Effects of Puffing, Acid, and High Hydrostatic Pressure Treatments on Ginsenoside Profile and Antioxidant Capacity of Mountain-Cultivated Panax ginseng.

The purpose of this study was to investigate the effects of puffing, acid, and high hydrostatic pressure (HHP) treatments on the ginsenoside profile and antioxidant capacity of mountain-cultivated Panax ginseng (MCPG) before and after treatments. Puffing and HHP treatments decreased extraction yield and increased crude saponin content. The combination of puffing and HHP treatment showed significantly higher crude saponin content than each single treatment. Puffing treatment showed the highest ginsenoside conversion compared with HHP and acid treatments. Significant ginsenoside conversion was not observed in HHP treatment but was in acid treatment. When the puffing and acid treatments were combined, Rg3 and compound K content (1.31 mg and 10.25 mg) was significantly higher than that of the control (0.13 mg and 0.16 mg) and acid treatment (0.27 mg and 0.76 mg). No synergistic effect was observed between acid and HHP treatments. In the case of functional properties, the puffing treatment showed a significant increase in TFC (29.6%), TPC (1072%), and DPPH radical scavenging capacity (2132.9%) compared to the control, while acid and HHP combined treatments did not significantly increase; therefore, the synergistic effects of HHP/puffing and acid/puffing treatments were observed in crude saponin content and ginsenoside conversion, respectively. Consequently, puffing combined with acid or HHP treatments may provide new ways to produce high-value-added MCPG with a higher content of Rg3 and compound K or crude saponin compared to untreated MCPG.

Circulating Small Extracellular Vesicles Activate TYRO3 to Drive Cancer Metastasis and Chemoresistance.

Extracellular vesicles (EV) in the tumor microenvironment have emerged as crucial mediators that promote proliferation, metastasis, and chemoresistance. However, the role of circulating small EVs (csEV) in cancer progression remains poorly understood. In this study, we report that csEV facilitate cancer progression and determine its molecular mechanism. csEVs strongly promoted the migration of cancer cells via interaction with phosphatidylserine of csEVs. Among the three TAM receptors, TYRO3, AXL, and MerTK, TYRO3 mainly interacted with csEVs. csEV-mediated TYRO3 activation promoted migration and metastasis via the epithelial-mesenchymal transition and stimulation of RhoA in invasive cancer cells. Additionally, csEV-TYRO3 interaction induced YAP activation, which led to increased cell proliferation and chemoresistance. Combination treatment with gefitinib and KRCT-6j, a selective TYRO3 inhibitor, significantly reduced tumor volume in xenografts implanted with gefitinib-resistant non-small cell lung cancer cells. The results of this study show that TYRO3 activation by csEVs facilitates cancer cell migration and chemoresistance by activation of RhoA or YAP, indicating that the csEV/TYRO3 interaction may serve as a potential therapeutic target for aggressive cancers in the clinic. SIGNIFICANCE: These findings demonstrate that circulating extracellular vesicles are a novel driver in migration and survival of aggressive cancer cells via TYRO3 activation. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/13/3539/F1.large.jpg.

Enhanced Antioxidant Capacity of Puffed Turmeric (Curcuma longa L.) by High Hydrostatic Pressure Extraction (HHPE) of Bioactive Compounds.

Turmeric (Curcuma longa L.) is known for its health benefits. Several previous studies revealed that curcumin, the main active compound in turmeric, has antioxidant capacity. It has been previously demonstrated that puffing, the physical processing using high heat and pressure, of turmeric increases the antioxidant and anti-inflammatory activities by increasing phenolic compounds in the extract. The current study sought to determine if high hydrostatic pressure extraction (HHPE), a non-thermal extraction at over 100 MPa, aids in the chemical changes and antioxidant functioning of turmeric. 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) analyses were conducted and assessed the content of total phenol compounds in the extract. The chemical changes of curcuminoids were also determined by high performance liquid chromatography (HPLC). Among the three variables of ethanol concentration, pressure level, and treatment time, ethanol concentration was the most influential factor for the HHPE of turmeric. HHPE at 400 MPa for 20 min with 70% EtOH was the optimal extraction condition for the highest antioxidant activity. Compositional analysis revealed that 2-methoxy-4-vinylphenol was produced by puffing. Vanillic acid and ferulic acid content increased with increasing HHPE time. Synergistic effect was not observed on antioxidant activity when the turmeric was sequentially processed using puffing and HHPE.

