Standard in vitro toxicity testing utilizes a single organ cell model to identify mechanisms of toxicity and screen a large number of compounds for efficacy or toxicity relative to reference compounds. These data are then used to rank order compounds. In addition, In vitro toxicity testing can be used to identify adverse outcome pathways, targets of toxicity critical to understanding overall chemical hazard and for performing risk assessment.

In the sections below we discuss common cell models and their uses. Many of the in vitro methods used industry wide were pioneered by IONTOX founder James McKim, Ph.D. D.A.B.T. 15 years ago. IONTOX continues Dr. McKim's trend of innovation by finding and developing the latest in vitro toxicity testing and putting them to work for your business.

Over the past 15 years approaches to dermal toxicity screening have significantly evolved. Human skin cell and tissue models have improved, we now have more sensitive markers of toxicity and new in vitro assays for assessing adverse effects.

Pharmaceutical, chemical, and cosmetic companies who design products for topical use not only have to understand if a product is safe, but they are often required to do these safety studies without the use of animals. This has led to the development of new in vitro models for evaluating dermal exposure to chemicals. These models have been shown to be highly predictive of actual effects in human skin.
HaCaT Cells

HaCaT cells offer a good first screen for companies seeking to understand epidermal compound exposure. Using the immortalized HaCaT cell line offers your company an affordable way to test multiple compounds in a human keratinocyte model prior to moving to a primary cell model or animal study.

To request a quote for an in vitro dermal toxicity study fill out the contact form on iontox.com or email info@iontox.com. All contact requests will be responded to within one to two business days.

Pharmaceutical, tobacco, nutraceutical, cosmetic, and agro-chemical companies often need to identify hazards associated with inhalation of products. Many chemical agents gain entry to the body via inhalation and therefore assessment of normal lung function is essential for understanding chemical safety.

When seeking to run inhalation studies, many companies use animal testing to identify potential effects of a compound on lung, but these tests are expensive and human inhalation studies are not ethically feasible. A human in vitro lung model gives your company the ability to understand in vivio toxicity following compound exposure without the added cost of traditional animal testing.

In animals and humans, pulmonary exposure to inhaled materials occurs in the lumen of the respiratory airways. To evaluate drugs and chemicals for their effects on lung health and function, multiple cell lines and tissue models are used to evaluate compound effects.
Human reconstructed tissues often provide the most relevant in vitro model. For lung toxicity testing IONTOX recommends the MucilAir™ tissue model manufactured by Epithelex in Geneve, Switzerland. The MucilAir™ tissue model provides a three dimensional system for understanding the effects of test compounds on the lung. MucilAir™ is cultured at an air-liquid interface, which allows test compounds to be applied in a more in vivo like manner.

For lung toxicity studies IONTOX uses monitor markers for inflammation ( e.g. IL-6, IL-8, TNFα, MMP1), metabolism (e.g. CYP1A1/2, CYP1B1, CYP2B6, CYP2E1, CYP2J2, and CYP3A5), and toxicity (e.g. ATP, membrane damage, oxidative stress, mitochondrial function, apoptosis). Additional markers are available on request. Effects on these endpoints are evaluated relative to dose and time, which gives your company a more accurate extrapolation of in vitro data to in vivo effects in humans.

To request a quote for an in vitro lung toxicity study fill out the contact form on iontox.com or email info@iontox.com. All contact requests will be responded to within one to two business days.

Companies with new pharmaceutical, nutraceutical, cosmetic, or agro-chemical compounds seeking to identify and understand potential adverse effects from chemical exposure must understand liver toxicity as a first step. The liver regulates several important processes necessary for survival and is often the first organ to be exposed to a test agent. Therefore, understanding compound effects on liver is a critical first step.

IONTOX offers a wide variety of standard tumor cell lines from multiple species, such as HepG2 cells (human) or H4IIE cells (Rat), that can provide important information on specific targets of toxicity, or be used to prioritize a large set of test compounds for toxicity relative to reference compounds in a screening environment. If desired, when a liver assay is performed with IONTOX in the context of exposure concentration relative to in vivo plasma concentrations reasonable extrapolations to animals or humans can be made.

The liver consists of a basolateral side (sinusoidal blood in vivo or media in vitro) and an apical side (canalicular membrane forming the bile pocket). Establishing this polarity with functional transporter proteins and maximal stability of metabolizing enzymes is essential for understanding whether a test compound will be hepatotoxic. Therefore, when it is necessary to understand compound effects under more physiologically relevant conditions a more in vivo like liver model is required.

