Multi-synergetic ZnO platform for high performance cancer therapy

Tripathy, Nirmalya,Ahmad, Rafiq,Ah Ko, Hyun,Khang, Gilson,Hahn, Yoon-Bong The Royal Society of Chemistry 2015 Chemical communications Vol.51 No.13

<P>ZnO platforms were evaluated for designing a high-performance anticancer drug (daunorubicin) carrier. Hollow structured ZnO, compared with nanorods, acts as a multi-purpose entity by serving as smart carriers and exhibiting synergetic photodynamic cytotoxic effects, which are ascribed to their high-specific surface area, hollow interior, pH-responsiveness and inherent photodynamism.</P> <P>Graphic Abstract</P><P>Hollow structured ZnO with high-performance drug-encapsulation for acid-triggered, chemo-photodynamic cancer therapy. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4cc10037a'> </P>

Time-Dependent Controlof Hole-Opening Degree of Porous ZnO Hollow Microspheres

Tripathy, Nirmalya,Ahmad, Rafiq,Jeong, Han-Sol,Hahn, Yoon-Bong American ChemicalSociety 2012 Inorganic Chemistry Vol.51 No.2

<P>Well-designed, monodispersed porous ZnO hollow microsphereswithcontrolled hole-opening were successfully synthesized by a faciletwo-step solution route at low temperature. The hollow microsphereshaving average diameter of 3–4 μm showed time-dependenthole-opening, i.e. 4–100% for 15–75 min. The hole-openingpercentage increases linearly with time until complete opening. TheZnO hollow microspheres also exhibited a high surface area (34 m<SUP>2</SUP> g<SUP>–1</SUP>), a large pore volume (0.19 cm<SUP>3</SUP> g<SUP>–1</SUP>) and an average pore diameter of 3.8nm. A plausible growth mechanism for the formation of ZnO hollow microsphereswas also proposed.</P><P>Well-designed, monodispersed porous ZnOhollow microsphereswith controlled hole-opening were synthesized by a facile low temperature,two-step solution route. The hollow microspheres having average diameterof 3−4 μm showed time-dependent hole-opening. The hole-openingpercentage increases linearly with time until complete opening. TheZnO hollow microspheres also exhibited high surface area, large porevolume and average pore diameter of 3.8 nm. A plausible growth mechanismfor the formation of ZnO hollow microspheres was also proposed.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/inocaj/2012/inocaj.2012.51.issue-2/ic2022598/production/images/medium/ic-2011-022598_0005.gif'></P>

Enhanced anticancer potency using an acid-responsive ZnO-incorporated liposomal drug-delivery system

Tripathy, Nirmalya,Ahmad, Rafiq,Ko, Hyun Ah,Khang, Gilson,Hahn, Yoon-Bong The Royal Society of Chemistry 2015 Nanoscale Vol.7 No.9

<P>The development of stimuli-responsive nanocarriers is becoming important in chemotherapy. Liposomes, with an appropriate triggering mechanism, can efficiently deliver their encapsulated cargo in a controlled manner. We explored the use of acid-sensitive zinc oxide nanoparticles (ZNPs) as modulators of the responsive properties of liposomes. Nanocomplexes formed by the incorporation of ZNPs in liposomes (ZNP-liposomes) were designed to demonstrate the pH-responsive release of a drug (daunorubicin) without premature drug leakage and with the maintenance of the relevant therapeutic concentrations. The nanocomplexes were spherical in shape with a narrow size distribution and showed a high drug-encapsulating efficiency. Under acidic conditions, the ZNP-liposome nanocomplexes released the loaded drug more rapidly than bare liposomes. Using flow cytometry, confocal microscopy and an MTT assay, we demonstrated that these nanocomplexes were readily taken up by cancer cells, resulting in significantly enhanced cytotoxicity. On exposure to the acidic conditions inside cancer cells, the ZNPs rapidly decomposed, releasing the entrapped drug molecules from the ZNP-liposome nanocomplexes, producing widespread cytotoxic effects. The incorporated ZNPs were multimodal in that they not only resulted in a pH-responsive drug-delivery system, but they also had a synergistic chemo-photodynamic anticancer action. This design provides a significant step towards the development of multimodal liposome structures.</P>

