Journal Of Nanomedicine & Nanotechnology[JOURNAL]
Sun
168 papers
Multiaction antibacterial nanofibrous membranes fabricated by electrospinning: an excellent system for antibacterial applications.
Wu Y, Jia W, An Q … +3 more , Liu Y, Chen J, Li G
Nanotechnology · 2009 Jun · PMID 19468171 · Publisher ↗
In this paper, novel multiaction antibacterial nanofibrous membranes containing apatite, Ag, AgBr and TiO2 as four active components were fabricated by an electrospinning technique. In this antibacterial membrane, each c...
In this paper, novel multiaction antibacterial nanofibrous membranes containing apatite, Ag, AgBr and TiO2 as four active components were fabricated by an electrospinning technique. In this antibacterial membrane, each component serves a different function: the hydroxyapatite acts as the adsorption material for capturing bacteria, the Ag nanoparticles act as the release-active antibacterial agent, the AgBr nanoparticles act as the visible sensitive and release-active antibacterial agent, and the TiO2 acts as the UV sensitive antibacterial material and substrate for other functional components. Using E. coli as the typical testing organism, such multicomponent membranes exhibit excellent antimicrobial activity under UV light, visible light or in a dark environment. The significant antibacterial properties may be due to the synergetic action of the four major functional components, and the unique porous structure and high surface area of the nanofibrous membrane. It takes only 20 min for the bacteria to be completely (99.9%) destroyed under visible light. Even in a dark environment, about 50 min is enough to kill all of the bacteria. Compared to the four component system in powder form reported previously, the addition of the electrospun membrane could significantly improve the antibacterial inactivation of E. coli under the same evaluation conditions. Besides the superior antimicrobial capability, the permanence of the antibacterial activity of the prepared free-standing membranes was also demonstrated in repeated applications.
Depth of photothermal conversion of gold nanorods embedded in a tissue-like phantom.
Didychuk CL, Ephrat P, Chamson-Reig A … +2 more , Jacques SL, Carson JJ
Nanotechnology · 2009 May · PMID 19420630 · Publisher ↗
Gold nanorod (AuNR)-assisted photothermal therapy has emerged as a viable method for selective killing of cancer cells and shows promise for tumor destruction in vivo. This study examined the distribution of AuNR convers...
Gold nanorod (AuNR)-assisted photothermal therapy has emerged as a viable method for selective killing of cancer cells and shows promise for tumor destruction in vivo. This study examined the distribution of AuNR conversion expected to occur during photothermal therapy in vivo. Tissue-like phantoms were prepared with polyethylene glycol AuNRs distributed homogeneously at a concentration representative of a systemic injection. Phantoms were illuminated with a nanosecond pulsed laser (800 nm) at a variety of combinations of pulse energy (12-120 mJ) and pulse count (1-1000). Operating at the American National Standards Institute safety limit for human skin exposure (30 mJ cm(-2)), a diameter of 13 mm and a depth of 7.6 mm of AuNR conversion were observed in the gel phantoms after 1000 laser pulses (100 s exposure). Significant AuNR conversion was measured to a depth of 6 mm after only 100 pulses. Comparison of the measured AuNR conversion distribution with Monte Carlo simulation suggested that the fluence threshold for AuNR conversion estimated from phantom measurements was in the range of 20-43 mJ cm(-2). The results suggest that AuNR-assisted photothermal therapy will be effective for tumors within 10 mm of the illuminated tissue surface.
A multifunctional magnetic nanocarrier bearing fluorescent dye for targeted drug delivery by enhanced two-photon triggered release.
Banerjee SS, Chen DH
Nanotechnology · 2009 May · PMID 19420604 · Publisher ↗
We report a novel nanoformulation for targeted drug delivery which utilizes nanophotonics through the fusion of nanotechnology with biomedical application. The approach involves an energy-transferring magnetic nanoscopic...
