligoelements (Cu, Zn, Mn and Se). Milk samples were collected from (31) lactating women recruited at the Service of Obstetrics of the Hospital de São João in Porto, after 1, 4, 8, 12 and 16 weeks after birth. The total antioxidant status (TAS) of human milk was measured by the Randox® commercial kit and trace metals by ICP-MS (inductively coupled plasma-mass spectrometry). The results found for TAS and oligoelements under study show a decrease in the concentration of these parameters from 7 days to 4 months of breast-feeding and significant correlations (p < 0.05) were found between TAS and Cu, Zn and Se (not Mn). The decreases of Cu, Zn and Se were also correlated, but not proportional between them, suggesting diverse excretion mechanisms for all. Between primipara and multipara women, a significant difference was found only for Cu and Zn concentrations at 7 days of lactation, but not for the other metals or TAS. With respect to the mother’s age, no correlation was found, either for trace metal concentrations or TAS.
- Fatty Acid Profile of Human Milk of Portuguese Lactating Women: Prospective Study from the 1st to the 16th Week of LactationPublication . Ribeiro, M.; Balcão, Victor; Guimaraes, H.; Rocha, G.; Moutinho, Carla; Matos, Carla; Almeida, Cristina; Casal, S.; Guerra, A.Background/Aims: Fatty acid (FA) composition varies over the course of the day and during lactation. The aim of this study was to evaluate FA composition and its compositional stability in human milk, from day 7 to week 16 of lactation. Methods: Human milk was collected from all feedings over 24 h at day 7 and weeks 4, 8, 12 and 16 of lactation in 31 lactating women. FAs were analyzed through gas chromatography. Comparisons were made with analysis of variance. Results: Total monounsaturated FAs decreased from 33.04 ± 2.58% wt/wt at day 7 to 31.48 ± 3.32% wt/wt at week 16 of lactation, much at the expenses of the decrease in the major monounsaturated FA found in human milk, oleic acid. Main polyunsaturated FAs n-6 and n-3 showed fluctuations from day 7 up to week 16 of lactation, but with no statistical significance. Arachidonic acid significantly decreased from transitional to mature milk. Conclusions: The FA profile obtained throughout the study time points presented very low levels of oleic acid and very high linoleic acid/α-linoleic acid ratios which reflect recent changes in Portuguese women’s food patterns. Despite this, the ascorbate/dehydroascorbate ratio remained constant during the study, suggesting a protective metabolic mechanism.
- Nanoencapsulation of bovine lactoferrin for food and biopharmaceutical applicationsPublication . Balcão, Victor; Costa, Carla I.; Matos, Carla; Moutinho, Carla; Amorim, Manuela; Pintado, Manuela E.; Gomes, Ana P.; Vila, Marta M.; Teixeira, José A.Lactoferrin has for long captured the interest of many researchers as a natural compound with a wide variety of uses. Lactoferrin is a monomeric, iron-binding 80 kDa glycoprotein, and appears to be the subfraction of whey with the best documented antiviral, antimicrobial, anticancer and immune modulating/enhancing effects. It belongs to the family of transferrin proteins, and serves to control iron levels in body fluids by sequestering and solubilizing ferric iron. In the present research effort, production of lactoferrin derivatives (starting from a purified commercial extract), encompassing full stabilization of its three-dimensional structure, has been attempted via nanoencapsulation within lipid nanovesicles, integrating a multiple water-in-oil-in-water emulsion. Long-term storage of the multiple nanoemulsions produced did not lead to leaching of protein, thus proving the effectiveness of the encapsulation procedure. Furthermore, lactoferrin nanovesicle derivatives prepared under optimal conditions were successfully employed at lab-scale antimicrobial trials.
- Alimentos potenciadores de saúde: produtos lácteos probióticosPublication . Balcão, Victor; Moutinho, Carla; Matos, Carla; Almeida, CristinaOs alimentos probióticos em geral têm sido definidos como sendo “suplementos alimentares incorporando microorganismos vivos (bactérias probióticas) que afectam beneficamente o hospedeiro, melhorando o equilíbrio da sua microflora a nível intestinal”. O leite e os produtos lácteos em geral contêm vários biocomponentes que fornecem elementos nutritivos críticos e protecção imunológica, bem como substâncias biologicamente activas tanto a recém-nascidos como a adultos, pelo que estes alimentos pertencem ao grupo dos chamados alimentos funcionais. Produtos alimentares à base de leite inteiro ou lácteos fortificados ou enriquecidos podem, de facto, produzir efeitos potencialmente benéficos na melhoria da saúde humana e na prevenção de doenças, quando consumidos como parte de uma dieta variada e de forma regular.
- Alimentos transgénicos: questões de biosegurançaPublication . Moutinho, Carla; Balcão, Victor; Matos, Carla; Almeida, CristinaAs técnicas de modificação genética (MG), suportadas pela tecnologia de DNA recombinante, encerram um tremendo potencial para oferecer melhorias muito significativas na quantidade, qualidade e aceitabilidade dos alimentos a nível mundial. Investigadores e técnicos e engenheiros alimentares podem apoiar a introdução responsável de técnicas de MG desde que sejam satisfatoriamente considerados problemas de segurança (alimentar) do produto, preocupações ambientais, informação ao consumidor e ética. Apenas desta forma se poderão traduzir os benefícios que a tecnologia de DNA recombinante pode trazer, quanto mais não seja para ajudar a alimentar a sempre em crescimento população mundial nas próximas décadas.
