Tissue culture system using a PANDA ring resonator and wavelength router for hydroponic plant

A novel system of nanofluidics trapping and delivery, which is known as a tissue culture system is proposed. By using the intense optical pulse(i.e., a soliton pulse) and a system constructed by a liquid core waveguide, the optical vortices (gradient optical fields/wells) can be generated, where the trapping tools in the same way as the optical tweezers in the PANDA ring resonator can be formed. By controlling the suitable parameters, the intense optical vortices can be generated within the PANDA ring resonator, in which the nanofluidics can be trapped and moved (transported) dynamically within the Tissue culture system(a wavelength router), which can be used for tissue culture and delivery in the hydroponic plant system.     

Hybrid transistor manipulation controlled by light within a PANDA microring resonator

In this paper, the novel type of transistor known as a hybrid transistor is proposed, in which all types of transistors can be formed by using a microring resonator called a PANDA microring resonator. In principle, such a transistor can be used to form for various transistor types by using the atom/molecule trapping tools, which is named by an optical tweezer, where in application all type of transistors, especially, molecule and photon transistors can be performed by using the trapping tools, which will be described in details.     

Alternative configuration for an optical ring resonator angular rate sensor by using a standard laser diode

In this work, we present an alternative approach to angular velocity optical sensing based on two-ring resonators. This configuration admits the use of a standard laser diode source (0.1 nm, 10,000 MHz, FWHM) reaching higher sensitivities when narrow spectral laser sources (1 MHz, FWHM) are used. We compare this configuration with the standard single-ring resonator angular rate sensor (SRARS), which must use a narrow laser at input. Finally, we conclude that the sensitivity of this new approach can also be enhanced by coupling high-power broadband laser sources in a large range (from 1°/h to 10,000°/h), reaching performance similar to that of a standard SRARS configuration.     

Self-microemulsifying smaller molecular volume oil (Capmul MCM) using non-ionic surfactants: a delivery system for poorly water-soluble drug

The main purpose of this work is to formulate self-microemulsifying drug delivery system (SMEDDS) using smaller molecular oil with Atorvastatin calcium as a model drug. Solubility of the selected drug was accessed in oils and surfactants. Percent transmittance (%T) test study was performed to identify the efficient self-microemulsifying formulations. Those formulations which showed higher value for %T were evaluated for droplet size, polydispersity index, ζ potential, refractive index and cloud point measurement. Effect of drug loading on droplet size, increasing dilution in different media, thermodynamic stability and in vitro dissolution was performed to observe the performance of the selected formulation. Further cytotoxicity and permeation enhancement studies were carried out on Caco2 cell lines. Of all the oils accessed for drug solubility, Capmul MCM showed higher solubility capacity for Atorvastatin calcium. Capmul MCM was better microemulsified using combination of Tween 20 and Labrasol surfactant. Droplet size was as low as 86.93?nm with polydispersity index and ζ potential at 0.195?±?0.011 and ?7.27?±?3.11 mV respectively. The selected undiluted formulation showed refractive index values ranging from 1.40 to 1.47 indicating the isotropicity of the formulation. The selected formulation was robust to dilution in different media and thermodynamically stable. Dissolution profile was enhanced for the selected drug as compared to marketed formulation with t85% and DE values at 10?min and 80.15 respectively. Also cytotoxicity measurement showed minimum effect with good permeation enhancing capacity. Thus our study demonstrates the use of smaller molecular oil (Capmul MCM) for developing self-microemulsifying drug delivery system for better in vitro and in vivo performance.     

Self-microemulsifying smaller molecular volume oil (Capmul MCM) using non-ionic surfactants: a delivery system for poorly water-soluble drug

The main purpose of this work is to formulate self-microemulsifying drug delivery system (SMEDDS) using smaller molecular oil with Atorvastatin calcium as a model drug. Solubility of the selected drug was accessed in oils and surfactants. Percent transmittance (%T) test study was performed to identify the efficient self-microemulsifying formulations. Those formulations which showed higher value for %T were evaluated for droplet size, polydispersity index, ζ potential, refractive index and cloud point measurement. Effect of drug loading on droplet size, increasing dilution in different media, thermodynamic stability and in vitro dissolution was performed to observe the performance of the selected formulation. Further cytotoxicity and permeation enhancement studies were carried out on Caco2 cell lines. Of all the oils accessed for drug solubility, Capmul MCM showed higher solubility capacity for Atorvastatin calcium. Capmul MCM was better microemulsified using combination of Tween 20 and Labrasol surfactant. Droplet size was as low as 86.93?nm with polydispersity index and ζ potential at 0.195?±?0.011 and -7.27?±?3.11 mV respectively. The selected undiluted formulation showed refractive index values ranging from 1.40 to 1.47 indicating the isotropicity of the formulation. The selected formulation was robust to dilution in different media and thermodynamically stable. Dissolution profile was enhanced for the selected drug as compared to marketed formulation with t85% and DE values at 10?min and 80.15 respectively. Also cytotoxicity measurement showed minimum effect with good permeation enhancing capacity. Thus our study demonstrates the use of smaller molecular oil (Capmul MCM) for developing self-microemulsifying drug delivery system for better in vitro and in vivo performance.     

