Demonstrating the immunostimulatory and cytokine-augmentation effects of bacterial ghosts on natural killer cells and Caenorhabditis Elegans.

The potential of bacteria-based immunotherapy lies in its ability to inherently enhance immune responses. However, the "liveness" of bacteria poses risks of bacterial escape, nonspecific immuno-stimulation, and ethical concerns, limiting their acceptability in immunotherapy. In this scenario, nonliving empty bacterial-cell envelopes, named bacterial ghosts (BGs), have emerged as immuno-stimulants with the potential to side-step the limitations of live bacterial therapies. This study demonstrates the capability of BGs in modulating the functionality of NK-92 cells and Caenorhabditis elegans (C. elegans), as well as perform as cytokine-therapy adjuvants. BGs were obtained through a pH-driven culture method, and were validated for their structural and chemical integrity via electron microscopy and spectroscopy. In NK-92 cells, BGs have shown significant immuno-stimulation by boosting the gene-expression of perforin, granzyme-B, Fas-L, and interferon-gamma by factors of 3.5-, 1.5-, 12.5-, and 8.6-folds, respectively. Combined BG and IL-12 treatment yielded a notable 10.2-fold increase in interferon-gamma protein expression in 24 h. The BGs also significantly influenced the innate immune response in C. elegans through the upregulation of lysozyme genes viz., ilys-3 (8.8-fold) and lys-2 (3.1-fold). Our investigation into the impact of BGs on natural killer cells and C. elegans highlights its potential as a valid alternative approach for new-age immunotherapy and cytokine augmentation.

Photostimulated Extended Nitric Oxide (NO) Release from Water-Soluble Block Copolymer to Enhance Antibacterial Activity.

N-Nitrosamines are well established motifs to release nitric oxide (NO) under photoirradiation. Herein, a series of amphiphilic N-nitrosamine-based block copolymers (BCPx-NO) are developed to attain controlled NO release under photoirradiation (365 nm, 3.71 mW/cm2). The water-soluble BCPx-NO forms micellar architecture in aqueous medium and exhibits a sustained NO release of 92-160 µM within 11.5 h, which is 36.8-64.0% of the calculated value. To understand the NO release mechanism, a small molecular NO donor (NOD) resembling the NO releasing functional motif of BCPx-NO is synthesized, which displays a burst NO release in DMSO within 2.5 h. The radical nature of the released NO is confirmed by electron paramagnetic resonance (EPR) spectroscopy. The gradual NO release from micellar BCPx-NO enhances antibacterial activity over NOD and exhibits a superior bactericidal effect on Gram-positive Staphylococcus aureus. In relation to biomedical applications, this work offers a comprehensive insight into tuning light-triggered NO release to improve antibacterial activity.

iRGD conjugated nimbolide liposomes protect against endotoxin induced acute respiratory distress syndrome.

Acute respiratory distress syndrome (ARDS) is a deadly respiratory illness associated with refractory hypoxemia and pulmonary edema. The recent pandemic outbreak of COVID-19 is associated with severe pneumonia and inflammatory cytokine storm in the lungs. The anti-inflammatory phytomedicine nimbolide (NIM) may not be feasible for clinical translation due to poor pharmacokinetic properties and lack of suitable delivery systems. To overcome these barriers, we have developed nimbolide liposomes conjugated with iRGD peptide (iRGD-NIMLip) for targeting lung inflammation. It was observed that iRGD-NIMLip treatment significantly inhibited oxidative stress and cytokine storm compared to nimbolide free-drug (f-NIM), nimbolide liposomes (NIMLip), and exhibited superior activity compared to dexamethasone (DEX). iRGD-NIMLip abrogated the LPS induced p65 NF-κB, Akt, MAPK, Integrin ß3 and ß5, STAT3, and DNMT1 expression. Collectively, our results demonstrate that iRGD-NIMLip could be a promising novel drug delivery system to target severe pathological consequences observed in ARDS and COVID-19 associated cytokine storm.

The miR-124 family of microRNAs is crucial for regeneration of the brain and visual system in the planarian Schmidtea mediterranea.

