Active and Intelligent Packaging: A Review of the Possible Application of Cyclodextrins in Food Storage and Safety Indicators.

Natural cyclodextrins (CDs) can be formed by 6, 7, or 8 glucose molecules (α-, ß-, and γ-, respectively) linked in a ring, creating a cone shape. Its interior has an affinity for hydrophobic molecules, while the exterior is hydrophilic and can interact with water molecules. This feature has been used to develop active packaging applied to food, interacting with the product or its environment to improve one or more aspects of its quality or safety. It also provides monitoring information when food is optimal for consumption, as intelligent packaging is essential for the consumer and the merchant. Therefore, this review will focus on discerning which packaging is most appropriate for each situation, solubility and toxicological considerations, characterization techniques, effect on the guest properties, and other aspects related to forming the inclusion complex with bioactive molecules applied to packaging.

N-(levodopa) chitosan derivative based on click chemistry shows biological functionality in brain cells.

OBJECTIVE: To develop N-(levodopa) chitosan derivatives through click chemistry to study their effect in brain cells.Significance: This study presents a proof-of-concept that macromolecules such as N-(Levodopa) chitosan derivatives traverse brain cell membranes and induce biomedical functionalities. METHODS: Through click chemistry, we developed N-(levodopa) chitosan derivatives. They were physically and chemically characterized by FT-IR, 1H-NMR, TGA and Dynamic Light Scattering analyses. Solution and nanoparticles of N-(levodopa) chitosan derivatives were tested in primary cell cultures from the postnatal rat olfactory bulb, substantia nigra and corpus callosum. Ca2+ imaging and UPLC experiments were used to investigate if the biomaterial modulated the brain cell physiology. RESULTS: N-(levodopa) chitosan derivatives induced intracellular Ca2+ responses in primary cell cultures of the rat brain. UPLC experiments indicated that levodopa attached to chitosan was converted into dopamine by brain cells. CONCLUSION: The present study shows that N-(levodopa) chitosan may be useful to develop new treatment strategies, which could serve as molecular reservoirs of biomedical drugs to treat degenerative disorders of the nervous system.

DEAE/Catechol-Chitosan Conjugates as Bioactive Polymers: Synthesis, Characterization, and Potential Applications.

This work provides the first description of the synthesis and characterization of water-soluble chitosan (Cs) derivatives based on the conjugation of both diethylaminoethyl (DEAE) and catechol groups onto the Cs backbone (Cs-DC) in order to obtain a Cs derivative with antioxidant and antimicrobial properties. The degree of substitution [DS (%)] was 35.46% for DEAE and 2.53% for catechol, determined by spectroscopy. Changes in the molecular packing due to the incorporation of both pendant groups were described by X-ray diffraction and thermogravimetric analysis. For Cs, the crystallinity index was 59.46% and the maximum decomposition rate appeared at 309.3 °C, while for Cs-DC, the values corresponded to 16.98% and 236.4 °C, respectively. The incorporation of DEAE and catechol groups also increases the solubility of the polymer at pH > 7 without harming the antimicrobial activity displayed by the unmodified polymer. The catecholic derivatives increase the radical scavenging activity in terms of the half-maximum effective concentration (EC50). An EC50 of 1.20 µg/mL was found for neat hydrocaffeic acid (HCA) solution, while for chitosan-catechol (Cs-Ca) and Cs-DC solutions, concentrations equivalent to free HCA of 0.33 and 0.41 µg/mL were required, respectively. Cell culture results show that all Cs derivatives have low cytotoxicity, and Cs-DC showed the ability to reduce the activity of reactive oxygen species by 40% at concentrations as low as 4 µg/mL. Polymeric nanoparticles of Cs derivatives with a hydrodynamic diameter (Dh) of around 200 nm, unimodal size distributions, and a negative ζ-potential were obtained by ionotropic gelation and coated with hyaluronic acid in aqueous suspension, providing the multifunctional nanoparticles with higher stability and a narrower size distribution.

