Three-Dimensional Printing of Food Foams Stabilized by Hydrocolloids for Hydration in Dysphagia.

Three-dimensional food printing offers the possibility of modifying the structural design, nutrition, and texture of food, which may be used for consumers with special dietary requirements such as dysphagic patients. One of the food matrices that can be used for liquid delivery to dysphagic patients is food foams. Foams are widely used in different food products to adjust food density, rheological properties, and texture. Foams allow the food to stay in the mouth for sufficient time to provide hydration while minimizing the danger of choking. Our work studies the foam properties and printability of both egg white foams and eggless foams with a strong focus on their foaming properties, rheological properties, printability, and suitability for dysphagic patients. Food hydrocolloid, xanthan gum (XG), is added to improve foam stability and rheological properties so that the inks are printable. Rheological and syneresis properties of the pre-printed foam inks are examined. The texture profile and microstructure properties are studied post-printing. International dysphagia diet standardization initiative tests are carried out to assess the inks' potential for dysphagic diets. Inks with XG performed better with minimal water seepage, better foam stability, and excellent printability. This suggests that hydrocolloids lead to more stable food foams that are suitable for 3DFP and safe for hydration delivery to dysphagic patients.

Hsp90 and its mitochondrial homologue TRAP-1 independently regulate hypoxia adaptations in Caenorhabditis elegans.

Mitochondrial adaptations to various environmental cues contribute to cellular and organismal adaptations across multiple model organisms. Due to increased complexity, a direct connection between mitochondrial integrity and oxygen fluctuations, and survival fitness was not demonstrated. Here, using C. elegans as a model system, we studied the role of HIF-1, Hsp90, and TRAP-1 in mitochondrial adaptations during chemical hypoxia. We show that Hsp90mt (Hsp90 mutant) but not HIF-1mt (HIF-1 mutant) affects hypoxia adaptation in nematodes. TRAP-1KD (TRAP-1 knockdown) interfered with the survival and fecundity of worms. Compared to Hsp90mt, TRAP-1KD has induced a significant decrease in mitochondrial integrity and oxygen consumption rate. The complex I inhibitor rotenone did not affect ATP levels in Hsp90mt worms. However, ATP levels were decreased in TRAP-1KD worms under similar conditions. The glucose restriction has reduced, and glucose supplementation has increased the survival rate in Hsp90mt worms. Neither glucose restriction nor glucose supplementation has significantly affected the survival of TRAP-1KD worms in response to hypoxia. However, TRAP-1 inhibition using a nanocarrier drug has dramatically reduced the survival rate in response to hypoxia. Our results suggest that Hsp90 and TRAP-1 independently regulate hypoxia adaptations and metabolic plasticity in C. elegans. Considering the emerging roles of TRAP-1 in altered energy metabolism and cellular adaptations, our findings gain importance.

C. elegans protein interaction network analysis probes RNAi validated pro-longevity effect of nhr-6, a human homolog of tumor suppressor Nr4a1.

Protein-protein interaction (PPI) studies are gaining momentum these days due to the plethora of various high-throughput experimental methods available for detecting PPIs. Proteins create complexes and networks by functioning in harmony with other proteins and here in silico network biology hold the promise to reveal new functionality of genes as it is very difficult and laborious to carry out experimental high-throughput genetic screens in living organisms. We demonstrate this approach by computationally screening C. elegans conserved homologs of already reported human tumor suppressor and aging associated genes. We select by this nhr-6, vab-3 and gst-23 as predicted longevity genes for RNAi screen. The RNAi results demonstrated the pro-longevity effect of these genes. Nuclear hormone receptor nhr-6 RNAi inhibition resulted in a C. elegans phenotype of 23.46% lifespan reduction. Moreover, we show that nhr-6 regulates oxidative stress resistance in worms and does not affect the feeding behavior of worms. These findings imply the potential of nhr-6 as a common therapeutic target for aging and cancer ailments, stressing the power of in silico PPI network analysis coupled with RNAi screens to describe gene function.

Specific Targeting of Melanotic Cells with Peptide Ligated Photosensitizers for Photodynamic Therapy.

A strategy combining covalent conjugation of photosensitizers to a peptide ligand directed to the melanocortin 1 (MC1) receptor with the application of sequential LED light dosage at near-IR wavelengths was developed to achieve specific cytotoxicity to melanocytes and melanoma (MEL) with minimal collateral damage to surrounding cells such as keratinocytes (KER). The specific killing of melanotic cells by targeted photodynamic therapy (PDT) described in this study holds promise as a potentially effective adjuvant therapeutic method to control benign skin hyperpigmentation or superficial melanotic malignancy such as Lentigo Maligna Melanoma (LMM).