Brain regeneration in planarians is mediated by precise spatiotemporal control of gene expression and is crucial for multiple aspects of neurogenesis. However, the mechanisms underpinning the gene regulation essential for brain regeneration are largely unknown. Here, we investigated the role of the miR-124 family of microRNAs in planarian brain regeneration. The miR-124 family (miR-124) is highly conserved in animals and regulates neurogenesis by facilitating neural differentiation, yet its role in neural wiring and brain organization is not known. We developed a novel method for delivering anti-miRs using liposomes for the functional knockdown of microRNAs. Smed-miR-124 knockdown revealed a key role for these microRNAs in neuronal organization during planarian brain regeneration. Our results also demonstrated an essential role for miR-124 in the generation of eye progenitors. Additionally, miR-124 regulates Smed-slit-1, which encodes an axon guidance protein, either by targeting slit-1 mRNA or, potentially, by modulating the canonical Notch pathway. Together, our results reveal a role for miR-124 in regulating the regeneration of a functional brain and visual system.

Deciphering the response of asymmetry in the hydrophobic chains of novel cationic lipids towards biological function.

Cationic liposomes, a type of non-viral vectors, often play the important biological function of delivering nucleic acids during cell transfection. Variations in the molecular architecture of di-alkyl dihydroxy ethyl ammonium chloride-based cationic lipids involving hydrophobic tails have been found to influence their biological function in terms of cell transfection efficiency. For example, liposomes based on a cationic lipid (Lip1814) with asymmetry in the hydrophobic chains were found to display higher transfection efficacy in cultured mammalian cell lines than those comprising of symmetric Lip1818 or asymmetric Lip1810. The effect of variations in the molecular architecture of the cationic lipids on the biological activity of liposomes has been explored here via the photophysical studies of 8-anilino-1-naphthalenesulphonate (ANS) and Nile Red (NR) in three cationic liposomes, namely Lip1810, Lip1814 and Lip1818. Time-resolved fluorescence of ANS revealed reduced hydration at the lipid-water interface and enhanced relaxation dynamics of surface water (lipid headgroup bound water molecules) in Lip1810- and Lip1814-based liposomes in the presence of cholesterol. As the probe ANS failed to be incorporated into the lipid-water interface of Lip1818 due to the significantly high rigidity of these liposomes, no information concerning the extent of hydration of the lipid-water interface or the interfacial water dynamics could be obtained. Time-resolved polarization-gated anisotropy measurements of NR in the presence of cholesterol revealed the rigidity of the cationic liposomes to be increasing in the order of Lip1810 < Lip1814 < Lip1818. In the presence of cholesterol, moderately higher rigidity, reduced membrane hydration and enhanced relaxation dynamics of the interfacial water molecules gave rise to the superior cell transfection efficacy of Lip1814-based cationic liposomes than those of the highly flexible Lip1810 or the highly rigid Lip1818.

Early animal model evaluation of an implantable contrast agent to enhance magnetic resonance imaging of arterial bypass vein grafts.

Background Non-invasive monitoring of autologous vein graft (VG) bypass grafts is largely limited to detecting late luminal narrowing. Although magnetic resonance imaging (MRI) delineates vein graft intima, media, and adventitia, which may detect early failure, the scan time required to achieve sufficient resolution is at present impractical. Purpose To study VG visualization enhancement in vivo and delineate whether a covalently attached MRI contrast agent would enable quicker longitudinal imaging of the VG wall. Material and Methods Sixteen 12-week-old male C57BL/6J mice underwent carotid interposition vein grafting. The inferior vena cava of nine donor mice was treated with a gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-based contrast agent, with control VGs labeled with a vehicle. T1-weighted (T1W) MRI was performed serially at postoperative weeks 1, 4, 12, and 20. A portion of animals was sacrificed for histopathology following each imaging time point. Results MRI signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were significantly higher for treated VGs in the first three time points (1.73 × higher SNR, P = 0.0006, and 5.83 × higher CNR at the first time point, P = 0.0006). However, MRI signal enhancement decreased consistently in the study period, to 1.29 × higher SNR and 2.64 × higher CNR, by the final time point. There were no apparent differences in graft morphometric analyses in Masson's trichrome-stained sections. Conclusion A MRI contrast agent that binds covalently to the VG wall provides significant increase in T1W MRI signal with no observed adverse effects in a mouse model. Further optimization of the contrast agent to enhance its durability is required.