Spatiotemporal Temperature Distribution of NIR Irradiated Polypyrrole Nanoparticles and Effects of pH.

The spatiotemporal temperature distributions of NIR irradiated polypyrrole nanoparticles (PPN) were evaluated by varying PPN concentrations and the pH of suspensions. The PPN were synthesized by oxidative chemical polymerization, resulting in a hydrodynamic diameter of 98 ± 2 nm, which is maintained in the pH range of 4.2-10; while the zeta potential is significantly affected, decreasing from 20 ± 2 mV to -5 ± 1 mV at the same pH range. The temperature profiles of PPN suspensions were obtained using a NIR laser beam (1.5 W centered at 808 nm). These results were analyzed with a three-dimensional predictive unsteady-state heat transfer model that considers heat conduction, photothermal heating from laser irradiation, and heat generation due to the water absorption. The temperature profiles of PPN under laser irradiation are concentration-dependent, while the pH increase only induces a slight reduction in the temperature profiles. The model predicts a value of photothermal transduction efficiency (η) of 0.68 for the PPN. Furthermore, a linear dependency was found for the overall heat transfer coefficient (U) and η with the suspension temperature and pH, respectively. Finally, the model developed in this work could help identify the exposure time and concentration doses for different tissues and cells (pH-dependent) in photothermal applications.

Cytotoxic activity of Crotalus molossus molossus snake venom-loaded in chitosan nanoparticles against T-47D breast carcinoma cells.

Nanomedicine has led to the development of new biocompatible and biodegradable materials able to improve the pharmaceutical effect of bioactive components, broadening the options of treatment for several diseases, including cancer. Additionally, some snake venom toxins have been reported to present cytotoxic activity in different tumor cell lines, making them an auspicious option to be used as cancer drugs. The present study aims to evaluate the cytotoxic activity of the northern black-tailed rattlesnake (Crotalus molossus molossus) venom-loaded chitosan nanoparticles (Cs-Venom NPs) against the T-47D breast carcinoma cell line. To do so, we first identified the significant proteins composing the venom; afterward, hemocompatibility and cytotoxic activity against tumoral cells were evaluated. The venom was then loaded into chitosan nanoparticles through the ionotropic gelation process, obtaining particles of 415.9±21.67 nm and ζ-potential of +28.3±1.17 mV. The Cs-Venom complex delivered the venom into the breast carcinoma cells, inhibiting their viability and inducing morphological changes in the T-47D cells. These features indicate that these nanoparticles are suitable for the potential use of C. m. molossus venom toxins entrapped within polymer nanoparticles for the future development and research of cancer drugs.

Synthesis and Characterization of a Bioconjugate Based on Oleic Acid and L-Cysteine.

One of the main challenges facing materials science today is the synthesis of new biodegradable and biocompatible materials capable of improving existing ones. This work focused on the synthesis of new biomaterials from the bioconjugation of oleic acid with L-cysteine using carbodiimide. The resulting reaction leads to amide bonds between the carboxylic acid of oleic acid and the primary amine of L-cysteine. The formation of the bioconjugate was corroborated by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and nuclear magnetic resonance (NMR). In these techniques, the development of new materials with marked differences with the precursors was confirmed. Furthermore, NMR has elucidated a surfactant structure, with a hydrophilic part and a hydrophobic section. Ultraviolet-visible spectroscopy (UV-Vis) was used to determine the critical micellar concentration (CMC) of the bioconjugate. Subsequently, light diffraction (DLS) was used to analyze the size of the resulting self-assembled structures. Finally, transmission electron microscopy (TEM) was obtained, where the shape and size of the self-assembled structures were appreciated.

European and Asian contribution to the genetic diversity of mainland South American chickens.

