Preparation of 2D sequences of corneal images for 3D model building

A confocal microscope provides a sequence of images, at incremental depths, of the various corneal layers and structures. From these, medical practioners can extract clinical information on the state of health of the patient's cornea. In this work we are addressing problems associated with capturing and processing these images including blurring, non-uniform illumination and noise, as well as the displacement of images laterally and in the anterior–posterior direction caused by subject movement. The latter may cause some of the captured images to be out of sequence in terms of depth. In this paper we introduce automated algorithms for classification, reordering, registration and segmentation to solve these problems. The successful implementation of these algorithms could open the door for another interesting development, which is the 3D modelling of these sequences

Quantifying nonspecific cell -surface interactions using total internal reflection microscopy.

Having an insight into nonspecific cell-surface interactions is a key to having a more comprehensive understanding of cell-surface adhesion, which benefits the development of biocompatible materials. The surfaces of the biocompatible materials must create appropriate interactions with other cells, particularly promoting or inhibiting cell adhesion. For example, to control diabetes, the surfaces of immunoprotective membranes used to protect the transplants of islets of Langerhans must not bind with protein molecules in the body fluids and must not cause cell adhesion. On the other hand, the surfaces of polymeric membranes used to grow tissues must initiate cell adhesion. To understand cell-surface adhesion controlled by nonspecific forces, it is critical to accurately quantify and control the magnitudes of forces experienced by the cell and surface when they encounter each other. This work utilizes Total Internal Reflection Microscopy (TIRM) to measure nonspecific interactions between liposomes used as model cells and glass plates. The liposomes, possessing ideal optical and physical properties were developed for use with TIRM. The objective was to identify the variables important for controlling electrostatic double layer, van der Waals, and steric forces and the effect of these variables on the adhesion of cells. The variables studied include the solution ionic strength, the liposome composition, the liposome size, the number of lamellae, the stabilizer molecular weight, and the stabilizer molar content. This work will enable the prediction and control of nonspecific cell-surface interactions. As a result, it will be possible to design biocompatible materials used for different purposes by the variation of the system parameters. In addition, this work shows that TIRM is very effective in quantifying nonspecific cell-surface interactions governed by electrostatic double layer, van der Waals, and steric forces.Ph.D.Applied SciencesChemical engineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/131566/2/3057922.pd

Pluronic F127/Pluronic P123/vitamin E TPGS mixed micelles for oral delivery of mangiferin and quercetin: Mixture-design optimization, micellization, and solubilization behavior

Mixed micelles (MMs) of Pluronic F127 (F127), Pluronic P123 (P123), and Vitamin E TPGS (TPGS) copolymers were prepared by the thin-film sonication method to encapsulate two phenolics with different polarities: magniferin (MGF) and quercetin (QCT). Mixture design was applied for the multi-response optimization of formulations of MGF-loaded MMs (MGF-MMs) and QCT-loaded MMs (QCT-MMs) with high encapsulation efficiency (EE) and drug loading (DL), but low critical micelle concentration (CMC). The optimal mass fractions of F127/P123/TPGS were 0.120/0.328/0.552 for MFG-MMs and 0.131/0.869/0.000 for QCT-MMs, providing EE (>95% (w/w)) and DL (>4.5% (w/w)) higher than those obtained by their individual copolymer components. The CMCs of MFG/QCT-MMs, detected by dynamic light scattering (DLS), were 0.009 ± 0.001 and 0.011 ± 0.001% (w/v), respectively, slightly lower than those obtained by profile analysis tensiometry (PAT). The results revealed that the PAT-CMC represented complete MM formation, while the DLS-CMC detected mono-molecular micelles. The MGF/QCT-MMs showed spherical morphology with diameters of 14.26 ± 0.52 and 21.50 ± 0.37 nm, and their zeta-potentials were −2.89 ± 1.70 and −3.22 ± 1.92 mV, respectively. Nuclear overhauser effect spectroscopy showed that MGF located in both hydrophilic and hydrophobic parts of MMs by orienting its xanthone backbone towards the core, but its glucoside close to the corona. QCT was preferentially located in the PPO core. Both MGF/QCT-MMs had excellent dissolution ability and sustained release in the simulated gastrointestinal environment. This study demonstrated that mixture design was successfully applied for multi-response optimization MM formulations of MGF and QCT, and the developed MMs had potential application as nanoparticle-based drug delivery systems