25 research outputs found
PATHOGEN-SPECIFIC ANTIBODY PROFILES IN PATIENTS WITH SEVERE SYSTEMIC INFECTIONS
Infections are often caused by pathobionts, endogenous bacteria that belong to the microbiota. Trauma and surgical intervention can allow bacteria to overcome host defences, ultimately leading to sepsis if left untreated. One of the main defence strategies of the immune system is the production of highly specific antibodies. In the present proof-of-concept study, plasma antibodies against 9 major pathogens were measured in sepsis patients, as an example of severe systemic infections. The binding of plasma antibodies to bacterial extracellular proteins was quantified using a semi-automated immunoblot assay. Comparison of the pathogen-specific antibody levels before and after infection showed an increase in plasma IgG in 20 out of 37 tested patients. This host-directed approach extended the results of pathogen-oriented microbiological and PCR diagnostics: a specific antibody response to additional bacteria was frequently observed, indicating unrecognised poly-microbial invasion. This might explain some cases of failed, seemingly targeted antibiotic treatment
Thermal and hydrolytic degradation of electrospun fish gelatin membranes
The thermal and hydrolytic degradation of electrospun gelatin membranes cross-linked with glutaraldehyde in vapor phase has been studied. In vitro degradation of gelatin membranes was evaluated in phosphate buffer saline solution at 37 °C. After 15 days under these conditions, a weight loss of 68% was observed, attributed to solvation and depolymerization of the main polymeric chains. Thermal degradation kinetics of the gelatin raw material and as-spun electrospun membranes showed that the electrospinning processing conditions do not influence polymer degradation. However, for cross-linked samples a decrease in the activation energy was observed, associated with the effect of glutaraldehyde cross-linking reaction in the inter- and intra-molecular hydrogen bonds of the protein. It is also shown that the electrospinning process does not affect the formation of the helical structure of gelatin chainsThis work was supported by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Project PEST-C/FIS/UI607/2011 and by projects project references NANO/NMed-SD/0156/2007 and PTDC/CTM-NAN/112574/2009. The authors also thank support from the COST Action MP1003, 2010 'European Scientific Network for Artificial Muscles'. DMC, JP and VS would like to acknowledge the FCT for the SFRH/BD/82411/2011, SFRH/BD/64901/2009 and SFRH/BPD/64958/2009 grants respectively
The use of electric fields for edible coatings and films development and production: A review
Edible films and coatings can provide additional
protection for food, while being a fully biodegradable,
environmentally friendly packaging system. A diversity of
raw materials used to produce edible coatings and films are
extracted from marine and agricultural sources, including
animals and plants. Electric fields processing holds advantage
in producing safe, wholesome and nutritious food.
Recently, the presence of a moderate electric field during
the preparation of edible coatings and films was shown to
influence their main properties, demonstrating its usefulness
to tailor edible films and coatings for specific applications.
This manuscript reviews the main aspects of the use of
electric fields in the production of edible films and coatings,
including the effect in their transport and mechanical
properties, solubility and microstructure.Fundação para a Ciência e a Tecnologia (FCT), Portugal.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brasil
Modifying fish gelatin electrospun membranes for biomedical applications: cross-linking and swelling behavior
Development of suitable membranes is a fundamental requisite for tissue and biomedical engineering applications. This work presents fish gelatin random and aligned electrospun membranes cross-linked with glutaraldehyde (GA). It was observed that the fiber average diameter and the morphology is not influenced by the GA exposure time and presents fibers with an average diameter around 250 nm. Moreover, when the gelatin mats are immersed in a phosphate buffered saline solution (PBS), they can retain as much as 12 times its initial weight of solution almost instantaneously, but the material microstructure of the fiber mats changes from the characteristic fibrous to an almost spherical porous structure. Cross-linked gelatin electrospun fiber mats and films showed a water vapor permeability of 1.37 ± 0.02 and 0.13 ± 0.10 (g.mm)/(m2.h.kPa), respectively. Finally, the processing technique and cross-linking process does not inhibit MC-3T3-E1 cell adhesion. Preliminary cell culture results showed good cell adhesion and proliferation in the cross-linked random and aligned gelatin fiber mats.This work is funded by FEDER funds through the "Programa Operacional Factores de Competitividade - COMPETE" and by the national funds arranged by FCT-Fundacao para a Ciencia e a Tecnologia, project references NANO/NMed-SD/0156/2007, PTDC/CTM-NAN/112574/2009, and PEST-C/FIS/UI607/2011. The authors also thank funding from Matepro - Optimizing Materials and Processes," ref. NORTE-07-0124-FEDER-000037," co-funded by the "Programa Operacional Regional do Norte" (ON.2 - O Novo Norte), under the "Quadro de Referencia Estrategico Nacional" (QREN), through the "Fundo Europeu de Desenvolvimento Regional" (FEDER). The authors also thank support from the COST Action MP1003, 2010 "European Scientific Network for Artificial Muscles." V. Sencadas, J. Padrao, and J. Silva thank the FCT for the SFRH/BPD/64958/2009, SFRH/BD/64901/2009, and SFRH/BPD/63148/2009 grants, respectively