Chickens (Gallus gallus domesticus) from the Americas have long been recognized as descendants of European chickens, transported by early Europeans since the fifteenth century. However, in recent years, a possible pre-Columbian introduction of chickens to South America by Polynesian seafarers has also been suggested. Here, we characterize the mitochondrial control region genetic diversity of modern chicken populations from South America and compare this to a worldwide dataset in order to investigate the potential maternal genetic origin of modern-day chicken populations in South America. The genetic analysis of newly generated chicken mitochondrial control region sequences from South America showed that the majority of chickens from the continent belong to mitochondrial haplogroup E. The rest belongs to haplogroups A, B and C, albeit at very low levels. Haplogroup D, a ubiquitous mitochondrial lineage in Island Southeast Asia and on Pacific Islands is not observed in continental South America. Modern-day mainland South American chickens are, therefore, closely allied with European and Asian chickens. Furthermore, we find high levels of genetic contributions from South Asian chickens to those in Europe and South America. Our findings demonstrate that modern-day genetic diversity of mainland South American chickens appear to have clear European and Asian contributions, and less so from Island Southeast Asia and the Pacific Islands. Furthermore, there is also some indication that South Asia has more genetic contribution to European chickens than any other Asian chicken populations.

Correction: Investigating the Global Dispersal of Chickens in Prehistory Using Ancient Mitochondrial DNA Signatures.

[This corrects the article DOI: 10.1371/journal.pone.0039171.].

Specific capture of glycosylated graphene oxide by an asialoglycoprotein receptor: a strategic approach for liver-targeting.

In this work, we report the evaluation of lactosylated graphene oxide (GO-AL) as a potential drug carrier targeted at an asialoglycoprotein receptor (ASGPR) from hepatic cancer cells. Structural-modification, safety evaluation, and functional analysis of GO-AL were performed. The structure and morphology of the composite were analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), while Raman and FTIR spectroscopy were used to track the chemical modification. For the safe application of GO-AL, an evaluation of the cytotoxic effect, hemolytic properties, and specific interactions of the glycoconjugate were also studied. SEM and AFM analysis of the GO showed graphene sheets with a layer size of 2-3 nm, though a few of them reached 4 nm. The Raman spectra presented characteristic peaks of graphene oxide at 1608 cm-1 and 1350 cm-1, corresponding to G and D bands, respectively. Besides, Si-O peaks for the APTES conjugates of GO were identified by FTIR spectroscopy. No cytotoxic or hemolytic effects were observed for GO samples, thus proving their biocompatibility. The interaction of Ricinus communis lectin confirmed that GO-AL has a biorecognition capability and an exposed galactose structure. This biorecognition capability was accompanied by the determination of the specific absorption of lactosylated GO by HepG2 cells mediated through the asialoglycoprotein receptor. The successful conjugation, hemolytic safety, and specific recognition described here for lactosylated GO indicate its promise as an efficient drug-delivery vehicle to hepatic tissue.

Chitosan Derivatives: Introducing New Functionalities with a Controlled Molecular Architecture for Innovative Materials.

The functionalization of polymeric substances is of great interest for the development of innovative materials for advanced applications. For many decades, the functionalization of chitosan has been a convenient way to improve its properties with the aim of preparing new materials with specialized characteristics. In the present review, we summarize the latest methods for the modification and derivatization of chitin and chitosan under experimental conditions, which allow a control over the macromolecular architecture. This is because an understanding of the interdependence between chemical structure and properties is an important condition for proposing innovative materials. New advances in methods and strategies of functionalization such as the click chemistry approach, grafting onto copolymerization, coupling with cyclodextrins, and reactions in ionic liquids are discussed.

Effect of the molecular architecture on the thermosensitive properties of chitosan-g-poly(N-vinylcaprolactam).