We report a novel nanoformulation for targeted drug delivery which utilizes nanophotonics through the fusion of nanotechnology with biomedical application. The approach involves an energy-transferring magnetic nanoscopic co-assembly fabricated of rhodamine B (RDB) fluorescent dye grafted gum arabic modified Fe(3)O(4) magnetic nanoparticle and photosensitive linker by which dexamethasone drug is conjugated to the magnetic nano-assembly. The advantage offered by this nanoformulation is the indirect photo-triggered-on-demand drug release by efficient up-converting energy of the near-IR (NIR) light to higher energy and intraparticle energy transfer from the dye grafted magnetic nanoparticle to the linker for drug release by cleavage. The synthesized nanoparticles were found to be of ultra-small size (13.33 nm) and are monodispersed in an aqueous suspension. Dexamethasone (Dexa) drug conjugated to RDB-GAMNP by photosensitive linker showed appreciable release of Dexa by photo-triggered response on exposure to radiation having a wavelength in the NIR region whereas no detectable release was observed in the dark. Photo-triggered response for the nanoformulation not bearing the rhodamine B dye was drastically less as less Dexa was released on exposure to NIR radiation which suggest that the photo-cleavage of linker and release of Dexa mainly originated from the indirect excitation through the uphill energy conversions based on donor-acceptor model FRET. The promising pathway of nanophotonics for the on-demand release of the drug makes this nanocarrier very promising for applications in nanomedicine.
Thermosensitive liposomes entrapping iron oxide nanoparticles for controllable drug release.
Tai LA, Tsai PJ, Wang YC … +3 more , Wang YJ, Lo LW, Yang CS
Nanotechnology · 2009 Apr · PMID 19420485 · Publisher ↗
Iron oxide nanoparticles can serve as a heating source upon alternative magnetic field (AMF) exposure. Iron oxide nanoparticles can be mixed with thermosensitive nanovehicles for hyperthermia-induced drug release, yet su...
Iron oxide nanoparticles can serve as a heating source upon alternative magnetic field (AMF) exposure. Iron oxide nanoparticles can be mixed with thermosensitive nanovehicles for hyperthermia-induced drug release, yet such a design and mechanism may not be suitable for controllable drug release applications in which the tissues are susceptible to environmental temperature change such as brain tissue. In the present study, iron oxide nanoparticles were entrapped inside of thermosensitive liposomes for AMF-induced drug release while the environmental temperature was maintained at a constant level. Carboxyfluorescein was co-entrapped with the iron oxide nanoparticles in the liposomes as a model compound for monitoring drug release and environmental temperature was maintained with a water circulator jacket. These experiments have been successfully performed in solution, in phantom and in anesthetized animals. Furthermore, the thermosensitive liposomes were administered into rat forearm skeletal muscle, and the release of carboxylfluorescein triggered by the external alternative magnetic field was monitored by an implanted microdialysis perfusion probe with an on-line laser-induced fluorescence detector. In the future such a device could be applied to simultaneous magnetic resonance imaging and non-invasive drug release in temperature-sensitive applications.
Preparation, characterization, and anti-tumor property of podophyllotoxin-loaded solid lipid nanoparticles.
Zhu RR, Qin LL, Wang M … +6 more , Wu SM, Wang SL, Zhang R, Liu ZX, Sun XY, Yao SD
Nanotechnology · 2009 Feb · PMID 19417361 · Publisher ↗
In an effort to develop an alternative formulation of podophyllotoxin suitable for drug release and delivery, podophyllotoxin-loaded solid lipid nanoparticles (PPT-SLNs) were constructed, characterized and examined for i...
In an effort to develop an alternative formulation of podophyllotoxin suitable for drug release and delivery, podophyllotoxin-loaded solid lipid nanoparticles (PPT-SLNs) were constructed, characterized and examined for in vitro cytotoxicity and tumor inhibition. The SLNs were prepared by using a solvent emulsification-evaporation method, and their size was around 50 nm. TEM detection showed that the SLNs were homogeneous and spherical in shape, and differential scanning calorimetry (DSC) measurement revealed a new conformation of PPT-SLNs. An in vitro drug release study showed that PPT was released from the SLNs in a slow but time-dependent manner. Furthermore, the treatment of 293T and HeLa cells with PPT-SLNs demonstrated that PPT-SLNs were less toxic to normal cells and more effective in anti-tumor potency compared with unconjugated PPT. A colony forming efficiency assay showed an effective long-term cancer growth suppression of PPT-SLNs; in addition, they can also enhance the apoptotic and cellular uptake processes on tumor cells compared with PPT. These results collectively demonstrated that this SLN formulation has a potential application as an alternative delivery system for anti-tumor drugs.
Preferential killing of cancer cells and activated human T cells using ZnO nanoparticles.
Hanley C, Layne J, Punnoose A … +5 more , Reddy KM, Coombs I, Coombs A, Feris K, Wingett D
Nanotechnology · 2008 Jul · PMID 18836572 · Full text
Nanoparticles are increasingly being recognized for their potential utility in biological applications including nanomedicine. Here we examine the response of normal human cells to ZnO nanoparticles under different signa...
