The Crucial Role of the Interstitial Cells of Cajal in Neurointestinal Diseases.

Neurointestinal diseases result from dysregulated interactions between the nervous system and the gastrointestinal (GI) tract, leading to conditions such as Hirschsprung's disease and irritable bowel syndrome. These disorders affect many people, significantly diminishing their quality of life and overall health. Central to GI motility are the interstitial cells of Cajal (ICC), which play a key role in muscle contractions and neuromuscular transmission. This review highlights the role of ICC in neurointestinal diseases, revealing their association with various GI ailments. Understanding the functions of the ICC could lead to innovative perspectives on the modulation of GI motility and introduce new therapeutic paradigms. These insights have the potential to enhance efforts to combat neurointestinal diseases and may lead to interventions that could alleviate or even reverse these conditions.

Tethered primary hepatocyte spheroids on polystyrene multi-well plates for high-throughput drug safety testing.

Hepatocyte spheroids are useful models for mimicking liver phenotypes in vitro because of their three-dimensionality. However, the lack of a biomaterial platform which allows the facile manipulation of spheroid cultures on a large scale severely limits their application in automated high-throughput drug safety testing. In addition, there is not yet a robust way of controlling spheroid size, homogeneity and integrity during extended culture. This work addresses these bottlenecks to the automation of hepatocyte spheroid culture by tethering 3D hepatocyte spheroids directly onto surface-modified polystyrene (PS) multi-well plates. However, polystyrene surfaces are inert toward functionalization, and this makes the uniform conjugation of bioactive ligands very challenging. Surface modification of polystyrene well plates is achieved herein using a three-step sequence, resulting in a homogeneous distribution of bioactive RGD and galactose ligands required for spheroid tethering and formation. Importantly, treatment of polystyrene tethered spheroids with vehicle and paradigm hepatotoxicant (chlorpromazine) treatment using an automated liquid handling platform shows low signal deviation, intact 3D spheroidal morphology and Z' values above 0.5, and hence confirming their amenability to high-throughput automation. Functional analyses performance (i.e. urea and albumin production, cytochrome P450 activity and induction studies) of the polystyrene tethered spheroids reveal significant improvements over hepatocytes cultured as collagen monolayers. This is the first demonstration of automated hepatotoxicant treatment on functional 3D hepatocyte spheroids tethered directly on polystyrene multi-well plates, and will serve as an important advancement in the application of 3D tethered spheroid models to high throughput drug screening.

Formulation approaches in mitigating toxicity of orally administrated drugs.

This paper provides an overview of current formulation approaches to mitigate toxicity of orally administrated drugs. The formulation approaches are characterized by their intended impact on a drug's pharmacokinetic parameters, pharmacological properties or metabolic pathways. Regulatory opportunities and constraints with focus on U.S. regulations in optimizing a drug's safety or efficacy profile are reviewed. The following formulation approaches are described: (i) pharmacokinetic-modulating and (ii) pharmacodynamic-modulating. In the pharmacokinetic-modulating approach, the pharmacokinetic profile of drug release is modified by, for example, a reduction in peak drug plasma concentration while preserving or improving AUC, thereby potentially reducing toxic effects that may be related to C(max). In the pharmacodynamic-modulating approach, the drug is co-dosed with pharmacologically active or nonpharmacologically active agent or agents intended for mitigation of the drug's toxicity. The pharmacodynamic-modulating approach requires information on the specificity of drug interactions with other compounds and also on metabolic pathways. Examples demonstrating successful formulation work in reducing drug toxicity are provided. The in-depth knowledge of the drug's PK and PD properties combined with a greater understanding of the biology of diseases are necessary for successful drug product formulation leading to optimized in vivo exposure and minimized toxicity.