A series of thermoresponsive copolymers based on chitosan-g-poly(N-vinylcaprolactam) were synthesized by amidation reaction using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride as coupling reagent. The effect of molecular architecture on the thermoresponsive properties of the graft copolymers solutions was studied by varying the chain length of the grafted poly(N-vinylcaprolactam), PVCL, (in the range from 4 to 26 kDa) and the spacing between grafted chains onto the chitosan backbone. The most interesting characteristic of these copolymers is their solubility in water at temperatures below their lower critical solution temperature (LCST). These solutions presented a LCST between 36 and 44 °C, which decreases with the spacing and length of grafted PVCL chains onto the chitosan backbone, in contrast with the limited decrease of the LCST of PVCL above a critical M¯n value around 18 kDa. This behavior offers tangible possibilities for the preparation and application of sensitive bioactive formulations and "smart" drug delivery systems.

Investigating the global dispersal of chickens in prehistory using ancient mitochondrial DNA signatures.

Data from morphology, linguistics, history, and archaeology have all been used to trace the dispersal of chickens from Asian domestication centers to their current global distribution. Each provides a unique perspective which can aid in the reconstruction of prehistory. This study expands on previous investigations by adding a temporal component from ancient DNA and, in some cases, direct dating of bones of individual chickens from a variety of sites in Europe, the Pacific, and the Americas. The results from the ancient DNA analyses of forty-eight archaeologically derived chicken bones provide support for archaeological hypotheses about the prehistoric human transport of chickens. Haplogroup E mtDNA signatures have been amplified from directly dated samples originating in Europe at 1000 B.P. and in the Pacific at 3000 B.P. indicating multiple prehistoric dispersals from a single Asian centre. These two dispersal pathways converged in the Americas where chickens were introduced both by Polynesians and later by Europeans. The results of this study also highlight the inappropriate application of the small stretch of D-loop, traditionally amplified for use in phylogenetic studies, to understanding discrete episodes of chicken translocation in the past. The results of this study lead to the proposal of four hypotheses which will require further scrutiny and rigorous future testing.

Cambios degenerativos coriónicos asociados a malformaciones fetales del tubo neural durante el tercer trimestre del embarazo / Chorionic degenerative changes associated to fetal neural tube malformations during the third trimester of pregnancy

Evaluar las características de las vellosidades placentarias, sus vasos y espacio intervelloso. Estudio descriptivo, observacional, cualitativo-cuantitativo, retrospectivo, con muestreo no probabilístico de 6 placentas asociadas con malformación del tubo neural, analizadas mediante miscrocopia de luz comparadas en igual número de placentas no asociadas a malformación del tubo neural que sirvieron como controles. Los resultados se analizaron con la prueba de tendencia para datos correlacionados de respuesta dicotómica. Laboratorio de Microscopia Electrónica, CIADANA, Facultad de Ciencias de la Salud, Maracay. Se observaron nódulos sincitiales, cambios fibrinoides, necrosis trofoblástica, edema, fibrosis estromal, trombosis, inflamación de la pared del vaso, un número de vasos de 4 a 6 por sección de vellosidad, calcificación intraluminal, daño de la pared del vaso, trombosis intervellosa y presencia mínima de células inflamatorias en las vellosidades observadas. Hubo diferencias significativas con respecto a edema y necrosis trofoblástica entre ambos grupos. En el grupo de estudio una mayor proporción de edema y necrosis trofoblástica provocarían la eliminación de vellosidades cuyas placentas están con deficienca placentaria indicando que aquellos cambios o agentes causales de la malformación fetal también estarían provocando anomalías en el desarrollo placentario.

Radiocarbon and DNA evidence for a pre-Columbian introduction of Polynesian chickens to Chile.

Two issues long debated among Pacific and American prehistorians are (i) whether there was a pre-Columbian introduction of chicken (Gallus gallus) to the Americas and (ii) whether Polynesian contact with South America might be identified archaeologically, through the recovery of remains of unquestionable Polynesian origin. We present a radiocarbon date and an ancient DNA sequence from a single chicken bone recovered from the archaeological site of El Arenal-1, on the Arauco Peninsula, Chile. These results not only provide firm evidence for the pre-Columbian introduction of chickens to the Americas, but strongly suggest that it was a Polynesian introduction.

