Polylactide Nanofibers Loaded with Vitamin B6 and Polyphenols as Bioactive Platform for Tissue Engineering

Elena Llorens,Luis J. del Valle,Angélica Díaz,María T. Casas,Jordi Puiggalí 한국고분자학회 2013 Macromolecular Research Vol.21 No.7

Electrospun polylactide nanofibers loaded with different antioxidants (i.e. vitamin B6 in pyridoxine and pyridoxal form, p-coumaric acid and caffeic acid) are prepared from N,N-dimethylformamide/dimethylsulfoxide solutions. Morphology, structure and crystallinity of the nanofibers are evaluated by transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction and differential scanning calorimetry (DSC)techniques. Fibers are highly amorphous but able to crystallize easily due to the high molecular orientation induced by the electrospinning process. The drug molecules are incorporated into the polymeric matrix or formed isolated crystals. A fast release of loaded drug occurs within the first 8 h in hydrophobic medium; but, a slow and sustained release during several days occurs in a hydrophilic medium. Cell attachment on the loaded scaffolds was unaffected by the incorporation of the antioxidants. In contrast, cell proliferation increases with high antioxidative activity against free radicals responsible for cell damage. These new electrospun scaffolds provide high protection of cells against oxidative stress and resulting in innovative 3D fibrous platforms for tissue growth and proliferation.

Inhibition of Radical-Induced Oxidative DNA Damage by Antioxidants Loaded in Electrospun Polylactide Nanofibers

Elena Llorens,Luis J. del Valle,Jordi Puiggalí 한국고분자학회 2014 Macromolecular Research Vol.22 No.4

Polylactide (PLA) nanofibers loaded with antioxidants, i.e. vitamin B6 or pyridoxine (PN) and its analoguepyridoxal (PL), and with hydroxycinnamic acids, i.e. p-coumaric acid (CUM) and caffeic acid (CAF), wereprepared by the electrospinning technique. The control consisted of nanofibers loaded with trolox (TRX). Experimentally,these new materials were tested on the inhibition of oxidative DNA damage caused by free radicals initiatedby 2,2'-azobis (2-amidinopropane hydrochloride) (AAPH). This damage was assessed in vitro and in vivo bymeasuring the conversion of supercoiled pUC19 plasmid DNA to open circular and linear forms. It was found thatthese antioxidants, in solution, could significantly inhibit oxidative DNA damage, and that the antioxidants loadedin the PLA nanofibers maintained in vitro and in vivo their protective role against oxidative DNA damage. Thus,electrospun mats derived from PLA nanofibers loaded with the considered compounds have the capacity to protectDNA against oxidative damage, and appear interesting, for their use in the purification of plasmidic or genomic DNA.

EU의 업무 관련 스트레스와 노사관계

Clara Llorens,Daniel Ortiz de Villacian 한국노동연구원 2011 국제노동브리프 Vol.9 No.1

Electrospun Scaffolds of Polylactide with a Different Enantiomeric Content and Loaded with Anti-Inflammatory and Antibacterial Drugs

Elena Llorens,Luis J. del Valle,Jordi Puiggalí 한국고분자학회 2015 Macromolecular Research Vol.23 No.7

Polylactide (PLA) electrospun microfibers were prepared and loaded with triclosan (TCS), ketoprofen (KTP), or their combination to obtain multifunctional scaffolds with bactericide and anti-inflammatory properties. Continuous and porous fibers with diameters in the micrometer scale and a unimodal distribution were successfully attained using a dual-electrospinning technique. Dual drug-loaded scaffolds showed a peculiar release that was in contrast to the single drug-loaded systems, which suggested the establishment of intermolecular interactions that delayed TCS and KTP release. Antimicrobial activity of all TCS-loaded electrospun scaffolds was demonstrated against E. coli and M. luteus bacteria; and furthermore, KTP-loaded samples slightly showed bactericide activity. Biocompatibility of scaffolds was evaluated by adhesion and proliferation assays, and interestingly, the dual drug-load systems were able to support high TCS doses without adverse effects.

The Third Version of the Copenhagen Psychosocial Questionnaire

Burr, Hermann,Berthelsen, Hanne,Moncada, Salvador,Nubling, Matthias,Dupret, Emilie,Demiral, Yucel,Oudyk, John,Kristensen, Tage S.,Llorens, Clara,Navarro, Albert,Lincke, Hans-Joachim,Bocerean, Christin Occupational Safety and Health Research Institute 2019 Safety and health at work Vol.10 No.4

Introduction: A new third version of the Copenhagen Psychosocial Questionnaire (COPSOQ III) has been developed in response to trends in working life, theoretical concepts, and international experience. A key component of the COPSOQ III is a defined set of mandatory core items to be included in national short, middle, and long versions of the questionnaire. The aim of the present article is to present and test the reliability of the new international middle version of the COPSOQ III. Methods: The questionnaire was tested among 23,361 employees during 2016-2017 in Canada, Spain, France, Germany, Sweden, and Turkey. A total of 26 dimensions (measured through scales or single items) of the middle version and two from the long version were tested. Psychometric properties of the dimensions were assessed regarding reliability (Cronbach α), ceiling and floor effects (fractions with extreme answers), and distinctiveness (correlations with other dimensions). Results: Most international middle dimensions had satisfactory reliability in most countries, though some ceiling and floor effects were present. Dimensions with missing values were rare. Most dimensions had low to medium intercorrelations. Conclusions: The COPSOQ III offers reliable and distinct measures of a wide range of psychosocial dimensions of modern working life in different countries; although a few measures could be improved. Future testing should focus on validation of the COPSOQ items and dimensions using both qualitative and quantitative approaches. Such investigations would enhance the basis for recommendations using the COPSOQ III.