Nanoparticles are increasingly being recognized for their potential utility in biological applications including nanomedicine. Here we examine the response of normal human cells to ZnO nanoparticles under different signaling environments and compare it to the response of cancerous cells. ZnO nanoparticles exhibit a strong preferential ability to kill cancerous T cells ( approximately 28-35x) compared to normal cells. Interestingly, the activation state of the cell contributes toward nanoparticle toxicity, as resting T cells display a relative resistance while cells stimulated through the T cell receptor and CD28 costimulatory pathway show greater toxicity in direct relation to the level of activation. Mechanisms of toxicity appear to involve the generation of reactive oxygen species, with cancerous T cells producing higher inducible levels than normal T cells. In addition, nanoparticles were found to induce apoptosis and the inhibition of reactive oxygen species was found to be protective against nanoparticle induced cell death. The novel findings of cell selective toxicity, towards potential disease causing cells, indicate a potential utility of ZnO nanoparticles in the treatment of cancer and/or autoimmunity.
A gold-nanoparticle-enhanced immune sensor based on fiber optic interferometry.
Tseng YT, Chuang YJ, Wu YC … +3 more , Yang CS, Wang MC, Tseng FG
Nanotechnology · 2008 Aug · PMID 21730648 · Publisher ↗
A method using gold nanoparticles (GNPs) to enhance fiber optic interferometry (GNPFOI) for immune-sensing is reported in this paper. It is suggested that an enlarged index mismatch and an elongated optical path by GNPs...
A method using gold nanoparticles (GNPs) to enhance fiber optic interferometry (GNPFOI) for immune-sensing is reported in this paper. It is suggested that an enlarged index mismatch and an elongated optical path by GNPs conjugated on recognition proteins will contribute most to signal enhancement in the interference fringe shift. Theoretical and experimental results show that the interference fringe shift is linearly related to both the amount and size of the GNPs binding on the sensor surface. The detected signal for 30 nm GNPs can reach a lowest detection limit of 18 pM (10(10) particles ml(-1)). Immune-sensing for rabbit IgG as the antigen to anti-rabbit IgG has been demonstrated and a detection cycle has been completed by elution buffer for surface regeneration. The repeatability of the immune-sensing on one GNPFOI sensor has also been verified by three identical cycles, and the detection limit for 13 nm GNPs conjugated anti-rabbit IgG reaches 0.17 nM (∼25.5 ng ml(-1)). The sensory mechanism has the potential to be engineered on the tip of a needle-type micro-device, which would allow it to monitor immune recognition signals in the future.
New mechanisms for non-porative ultrasound stimulation of cargo delivery to cell cytosol with targeted perfluorocarbon nanoparticles.
Soman N, Marsh J, Lanza G … +1 more , Wickline S
Nanotechnology · 2008 May · PMID 21494419 · Full text
The cell membrane constitutes a major barrier for non-endocytotic intracellular delivery of therapeutic molecules from drug delivery vehicles. Existing approaches to breaching the cell membrane include cavitational ultra...
The cell membrane constitutes a major barrier for non-endocytotic intracellular delivery of therapeutic molecules from drug delivery vehicles. Existing approaches to breaching the cell membrane include cavitational ultrasound (with microbubbles), electroporation and cell-penetrating peptides. We report the use of diagnostic ultrasound for intracellular delivery of therapeutic bulky cargo with the use of molecularly targeted liquid perfluorocarbon (PFC) nanoparticles. To demonstrate the concept, we used a lipid with a surrogate polar head group, nanogold-DPPE, incorporated into the nanoparticle lipid monolayer. Melanoma cells were incubated with nanogold particles and this was followed by insonication with continuous wave ultrasound (2.25 MHz, 5 min, 0.6 MPa). Cells not exposed to ultrasound showed gold particles partitioned only in the outer bilayer of the cell membrane with no evidence of the intracellular transit of nanogold. However, the cells exposed to ultrasound exhibited numerous nanogold-DPPE components inside the cell that appeared polarized inside intracellular vesicles demonstrating cellular uptake and trafficking. Further, ultrasound-exposed cells manifested no incorporation of calcein or the release of lactate dehydrogenase. These observations are consistent with a mechanism that suggests that ultrasound is capable of stimulating the intracellular delivery of therapeutic molecules via non-porative mechanisms. Therefore, non-cavitational adjunctive ultrasound offers a novel paradigm in intracellular cargo delivery from PFC nanoparticles.
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