- Development of innovative nanotechnology-based drug delivery systems for cancer therapyPublication . Moutinho, Carla; Matos, Carla; Balcão, VictorControlled drug delivery systems are not a new subject in the biomedical field. The continuously increasing need for the improvement of health care services has been the driving force for both search and development of such systems. Among these, micro- and nano-sized vehicles (e.g. nanocapsules, liposomes and mixed micelles) have received special attention over the last decade; they have been used for the delivery and vectorization of many pharmacologically active molecules, as is the case of anti-neoplastic drugs.
- Alterações na composição lipídica do leite materno durante as primeiras dezasseis semanas de amamentaçãoPublication . Matos, Carla; Moutinho, Carla; Almeida, Cristina; Pereira, Adriana; Balcão, Victor; Ribeiro, Marta; Guimarães, Hercília; Rocha, Gustavo; Guerra, AntónioO estudo realizado teve como objectivo a avaliação da composição de ácidos gordos (AG) no leite materno aos 7 dias e 4, 8, 12 e 16 semanas de lactação. A metodologia para a extracção da gordura do leite materno foi adaptada da norma ISO 14156:2001. Os ácidos gordos foram quantificados após derivatização, com base na norma ISO 15885:2002, por cromatografia gasosa com detector por ionização em chama. Concluiu-se com este trabalho de investigação que o decréscimo na percentagem dos ácidos araquidónico (AA) e docosahexaenóico (DHA), para o valor total de AG, não se traduz num aporte desequilibrado destas moléculas para o lactente, dado que, o que realmente importa, é o rácio estável destes AG ao longo do período de lactação. The research effort described herein has as main goal the evaluation of the fatty acid composition (AG) in human mother’s milk at 7 days and 4, 8, 12 and 16 weeks of breastfeeding after giving birth. The methodology used for the extraction of fat in human milk was adapted from the ISO 14156:2001 norm. Individual fatty acids were quantified by gas chromatography (GC-FID) with flame ionization detector, after derivatization, following the procedure described in the ISO 15885:2002 norm. As a major conclusion evolving from the results obtained in this research effort, the decrease in the percentage of arachidonic (AA) and docosahexaenoic (DHA) acids, relative to the total content of fatty acids (AG), does not translate into an unbalanced uptake of these molecules by the suckling baby, since that, what really matters, is the stable ratio of these fatty acids throughout the lactation period.
- Trace element compositional changes in human milk during the first four months of lactationPublication . Matos, Carla; Moutinho, Carla; Almeida, Cristina; Guerra, António; Balcão, VictorThe aims of this paper were to evaluate changes in specific oligoelements in human milk during the first four months of lactation and to correlate such changes with total antioxidant status (TAS) and other parameters, such as the mother's age, primipara versus multipara, and supplement intake. Milk samples were collected from 31 lactating women following 1, 4, 8, 12 and 16 weeks after birth. Trace levels of 13 elements were measured by inductively coupled plasma-mass spectrometry (ICP-MS). The results obtained for the oligoelements exhibited a decrease in concentration from 7 days to 4 months of breast-feeding, with exceptions. Correlations were found between TAS and Co, V, Rb and Tl. Between primipara and multipara, differences were found for Ni and Rb. Regarding the mother's age, correlation was found for Rb and Ba (increased for mothers older than 30 years). Increased amounts of Rb, Mo and Tl at any lactation period appeared in women who took supplements.
- Nanocarrier possibilities for functional targeting of bioactive peptides and proteins:state-of-the-artPublication . Moutinho, Carla; Matos, Carla; Teixeira, José A.; Balcão, VictorThis review attempts to provide an updated compilation of studies reported in the literature pertaining to production of nanocarriers encasing peptides and/or proteins, in a way that helps the reader direct a bibliographic search and develop an integrated perspective of the subject. Highlights are given to bioactive proteins and peptides, with a special focus on those from dairy sources (including physicochemical characteristics and properties, and biopharmaceutical application possibilities of e.g. lactoferrin and glycomacropeptide), as well as to nanocarrier functional targeting. Features associated with micro- and (multiple) nanoemulsions, micellar systems, liposomes and solid lipid nanoparticles, together with biopharmaceutical considerations, are presented in the text in a systematic fashion.
- Lipossomas: vectores atractivos e versáteis para o direccionamento de (bio)fármacosPublication . Conceição, Ana Isabel F. S.; Matos, Carla; Moutinho, Carla; Balcão, VictorOs lipossomas são microsistemas constituídos por uma ou mais bicamadas lipídicas dispostas esfericamente, separadas por fases aquosas, cujo cerne é um compartimento aquoso. Tais estruturas esféricas fechadas, cujo diâmetro varia tipicamente entre os 50 nm e os 5 mm, formam-se espontaneamente quando alguns lípidos são colocados em solução aquosa. Logo após a sua descoberta, na década de sessenta, surgiu a ideia de que poderiam ser usados como transportadores de compostos farmacologicamente activos, dado serem constituídos por compostos naturais, relativamente não-tóxicos e biodegradáveis. Liposomes are microsystems constituted by one or more lipid bilayers, arranged spherically, separated by aqueous phases, with an aqueous core. Such closed spherical structures, typically ranging in diameter from 50 nm to 5 mm, form spontaneously when certain lipids are placed in aqueous solution. Right after their discovery in the sixties, the idea that they could work as carriers for active drugs arose within the scientific community, since they are composed of natural compounds which are relatively non-toxic and biodegradable.