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Argyropoulos C.,University of Texas at Austin | Chen P.-Y.,University of Texas at Austin | Monticone F.,University of Texas at Austin | D'Aguanno G.,Aegis USA | Alu A.,University of Texas at Austin
Physical Review Letters | Year: 2012

Here we extend the reach of Fano resonant coupling by combining this concept with cloaking and plasmonic resonances in a single nonlinear nanoparticle, in order to realize giant all-optical scattering nanoswitches controlled by moderate pumping intensities. We show that a core-shell nonlinear plasmonic particle may be designed to abruptly switch from being completely cloaked to being strongly resonant, with up to a 40 dB cross-sectional difference. Self-tunable optical cloaks and resonant scatterers are envisioned for use as efficient all-optical switches and nanomemories. © 2012 American Physical Society. Source


Argyropoulos C.,University of Texas at Austin | Chen P.-Y.,University of Texas at Austin | D'Aguanno G.,Aegis USA | Engheta N.,University of Pennsylvania | Alu A.,University of Texas at Austin
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

The anomalous transmission properties of zero-permittivity ultranarrow channels are used to boost Kerr nonlinearities and achieve switching and bistable response for moderate optical intensities. Strong field enhancement, uniform all along the channel, is a typical feature of ε-near-zero supercoupling and is shown to be particularly suited to enhance nonlinear effects. This is obtained by designing narrow apertures at cutoff in a plasmonic screen. We show that this nonlinear mechanism can significantly outperform nonlinearities in traditional Fabry-Pérot resonant gratings. © 2012 American Physical Society. Source


Maggio E.T.,Aegis USA
Journal of Excipients and Food Chemicals | Year: 2010

Aggregation is rapidly emerging as a key issue underlying multiple deleterious effects for peptide and protein-based therapeutics, including loss of efficacy, altered pharmacokinetics, reduced stability or product shelf life, and induction of unwanted immunogenicity. In addition, bioavailability and pharmacokinetics of a self-associating peptide can be influenced by aggregate size and the ease of disruption of the non-covalent intermolecular interactions at the subcutaneous site. This review highlights the various types of aggregates encountered in peptide and protein formulation, methods useful in detecting aggregates, and recent developments in the use of excipients to prevent or reduce peptide and protein aggregation. © IPEC-Americas Inc. Source


Maggio E.T.,Aegis USA
Journal of Excipients and Food Chemicals | Year: 2014

Intranasal drug delivery is becoming an increasingly important form of drug administration for chronic and chronic-intermittent diseases. Important new applications currently in development include drugs for diabetes, osteoporosis, obesity, certain types of convulsive disorders, migraine headaches, symptomatic pain relief, nausea, and anxiety, among others. Transmucosal absorption across the nasal mucosa is generally limited to molecules less than 1,000 Da. Systemic delivery of larger molecules requires formulations with a suitable transmucosal absorption enhancer. More than one hundred potential transmucosal absorption enhancing excipients have been tested to date. Nearly all have failed due to poor effectiveness or unacceptable toxicity to the mucosal tissue. Alkylsaccharides, cyclodextrins, and chitosans have emerged as leading candidates for potential broad clinical applications allowing the development of convenient, patient-friendly, needle free formulations of small molecule drugs, as well as, peptide and protein drugs that can be administered at home, at work, or in other public and private settings outside of the doctor's office or hospital environment. © IPEC-Americas Inc. Source


The most effective option for the medical treatment of patients with acromegaly is the use of somatostatin analogs. Octreotide acetate is a synthetic analog of somatostatin, with similar effects but a prolonged duration of action. Octreotide acetate is routinely given by subcutaneous (s.c.) or intramuscular injection. In the present study, we examined the feasibility of oral delivery of octreotide acetate reconstituted with increasing concentrations (0.5%, 1.5% and 3.0%) of Intravail®, a patented alkylsaccharide transmucosal absorption enhancing agent. The pharmacokinetics of orally delivered (by gavage) octreotide acetate in Intravail® were compared to those of octreotide acetate administered subcutaneously in sodium acetate buffer to male Swiss Webster mice. Oral delivery of octreotide acetate in 0.5% Intravail® significantly enhanced total uptake (1254.08. ng/ml/min vs. 311.63. ng/ml/min, respectively), serum half-life (52.1. min vs. 1.3. min, respectively), and relative bioavailability (4.0 vs. 1.0, respectively) when compared to delivery by s.c. injection. Higher concentrations of Intravail® did not further enhance uptake, serum half-life, or bioavailability. The results of this study indicate that oral delivery of octreotide acetate in Intravail® is feasible, and is an effective method of administration which significantly improves uptake, bioavailability and half-life when compared to s.c. injection. Thus, oral delivery of octreotide acetate in Intravail® may have significant potential as a novel, non-invasive approach to the treatment of acromegaly and octreotide-mediated symptoms of carcinoid and VIP-secreting tumors. © 2011 Elsevier B.V. Source

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