Tailored lysozyme–ZnO nanoparticle conjugates as nanoantibiotics

Tripathy, Nirmalya,Ahmad, Rafiq,Bang, Seung Hyuck,Min, Jiho,Hahn, Yoon-Bong The Royal Society of Chemistry 2014 Chemical communications Vol.50 No.66

<P>Covalently attached lysozyme–ZnO nanoparticle (L–ZNP) conjugates were synthesized by a low temperature solution route. Tailored L–ZNP conjugates exhibit pronounced antibacterial features against <I>Escherichia coli</I> (<I>E. coli</I>) and <I>Staphylococcus aureus</I> (<I>S. aureus</I>).</P> <P>Graphic Abstract</P><P>Covalently attached lysozyme–ZnO nanoparticle conjugates exhibit pronounced antibacterial features against <I>Escherichia coli</I> and <I>Staphylococcus aureus</I>. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4cc03712j'> </P>

Metal oxide modified ZnO nanomaterials for biosensor applications

Tripathy Nirmalya,Kim Deok-Ho 나노기술연구협의회 2018 Nano Convergence Vol.5 No.27

Advancing as a biosensing nanotechnology, nanohybrids present a new class of functional materials with high selectivity and sensitivity, enabling integration of nanoscale chemical/biological interactions with biomedical devices. The unique properties of ZnO combined with metal oxide nanostructures were recently demonstrated to be an efficient approach for sensor device fabrication with accurate, real-time and high-throughput biosensing, creating new avenues for diagnosis, disease management and therapeutics. This review article collates recent advances in the modified ZnO nanostructured metal oxide nanohybrids for efficient enzymatic and non-enzymatic biosensor applications. Furthermore, we also discussed future prospects for nanohybrid materials to yield high-performance biosensor devices.

Outstanding Antibiofilm Features of Quanta-CuO Film on Glass Surface

Tripathy, Nirmalya,Ahmad, Rafiq,Bang, Seung Hyuck,Khang, Gilson,Min, Jiho,Hahn, Yoon-Bong American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.24

<P>Intelligently designed surface nanoarchitecture provides defined control over the behavior of cells and biomolecules at the solid liquid interface. In this study, CuO quantum dots (quanta-CuO; similar to 3-5 nm) were synthesized by a simple, low-temperature solution process and further formulated as paint to construct quanta-CuO thin film on glass. Surface morphological characterizations of the as-coated glass surface reveal a uniform film thickness (similar to 120 +/- 10 nm) with homogeneous distribution of quanta-CuO. The antibiofilm assay showed a very high contact bacteria-killing capacity of as coated quanta-CuO glass surfaces toward Staphylococcus aureus and Escherichia coli. This efficient antibacterial/antibiofilm activity was ascribed to the intracellular reactive oxygen species (ROS) generated by the quanta-CuO attached to the bacterial cells, which leads to an oxidative assault and finally results in bacterial cell death. Although there is a significant debate regarding the CuO nanostructure's antibacterial mode of action, we propose both contact killing and/or copper ion release killing mechanisms for the antibiofilm activity of quanta-CuO paint. Moreover, synergism of quanta-CuO with conventional antibiotics was also found to further enhance the antibacterial efficacy of commonly used antibiotics. Collectively, this state-of-the-art design of quanta-CuO coated glass can be envisioned as promising candidates for various biomedical and environmental device coatings.</P>

In vivo Bone Regeneration Evaluation of Duck’s Feet Collagen/PLGA Scaffolds in Rat Calvarial Defect

송정은,Nirmalya Tripathy,신재훈,이대훈,차재근,박찬흠,서동삼,강길선 한국고분자학회 2017 Macromolecular Research Vol.25 No.10

Tissue engineered bone substitutes should mimic natural bone characteristics to be highly-suitable for treating bone defects in addition to its biocompatibility and good mechanical stability. In this study, we performed a detailed in vivo bone regeneration evaluation of 80wt% duck’s feet collagen/poly(lactide-co-glycolide) scaffolds (DC/ PLGA) fabricated by solvent casting/salt leaching strategy in a rat calvarial defect as model. We have already shown a strong influence of DC/ PLGA scaffolds on bone regeneration in terms of biomaterial cohesion, architecture, mechanical features, and in vitro biological properties. The as-fabricated scaffold has shown significant increase in osteogenesis, initial bone formation and differentiation, ascribed to the high percentage of DC in the 80wt% DC/PLGA scaffold. The in vivo implanted scaffold was found be well-attached to the bone defect region and eventually gets integrated with the surrounding tissues without any pronounced inflammatory reactions. Compared to bare PLGA, an increased recovery in bone volume was observed at 8th week post-surgery. Thus, the 80 wt% DC/PLGA scaffold can be envisioned as a potential alternative bone graft in bone tissue engineering.