Broadband absorbance in a liquid-core optical ring resonator

We have demonstrated the application of broadband absorption spectroscopy in a liquid-core optical ring resonator. An initial proof of concept of the broadband liquid-core optical ring resonator (BLCORR) was constructed using a thinned-wall, 250-μm-inner-diameter fused silica capillary, tapered multimode optical fibers for input and output coupling, and a light-emitting diode (LED) source. When compared with standard cuvette measurements, an apparent path length as high as 5 cm was observed for methylene blue (MB). MB is a cationic dye that exhibits strong surface interaction with bare silica. Bromothymol blue (BTB), on the other hand, has a similar absorbance spectrum but does not share this same surface activity. On comparing these two dyes, the apparent path length for MB was found to reach more than 50 times that of BTB, confirming the expectation that the sensing region being probed is largely within the evanescent field at the inner surface of the capillary. The BLCORR may also inherit, from attenuated total reflection (ATR) spectroscopy, the ability to analyze highly concentrated chromophores. Concentrations of BTB as high as 10(-2) and 10(-3) M were easily distinguished from each other at the λ(max) in the BLCORR, whereas this was not the case in a 4-mm cuvette cell. Our presented device employs commercially available materials and could incorporate well into microfluidic systems. These benefits, along with the demonstrated ability to take enhanced surface absorbance measurements in a capillary, give the BLCORR potential in a variety of applications.     

Dielectric constant measurement of low loss liquids using stacked multi ring resonator

The concept of dielectric constant measurement has been extended and applied in agriculture, pharmaceutical and food industry for quality control of liquids. Dielectric analysis of material at microwave frequencies can be done using novel shielded stacked multi-ring resonator (SMRR). The dielectric constant of liquids and paste has been calculated using SMRR with greater accuracy than the planar resonator, boxed resonator and stacked resonator. SMRR contains a ring resonator with fed patch and parasitic patch with different numbers and sizes of rings. The dimensions of rings on the parasitic patch are optimized to achieve Quality factor Q greater than 100 and return loss less than ?2 dB. Due to dual resonance in novel SMRR, structure losses are reduced by 50% than planar resonator structure. The behavior of SMRR structure at the 2.45 GHz frequency is studied with E field and H field. 3D model is designed in Computer Simulation Technology Microwave Studio (CST MWS) using TLM (Transmission Line Modeling) solver. Electromagnetic field analysis as well as impedance bandwidth of SMRR using CST MWS 3D model prove that electromagnetic coupling in SMRR structure increases thus improves quality factor. In SMRR quality factor increases and losses reduce help us to predict the complex permittivity of material for quality analysis.     

A method for radiation-force localized drug delivery using gas-filled lipospheres

We have developed a method using ultrasound and acoustically active lipospheres (AALs) that might be used to deliver bioactive substances to the vascular endothelium. The AALs consist of a small gas bubble surrounded by a thick oil shell and enclosed by an outermost lipid layer. The AALs are similar to ultrasound contrast agents: they can be nondestructively deflected using ultrasound radiation force, and fragmented with high-intensity ultrasound pulses. The lipid-oil complex might be used to carry bioactive substances at high concentrations. An optimized sequence of ultrasound pulses can deflect the AALs toward a vessel wall then disrupt them, painting their contents across the vascular endothelium. This paper presents results from a series of in vitro and ex vivo experiments demonstrating localization of a fluorescent model drug. In experiments using a human melanoma cell (A2085) monolayer, a specific radiation force-fragmentation ultrasound pulse sequence increased cell fluorescence more than 10-fold over no ultrasound or fragmentation pulses alone, and by 50% over radiation force pulses alone. We observe that dye transfer is limited to cells that are in the region of ultrasonic focus, indicating that the application of radiation force pulses to bring the delivery vehicle into proximity with the cell is required for successful adhesion of the vehicle fragments to the cell membrane. We also demonstrate dye transfer from flowing AALs, both in a mimetic vessel and in excised rat cecum. We believe that this method could be successfully used for drug delivery in vivo.     

Interferometric optical switch enhanced by a multi-resonance ring resonator structure

We propose a novel configuration for optical switches by the use of two coupled ring resonators acting as a phase-shifting element in a Mach–Zehnder interferometer. Because the ring structure is multi-resonant within one period of its phase response, light at any frequency within the period can be addressed by tuning the device across a small frequency interval. This enables the use of low voltages for electro-optic control of the switch, allowing for a tunable photonic switching device that operates at 1?V voltage levels.     