An antidiabetic polyherbal phytomedicine confers stress resistance and extends lifespan in Caenorhabditis elegans.

An Ayurvedic polyherbal extract (PHE) comprising six herbs viz. Berberis aristata, Cyperus rotundus, Cedrus deodara, Emblica officinalis, Terminalia chebula and Terminalia bellirica is mentioned as an effective anti-hyperglycemic agent in 'Charaka Samhita', the classical text of Ayurveda. Previously, antidiabetic drug metformin was found to elicit antiaging effects and PHE was also found to exhibit antidiabetic effects in humans. Therefore, we screened it for its in vivo antioxidant antiaging effect on stress and lifespan using human homologous Caenorhabditis elegans model system. The effect on aging is evaluated by studying effect of PHE on mean survival in worms. The stress modulatory potential was assessed by quantification of intracellular ROS level, autofluorescent age pigment lipofuscin, oxidative and thermal stress assays. Additionally, stress response was quantified using gene reporter assays. The 0.01 µg/ml dose of PHE was able to enhance mean lifespan by 16.09% (P < 0.0001) in C. elegans. Furthermore, PHE treated worms demonstrated oxidative stress resistance in both wild type and stress hypersensitive mev-1 mutant along with upregulation of stress response genes sod-3 and gst-4. The delayed aging under stress can be attributed to its direct reactive oxygen species-scavenging activity and regulation of some age associated genes like daf-2, daf-16, skn-1, sod-3 and gst-4 in wild-type worms. Additonally, PHE delayed age related paralysis phenotype in CL4176 transgenic worms. Altogether, our results suggest PHE significantly improves the oxidative stress and life span in C. elegans. Overall the present study suggests this polyherbal formulation might play important role in regultaing aging and related complications like diabetes.

Curcumin and ß-caryophellene attenuate cadmium quantum dots induced oxidative stress and lethality in Caenorhabditis elegans model system.

Curcumin (CUR) and ß-caryophellene (BCP) are well known bioactive phytomolecules which are known to reduce oxidative stress in living organisms. Therefore, the present study was envisaged to explore the possible effects of CUR and BCP in suppression of cadmium quantum dots (CdTe QDs) induced toxicity in Caenorhabditis elegans. CdTe QD are luminescent nanoparticles extensively exploited for in vivo imaging, but long term bioaccumulation confer deleterious effects on living organisms. The 24-h LC50 and LC100 of CdTe QD were found to be 18.40 µg/ml and 100 µg/ml respectively. The CdTe QD exposure elevated HSP-16.2 expression mediating induction of the stress response. The CdTe QD lethality was due to increment in ROS and decline in SOD and GST expression. The present study demonstrates improved survival in BCP (50 µM) and CUR (20 µM) treated worms by over 60% (P<0.01) and 50% (P<0.029) in CdTe QD (100 µg/ml) exposed worms. Furthermore, BCP and CUR attenuate oxidative stress triggered by QD. The present study for the first time demonstrates CdTe QD toxicity remediation via BCP and CUR. The future investigations can unravel underlying protective effects of phytomolceules for remediating cyotoxicolgical effects of QDs.

Acacetin 7-O-α-l-rhamnopyranosyl (1-2) ß-D-xylopyranoside Elicits Life-span Extension and Stress Resistance in Caenorhabditis elegans.

The advancements in the field of gerontology have unraveled the signaling pathways that regulate life span, suggesting that it might be feasible to modulate aging. To this end, we isolated a novel phytomolecule Acacetin 7-O-α-l-rhamnopyranosyl (1-2) ß-D-xylopyranoside (ARX) from Premna integrifolia and evaluated its antiaging effects in Caenorhabditis elegans The spectral data analysis revealed the occurrence of a new compound ARX. Out of the three tested pharmacological doses of ARX, viz. 5, 25, and 50 µM, the 25-µM dose was able to extend life span in C. elegans by more than 39%. The present study suggests that ARX affects bacterial metabolism, which in turn leads to dietary restriction (DR)-like effects in the worms. The effect of ARX on worms with mutations (mev-1, eat-2, sir-2.1, skn-1, daf-16, and hsf-1) indicates that ARX-mediated life-span extension involves mechanisms associated with DR and maintenance of cellular redox homeostasis. This study is the first time report on longevity-promoting activity of ARX in C. elegans mediated by stress and DR-regulating genes. This novel phytomolecule can contribute in designing therapeutics for managing aging and age-related diseases.

