Observation of Silicone Oil Within the Vitreous and Sclera Following Intravitreal Administration of Biotherapeutics Using Insulin Syringes in Cynomolgus Monkeys.

Silicone oil droplets have been reported in the eyes of human patients following intravitreous (IVT) injections with several marketed biotherapeutic products. Intravitreous administration of a novel biotherapeutic in a 14-week cynomolgus monkey study using insulin syringes was associated with 2, non-test-article-related phenomena: "vitreous floater/clear sphere" on indirect ophthalmoscopy and intrascleral "foreign material near injection track" on histopathology. Retrospective analysis of 81 other preclinical studies of IVT administration of novel biotherapeutics found a greater frequency of clear spheres in monkey IVT studies using insulin syringes and formulations containing polysorbate.

Intraosseous Catheter Flow Rates and Ease of Placement at Various Sites in Canine Cadavers.

To compare intraosseous catheter placement difficulty, success rates, and flow rates at four different locations in canine cadavers. Prospective study. Private referral center.

Combined Falling Drop/Open Port Sampling Interface System for Automated Flow Injection Mass Spectrometry.

The aim of this work was to demonstrate and to evaluate the analytical performance of a combined falling drop/open port sampling interface (OPSI) system as a simple noncontact, no-carryover, automated system for flow injection analysis with mass spectrometry. The falling sample drops were introduced into the OPSI using a widely available autosampler platform utilizing low cost disposable pipet tips and conventional disposable microtiter well plates. The volume of the drops that fell onto the OPSI was in the 7-15 μL range with an injected sample volume of several hundred nanoliters.

Compound Property Optimization in Drug Discovery Using Quantitative Surface Sampling Micro Liquid Chromatography with Tandem Mass Spectrometry.

Surface sampling micro liquid chromatography tandem mass spectrometry (SSμLC-MS/MS) was explored as a quantitative tissue distribution technique for probing compound properties in drug discovery. A method was developed for creating standard curves using surrogate tissue sections from blank tissue homogenate spiked with compounds. The resulting standard curves showed good linearity and high sensitivity.

Effects of aberrant Pax6 gene dosage on mouse corneal pathophysiology and corneal epithelial homeostasis.

Background: Altered dosage of the transcription factor PAX6 causes multiple human eye pathophysiologies. PAX6⁺/⁻ heterozygotes suffer from aniridia and aniridia-related keratopathy (ARK), a corneal deterioration that probably involves a limbal epithelial stem cell (LESC) deficiency. Heterozygous Pax6(+/Sey-Neu) (Pax6⁺/⁻) mice recapitulate the human disease and are a good model of ARK.

Expression of ERα, its ERαΔ3 Splice Variant and γ-SYNUCLEIN in Ovarian Cancer: A Pilot Study.

AIMS: Ovarian cancer has the highest mortality of any gynaecological malignancy; this is due to rapid peritoneal spread of tumour cells and neovascularization. Understanding the mechanisms underlying this is critical to developing early diagnostic or treatment strategies. We devised a pilot study to examine the role of γ-SYNUCLEIN (γ-SYN), oestrogen receptor (ER)α, and the splice variant ERαΔ3.

Combining immunolabeling and surface-enhanced Raman spectroscopy on cell membranes.

We applied surface-enhanced Raman spectroscopy (SERS) to immunolabeled endothelial cells to derive enhanced spectra of the biomolecular makeup of the cellular surface. A two-step immunolabeling protocol with gold-conjugated antibodies coupled with silver enhancement to attach silver nanoparticles to the cell surface was employed. This approach generated ∼50-fold SERS enhancement of spectral signals.

Imaging sclera with hard X-ray microscopy.

In this study, the organization of collagen fibrils within the sclera of the eye was investigated using the 7 keV hard X-ray microscope of the Pohang light source and compared to images from electron and atomic force microscopy. From the captured X-ray images, individual collagen fibrils were observed clearly in a spatial resolution much better than 100 nm, both in longitudinal sections and in transverse sections. Some of the collagen fibrils showed evidence of axial periodicity.

Corneal epithelialisation on surface-modified hydrogel implants: artificial cornea.

The objective was to investigate corneal re-epithelialisation of surface-modified polymethacrylate hydrogel implants in order to evaluate them as potential materials for an artificial cornea. Polymethacrylate hydrogels were modified with amines and then coated with different extracellular matrix proteins (collagen I, IV, laminin and fibronectin). The modified hydrogels were surgically implanted into bovine corneas maintained in a 3-D culture system for 5 days.

Microspectroscopy of spectral biomarkers associated with human corneal stem cells.

Purpose: Synchrotron-based radiation (SRS) Fourier-transform infrared (FTIR) microspectroscopy potentially provides novel biomarkers of the cell differentiation process. Because such imaging gives a "biochemical-cell fingerprint" through a cell-sized aperture, we set out to determine whether distinguishing chemical entities associated with putative stem cells (SCs), transit-amplifying (TA) cells, or terminally-differentiated (TD) cells could be identified in human corneal epithelium.