In Situ Synthesis of Metal Nanoparticle Embedded Hybrid Soft Nanomaterials.

The allure of integrating the tunable properties of soft nanomaterials with the unique optical and electronic properties of metal nanoparticles has led to the development of organic-inorganic hybrid nanomaterials. A promising method for the synthesis of such organic-inorganic hybrid nanomaterials is afforded by the in situ generation of metal nanoparticles within a host organic template. Due to their tunable surface morphology and porosity, soft organic materials such as gels, liquid crystals, and polymers that are derived from various synthetic or natural compounds can act as templates for the synthesis of metal nanoparticles of different shapes and sizes. This method provides stabilization to the metal nanoparticles by the organic soft material and advantageously precludes the use of external reducing or capping agents in many instances. In this Account, we exemplify the green chemistry approach for synthesizing these materials, both in the choice of gelators as soft material frameworks and in the reduction mechanisms that generate the metal nanoparticles. Established herein is the core design principle centered on conceiving multifaceted amphiphilic soft materials that possess the ability to self-assemble and reduce metal ions into nanoparticles. Furthermore, these soft materials stabilize the in situ generated metal nanoparticles and retain their self-assembly ability to generate metal nanoparticle embedded homogeneous organic-inorganic hybrid materials. We discuss a remarkable example of vegetable-based drying oils as host templates for metal ions, resulting in the synthesis of novel hybrid nanomaterials. The synthesis of metal nanoparticles via polymers and self-assembled materials fabricated via cardanol (a bioorganic monomer derived from cashew nut shell liquid) are also explored in this Account. The organic-inorganic hybrid structures were characterized by several techniques such as UV-visible spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Utilization of silver nanoparticle-based hybrid nanomaterials as an antimicrobial material is another illustration of the advantage of hybrid nanomaterials. We envision that the results summarized in this Account will help the scientific community to design and develop diverse organic-inorganic hybrid materials using environmentally benign methods and that these materials will yield advanced properties that have multifaceted applications in various research fields.

Recent advances in cardanol chemistry in a nutshell: from a nut to nanomaterials.

This tutorial review could serve as an introduction of cardanol into the world of soft nanomaterials; it is a biobased lipid-mixture obtained from the plant Anacardium occidentale L. Cardanol is a renewable raw material derived from a byproduct of cashew nut processing industry: Cashew Nut Shell Liquid (CNSL). Cardanol is a rich mixture of non-isoprenoic phenolic compounds that is a valuable raw material for generating a variety of soft nanomaterials such as nanotubes, nanofibers, gels and surfactants. These nanostructures may then serve as templates for the synthesis of additional nanomaterials. The wealth and diversity of cardanol-derived functional nanomaterials has urged us to present an article that will give readers a taste of a new class of cardanol-derived functional amphiphiles, along with their ability to generate hierarchical functional nanomaterials through non-covalent soft-chemical routes. In this concise review, we discuss selected examples of novel biobased surfactants, glycolipids, and polymers derived from cardanol, and their subsequent self-assembly into functional soft materials.

Harnessing the innate immune system by revolutionizing macrophage-mediated cancer immunotherapy.