BioMEMS for drug delivery

Recent research into methods of using microelectromechanical systems (MEMS) technology for medical and biological applications has developed several interesting devices. This paper reviews various approaches to the use of MEMS for drug therapy, including devices based on microporous silicon, microneedles, micropumps, and microreservoirs. Microdevices can improve drug therapy because they allow precise and complex dosing, induce less pain, or increase compliance. Microneedles have been tested on humans, and the other drug delivery MEMS have shown promise in vitro and in vivo. Investigations into the use of microelectromechanical systems (MEMS) technology to produce microdevices for drug delivery have expanded recently. We present several different approaches to the use of microdevices for drug therapy and the current state of the field.     

Integrated refractive index optical ring resonator detector for capillary electrophoresis

We developed a novel miniaturized and multiplexed, on-capillary, refractive index (RI) detector using liquid core optical ring resonators (LCORRs) for future development of capillary electrophoresis (CE) devices. The LCORR employs a glass capillary with a diameter of approximately 100 mum and a wall thickness of a few micrometers. The circular cross section of the capillary forms a ring resonator along which the light circulates in the form of the whispering gallery modes (WGMs). The WGM has an evanescent field extending into the capillary core and responds to the RI change due to the analyte conducted in the capillary, thus permitting label-free measurement. The resonating nature of the WGM enables repetitive light-analyte interaction, significantly enhancing the LCORR sensitivity. This LCORR architecture achieves dual use of the capillary as a sensor head and a CE fluidic channel, allowing for integrated, multiplexed, and noninvasive on-capillary detection at any location along the capillary. In this work, we used electro-osmotic flow and glycerol as a model system to demonstrate the fluid transport capability of the LCORRs. In addition, we performed flow speed measurement on the LCORR to demonstrate its flow analysis capability. Finally, using the LCORR's label-free sensing mechanism, we accurately deduced the analyte concentration in real time at a given point on the capillary. A sensitivity of 20 nm/RIU (refractive index units) was observed, leading to an RI detection limit of 10-6 RIU. The LCORR marries photonic technology with microfluidics and enables rapid on-capillary sample analysis and flow profile monitoring. The investigation in this regard will open a door to novel high-throughput CE devices and lab-on-a-chip sensors in the future.     

Measurement and analysis of a microwave oscillator stabilized by a sapphire dielectric ring resonator for ultra-low noise

Phase-noise measurements are presented for a microwave oscillator whose frequency is stabilized by a whispering gallery mode sapphire ring resonator with Q of 2x10(5). The nature of the mode, which involves little metallic conduction, allows nearly full use of the very low dielectric loss in sapphire. Several mode families have been identified with good agreement with calculated frequency predictions. Waveguide coupling parameters have been characterized for the principal (lowest frequency) mode family, for n=5 to n =10 full waves around the perimeter. For a 5-cm wheel resonator in a 7.6-cm container, Q-values of above 10(5) were found at room temperature for all of the modes in this sequence. Coupling Q-values for the same modes ranged from 10(4) (n =5) to 10(5) (n=10) for a WR112 waveguide port at the center of the cylinder wall of the containing can. Phase noise measurements for a transistor oscillator locked to the n=10 (7.84-GHz) mode showed a 1/f(3) dependence for low offset frequencies, and a value of L(f)=-55 dB/Hz at an offset of 10 Hz from the carrier. The oscillator shows phase noise below the previously reported for any X-band source.     

Optimum filtration of microwave signals by a multiband spin-wave ring resonator

The optimum filtration of pulsed microwave signals by a multiband active spin-wave ring resonator has been studied for the first time. The ring resonator, which comprises a spin-wave delay line based on a ferromagnetic single crystal film of yttrium iron garnet with a microwave amplifier in the feedback chain, possesses a comblike amplitude-frequency characteristic with a large number of pass bands. It is established that the best filtration of a periodic train of rectangular microwave pulses is achieved provided that harmonics of the signal coincide with the positions of the resonator pass bands. Thus, an active spin-wave ring resonator can be used as the optimum filter for periodic pulsed microwave signals.     

