Person: Zafra Amorós, Olga
Loading...
First Name
Olga
Last Name
Zafra Amorós
Affiliation
Faculty
Ciencias Experimentales
Department
Area
Identifiers
3 results
Search Results
Now showing 1 - 3 of 3
Item Mechanisms and Regulation of Extracellular DNA Release and Its Biological Roles in Microbial Communities.(Frontiers in Microbiology, 2017) Ibáñez de Aldecoa, Alejandra L.; Zafra Amorós, Olga; González-Pastor, José E.The capacity to release genetic material into the extracellular medium has been reported in cultures of numerous species of bacteria, archaea, and fungi, and also in the context of multicellular microbial communities such as biofilms. Moreover, extracellular DNA (eDNA) of microbial origin is widespread in natural aquatic and terrestrial environments. Different specific mechanisms are involved in eDNA release, such as autolysis and active secretion, as well as through its association with membrane vesicles. It is noteworthy that in microorganisms, in which DNA release has been studied in detail, the production of eDNA is coordinated by the population when it reaches a certain cell density, and is induced in a subpopulation in response to the accumulation of quorum sensing signals. Interestingly, in several bacteria there is also a relationship between eDNA release and the development of natural competence (the ability to take up DNA from the environment), which is also controlled by quorum sensing. Then, what is the biological function of eDNA? A common biological role has not been proposed, since different functions have been reported depending on the microorganism. However, it seems to be important in biofilm formation, can be used as a nutrient source, and could be involved in DNA damage repair and gene transfer. This review covers several aspects of eDNA research: (i) its occurrence and distribution in natural environments, (ii) themechanisms and regulation of its release in cultured microorganisms, and (iii) its biological roles. In addition, we propose that eDNA release could be considered a social behavior, based on its quorum sensing-dependent regulation and on the described functions of eDNA in the context of microbial communities.Item Dichotomous colorectal cancer behaviour.(Critical Reviews in Oncology/Hematology, 2023) Aljama, Sara; Pérez Lago, Estela; Zafra Amorós, Olga; Sierra Isturiz, Javier; Simón, Diana; Santos Tejedor, Cruz; Rodriguez Pascual, Jesus; García Romero, NoemíColorectal cancer (CRC) is the third most common malignant tumor and one of the deadliest cancers. At molecular level, CRC is a heterogeneous disease that could be divided in four Consensus Molecular Subtypes. Given the differences in the disease due to its anatomical location (proximal and distal colon), another classification should be considered. Here, we review the current knowledge on CRC dichotomic´s behaviour based on two different entities; right and left-sided tumors, their impact on clinical trial data, microbiota spatial composition and the interaction with the nervous system. We discuss recent advances in understanding how the spatial tumor heterogeneity influences the tumor growth, progression, and responses to current therapiesItem Polydopamine surface functionalized submicron ZnO for broadening the processing window of 3D printable PLA composites.(Journal of Polymer Research, 2023) Yang, Xiao‑Mei; Yin, Guang-Zhong; Zafra Amorós, Olga; Arroyo-Hernández, María; De la Vega, Jimena; Torralba, José ManuelThe “catalytic degradation” of metal oxides limits the wide application of PLA when PLA needs to be modified by adding metal oxides to achieve desired properties. Zinc oxide (ZnO) is a common and widely used agent as it can be used for many properties, such as antioxidant, antibacterial, etc. However, detrimental effects often exist on the properties of polymers after introducing the ZnO, due to the catalytic degradation. In this study, we used polydopamine (PDA) to construct ZnO@PDA core-shell submicron particles via the self-polymerization of dopamine (DA) in alkaline solution, aimed to produce a surface functionalization that would be used to control the rate of degradation of PLA by ZnO during thermal processing, and promote the preservation of mechanical properties. PLA with different contents of ZnO and ZnO@PDA were prepared by a simple melt extrusion method. The degradation behavior, mechanical properties and antibacterial activity of ZnO/PLA and ZnO@PDA/PLA were investigated. It was found that the incorporation of ZnO@PDA in PLA at different contents exhibits a dramatic control over the degradation rate when compared to that of the ZnO/PLA with the same filler content. Notably, the T5% and T50% of 3%-ZnO@PDA/PLA increased by 36.4 oC and 31.9 oC. GPC results showed the molecular weight of 3%-ZnO@PDA/PLA was only reduced by 15.8% after thermal processing. In addition, 3%-ZnO@PDA/PLA can be 3D-printed smoothly. That is to say, the introduction of ZnO@PDA can increase the processing window of PLA/ZnO composites, providing the possibility for materials that need to be included in civil application. Accordingly, ZnO@PDA/PLA samples showed higher tensile strength and elongation at break than that of corresponding ZnO/PLA samples. Regarding the antibacterial behavior, the ZnO@PDA/PLA have more bacterial growth disability effect against Gram(+) bacteria than that of pure PLA.