Immunotherapy is a promising and safer alternative to conventional cancer therapies. It involves adaptive T-cell therapy, cancer vaccines, monoclonal antibodies, immune checkpoint blockade (ICB), and chimeric antigen receptor (CAR) based therapies. However, most of these modalities encounter restrictions in solid tumours owing to a dense, highly hypoxic and immune-suppressive microenvironment as well as the heterogeneity of tumour antigens. The elevated intra-tumoural pressure and mutational rates within fastgrowing solid tumours present challenges in efficient drug targeting and delivery. The tumour microenvironment is a dynamic niche infiltrated by a variety of immune cells, most of which are macrophages. Since they form a part of the innate immune system, targeting macrophages has become a plausible immunotherapeutic approach. In this review, we discuss several versatile approaches (both at pre-clinical and clinical stages) such as the direct killing of tumour-associated macrophages, reprogramming pro-tumour macrophages to anti-tumour phenotypes, inhibition of macrophage recruitment into the tumour microenvironment, novel CAR macrophages, and genetically engineered macrophages that have been devised thus far. These strategies comprise a strong and adaptable macrophage-toolkit in the ongoing fight against cancer and by understanding their significance, we may unlock the full potential of these immune cells in cancer therapy.

Oxime-functionalized anti-insecticide fabric reduces insecticide exposure through dermal and nasal routes, and prevents insecticide-induced neuromuscular-dysfunction and mortality.

Farmers from South Asian countries spray insecticides without protective gear, which leads to insecticide exposure through dermal and nasal routes. Acetylcholinesterase plays a crucial role in controlling neuromuscular function. Organophosphate and carbamate insecticides inhibit acetylcholinesterase, which leads to severe neuronal/cognitive dysfunction, breathing disorders, loss of endurance, and death. To address this issue, an Oxime-fabric is developed by covalently attaching silyl-pralidoxime to the cellulose of the fabric. The Oxime-fabric, when stitched as a bodysuit and facemask, efficiently deactivates insecticides (organophosphates and carbamates) upon contact, preventing exposure. The Oxime-fabric prevents insecticide-induced neuronal damage, neuro-muscular dysfunction, and loss of endurance. Furthermore, we observe a 100% survival rate in rats when repeatedly exposed to organophosphate-insecticide through the Oxime-fabric, while no survival is seen when organophosphate-insecticide applied directly or through normal fabric. The Oxime-fabric is washable and reusable for at least 50 cycles, providing an affordable solution to prevent insecticide-induced toxicity and lethality among farmers.

Engineered cell homing.

One of the greatest challenges in cell therapy is to minimally invasively deliver a large quantity of viable cells to a tissue of interest with high engraftment efficiency. Low and inefficient homing of systemically delivered mesenchymal stem cells (MSCs), for example, is thought to be a major limitation of existing MSC-based therapeutic approaches, caused predominantly by inadequate expression of cell surface adhesion receptors. Using a platform approach that preserves the MSC phenotype and does not require genetic manipulation, we modified the surface of MSCs with a nanometer-scale polymer construct containing sialyl Lewis(x) (sLe(x)) that is found on the surface of leukocytes and mediates cell rolling within inflamed tissue. The sLe(x) engineered MSCs exhibited a robust rolling response on inflamed endothelium in vivo and homed to inflamed tissue with higher efficiency compared with native MSCs. The modular approach described herein offers a simple method to potentially target any cell type to specific tissues via the circulation.

Optimization and characterization of gastroretentive floating drug delivery system using Box-Behnken design.

CONTEXT: One among many strategies to prolong gastric residence time and improve local effect of the metronidazole in stomach to eradicate Helicobacter pylori in the treatment of peptic ulcer was floating drug delivery system particularly effervescent gastroretentive tablets. OBJECTIVE: The objective of this study was to prepare and evaluate, effervescent floating drug delivery system of a model drug, metronidazole. METHODS: Effervescent floating drug delivery tablets were prepared by wet granulation method. A three-factor, three levels Box-Behnken design was adopted for the optimization. The selected independent variables were amount of hydroxypropyl methylcellulose K 15M (X1), sodium carboxy methylcellulose (X2) and NaHCO3 (X3). The dependent variables were floating lag time (YFLT), cumulative percentage of metronidazole released at 6th h (Y6) and cumulative percentage of metronidazole released at 12th h (Y12). Physical properties, drug content, in vitro floating lag time, total floating time and drug release behavior were assessed. RESULTS: YFLT range was found to be from 1.02 to 12.07 min. The ranges of other responses, Y6 and Y12 were 25.72 ± 2.85 to 77.14 ± 3.42 % and 65.47 ± 1.25 to 99.65 ± 2.28 %, respectively. Stability studies revealed that no significant change in in vitro floating lag time, total floating time and drug release behavior before and after storage. CONCLUSION: It can be concluded that a combination of hydroxypropyl methylcellulose K 15M, sodium carboxy methylcellulose and NaHCO3 can be used to increase the gastric residence time of the dosage form to improve local effect of metronidazole.