Puffing of Turmeric (Curcuma longa L.) Enhances its Anti-Inflammatory Effects by Upregulating Macrophage Oxidative Phosphorylation.

Turmeric (Curcuma longa L.), a widely used spice, has anti-inflammatory properties and other health benefits, but the detailed mechanisms of these effects are still poorly understood. Recent advances in assessment of cellular energy metabolism have revealed that macrophage mitochondrial respiration is critical in inflammatory responses. In an effort to enhance the anti-inflammatory function of turmeric with a simple processing method, extract of puffed turmeric was investigated for effect on macrophage energy metabolism. The high-performance liquid chromatography analysis revealed that puffing of turmeric significantly induced the degradation of curcumin to smaller active compounds including vanillic acid, vanillin and 4-vinylguaiacol. The in vitro consumption of oxygen as expressed by the oxygen consumption rate (OCR) was significantly downregulated following lipopolysaccharides stimulation in RAW 264.7 macrophages. Puffed turmeric extract, but not the non-puffed control, reversed the LPS-induced decrease in OCR, resulting in downregulated transcription of the pro-inflammatory genes cyclooxygenase-2 and inducible nitric oxide synthase. Dietary intervention in high-fat diet-induced obese mice revealed that both control and puffed turmeric have anti-obesity effects in vivo, but only puffed turmeric exhibited reciprocal downregulation of the inflammatory marker cluster of differentiation (CD)11c and upregulation of the anti-inflammatory marker CD206 in bone marrow-derived macrophages. Puffed turmeric extract further modulated the low-density lipoprotein/high-density lipoprotein cholesterol ratio toward that of the normal diet group, indicating that puffing is a simple, advantageous processing method for turmeric as an anti-inflammatory food ingredient.

Assessment of clinical performance of an ultrasensitive nanowire assay for detecting human papillomavirus DNA in urine.

OBJECTIVE: To evaluate whether HPV DNA in urine has potential advantages as an alternative biomarker for HPV-based cervical cancer screening. METHODS: Among patients with Cobas HPV test results, a total of 67 HPV-positive (n = 42) and -negative (n = 25) women who agreed to participate in this study were willing to provide paired cervical and urine samples, and we observed concordance between sample types from each patient in identifying HPV genotypes using the nanowire assay. RESULTS: We detected high-risk strains of HPV DNA in unprocessed urine specimens using polyethyleneimine-conjugated nanowires (PEI-NWs). Concordance for high-risk HPV (hrHPV) between paired urine and cervical samples was 90.4% (κ = 0.90; 95% CI: 0.80-100.00). The virological sensitivity and specificity for detection of HPV DNA from a small urine sample (200 µL) were 81.3% (κ = 0.83; 95% CI: 62.1-100.0) and 98.0% (κ = 0.83; 95% CI: 94.2-100.0) for HPV16 group, 100.0% (κ = 0.65; 95% CI: 100.0-100.0) and 95.3% (κ = 0.65; 95% CI: 90.1-100.0) for HPV18 group, and 96.4% (κ = 0.97; 95% CI: 89.6-100.0) and 100.0% (κ = 0.97; 95% CI: 100.0-100.0) for other hrHPV group, respectively. CONCLUSIONS: The nanowire assay demonstrated excellent ability to identify HPV DNA from urine specimens. We observed an excellent agreement in the detection of high-risk HPV between paired urine and cervical samples, even with small urine sample volume.

