Delivery of Exenatide and Insulin Using Mucoadhesive Intestinal Devices.

A major disadvantage associated with current diabetes therapy is dependence on injectables for long-term disease management. In addition to insulin, incretin hormone replacement therapies including exenatide have added a new class of drugs for Type-2 diabetes. Although efficacious, patient compliance with current diabetic therapy is poor due to requirement of injections, inability to cross the intestinal epithelium and instability in the gastrointestinal tract.

Mucoadhesive intestinal devices for oral delivery of salmon calcitonin.

One of the major challenges faced by therapeutic polypeptides remains their invasive route of delivery. Oral administration offers a potential alternative to injections; however, this route cannot be currently used for peptides due to their limited stability in the stomach and poor permeation across the intestine. Here, we report mucoadhesive devices for oral delivery that are inspired by the design of transdermal patches and demonstrate their capabilities in vivo for salmon calcitonin (sCT).

A permeation enhancer for increasing transport of therapeutic macromolecules across the intestine.

Delivery of therapeutic macromolecules is limited by the physiological limitations of the gastrointestinal tract including poor intestinal permeability, low pH and enzymatic activity. Several permeation enhancers have been proposed to enhance intestinal permeability of macromolecules; however their utility is often hindered by toxicity and limited potency. Here, we report on a novel permeation enhancer, Dimethyl palmitoyl ammonio propanesulfonate (PPS), with excellent enhancement potential and minimal toxicity.

Permeation of insulin, calcitonin and exenatide across Caco-2 monolayers: measurement using a rapid, 3-day system.

Objectives: Caco-2 monolayers are one of the most widely used in vitro models for prediction of intestinal permeability of therapeutic molecules. However, the conventional Caco-2 monolayer model has several drawbacks including labor-intensive culture process, unphysiological growth conditions, lack of reproducibility and limited throughput. Here, we report on the use of 3-day Caco-2 monolayers for assessing permeability of polypeptide drugs.

A reagent to facilitate protein recovery from cells and tissues.

Collection of cytosolic proteins from cells and tissues is the first and essential step in many bioanalytical assays that play a key role in medical applications such as diagnostics, theranostics, and regenerative medicine. Dissolution of cell and tissue constituents without deactivation of their constituents, especially proteins, is a challenging task. Here, we report on a recently identified cell and tissue lysis agent in terms of its ability to solubilize cells and tissues as well as preservation of cellular proteins, particularly enzymes.

Mucociliary clearance of micro- and nanoparticles is independent of size, shape and charge--an ex vivo and in silico approach.

The fate of inhaled particles after deposition onto the pulmonary mucosa is far from being solved, in particular with respect to mucociliary clearance and mucus penetration. Due to the fact that these phenomena govern pulmonary residence time and thus bioavailability, they are highly relevant for any kind of controlled release formulation delivered via that route. This study applies ex vivo and in silico approaches to investigate the dependency of muciliary clearance of micro-, submicrometer and nanoparticles on size, shape, charge and surface chemistry of such particles.

Polymer nanoneedle-mediated intracellular drug delivery.

Delivery of drugs into the cellular cytoplasm of target cells represents a major hurdle in treating various diseases. This challenge can be addressed by encapsulation of drugs onto or within nanoparticles, which can then be targeted to diseased cells. Here, needle-shaped particles are shown to exhibit substantially higher cytoplasmic delivery of drugs such as siRNA compared to their spherical counterparts.

Adaptive micro and nanoparticles: temporal control over carrier properties to facilitate drug delivery.

Recent studies have led to significant advances in understanding the impact of key drug carrier properties such as size, surface chemistry and shape on their performance. Converting this knowledge into improved therapeutic outcomes, however, has proved challenging. This owes to the fact that successful drug delivery carriers have to navigate through multiple physiological hurdles including reticuloendothelial system (RES) clearance, target accumulation, intracellular uptake and endosomal escape.

Needle-shaped polymeric particles induce transient disruption of cell membranes.

Nano- and microparticles of various shapes have recently been introduced for various drug-delivery applications. Shape of particles has been shown to have an impact on various processes including circulation, vascular adhesion and phagocytosis. Here, we assess the role of particle geometry and surface chemistry in their interactions with cell membranes.

Macrophages recognize size and shape of their targets.

Recognition by macrophages is a key process in generating immune response against invading pathogens. Previous studies have focused on recognition of pathogens through surface receptors present on the macrophage's surface. Here, using polymeric particles of different geometries that represent the size and shape range of a variety of bacteria, the importance of target geometry in recognition was investigated.

Flow and adhesion of drug carriers in blood vessels depend on their shape: a study using model synthetic microvascular networks.

Development of novel carriers and optimization of their design parameters has led to significant advances in the field of targeted drug delivery. Since carrier shape has recently been recognized as an important design parameter for drug delivery, we sought to investigate how carrier shape influences their flow in the vasculature and their ability to target the diseased site. Idealized synthetic microvascular networks (SMNs) were used for this purpose since they closely mimic key physical aspects of real vasculature and at the same time offer practical advantages in terms of ease of use and direct observation of particle flow.

Endocytosis and Intracellular Distribution of PLGA Particles in Endothelial Cells: Effect of Particle Geometry.

Targeting, internalization, and intracellular trafficking of carriers are key processes in drug delivery to endothelial cells. We synthesized PLGA particles with spherical and elliptical disk geometries and investigated the effect of particle shape on rate of particle endocytosis and their intracellular distribution in endothelial cells. Elliptical disks (aspect ratio of 5) were endocytosed at a slower rate compared to spheres (1.

Red blood cell-mimicking synthetic biomaterial particles.

Biomaterials form the basis of current and future biomedical technologies. They are routinely used to design therapeutic carriers, such as nanoparticles, for applications in drug delivery. Current strategies for synthesizing drug delivery carriers are based either on discovery of materials or development of fabrication methods.