Robert L. Chapman

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NOVAFECT chitosans are ultrapure chitosan oligomers that were recently marketed as carriers for non-viral gene therapy. There are no reports on systematic design and improvement of formulations based on NOVAFECT chitosans for gene delivery. Therefore, we have designed and characterized chitosan-DNA nanoparticles based on NOVAFECT. We found that the size of(More)
BACKGROUND Corneal gene therapy can potentially treat acquired and inherited corneal disorders that otherwise lead to blindness. In a previous study on the development of effective vectors for corneal gene delivery, we showed that a particular formulation of chitosan-DNA nanoparticles, based on ultrapure chitosan oligomers injected into rat corneas, led to(More)
Freeze-fracture electron microscopy of propane-jet-frozen samples has been employed to investigate vesicle-mediated secretion and membrane recycling events in carrot (Daucus carota L.) and sycamore maple (Acer pseudoplatanus L.) suspension-culture cells. Stabilization of the cells by means of ultrarapid freezing has enabled us to preserve the cells in a(More)
Gene therapy to the cornea can potentially correct inherited and acquired diseases of the cornea. Factors that facilitate corneal gene delivery are the accessibility and transparency of the cornea, its stability ex vivo and the immune privilege of the eye. Initial corneal gene delivery studies characterized the relationship between intraocular modes of(More)
Suspension culture cells of carrot, Daucus carota L., and sycamore, Acer pseudoplatanus L., were freeze-fractured after ultrarapid freezing without fixation or cryoprotection in a propane-jet freezer. Infrequently, rosettes (ca. 24 nm diameter) of six (occasionally five) subunits (ca. 8 nm diameter) were observed in P-face views of the plasma membrane of(More)
INTRODUCTION It is estimated that about 70-80% of the world's population relies on non-conventional medicine, mainly of herbal origin. However, owing to the nature and sources of herbal medicines, they are sometimes contaminated with toxic heavy metals such as lead, arsenic, mercury and cadmium, which impose serious health risks to consumers. It is critical(More)
The American Association of Pharmaceutical Scientists (AAPS) covers the full range of areas of expertise associated with the resolution of concerns pertaining to drugs and drug products. This editorial highlights the initiatives, issues, and challenges that are the forefront of the pharmaceutical sciences in 2007. It also provides an overview of how these(More)
Abbreviations: Å: Angstrom; AUC: Area Under The Curve; cGMP: Current Good Manufacturing Practices; °C: Degrees Celcius; hplc: High Performance Liquid Chromatography; hr: Hour; Mg: Microgram; ML: microliter; mc: micron; mg: milligram; mL: milliliters; mL/min.: milliliters per minute; mm: millimeters; nm: nanometer; C18: octadecylsilane; PC: Personal(More)