Tracking mesenchymal stem cells with iron oxide nanoparticle loaded poly(lactide-co-glycolide) microparticles.

Monitoring the location, distribution and long-term engraftment of administered cells is critical for demonstrating the success of a cell therapy. Among available imaging-based cell tracking tools, magnetic resonance imaging (MRI) is advantageous due to its noninvasiveness, deep penetration, and high spatial resolution. While tracking cells in preclinical models via internalized MRI contrast agents (iron oxide nanoparticles, IO-NPs) is a widely used method, IO-NPs suffer from low iron content per particle, low uptake in nonphagocytotic cell types (e.g., mesenchymal stem cells, MSCs), weak negative contrast, and decreased MRI signal due to cell proliferation and cellular exocytosis. Herein, we demonstrate that internalization of IO-NP (10 nm) loaded biodegradable poly(lactide-co-glycolide) microparticles (IO/PLGA-MPs, 0.4-3 µm) in MSCs enhances MR parameters such as the r(2) relaxivity (5-fold), residence time inside the cells (3-fold) and R(2) signal (2-fold) compared to IO-NPs alone. Intriguingly, in vitro and in vivo experiments demonstrate that internalization of IO/PLGA-MPs in MSCs does not compromise inherent cell properties such as viability, proliferation, migration and their ability to home to sites of inflammation.

Niacinamide enhances cathelicidin mediated SARS-CoV-2 membrane disruption.

The continual emergence of SARS-CoV-2 variants threatens to compromise the effectiveness of worldwide vaccination programs, and highlights the need for complementary strategies for a sustainable containment plan. An effective approach is to mobilize the body's own antimicrobial peptides (AMPs), to combat SARS-CoV-2 infection and propagation. We have found that human cathelicidin (LL37), an AMP found at epithelial barriers as well as in various bodily fluids, has the capacity to neutralise multiple strains of SARS-CoV-2. Biophysical and computational studies indicate that LL37's mechanism of action is through the disruption of the viral membrane. This antiviral activity of LL37 is enhanced by the hydrotropic action of niacinamide, which may increase the bioavailability of the AMP. Interestingly, we observed an inverse correlation between LL37 levels and disease severity of COVID-19 positive patients, suggesting enhancement of AMP response as a potential therapeutic avenue to mitigate disease severity. The combination of niacinamide and LL37 is a potent antiviral formulation that targets viral membranes of various variants and can be an effective strategy to overcome vaccine escape.

Flow Cytometry Analysis of Planarian Stem Cells Using DNA and Mitochondrial Dyes.

Planarians are free-living flatworms that emerged as a crucial model system to understand regeneration and stem cell biology. The ability to purify neoblasts, the adult stem cell population of planaria, through fluorescence-activated cell sorting (FACS) has tremendously increased our understanding of pluripotency, specialization, and heterogeneity. To date, the FACS-based purification methods for neoblasts relied on nuclear dyes that discriminate proliferating cells (>2N), as neoblasts are the only dividing somatic cells. However, this method does not distinguish the functional states within the neoblast population. Our work has shown that among the neoblasts, the pluripotent stem cells (PSCs) are associated with low mitochondrial content and this property could be leveraged for purification of the PSC-enriched population. Using the mitochondrial dye MitoTracker Green (MTG) and the nuclear dye SiR-DNA, we have described a method for isolation of PSCs that are viable and compatible with downstream experiments, such as transplantation and cell culture. In this protocol, we provide a detailed description for sample preparation and FACS gating for neoblast isolation in planaria.