Specioside ameliorates oxidative stress and promotes longevity in Caenorhabditis elegans.

Specioside (6-O-coumaroylcatalpol) is an iridoid glucoside which possesses multifunctional activities viz. analgesic, antidyspeptic, astringent, liver stimulating and wound healing properties. The present study for the first time delineates stress alleviating and lifespan prolonging action of specioside (SPC), isolated from Stereospermum suaveolens in the free living, multicellular nematode model Caenorhabditis elegans. A strong correlation between lifespan extension and stress modulation in adult worms was established in a dose dependent manner. The dietary intake of this phytomolecule elevated juglone induced oxidative and heat induced thermal stress tolerance in C. elegans. On evaluation, it was found that 25 µM dose of SPC significantly extended lifespan by 15.47% (P≤0.0001) with reduction in stress level. Furthermore, SPC enhanced mean survival in mev-1 mutant suggesting its oxidative stress reducing potential. Furthermore, SPC augmented stress modulatory enzymes superoxide dismutase (SOD) and catalase (CAT) level in C. elegans. Altogether, these findings broaden current perspectives concerning stress alleviating potentials of SPC and have implications in development of therapeutics for curing age related disorders.

Evidence for a role of the polysaccharide capsule transport proteins in pertussis pathogenesis.

Polysaccharide (PS) capsules are important virulence determinants for many bacterial pathogens. Bordetella pertussis, the agent of whooping cough, produces a surface associated microcapsule but its role in pertussis pathogenesis remained unknown. Here we showed that the B. pertussis capsule locus is expressed in vivo in murine lungs and that absence of the membrane-associated protein KpsT, involved in the transport of the PS polymers across the envelope, but not the surface-exposed PS capsule itself, affects drastically B. pertussis colonization efficacy in mice. Microarray analysis revealed that absence of KpsT in B. pertussis resulted in global down-regulation of gene expression including key virulence genes regulated by BvgA/S, the master two-component system. Using a BvgS phase-locked mutant, we demonstrated a functional link between KpsT and BvgA/S-mediated signal transduction. Whereas pull-down assays do not support physical interaction between BvgS sensor and any of the capsule locus encoded proteins, absence of KpsT impaired BvgS oligomerization, necessary for BvgS function. Furthermore, complementation studies indicated that instead of KpsT alone, the entire PS capsule transport machinery spanning the cell envelope likely plays a role in BvgS-mediated signal transduction. Our work thus provides the first experimental evidence of a role for a virulence-repressed gene in pertussis pathogenesis.

Beta-caryophyllene modulates expression of stress response genes and mediates longevity in Caenorhabditis elegans.

Beta-caryophyllene (BCP) is a natural bicyclic sesquiterpene and is a FDA approved food additive, found as an active ingredient in essential oils of numerous edible plants. It possesses a wide range of biological activities including anti-oxidant, anti-inflammatory, anti-cancerous and local anesthetic actions. We used the well established Caenorhabditis elegans model system to elucidate the stress modulatory and lifespan prolonging action of BCP. The present study for the first time reports the lifespan extension and stress modulation potential of BCP in C. elegans. Upon evaluation, it was found that 50µM dose of BCP increased the lifespan of C. elegans by over 22% (P≤0.0001) and significantly reduced intracellular free radical levels, maintaining cellular redox homeostasis. Moreover, the results suggest that BCP modulates feeding behavior, pharyngeal pumping and body size effectively. Further, this compound also exhibited significant reduction in intestinal lipofuscin levels. In the present investigation, we have predicted possible biological molecular targets for BCP using molecular docking approaches and BCP was found to have interaction with SIR-2.1, SKN-1 and DAF-16. The prediction was further validated in vivo using mutants and transgenic strains unraveling underlying genetic mechanism. It was observed that BCP increased lifespan of mev-1 and daf-16 but failed to augment lifespan in eat-2, sir-2.1 and skn-1 mutants. Relative quantification of mRNA demonstrated that several genes regulating oxidative stress, xenobiotic detoxification and longevity were modulated by BCP treatment. The study unravels the involvement of multiple signaling pathways in BCP mediated lifespan extension.