Enhancement of Minor Ginsenosides Contents and Antioxidant Capacity of American and Canadian Ginsengs (Panax quinquefolius) by Puffing.

The effects of puffing on ginsenosides content and antioxidant activities of American and Canadian ginsengs, Panax quinquefolius, were investigated. American and Canadian ginsengs puffed at different pressures were extracted using 70% ethanol. Puffing formed a porous structure, inducing the efficient elution of internal compounds that resulted in significant increases in extraction yields and crude saponin content. The content of minor ginsenosides (Rg2, Rg3, compound K) increased with increasing puffing pressure, whereas that of major ginsenosides (Rg1, Re, Rf, Rb1, Rc, Rd) decreased, possibly due to their deglycosylation and pyrolysis. Furthermore, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity, total phenolic content, total flavonoid content, amount of Maillard reaction products, and acidic polysaccharides content increased with increasing puffing pressure, but 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity did not. There was no substantial difference in the results between puffed American and Canadian ginsengs. Consequently, these results suggest that puffing can be a promising novel technology for processing P. quinquefolius to achieve higher levels of minor ginsenosides and obtain value-added products.

Puffing as a Novel Process to Enhance the Antioxidant and Anti-Inflammatory Properties of Curcuma longa L. (Turmeric).

Curcuma longa L. (turmeric) is used as a food spice; however, its strong taste restricts wider applications as a food ingredient despite its well-known health benefits. To develop an effective yet simple process for enhancing its antioxidant and anti-inflammatory activities, turmeric was gun-puffed at various pressures. Puffed turmeric exhibited an increase in its brown color and porous structures, indicating the occurrence of the Maillard reaction and vaporization during the process. Proximal analysis revealed that puffing did not alter the major constituents, although a very small decrease in crude fat extraction was observed under some circumstances. Total phenolic compounds in the extract were significantly increased after puffing, and subsequent assessment of antioxidant capacity, as determined using independent 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays, demonstrated enhanced antioxidant capacity in a puffing-pressure-dependent manner. Turmeric extract was further tested for the regulation of inflammatory responses in the murine macrophage RAW264.7 cell line. Suppression of pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α in lipopolysaccharides (LPS)-induced macrophages was amplified using puffed-turmeric extracts compared to the control extract. Furthermore, macrophage-activation assessment revealed downregulated expression of inflammation-relevant cluster of differentiation (CD)80 and CD86 using puffed-turmeric extract in a puffing-pressure-dependent manner. However, expression of major histocompatibility complex (MHC)-II, which controls adoptive immunity, was not affected by treatment with any of the turmeric extracts. Overall, the current study demonstrated that puffing is a promising and simple method for enhancing the antioxidant and anti-inflammatory properties of turmeric.

Change of Ginsenoside Profiles in Processed Ginseng by Drying, Steaming, and Puffing.

Korean ginseng (Panax ginseng Meyer) was processed by drying, steaming, or puffing, and the effects of these processes on the ginsenoside profile were investigated. The main root of 4-year-old raw Korean ginseng was dried to produce white ginseng. Steaming, followed by drying, was employed to produce red or black ginseng. In addition, these three varieties of processed ginseng were puffed using a rotational puffing gun. Puffed ginseng showed significantly higher extraction yields of ginsenosides (49.87-58.60 g solid extract/100 g of sample) and crude saponin content (59.40-63.87 mg saponin/g of dried ginseng) than nonpuffed ginseng, respectively. Moreover, puffing effectively transformed the major ginsenosides (Rb1, Rb2, Rc, Rd, Re, and Rg1) of ginseng into minor ones (F2, Rg3, Rk1, and Rg5), comparable to the steaming process effect on the levels of the transformed ginsenosides. However, steaming takes much longer (4 to 36 days) than puffing (less than 30 min) for ginsenoside transformation. Consequently, puffing may be an effective and economical technique for enhancing the extraction yield and levels of minor ginsenosides responsible for the major biological activities of ginseng.

