Many research projects are underway to improve the diagnosis and therapy in ophthalmology. Indeed, visual acuity deficits affect 285 million people worldwide and different strategies are being developed to strengthen patient care. One of these strategies is the use of gold nanoparticles (GNP) for their multiple properties and their ability to be used as both diagnosis and therapy tools. This review exhaustively details research developing GNPs for use in ophthalmology. The toxicity of GNPs and their distribution in the eye are described through in vitro and in vivo studies. All publications addressing the pharmacokinetics of GNPs administered in the eye are extensively reviewed. In addition, their use as biosensors or for imaging with optical coherence tomography is illustrated. The future of GNPs for ophthalmic therapy is also discussed. GNPs can be used to deliver genes or drugs through different administration routes. Their antiangiogenic and anti-inflammatory properties are of great interest for different ocular pathologies. Finally, GNPs can be used to improve stereotactic radiosurgery, brachytherapy, and photothermal therapy because of their many properties.
A large number of drugs are administered on different mucosal surfaces. However, due to the poor mucoadhesion of the current formulations, their bioavailability is often very low. The development of efficient mucoadhesive drug delivery systems is thus crucial for improving the performance of these drugs. The mucoadhesive properties of gold nanoparticles were investigated. First, two types of gold nanoparticles were synthesized: AuNP1 and AuNP2. AuNP1 only contain internal thiol groups on their metallic core, and AuNP2 contain both internal and peripheral thiol groups. Different protocols based on an adapted quantitative colorimetric method, UV-visible and fluorescence spectroscopies were then developed to gather information on their mucoadhesive properties. Moreover, a global correction factor for the inner filter effect in spectrofluorimetry was proposed, and the data obtained were compared to those commonly used in the literature. Mucins deeply interact with AuNP1, perturbing their core, whereas they remain at the periphery of AuNP2. The quantitative method suggests that a larger number of mucins interact with AuNP2. The establishment of this protocol could be applied to assess the mucoadhesive properties of other stable molecules. This mucoadhesive property of gold nanoparticles could be combined with their drug delivery ability in order to improve the medication administered on mucosa.
Nanotechnologies are increasingly being developed for medical purposes. However, these nanomaterials require ultrastability for better control of their pharmacokinetics. The present study describes three types of ultrastable gold nanoparticles stabilized by thiolated polyethylene glycol groups remaining intact when subjected to some of the harshest conditions described thus far in the literature, such as autoclave sterilization, heat and freeze-drying cycles, salts exposure, and ultracentrifugation. Their stability is characterized by transmission electron microscopy, UV-visible spectroscopy, and dynamic light scattering. For comparison purposes, two conventional nanoparticle types were used to assess their colloidal stability under all conditions. The ability of ultrastable gold nanoparticles to encapsulate bimatoprost, a drug for glaucoma treatment, is demonstrated. MTS assays on human corneal epithelial cells is assessed without changing cell viability. The impact of ultrastable gold nanoparticles on wound healing dynamics is assessed on tissue engineered corneas. These results highlight the potential of ultrastable gold nanoparticles as a drug delivery system in ocular therapy.
UDP-3-O-((R)-3-hydroxymyristoyl)-N-glucosamine deacetylase (LpxC) is as an attractive target
for the discovery and development of novel antibacterial drugs to
address the critical medical need created by multidrug resistant Gram-negative
bacteria. By using a scaffold hopping approach on a known family of
methylsulfone hydroxamate LpxC inhibitors, several hit series eliciting
potent antibacterial activities against Enterobacteriaceae and Pseudomonas aeruginosa were identified. Subsequent
hit-to-lead optimization, using cocrystal structures of inhibitors
bound to Pseudomonas aeruginosa LpxC
as guides, resulted in the discovery of multiple chemical series based
on (i) isoindolin-1-ones, (ii) 4,5-dihydro-6H-thieno[2,3-c]pyrrol-6-ones, and (iii) 1,2-dihydro-3H-pyrrolo[1,2-c]imidazole-3-ones. Synthetic methods,
antibacterial activities and relative binding affinities, as well
as physicochemical properties that allowed compound prioritization
are presented. Finally, in vivo properties of lead molecules which
belong to the most promising pyrrolo-imidazolone series, such as 18d, are discussed.
LpxC inhibitors were optimized starting from lead compounds
with
limited efficacy and solubility and with the goal to provide new options
for the treatment of serious infections caused by Gram-negative pathogens
in hospital settings. To enable the development of an aqueous formulation
for intravenous administration of the drug at high dose, improvements
in both solubility and antibacterial activity in vivo were prioritized
early on. This lead optimization program resulted in the discovery
of compounds such as 13 and 30, which exhibited
high solubility and potent efficacy against Gram-negative pathogens
in animal infection models.
Several
synthetic routes toward triazole building block 2-(3-methyl-1H-1,2,4-triazol-1-yl)acetic acid are described. The main
problems of the initial synthetic route via alkylation of 3-Me-1H-1,2,4-triazole, such as poor regioselectivity, low yield,
and purification by column chromatography, could be significantly
improved or completely avoided in the second-generation approaches.
Key concepts for the design of the alternative synthesis approaches
to solve the problem of regioselectivity were the desymmetrization
of 3,5-dibromo-1H-1,2,4-triazole and the de novo synthesis of the triazole core. The scalability
of all routes was demonstrated on >100 g scale.
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