Genetic revelation of hexavalent chromium toxicity using Caenorhabditis elegans as a biosensor.

The interaction of heavy metals such as hexavalent chromium, Cr (VI) with the environment drastically influences living organisms leading to an ecological imbalance. Caenorhabditis elegans, a saprophytic nematode having 60-80% homology with human genes offers a distinct advantage to be used as a biosensor for the appraisal of heavy metal-induced environmental toxicity and risk monitoring. The present study examines the toxicity effects of K2Cr2O7 as Cr (VI) on stress-related gene expression and morphometric parameters of C. elegans under in vitro conditions to identify genetic markers for environmental pollution. Alterations in growth and modified gene expression were observed in Cr (VI)-exposed N2 worms. The 24-h median lethal concentration for Cr (VI) was observed as 158.5 mgl(-1). Use of the responses of stress-related gene expression suggests that C. elegans can be used as an efficient biosensor for figuring out the precise route of Cr (VI)-induced environmental toxicity in a quick, simple, and inexpensive manner.

Development of stretchable membrane based nanofilters using patterned arrays of vertically grown carbon nanotubes.

A unique process which utilizes membrane based vertically grown carbon nanotubes (CNTs) as nanofilters for a mass transport study is presented here. By using ions, ss-DNA and haemagglutinin as testing molecules of different dimensions, the mass transport function of the CNT membrane is investigated under pressure difference and/or electric field.

Development of vertical SU-8 microtubes integrated with dissolvable tips for transdermal drug delivery.

Polymer-based microneedles have drawn much attention in the transdermal drug delivery resulting from their flexibility and biocompatibility. Traditional fabrication approach deploys various kinds of molds to create sharp tips at the end of needles for the penetration purpose. This approach is usually time-consuming and expensive. In this study, we developed an innovative fabrication process to make biocompatible SU-8 microtubes integrated with biodissolvable maltose tips as novel microneedles for the transdermal drug delivery applications. These microneedles can easily penetrate the skin's outer barrier represented by the stratum corneum (SC) layer. The drug delivery device of mironeedles array with 1000 µm spacing between adjacent microneedles is proven to be able to penetrate porcine cadaver skins successfully. The maximum loading force on the individual microneedle can be as large as 7.36 ± 0.48N. After 9 min of the penetration, all the maltose tips are dissolved in the tissue. Drugs can be further delivered via these open biocompatible SU-8 microtubes in a continuous flow manner. The permeation patterns caused by the solution containing Rhodamine 110 at different depths from skin surface were characterized via a confocal microscope. It shows successful implementation of the microneedle function for fabricated devices.

Development of vertical SU-8 microneedles for transdermal drug delivery by double drawing lithography technology.

Polymer-based microneedles have drawn much attention in transdermal drug delivery resulting from their flexibility and biocompatibility. Traditional fabrication approaches are usually time-consuming and expensive. In this study, we developed a new double drawing lithography technology to make biocompatible SU-8 microneedles for transdermal drug delivery applications. These microneedles are strong enough to stand force from both vertical direction and planar direction during penetration. They can be used to penetrate into the skin easily and deliver drugs to the tissues under it. By controlling the delivery speed lower than 2 µl/min per single microneedle, the delivery rate can be as high as 71%.

Evidence for an intact polysaccharide capsule in Bordetella pertussis.

Polysaccharide capsules contribute to the pathogenesis of many bacteria species by providing resistance against various defense mechanisms. The production of a capsule in Bordetella pertussis, the etiologic agent of whooping cough, has remained controversial; earlier studies reported this pathogen as a capsulated microorganism whereas the recent B. pertussis genome analysis revealed the presence of a truncated capsule locus. In this work, using transmission electron microscopy and immunostaining approaches, we provide a formal evidence for the presence of an intact microcapsule produced at the surface of both laboratory strain and clinical isolates of B. pertussis. In agreement with previous studies, we found that the capsule is optimally produced in avirulent phase. Unexpectedly, the presence of the capsule was also detected at the surface of virulent B. pertussis bacteria. Consistently, a substantial transcriptional activity of the capsule operon was detected in virulent phase, suggesting that the capsular polysaccharide may play a role during pertussis pathogenesis. In vitro assays indicated that the presence of the capsule does not affect B. pertussis adherence to mammalian cells and does not further protect the bacterium from phagocytosis, complement-mediated killing or antimicrobial peptide attack.