Direct isolation and characterization of circulating exosomes from biological samples using magnetic nanowires.

BACKGROUND: Tumor-derived exosomes are gaining attention as important factors that facilitate communication between neighboring cells and manipulate cellular processes associated with cancer development or progression. The conventional techniques for the isolation and detection of exosomes face several limitations, restricting their clinical applications. Hence, a highly efficient technique for the isolation and identification of exosomes from biological samples may provide critical information about exosomes as biomarkers and improve our understanding of their unique role in cancer research. Here, we describe the use of antibody cocktail-conjugated magnetic nanowires to isolate exosomes from plasma of breast and lung cancer patients. METHODS: The isolated exosomes were characterized based on size and concentration using nanoparticle tracking analysis. Levels of exosomal proteins were measured by bicinchoninic acid assay and enzyme-linked immunosorbent assay. Morphology was visualized by transmission electron microscopy. Immunoblotting (Western blotting) was used to detect the presence of exosomal markers. RESULTS: The use of antibody cocktail-conjugated magnetic nanowires resulted in approximately threefold greater yield when compared to the conventional methods. The elongated feature of nanowires significantly improved the efficiency of exosome isolation, suggesting its potential to be translated in diverse clinical applications, including cancer diagnosis and treatment. CONCLUSIONS: The nanowire-based method allows rapid isolation of homogeneous population of exosomes with relatively high yield and purity from even small amounts of sample. These results suggest that this method has the potential for clinical applications requiring highly purified exosomes for the analysis of protein, lipid, mRNA, and miRNA.

Immune-Enhancement and Anti-Inflammatory Activities of Fatty Acids Extracted from Halocynthia aurantium Tunic in RAW264.7 Cells.

Halocynthia aurantium, an edible ascidian species, has not been studied scientifically, even though tunicates and ascidians are well-known to contain several unique and biologically active materials. The current study investigated the fatty acid profiles of the H. aurantium tunic and its immune-regulatory effects on RAW264.7 macrophage cells. Results of the fatty acid profile analysis showed a difference in ratios, depending on the fatty acids being analysed, including those of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA). In particular, omega-3 fatty acids, such as eicosatrienoic acid n-3 (ETA n-3), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), were much higher than omega-6 fatty acids. Moreover, the H. aurantium tunic fatty acids, significantly and dose-dependently, increased the NO and prostaglandin E2 (PGE2) production in RAW264.7 cells, for immune-enhancement without cytotoxicity. In addition, these fatty acids regulated the transcription of immune-associated genes, including iNOS, IL-1ß, IL-6, COX-2, and TNF-α. These actions were activated and deactivated via Mitogen-activated protein kinase (MAPK)and NF-κB signaling, to regulate the immune responses. Conversely, the H. aurantium tunic fatty acids effectively suppressed the inflammatory cytokine expressions, including iNOS, IL-1ß, IL-6, COX-2, and TNF-α, in LPS-stimulated RAW264.7 cells. Productions of COX-2 and PGE2, which are key biomarkers for inflammation, were also significantly reduced. These results elucidated the immune-enhancement and anti-inflammatory mechanisms of the H. aurantium tunic fatty acids in macrophage cells. Moreover, the H. aurantium tunic might be a potential fatty acid source for immune-modulation.

A Versatile Nanowire Platform for Highly Efficient Isolation and Direct PCR-free Colorimetric Detection of Human Papillomavirus DNA from Unprocessed Urine.