The Third Version of the Copenhagen Psychosocial Questionnaire

Hermann Burr,Hanne Berthelsen,Salvador Moncada,Matthias Nübling,Emilie Dupret,Yucel Demiral,John Oudyk,Tage S. Kristensen,Clara Llorens,Albert Navarro,Hans-Joachim Lincke,Christine Bocéréan,Ceyda Saha 한국산업안전보건공단 산업안전보건연구원 2019 Safety and health at work Vol.10 No.4

Introduction: A new third version of the Copenhagen Psychosocial Questionnaire (COPSOQ III) has been developed in response to trends in working life, theoretical concepts, and international experience. A key component of the COPSOQ III is a defined set of mandatory core items to be included in national short, middle, and long versions of the questionnaire. The aim of the present article is to present and test the reliability of the new international middle version of the COPSOQ III. Methods: The questionnaire was tested among 23,361 employees during 2016e2017 in Canada, Spain, France, Germany, Sweden, and Turkey. A total of 26 dimensions (measured through scales or single items) of the middle version and two from the long version were tested. Psychometric properties of the dimensions were assessed regarding reliability (Cronbach a), ceiling and floor effects (fractions with extreme answers), and distinctiveness (correlations with other dimensions). Results: Most international middle dimensions had satisfactory reliability in most countries, though some ceiling and floor effects were present. Dimensions with missing values were rare. Most dimensions had low to medium intercorrelations. Conclusions: The COPSOQ III offers reliable and distinct measures of a wide range of psychosocial dimensions of modern working life in different countries; although a few measures could be improved. Future testing should focus on validation of the COPSOQ items and dimensions using both qualitative and quantitative approaches. Such investigations would enhance the basis for recommendations using the COPSOQ III.

Molecular Markers for Interspecies Transmission of Avian Influenza Viruses in Mammalian Hosts

Lloren, Khristine Kaith S.,Lee, Taehyung,Kwon, Jin Jung,Song, Min-Suk MDPI 2017 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.18 No.12

<P>In the last decade, a wide range of avian influenza viruses (AIVs) have infected various mammalian hosts and continuously threaten both human and animal health. It is a result of overcoming the inter-species barrier which is mostly associated with gene reassortment and accumulation of mutations in their gene segments. Several recent studies have shed insights into the phenotypic and genetic changes that are involved in the interspecies transmission of AIVs. These studies have a major focus on transmission from avian to mammalian species due to the high zoonotic potential of the viruses. As more mammalian species have been infected with these viruses, there is higher risk of genetic evolution of these viruses that may lead to the next human pandemic which represents and raises public health concern. Thus, understanding the mechanism of interspecies transmission and molecular determinants through which the emerging AIVs can acquire the ability to transmit to humans and other mammals is an important key in evaluating the potential risk caused by AIVs among humans. Here, we summarize previous and recent studies on molecular markers that are specifically involved in the transmission of avian-derived influenza viruses to various mammalian hosts including humans, pigs, horses, dogs, and marine mammals.</P>

The significance of avian influenza virus mouse-adaptation and its application in characterizing the efficacy of new vaccines and therapeutic agents

최원석,Khristine Kaith S. Lloren,백윤희,송민석 대한백신학회 2017 Clinical and Experimental Vaccine Research Vol.6 No.2

Due to the increased frequency of interspecies transmission of avian influenza viruses, studies designed to identify the molecular determinants that could lead to an expansion of the host range have been increased. A variety of mouse-based mammalian-adaptation studies of avian influenza viruses have provided insight into the genetic alterations of various avian influenza subtypes that may contribute to the generation of a pandemic virus. To date, the studies have focused on avian influenza subtypes H5, H6, H7, H9, and H10 which have recently caused human infection. Although mice cannot fully reflect the course of human infection with avian influenza, these mouse studies can be a useful method for investigating potential mammalian adaptive markers against newly emerging avian influenza viruses. In addition, due to the lack of appropriate vaccines against the diverse emerging influenza viruses, the generation of mouse-adapted lethal variants could contribute to the development of effective vaccines or therapeutic agents. Within this review, we will summarize studies that have demonstrated adaptations of avian influenza viruses that result in an altered pathogenicity in mice which may suggest the potential application of mouse-lethal strains in the development of influenza vaccines and/or therapeutics in preclinical studies.

Thermoelectrical detection of Majorana states

Ló,pez, Rosa,Lee, Minchul,Serra, Llorenç,Lim, Jong Soo American Physical Society 2014 Physical review. B, Condensed matter and materials Vol.89 No.20

We discuss the thermoelectrical properties of nanowires hosting Majorana states. For a Majorana nanowire directly coupled to two normal reservoirs the thermopower always vanishes regardless of the value of the Majorana overlap parameter epsilon(M), due to the particle-hole symmetric nature of the Majorana states. This situation changes drastically if a quantum dot (QD) is inserted to break the particle-hole symmetry. Then, the Majorana-side-coupled QD system exhibits a different behavior for the thermopower depending on the value of epsilon(M). The thermopower globally reverses its sign when the half-fermionic nature of the Majorana state is relevant, i.e., for epsilon(M) less than or similar to k(B)T(b), where T-b is the background temperature. For large overlap, epsilon(M) greater than or similar to k(B)T(b), on the other hand, the Seebeck coefficient behaves similarly to that in a resonant level system. The sign change of the thermopower and the fact that both the electrical and thermal conductances reach their half-fermionic value when Majorana physics are maximal could serve as a proof of the existence of Majorana states in nanowires.

Strongly modulated transmission of a spin-split quantum wire with local Rashba interaction

Sá,nchez, David,Serra, Llorenç,Choi, Mahn-Soo American Physical Society 2008 Physical review. B, Condensed matter and materials Vol.77 No.3