Microscale engineering of hollow microneedle tips: design, manufacturing, optimization and validation.

Transdermal and intradermal drug delivery utilizing microneedles is an emerging front in painless therapeutics. Drug delivery using hollow microneedles is the most preferred method for delivering generic transdermal drugs in the clinical setup. The needle tip must be extremely short as the drug is administered to sub-millimeter depths. Also, they need to be sharp enough to pierce through the skin with minimal skin flexing. There are multiple challenges in engineering a tip profile that is short and sharp at the same time. Stainless steel (SS) hypodermic needles with the lancet tip profile are ubiquitous in subcutaneous and intramuscular injections. They have long bevel lengths that make them inappropriate as microneedles. Thus, designing a unique tip profile and developing the manufacturing technology for microneedle applications are necessary. This article presents the design and optimization of microneedle tip profiles through analytical models. Further, manufacturing strategies for reliably obtaining designed profiles are discussed. The article concludes with experimental validation of improved piercing performance of the optimized tip profile compared to other tip profiles. The article discusses about tip geometries of stainless steel needles for microneedle applications, where depth of delivery is less than 1 mm. Through series of analyses, the optimum needle tip geometry evolved from single plane bevel (SPB) to hex plane bevel (HPB) progressively improving piercing performance.

Intermittent scavenging of storage lesion from stored red blood cells by electrospun nanofibrous sheets enhances their quality and shelf-life.

Transfusion of healthy red blood cells (RBCs) is a lifesaving process. However, upon storing RBCs, a wide range of damage-associate molecular patterns (DAMPs), such as cell-free DNA, nucleosomes, free-hemoglobin, and poly-unsaturated-fatty-acids are generated. DAMPs can further damage RBCs; thus, the quality of stored RBCs declines during the storage and limits their shelf-life. Since these DAMPs consist of either positive or negative charged species, we developed taurine and acridine containing electrospun-nanofibrous-sheets (Tau-AcrNFS), featuring anionic, cationic charges and an DNA intercalating group on their surfaces. We show that Tau-AcrNFS are efficient in scavenging DAMPs from stored human and mice RBCs ex vivo. We find that intermittent scavenging of DAMPs by Tau-AcrNFS during the storage reduces the loss of RBC membrane integrity and reduces discocytes-to-spheroechinocytes transformation in stored-old-RBCs. We perform RBC-transfusion studies in mice to reveal that intermittent removal of DAMPs enhances the quality of stored-old-RBCs equivalent to freshly collected RBCs, and increases their shelf-life by ~22%. Such prophylactic technology may lead to the development of novel blood bags or medical device, and may therefore impact healthcare by reducing transfusion-related adverse effects.

Skin-Permeable Nano-Lithocholic Lipidoid Efficiently Alleviates Psoriasis-like Chronic Skin Inflammations.

Long-term application of topical therapeutics for psoriasis has a plethora of side effects. Additionally, skin-permeating agents used in their formulations for deeper dermal delivery damage the skin. To address these limitations, we developed novel lithocholic acid analogues that could form lipid nanoparticles (nano-LCs) spontaneously in the aqueous milieu, permeate through the skin, penetrate the deeper dermal layers, and exert anti-inflammatory effects against psoriasis-like chronic skin inflammations. Prior findings demonstrated that lithocholic acid acts as a vitamin D receptor agonist without affecting the Ca+2 metabolism and also as an antagonist for ephrin type-A receptor 2 (EphA2). Taking cues from the previous findings, lithocholic acid derivatives with twin alkyl chains (LC6, LC8, LC10, and LC-12) were synthesized, nanoparticles (nano-LCs) were prepared, and they were evaluated for their skin permeability and anti-inflammatory properties. Among these nano-LCs, nano-LC10 demonstrated superior anti-inflammatory properties and inhibition of keratinocyte proliferation in various cell-based evaluations. Furthermore, the therapeutic efficiency of nano-LC10 was evaluated in an imiquimod-induced psoriasis-like mouse model and demonstrated comparable efficiency with the standard topical formulation, Sorvate, in reducing skin inflammations. Nano-LC10 also reduced systemic inflammation, organ toxicity, and also proinflammatory serum cytokine levels. Overall, nano-lithocholic lipidoid (nano-LC10) can be a potential novel class of therapeutics for topical application in treating psoriasis.