Purpose: As human papillomavirus (HPV) is primarily responsible for the development of cervical cancer, significant efforts have been devoted to develop novel strategies for detecting and identifying HPV DNA in urine. The analysis of target DNA sequences in urine offers a potential alternative to conventional methods as a non-invasive clinical screening and diagnostic assessment tool for the detection of HPV. However, the lack of efficient approaches to isolate and directly detect HPV DNA in urine has restricted its potential clinical use. In this study, we demonstrated a novel approach of using polyethylenimine-conjugated magnetic polypyrrole nanowires (PEI-mPpy NWs) for the extraction, identification, and PCR-free colorimetric detection of high-risk strains of HPV DNA sequences, particularly HPV-16 and HPV-18, in urine specimens of cervical cancer patients. Materials and Methods: We fabricated and characterized polyethylenimine-conjugated magnetic nanowires (PEI/mPpy NWs). PEI/mPpy NWs-based HPV DNA isolation and detection strategy appears to be a cost-effective and practical technology with greater sensitivity and accuracy than other urine-based methods. Results: The analytical and clinical performance of PEI-mPpy NWs was evaluated and compared with those of cervical swabs, demonstrating a superior type-specific concordance rate of 100% between urine and cervical swabs, even when using a small volume of urine (300 µL). Conclusion: We envision that PEI-mPpy NWs provide substantive evidence for clinical diagnosis and management of HPV-associated disease with their excellent performance in the recovery and detection of HPV DNA from minimal amounts of urine samples.

Magnetic Nanowire Networks for Dual-Isolation and Detection of Tumor-Associated Circulating Biomarkers.

Purpose: Recent developments in genomic and molecular methods have revolutionized the range of utilities of tumor-associated circulating biomarkers in both basic and clinical research. Herein, we present a novel approach for ultrasensitive extraction of cfDNA and CTCs, at high yield and purity, via the formation of magnetic nanowire networks. Materials and Methods: We fabricated and characterized biotinylated cationic polyethylenimine and biotinylated antibody cocktail-conjugated magnetic polypyrrole NWs (PEI/mPpy NW and Ab cocktail/mPpy NW, respectively). We applied these NWs to the extraction of cfDNA and CTC from the blood of 14 patients with lung cancer. We demonstrated reliable detection of EGFR mutations based on digital droplet PCR analysis of cfDNA and CTC DNA from patients with lung cancer. Results: The NW networks confined with a high density of magnetic nanoparticles exhibited superior saturation magnetization, which enabled rapid and high-yield capture whilst avoiding or minimizing damage and loss. The NW networks enabled the co-isolation of CTCs and cfDNA of high quality and sufficient quantities, thus allowing the amplification of rare and low-prevalence cancer-related mutations. Conclusion: The simple, versatile, and highly efficient nanowire network tool allows sensitive and robust assessment of clinical samples.

Immune Enhancement Effect of Asterias amurensis Fatty Acids through NF-κB and MAPK Pathways on RAW 264.7 Cells.

Asterias amurensis is a marine organism that causes damage to the fishing industry worldwide; however, it has been considered a promising source of functional components. The present study aimed to investigate the immune-enhancing effects of fatty acids from three organs of A. amurensis on murine macrophages (RAW 264.7 cells). A. amurensis fatty acids boosted production of immune-associated factors such as nitric oxide (NO) and prostaglandin E2 in RAW 264.7 cells. A. amurensis fatty acids also enhanced the expression of critical immune-associated genes, including iNOS, TNF-α, IL-1ß, and IL-6, as well as COX-2. Western blotting showed that A. amurensis fatty acids stimulated the NF-κB and MAPK pathways by phosphorylation of NF-κB p-65, p38, ERK1/2, and JNK. A. amurensis fatty acids from different tissues resulted in different levels of NF-κB and MAPK phosphorylation in RAW 264.7 cells. The results increase our understanding of how A. amurensis fatty acids boost immunity in a physiological system, as a potential functional material.

A Novel Multifunctional Nanowire Platform for Highly Efficient Isolation and Analysis of Circulating Tumor-Specific Markers.

