Mohamed Al-Fandi

Engineered nanoparticles as precise drug delivery systems

With the remarkable development of nanotechnology in recent years, new drug delivery approaches based on the state‐of‐the‐art nanotechnology have been receiving significant attention. Nanoparticles, an evolvement of nanotechnology, are increasingly considered as a potential candidate to carry therapeutic agents safely into a targeted compartment in an organ, particular tissue or cell. These particles are colloidal structures with a diameter smaller than 1,000 nm, and therefore can penetrate through diminutive capillaries into the cells internal machinery. This innovative delivery technique might be a promising technology to meet the current challenges in drug delivery. When loaded with a gene or drug agent, nanoparticles can become nanopills, which can effectively treat problematical diseases such as cancer. This article summarizes different types of nanoparticles drug delivery systems under investigation and their prospective therapeutic applications. Also, this article presents a closer look at the advances, current challenges, and future direction of nanoparticles drug delivery systems. J. Cell. Biochem. 97: 1184–1190, 2006.

Optimal PI-fuzzy logic controller of glucose concentration using genetic algorithm

In this paper, an optimal PI-fuzzy controller to regulate plasma glucose in Type1 diabetic patients is introduced. This controller is designed to mimic the functionality of β-cell in pancreas. Complete lack of insulin resulting from β-cell deficiency leads to a high blood glucose concentration or the so-called Type 1 diabetes. Patients having this disease need external insulin treatment to keep their blood glucose within normal ranges and to protect themselves from hyperglycemia risk. A miniaturized insulin infusion pump integrated with a continuous glucose sensor and driven by a closed-loop control algorithm can be implemented to create an artificial β-cell. For simulation purpose, the control algorithm needs a mathematical model representing the natural interaction between insulin and glucose. The up-to-date nonlinear delay differential model of glucose-insulin regulatory system, which represents the glucose-insulin metabolic system within the human body, is used as a reference and as a patient model. The controller parameters, which include membership functions and scaling parameters, are optimized by the genetic algorithm. Controller performance is evaluated thorough simulation studies and compared to that of the reference model. The results show that the plasma glucose and insulin ranges, average glucose value, and total amount of delivered insulin under the controller are very close to that of the reference model.

ADAPTIVE NEURO-FUZZY INFERENCE SYSTEM FOR AUTOMATIC SLEEP MULTISTAGE LEVEL SCORING EMPLOYING EEG, EOG, AND EMG EXTRACTED FEATURES

A new system for sleep multistage level scoring by employing extracted features from twenty five polysomnographic recording is presented. For the new system, an adaptive neuro-fuzzy inference system (ANFIS) is developed for each sleep stage. Initially, three types of electrophysiological signals including electroencephalogram (EEG), electrooculogram (EOG), and electromyogram (EMG) were collected from twenty five healthy subjects. The input pattern used for training the ANFIS subsystem is a set of extracted features based on the entropy measure which characterize the recorded signals. Finally an output selection subsystem is utilized to provide the appropriate sleep stage according to the ANFIS stage subsystems outputs. The developed system was able to provide an acceptable estimation for six sleep stages with an average accuracy of about 76.43% which confirmed its ability for multistage sleep level scoring based on the extracted features from the EEG, EOG and EMG signals compared to other approaches.

Optimal PID-Fuzzy Logic Controller for type 1 diabetic patients

In this paper, an optimal PID-FLC (Proportional Integral Derivative Fuzzy Logic Controller) is proposed. The design of this system aims to control blood glucose elevation in type 1 diabetic patients. An automated system integrated with a miniaturized insulin infusion pump and a continuous biosensor that measures the glucose level has been developed recently to replace beta cells in the pancreas. The main contribution of the paper is that it introduces an automated insulin delivery system based on a parallel PID-FLC structure tuned with genetic algorithms. This control system was compared to an optimal PIFLC and PD-FLC as well as a reference model. The results revealed that the controllers could maintain the glucose level within a normal range. In addition, the performance of the PIFLC and the PID-FLC was very close to that of beta cells in normal individuals. So, they can be exploited prosperously as control systems to manage blood glucose concentrations in Type 1 diabetic patients. In addition, the PID-FLC saved the amount of the daily delivered insulin, while, its performance was approximately the same as that of the PI-FLC.

Nano-engineered living bacterial motors for active microfluidic mixing

Active micromixers with rotating elements are attractive microfluidic actuators in many applications because of their mixing ability at a short distance. However, miniaturising the impeller design poses technical challenges including the fabrication and driving means. As a possible solution inspired by macro magnetic bar-stirrers, this study proposes the use of tethered, rotating bacteria as mixing elements. A tethered cell is a genetically engineered, harmless Escherichia coli (E. coli) attached to a surface by a single, shortened flagellum. The tethered flagellum acts as a pivot around which the entire cell body smoothly rotates. Videomicroscopy, image analysis and computational fluid dynamics (CFD) are utilised to demonstrate a proof-of-concept for the micro mixing process. Flow visualisation experiments show that a approximately 3 microm long tethered E. coli rotating at approximately 240 rpm can circulate a 1 microm polystyrene bead in the adjacent area at an average speed of nearly 4 microm/s. The Peclet (Peb) number for the stirred bead is evaluated to approximately 4. CFD simulations show that the rotary motion of a tethered E. coli rotating at 240 rpm can generate fluid velocities, up to 37 microm/s bordering the cell envelop. Based on these simulations, the Strouhal number (St) is calculated to about 2. This hybrid bio-inorganic micromxer could be used as a local, disposable mixer.