Microbial metabolite restricts 5-fluorouracil-resistant colonic tumor progression by sensitizing drug transporters via regulation of FOXO3-FOXM1 axis.

The survival rate of colorectal cancer patients is adversely affected by the selection of tumors resistant to conventional anti-cancer drugs such as 5-fluorouracil (5FU). Although there is mounting evidence that commensal gut microbiota is essential for effective colon cancer treatment, the detailed molecular mechanisms and the role of gut microbial metabolites remain elusive. The goal of this study is to decipher the impact and mechanisms of gut microbial metabolite, urolithin A (UroA) and its structural analogue, UAS03 on reversal of 5FU-resistant (5FUR) colon cancers. Methods: We have utilized the SW480 and HCT-116 parental (5FU-sensitive) and 5FUR colon cancer cells to examine the chemosensitization effects of UroA or UAS03 by using both in vitro and in vivo models. The effects of mono (UroA/UAS03/5FU) and combinatorial therapy (UroA/UAS03 + 5FU) on cell proliferation, apoptosis, cell migration and invasion, regulation of epithelial mesenchymal transition (EMT) mediators, expression and activities of drug transporters, and their regulatory transcription factors were examined using molecular, cellular, immunological and flowcytometric methods. Further, the anti-tumor effects of mono/combination therapy (UroA or UAS03 or 5FU or UroA/UAS03 + 5FU) were examined using pre-clinical models of 5FUR-tumor xenografts in NRGS mice and azoxymethane (AOM)-dextran sodium sulfate (DSS)-induced colon tumors. Results: Our data showed that UroA or UAS03 in combination with 5FU significantly inhibited cell viability, proliferation, invasiveness as well as induced apoptosis of the 5FUR colon cancer cells compared to mono treatments. Mechanistically, UroA or UAS03 chemosensitized the 5FUR cancer cells by downregulating the expression and activities of drug transporters (MDR1, BCRP, MRP2 and MRP7) leading to a decrease in the efflux of 5FU. Further, our data suggested the UroA or UAS03 chemosensitized 5FUR cancer cells to 5FU treatment through regulating FOXO3-FOXM1 axis. Oral treatment with UroA or UAS03 in combination with low dose i.p. 5FU significantly reduced the growth of 5FUR-tumor xenografts in NRGS mice. Further, combination therapy significantly abrogated colonic tumors in AOM-DSS-induced colon tumors in mice. Conclusions: In summary, gut microbial metabolite UroA and its structural analogue UAS03 chemosensitized the 5FUR colon cancers for effective 5FU chemotherapy. This study provided the novel characteristics of gut microbial metabolites to have significant translational implications in drug-resistant cancer therapeutics.

Immobilized contrast-enhanced MRI: Gadolinium-based long-term MR contrast enhancement of the vein graft vessel wall.

An implantable MR contrast agent that can be covalently immobilized on tissue during surgery has been developed. The rationale is that a durable increase in tissue contrast using an implantable contrast agent can enhance postsurgical tissue differentiation using MRI. For small-vessel (e.g., vein graft) MRI, the direct benefit of such permanent "labeling" of the vessel wall by modification of its relaxation properties is to achieve more efficient imaging. This efficiency can be realized as either increased contrast leading to more accurate delineation of vessel wall and lesion tissue boundaries, or, faster imaging without penalizing contrast-to-noise ratio, or a combination thereof. We demonstrate, for the first time, stable long-term MRI enhancement using such an exogenous contrast mechanism based on immobilizing a modified diethylenetriaminepentaacetic acid gadolinium(3+) dihydrogen complex on a human vein using a covalent amide bond. Signal enhancement due to the covalently immobilized contrast agent is demonstrated for excised human vein specimens imaged at 3 T, and its long-term stability is demonstrated during a 4-month incubation period.