Observaciones en la hiperplasia mesenquimal placentaria con el microscopio electrónico de barrido / Observations in the placental mesenchymal hyperplasia by scanning electron microscopy

Material de una placenta de embarazo con diagnóstico de enfermedad mesenquimatosa placentaria a las 27 semanas de gestación y dolicocefalia fetal fue obtenido para ser procesado con las técnicas de microscopia electrónica de barrido previo análisis macro y microscópico del mismo. El examen macroscopico mostró placentomegalia, vellosidades troncales hidrópticas de tamaño entre 2 y 35 mm, placa carionica comprimida, hematoma retroplacentario

Microscopía electrónica de barrido de la vellocidad placentaria en la malformación de Chiari tipo II / Scanning electron microscopy of the placental villi in Chiari type II malformation

Nuestro proposito es el evaluar la morfología de la vellocidad placentaria en un caso de malformación de Chiari tipo II, diagnosticada ultrasonográficamente antes del naciemiento, para determinar variaciones de forma o tipo de ramificación, como las encontradas cuando existe un cariotipo anormal, según datos de la literatura, utilizando la microscopía electrónica de barrido y análisis previo con microscop¡a de luz. La malformación de Chiari es una hidrocefalia congénita comunicante, que coexiste con trisomías del par 13 o 18 y meningomielocele. Las alteraciones cromosómicas no solamente implican anomalías morfológicas características en embriones o fetos sino tambien en las vellosidades placentarias. Los resultados obtenidos de una placenta de la paciente de 24 semanas de gestación complicada con muerte neonatal confirman vellosidades troncales, intermedias maduras e inmaduras y vellosidades terminales originándose de intermedias maduras que fueron rastreadas sin observarse modificaciones en el patrón morfológico normal o su ramificación, cuando se comparan con vellosidades normales de la misma edad gestacional. La superficie de las vellosidades se mostraron lisas, con escasas microvellosidades. No se encontraron variaciones con respecto al diámetro de los diferentes tipos de vellosidades. La deposición de fibrinoide es similar a la normal. No se observó hiperplasia de trofoblasto ni cambios en los elementos estromales. Los resultados reportan la inmadurez vellosa confirmada previamente con microscopía de luz, con retraso en la maduración de árbol vellosos. Estas imágenes muestran una visión tridimensional de la vellosidad con inmadurez persistente, ligeramente asincrónica, sin la expresión de alguna anomalía morfológica específica indicativa de algún cariotipo anormal, proporcionando una mayor confianza al histopatólogo en la evaluación completa de la vellosidad en esta malformación

La vellosidad placentaria en la malformación de Chiari tipo II / Placental villi in Chiari malformation type II

Nuestro propósito es el de evaluar con las técnicas de microscopía de luz una visión general del árbol velloso placentario con sus tipos de estructura vellosa y el grado de maduración en caso de malformación de Chiari II. Muestras de placenta, con grado I de madurez, de las últimas ramificaciones del árbol velloso, en la semana 24 gestación, se comparan con las normales de la misma edad. Laboratorio de Microscopía Electrónica, CIADANA. Vellosidades troncales con un centro estromal fibroso que abarca a todo el estroma fueron observadas. Un predominio de vellosidades intermedias inmaduras con escasas intermedias maduras dominan el campo. Escasas terminales sobresalen de las intermedias maduras. Los resultados indican una madurez vellosa persistente mostrando un retraso de cuatro semanas y media, con respecto al patrón normal, siendo ligeramente asincrónica. Esta malformación blastogenética originada por defecto embrionario de la línea primitiva, frecuentemente letal y multisistémica envuelve defectos de placentación o en la malformación de cordón que tiende a ser severa y compleja provocando bajo peso al nacer y muerte fetal