Hierarchically assembled ZnO nanosheets microspheres for enhanced glucose sensing performances

Ahmad, Rafiq,Tripathy, Nirmalya,Khan, Muhammad Yasir,Bhat, Kiesar Sideeq,Ahn, Min-sang,Khang, Gilson,Hahn, Yoon-Bong Elsevier 2016 CERAMICS INTERNATIONAL Vol.42 No.12

<P><B>Abstract</B></P> <P>Nanostructures with higher surface specific area has great potential applications in sensing devices because higher surface specific area not only improve protein/enzyme immobilization efficiency, but also enhances charge transport and sensing performances. Herein, hierarchically assembled ZnO nanosheets microspheres (HAZNMs) were synthesized by facile one-pot solution process at low-temperature. Results showed that as-synthesized HAZNMs possessing higher specific surface area, significantly increased the enzyme loading efficiency which in turn improved the sensing performances. The as-fabricated biosensors showed a remarkably high sensitivity (210.8μA/mMcm<SUP>2</SUP>) in the wide-linear response range of 0.05–23mM, favorable stability for long-term storage, excellent anti-interference ability and high reliability for glucose detection in human blood serum samples. The improved sensing performances can be ascribed to the high glucose oxidase (GOx) enzyme immobilization on HAZNMs that provides a favorable microenvironment for the maintenance of GOx enzyme bioactivity.</P>

Highly stable hydrazine chemical sensor based on vertically-aligned ZnO nanorods grown on electrode

Ahmad, Rafiq,Tripathy, Nirmalya,Ahn, Min-Sang,Hahn, Yoon-Bong Elsevier 2017 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.494 No.-

<P><B>Abstract</B></P> <P>Herein, we report a binder-free, stable, and high-performance hydrazine chemical sensor based on vertically aligned zinc oxide nanorods (ZnO NRs), grown on silver (Ag) electrode via low-temperature solution route. The morphological characterizations showed that the NRs were grown vertically in high density and possess good crystallinity. The as-fabricated hydrazine chemical sensors showed an excellent sensitivity of 105.5 μAμM<SUP>−1</SUP> cm<SUP>−2</SUP>, a linear range up to 98.6μM, and low detection limit of 0.005μM. It also showed better long-term stability, good reproducibility and selectivity. Furthermore, the fabricated electrodes were evaluated for hydrazine detection in water samples. We found the approach of directly growing nanostructures as a key factor for enhanced sensing performance of our electrodes, which effectively transfers electron from ZnO NRs to conductive Ag electrode. Thus it holds future prospective applications as binder-free, cost-effective, and stable sensing devices fabrication.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Development of high-performance hydrazine chemical sensor electrodes. </LI> <LI> ZnO NRs on Ag electrode provided high surface and easy substrate penetration structures. </LI> <LI> Sensor showed an excellent sensitivity, long-term stability, and good reproducibility. </LI> <LI> The sensor has potential for detection of hydrazine in water. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A comprehensive biosensor integrated with a ZnO nanorod FET array for selective detection of glucose, cholesterol and urea

Ahmad, Rafiq,Tripathy, Nirmalya,Park, Jin-Ho,Hahn, Yoon-Bong The Royal Society of Chemistry 2015 Chemical communications Vol.51 No.60

<P>We report a novel straightforward approach for simultaneous and highly-selective detection of multi-analytes (<I>i.e.</I> glucose, cholesterol and urea) using an integrated field-effect transistor (i-FET) array biosensor without any interference in each sensor response. Compared to analytically-measured data, performance of the ZnO nanorod based i-FET array biosensor is found to be highly reliable for rapid detection of multi-analytes in mice blood, and serum and blood samples of diabetic dogs.</P> <P>Graphic Abstract</P><P>A ZnO NR integrated FET array biosensor with immobilized enzymes. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c5cc03656a'> </P>