Circulating tumor-specific markers are crucial to understand the molecular and cellular processes underlying cancer, and to develop therapeutic strategies for the treatment of the disease in clinical applications. Many approaches to isolate and analyze these markers have been reported. Here, we propose a straightforward method for highly efficient capture and release of exosomes and circulating tumor cells (CTCs) in a single platform with well-ordered three-dimensional (3D) architecture that is constructed using a simple electrochemical method. Conductive polypyrrole nanowires (Ppy NWs) are conjugated with monoclonal antibodies that specifically recognize marker proteins on the surface of exosomes or CTCs. In response to electrical- or glutathione (GSH)-mediated stimulation, the captured exosomes or cells can be finely controlled for retrieval from the NW platform. A surface having nano-topographic structures allows the specific recognition and capture of small-sized exosome-like vesicles (30-100 nm) by promoting topographical interactions, while physically blocking larger vesicles (i.e., microvesicles, 100-1,000 nm). In addition, vertically aligned features greatly improve cell capture efficiency after modification with desired high-binding affinity biomolecules. Notably, exosomes and CTCs can be sequentially isolated from cancer patients' blood samples using a single NW platform via modulating electrochemical and chemical cues, which clearly exhibits great potential for the diagnosis of various cancer types and for downstream analysis due to its facile, effective, and low-cost performance.

Magnetic nanowires for rapid and ultrasensitive isolation of DNA from cervical specimens for the detection of multiple human papillomaviruses genotypes.

Detecting human papillomavirus (HPV) is central in diagnosing and monitoring HPV-related disease. However, limited sensitivity and the wide variability of the HPV genome pose challenges in the identification of HPV genes, particularly high-risk types. This study reports the development of polyethyleneimine-conjugated magnetic nanowires (PEI-MNWs) and their use in the isolation, identification, and analysis of multiple genotypes of HPV DNA from cervical cancer specimens. The nanowires are electrochemically doped with a high density of magnetic nanoparticles and biotin moieties during potentiostatic deposition, thereby allowing conjugating cationic branched polymers to direct the attachment of negatively charged DNA molecules with strong magnetic response. For proof of concept, the rapid and ultrasensitive isolation of HPV DNA is performed at concentrations as low as 10pg/mL with an efficiency of >95%. For clinical optimization, the analytical and clinical sensitivity of PEI-MNWs is compared with that of the Roche Cobas 4800 HPV Test and demonstrates excellent correlation for multiple HPV DNA genotypes with superior threshold cycle values. The high sensitivity, specificity, and good reproducibility of PEI-MNWs are particularly well suited for the recovery of DNA and provide significant and clinically meaningful evidence for the early detection and treatment of HPV-associated cancers.

A novel strategy for highly efficient isolation and analysis of circulating tumor-specific cell-free DNA from lung cancer patients using a reusable conducting polymer nanostructure.

We have developed a reusable nanostructured polypyrrole nanochip and demonstrated its use in the electric field-mediated recovery of circulating cell-free DNA (cfDNA) from the plasma of lung cancer patients. Although cfDNA has been recognized and widely studied as a versatile and promising biomarker for the diagnosis and prognosis of cancers, the lack of efficient strategies to directly isolate cfDNA from the plasma has become a great hindrance to its potential clinical use. As a proof-of-concept study, we demonstrated a technique for the rapid and efficient isolation of cfDNA with high yield and purity. In particular, the synergistic effects of the electro-activity and the nanostructured features of the polypyrrole polymer enabled repeated retrieval of cfDNA using a single platform. Moreover, polypyrrole nanochip facilitated the amplification of tumor-specific DNA fragments from the plasma samples of patients with lung cancer characterized by mutations in exons 21 of the epidermal growth factor receptor gene (EGFR). Overall, the proposed polypyrrole nanochip has enormous potential for industrial and clinical applications with significantly enhanced efficiency in the recovery of tumor-associated circulating cfDNA. This may ultimately contribute to more robust and reliable evaluation of gene mutations in peripheral blood.

Efficient Capture and Isolation of Tumor-Related Circulating Cell-Free DNA from Cancer Patients Using Electroactive Conducting Polymer Nanowire Platforms.