Methods: Desiccated cryosections (10 microm thick) of cornea on barium fluoride infrared transparent windows were interrogated using SRS FTIR microspectroscopy.

Novel sutureless keratoplasty with a chemically defined bioadhesive.

Purpose: The purpose of this study was to evaluate sutureless keratoplasty using a chemically-defined bioadhesive (CDB) made from food or medical additives.

Methods: Sutureless automated lamellar therapeutic keratoplasty (ALTK) using a CDB was performed on three rabbit eyes. Allogenic lamellar graft was transplanted onto the recipient bed using either suture fixation or a sutureless technique using the CDB.

The use of trehalose-treated freeze-dried amniotic membrane for ocular surface reconstruction.

The aim of this study was to evaluate the efficacy and safety of trehalose-treated freeze-dried amniotic membrane (TT-FDAM) for ocular surface reconstruction. Human AM deprived of amniotic epithelial cells was first incubated with 10% trehalose solution, and then freeze-dried, vacuum-packed, and sterilized with gamma-irradiation. The resultant newly developed TT-FDAM was characterized for its physical, biological, and morphological properties by comprehensive physical assays, immunohistochemistry, electron microscopy, cell adhesion assay, 3D cell culture, and an in vivo biocompatibility test.

Targeted cornea limbal stem/progenitor cell transfection in an organ culture model.

Purpose: To optimize a nonviral gene transfection system targeting the corneal limbal stem/progenitor cells.

Methods: A plasmid containing LacZ gene coding for beta-galactosidase (beta-gal) was transfected into human corneal epithelial cells (HCECs) and multilineage progenitor cells (MLPCs) with different transfection reagents, to determine the optimal transfection reagent. In an ex vivo study, the bovine corneal epithelium and limbal stem/progenitor cells were transfected with a microinjection system with a 36-gauge needle that delivered plasmid/transfection reagent (Lipofectamine 2000; Invitrogen, Carlsbad, CA) complexes.

The Saccharomyces cerevisiae actin cytoskeletal component Bsp1p has an auxiliary role in actomyosin ring function and in the maintenance of bud-neck structure.

Iqg1p is a component of the actomyosin contractile ring that is required for actin recruitment and septum deposition. Cells lacking Iqg1p function have an altered bud-neck structure and fail to form a functional actomyosin contractile ring resulting in a block to cytokinesis and septation. Here it is demonstrated that increased expression of the actin cytoskeleton associated protein Bsp1p bypasses the requirement for contractile ring function.

Sutureless amniotic membrane transplantation for ocular surface reconstruction with a chemically defined bioadhesive.

The purpose of this study was to evaluate the efficiency and safety of a sutureless amniotic membrane transplantation (AMT) for ocular surface reconstruction with a chemically defined bioadhesive (CDB). The CDB was synthesized from aldehyded polysaccharides and epsilon-poly(L-lysine), two kinds of medical and food additives, as starting materials. Biocompatibility assay indicated that the CDB showed excellent biocompatibility with in vitro and in vivo ocular surface tissues and most of the CDB was histologically degraded within 4 weeks.

Near-field photothermal microspectroscopy for adult stem-cell identification and characterization.

The identification of stem cells in adult tissue is a challenging problem in biomedicine. Currently, stem cells are identified by individual epitopes, which are generally tissue specific. The discovery of a stem-cell marker common to other adult tissue types could open avenues in the development of therapeutic stem-cell strategies.

Characterization of human corneal stem cells by synchrotron infrared micro-spectroscopy.

Purpose: The purpose of this study was to use high resolution synchrotron radiation-based Fourier Transform Infrared (FTIR) micro-spectroscopy coupled with multivariate analysis to investigate the characteristics of adult stem cell (SC) and transit amplifying (TA) cell populations of the human corneal epithelium.

Methods: Spectra of individual SC and TA cells in situ from cryosections of human cornea were collected using a synchrotron micro-spectroscopy facility at Daresbury laboratory, UK. Multivariate analysis and Mann Whitney U tests were used to analyse the spectral data from the SC and TA cell populations.

The role of dermatopontin in the stromal organization of the cornea.

Purpose: Dermatopontin (DPT) is an abundant component of the stromal extracellular matrix; however, its function in the cornea is poorly understood. This study was conducted to determine whether DPT has a direct role in corneal matrix organization by investigating the ultrastructure of Dpt-null (Dpt(-/-)) mouse corneas.

Methods: Conventional light microscopy was used to compare the corneal thickness of Dpt(-/-) mice with that of the wild type.

Characterization of putative stem cell populations in the cornea using synchrotron infrared microspectroscopy.

Purpose: High-resolution synchrotron radiation-based Fourier transform infrared (SR-FTIR) microspectroscopy coupled with multivariate analysis was used to investigate the characteristics of putative adult stem cell (SC), transiently amplified (TA) cell, and terminally differentiated (TD) cell populations of the corneal epithelium.

Methods: Spectra of individual cells in situ in cryosections of bovine cornea were collected by using a synchrotron microspectroscopy facility at Daresbury Laboratory (United Kingdom). The resultant spectra were analyzed by multivariate analysis.