A prototype Ultraviolet Light Sensor based on ZnO Nanoparticles/Graphene Oxide Nanocomposite Using Low Temperature Hydrothermal Method

A new prototype UV nanosensor using ZnO nanoparticles (NPs)/graphene oxide (GO) nanocomposite (ZnO-NP/GO) on silicon substrate is reported in this paper. The hybrid nanocomposite structure has been developed by an optimized hydrothermal process at low growth temperature (~50 °C). In this hybrid nanosensor, the ZnO nanoparticles act as UV- absorbing and charge carrier generating material, while graphene with its superior electrical conductivity has been used as a charge transporting material. Various nanostructure characterization techniques were intensively utilized including SEM, EDX, XRD, FTIR and UV-VIS. Also, the I-V measurement was employed to evaluate the prototype sensor. The morphological SEM analysis showed that the ZnO-NPs (average diameter of 20 nm) were dispersed evenly on the GO sheets. As well, the EDX spectra confirmed the exact chemical composition of the intended structure. The room temperature UV-VIS measurement revealed an enhanced optical absorption of UV-light at an absorption band centered on 375 nm. The improved optical and electrical properties were observed at an optimum relative concentration of 1:10. Under UV light illumination, the measured I-V characteristic of the prototype detector exhibited a considerable photocurrent increase of the ZnO-NP/GO nanocomposite compared to pristine ZnO nanostructure. These results can be promising for future enhanced UV- sensing applications.

A living biological nano robot as self-navigator sensor for diseases

In this paper, we experimentally investigated the navigation system of the nonpathogenic strain of E. coli (AW405) and developed a simulator for the locomotion performance of these swimming nanorobots. The swimming behavior of these cells is sensitive to the chemical gradients in their medium. Tissue and disease cells might produce chemical signals in their surroundings. These chemicals have the potential to affect the locomotion behavior of the bacterial cells. Therefore, bacterial cells can be considered as self-navigator nanorobots that are able to discriminate between disease cells such as cancer. Our current experimental and theoretical work is considered as a platform to this novel idea of early detection of problematic diseases.

A real time vision feedback system for automation of a nano-assembly manipulator inside scanning electron microscope

In this paper, a vision feedback mechanism is simulated and proposed to automate the assembly process of nano-devices. The bottom-up approach using heterogeneous assembly at the nanoscale is become recently a doable trail in nano-manufacturing. Nano-manipulators inside a scanning electron microscope (SEM) have been adopted as a nanofabrication method to build nano-devices from various nano-components in real-time. Most of the current nanomanipulators inside SEM are operated manually and take relatively long time to construct nano-devices. Obtaining a feedback signal for precise automated nanomanipulations poses a major technical challenge. This research proposes the use of a vision feedback control to automate the most well-known Zyvex® nano-manipulators inside SEM. A proof of concept is demonstrated using a macroscale stage with a vision feedback system, end-effector and computer integrated controller based on Labview package. The evaluation of this mechanism is conducted by observing the positioning of an X-Y actuated end-effector accurately near a predefined target. This feedback system can be integrated with Zyvex® nano-manipulators inside a SEM to automate the nano-manufacturing process.

Novel Selective Detection Method of Tumor Angiogenesis Factors Using Living Nano-Robots

This paper reports a novel self-detection method for tumor cells using living nano-robots. These living robots are a nonpathogenic strain of E. coli bacteria equipped with naturally synthesized bio-nano-sensory systems that have an affinity to VEGF, an angiogenic factor overly-expressed by cancer cells. The VEGF-affinity/chemotaxis was assessed using several assays including the capillary chemotaxis assay, chemotaxis assay on soft agar, and chemotaxis assay on solid agar. In addition, a microfluidic device was developed to possibly discover tumor cells through the overexpressed vascular endothelial growth factor (VEGF). Various experiments to study the sensing characteristic of the nano-robots presented a strong response toward the VEGF. Thus, a new paradigm of selective targeting therapies for cancer can be advanced using swimming E. coli as self-navigator miniaturized robots as well as drug-delivery vehicles.

Intelligent control of miniature holonomic vertical take-off and landing robot

This paper discusses the development of a fuzzy based controller for miniaturized unmanned aerial vehicle (UAV).This controller is designed to control the center-of-gravity (CoG) in a new configuration of coaxial miniaturized flying robot (MFR). The idea is to shift the CoG by controlling two pendulums located in perpendicular directions; each pendulum ends with a small mass. A key feature of this work is that the control algorithm represents the original nonlinear function that describes the dynamics of the proposed system. The controller model incorporates two cascaded subsystems: PD and PI fuzzy logic controllers. These two controllers regulate the attitude and the position of the flying robot, respectively. A model of the proposed controllers has been developed and evaluated in terms of stability and maneuverability. The results show that the presented control system can be used efficiently for the MFR applications.