Optimization of self nanoemulsifying drug delivery system for poorly water-soluble drug using response surface methodology

There is an increasing interest on self-nanoemulsifying drug delivery system (SNEDDS) for oral delivery of poorly water-soluble drugs. However, development of SNEDDS is often driven by empiric, pseudo-ternary diagrams and solubility of drugs, and it is lacking a systematic approach for evaluating impact of excipients on the performance of formulations as well as the fate of drug. The aim of this study was to rationalize the SNEDDS development procedure and to get a better understanding on the role of excipients on the SNEDDS. The formulations consist of soybean oil or rapeseed oil, Cremophor^® RH40, Maisine? 35-1 and ethanol. Response surface methodology (RSM) was used in the development of SNEDDS. Significant advantages of RSM were found in reducing the work load and determining the impact of excipients on formulation characteristics. The most significant factor in influencing droplet size was the co-surfactant Maisine? 35-1, the droplet size increased with increasing concentration of Maisine? 35-1. It suggests that Maisine? 35-1 has double functions in the SNEDDS; it functions as co-surfactant to improve the emulsification of oil, meanwhile it also works as the oil phase and results in larger droplets. A significant reduction in droplet size was interestingly observed when fenofibrate was loaded in the vehicles, probably due to the surface activity of fenofibrate, promoting the self-emulsifying process. It was evident that drug precipitation during lipolysis was not affected by the level of co-solvent ethanol in the formulation, while it had pronounced impact on drug solubilization during the initial dispersion stage.     

Unstable resonator misalignment in ring and linear toroidal resonators

Optical axis motion in a ring resonator is investigated as a function of resonator mirror misalignment by constructing an equivalent paraxial model and applying the ray matrix formalism. Analytical expressions are derived for the optical axis motion. The paraxial model of the ring is shown to imply a linear resonator as a specific case, and the ring resonator expressions collapse to the familiar Krupke-Sooy results for that case. Using this method, new misalignment expressions are determined for more complex linear resonators. Uncorrectable misalignment conditions caused by toroidal mirror parameter errors are studied analytically and with a geometric optics code, and resulting phase front errors are given for a special case. These results are also examined as a basis for toroidal mirror quality specifications.     

Design of self-microemulsifying drug delivery systems using a high-throughput formulation screening system

Purpose: A high-throughput formulation screening (HTFS) system that enabled to rapidly and efficiently select self-microemulsifying drug delivery system (SMEDDS) formulations has been developed in our previous study. The purpose of this study was to investigate the applicability of the HTFS system to SMEDDS designs. Methods: A poorly soluble drug (Nilvadipine), an oil (Sefsol-218), 11 hydrophilic surfactants (HS), and 10 lipophilic surfactants (LS) were used. Formulations were prepared and SMEDDS formulations were chosen by the HTFS system. A HS with the largest number of SMEDDS formulations was selected. In the selected HS system, a LS with the largest number of SMEDDS formulations was selected. Formulations with minimum turbidity at each ratio of the selected HS/LS were chosen as optimized formulations. Results: A total of 2455 formulations were prepared and SMEDDS formulations were selected using the HTFS system. From the screening data, HCO60 was selected as a superior emulsifiable HS, and Plurol (PLUROL OLEIQUE CC497) was selected as a suitable LS to HCO60. Five optimized formulations were chosen from the HCO60/Plurol system. The formulations formed fine microemulsions (<33.6 nm) without phase separation and drug precipitation. These formulation designs were conducted using 600 mg of the drug at a rate of 400 formulations/person/day. Conclusion: SMEDDS formulations could be rapidly and efficiently designed using the HTFS system.     

Equivalent circuit for the microstrip ring resonator suitable for broadband materials characterisation

A simple equivalent circuit of the edge coupled microstrip ring resonator is developed based on both circuit and electromagnetic theory. The new model extends the work done by previous authors by including the effects of radiation loss, the coupling gap and the feed network as well as extending the frequency range by including higher-order modes. The model accurately predicts the resonant frequencies of the ring including the effects of dispersion and thick conductors. The equivalent circuit allows measurement of the resonance frequencies and the Q factors to be made independently of the coupling gap dimensions, which traditionally have been difficult to accurately model. A method of determining radiation loss is also presented, which has often been incorrectly neglected in the past. Experimental results support the accuracy of the equations and measurements on alumina rings that demonstrate a frequency accuracy of better than 1% over 12 resonant modes in the frequency range 3-33 GHz.     

Bioeliminable nanohydrogels for drug delivery

One of the most significant obstacles for systematic delivery of nanopayloads is the foreign particle clearance by the mononuclear phagocyte system (MPS). The majority of biocompatible nanopayloads with charged groups on their surface cannot fully evade the clearance by MPS during systemic circulation. For safe and effective targeted nanodrug delivery in vivo, we describe a novel approach for evading the macrophage clearance. We demonstrate that neutral and hydrophilic materials can effectively evade the macrophage uptake and also quickly degrade into bioeliminable fragments. We show that there is no opsonization effect and no toxic effect on living cells. In addition, the payloads are stable in an aqueous environment, and they can release drugs in a cellular environment. These results suggest that the unique properties of this kind of payloads may make them useful for designing new drug delivery systems.