Circulating cell-free DNA (cfDNA) is currently recognized as a key non-invasive biomarker for cancer diagnosis and progression and therapeutic efficacy monitoring. Because cfDNA has been detected in patients with diverse types of cancers, the use of efficient strategies to isolate cfDNA not only provides valuable insights into tumour biology, but also offers the potential for developing new cancer-specific targets. However, the challenges associated with conventional cfDNA extraction methods prevent their further clinical applications. Here, we developed a nanostructured conductive polymer platform for the efficient capture and release of circulating cfDNA and demonstrated its potential clinical utility using unprocessed plasma samples from patients with breast and lung cancers. Our results confirmed that the platform's enhanced efficiency allows tumor-specific circulating cfDNA to be recovered at high yield and purity.

Fatty Acid Desaturases, Polyunsaturated Fatty Acid Regulation, and Biotechnological Advances.

Polyunsaturated fatty acids (PUFAs) are considered to be critical nutrients to regulate human health and development, and numerous fatty acid desaturases play key roles in synthesizing PUFAs. Given the lack of delta-12 and -15 desaturases and the low levels of conversion to PUFAs, humans must consume some omega-3 and omega-6 fatty acids in their diet. Many studies on fatty acid desaturases as well as PUFAs have shown that fatty acid desaturase genes are closely related to different human physiological conditions. Since the first front-end desaturases from cyanobacteria were cloned, numerous desaturase genes have been identified and animals and plants have been genetically engineered to produce PUFAs such as eicosapentaenoic acid and docosahexaenoic acid. Recently, a biotechnological approach has been used to develop clinical treatments for human physiological conditions, including cancers and neurogenetic disorders. Thus, understanding the functions and regulation of PUFAs associated with human health and development by using biotechnology may facilitate the engineering of more advanced PUFA production and provide new insights into the complexity of fatty acid metabolism.

Antimicrobial activity of solvent fractions and bacterial isolates of Korean domestic honey from different floral sources.

Forty solvent fractions and 387 bacterial isolates of seven varieties of Korean domestic honey and manuka honey from New Zealand were screened for antimicrobial activity. The minimum inhibitory concentrations and minimum bactericidal concentrations of the honey fractions were determined; only Bacillus cereus ATCC 14579, ATCC 11778, and F4552 were inhibited by 11, 1, and 16, respectively, out of the 40 honey fractions. The bacterial isolates showed the highest incidence (30.2%) of antimicrobial activity against Listeria monocytogenes ATCC 15313. The growth of at least one of the five foodborne pathogens tested was inhibited by 109 of the 327 isolates (33.3%) from seven types of Korean domestic honey. The percentage of such isolates of manuka honey was significantly higher (76.7%). Solvent fractionation of honey could contribute to the detection of antimicrobial activity of the nonsugar compounds in honey. Moreover, the bacterial isolates from Korean domestic honey may be good sources for the natural antimicrobials used in the food industry and other related industries.

An Innovative Strategy for the Fabrication of Functional Cell Sheets Using an Electroactive Conducting Polymer.

Here, we report the development of an electric field-assisted methodology for constructing 3D C2C12 cell sheets with the potential for cell surface modification. In this method, a conducting polymer, polypyrrole (Ppy), is electrodeposited via biotin doping, and then chemical conjugation of biotinylated bone morphogenetic protein 2 (BMP2) is achieved using a biotin-streptavidin cross-linker. Subsequently, C2C12 cells are cultured on BMP2-immobilized Ppy surfaces to induce interactions between cell surface receptors and bound BMP2 ligands. Following these procedures, layers of BMP2-immobilized cells can be easily detached from the Ppy surface by applying an electrical potential. This novel method results in high affinity, ligand-bound cell sheets, which exhibit homogeneous coverage with membrane-bound proteins and signal activation that occurs via maximal receptor accessibility. Using this strategy to engineer the cell surface with desirable ligands results in structures that mimic in vivo tissues; thus, the method reported here has potential applications in regenerative medicine and tissue engineering.