To give your company the best possible understanding of chemical effects on the liver, in vitro, IONTOX collaborates with Qualyst Transporter Solutions utilizing the company’s state-of-the art B-Clear Technology. By using the Qualyst B-Clear Technology it is possible to test the effects of chemicals on liver transporters, and cytochrome P450 enzyme induction/inhibition, intracellular accumulation of the test material, biliary clearance, intrinsic liver clearance, potential drug-drug interactions and cytotoxicity. In addition, Qualyst has refined their liver system to allow for detection of chemically induced cholestatic liver toxicity and steatosis. This model is still considered to be the gold standard for the in vitro evaluation of chemical effects on the liver.

A wide range of endpoint assays for evaluating liver toxicity allow our clients to study the key markers of inflammation, apoptosis, necrosis, mitochondrial damage, and oxidative stress. In addition to primary human and rat hepatocytes, IONTOX offers clients many other hepatic cell-lines as potential test systems. For help selecting the best in vitro test system to answer your specific research or screening questions, contact an IONTOX scientist today.

What IONTOX can help you understand in regards to liver toxicity:
✓Chemical/ drug accumulation
✓Compound effects on transporters
✓Determine biliary clearance
✓Identify cholestatic compounds
✓Describe the mechanism of toxicity

To request a quote for anin vitro liver toxicity study fill out the contact form on iontox.com or email info@iontox.com. All contact requests will be responded to within one to two business days.

Pharmaceutical, nutraceutical, food additive, and chemical companies need to know how their compounds affect the intestinal cell health. Chemicals entering the intestinal tract can affect the intestinal epithelium.

Compounds that enter the body by the oral route, enter the gastrointestinal tract (GIT). The GIT is a complex system that facilitates the digestion and absorption of food derived fats, carbohydrates, and proteins. The primary site of enzymatic breakdown and absorption is the upper portion of the small intestine (duodenum). Chemicals that enter the intestine via ingestion of medicines or food products are absorbed into the portal circulation and carried to the liver. During the absorption process compounds can undergo metabolism by Cytochrome P450 enzymes in the intestinal epithelium. Exogenous compounds can also induce inflammatory responses in the intestine or cause direct toxicity.

The effects of chemicals on human intestinal heath must be evaluated using an in vitro model that is physiologically relevant. Standard tumor derived intestinal cell lines, such as HT-29, Caco2, and HCT-8 have been used to understand permeability or specific mechanisms of chemical toxicity. However, these models do not provide the multiple cell layers, or the production of mucous that are present in vivo. These components of the intestinal tract can have a tremendous influence on chemical toxicity and permeability.To address this issue the use of reconstructed human three dimensional tissues cultured at an air-liquid interface provides an excellent solution. A three dimensional tissue model has many of the physiological attributes of in vivo intestinal epithelium.

Based on the questions being asked, IONTOX scientists will assist you in selecting the best in vitro model for your study.

Advantages to working with IONTOX scientists to study intestinal toxicity.
✓Extensive experience with human 3D models
✓Able to obtain compound permeability data
✓Determine effects on key intracellular pathways
✓Choice of intestine model that best fits your research goals
✓Custom designed experimental protocols

When working with IONTOX your company can select a wide range of intestinal toxicity tests that can be utilized with a verity of different intestinal models. The question being asked will determine the best cell model for your application. The most in vivo like model is EpiIntestinal™ (MatTek, Corp). This human reconstructed 3-dimensional tissue represents many key features of in vivo intestinal epithelium (see figure below). The tissue incorporates enterocytes, paneth cell, M cells, tuft cells and intestinal stem cells into a highly differentiated, polarized epithelium.

The EpiIntestinal™ tissue is cultured at the air-liquid interface (ALI), which enables physiological (luminal) exposures to occur. EpiIntestinal™ recapitulates many aspects of normal intestinal function including barrier, metabolism, inflammatory and toxicity responses, similar to native human intestinal tissue.

MatTek’s EpiIntestinal combined with the expertise of IONTOX scientists gives your company a precise understanding of compound permeability, metabolism, and inflammation processes in regards to the gastrointestinal tract (GIT).

In addition to using a 3-dimensional model for studying intestinal toxicity, your company can select from a variety of human cell lines including, Caco-2, HT-29, HT-29-MTX, and HCT8 (McKim et al., 2016). These cell lines are extremely useful when questions related to compound effects on a specific pathway are asked or when a larger number of compounds must be screened for relative effect and prioritization. When working with these models IONTOX scientists put half a century of experience and knowledge of the latest in vitro technology to work for your business.

To request a quote for an in vitro intestinal toxicity study fill out the contact form on iontox.com or email info@iontox.com. All contact requests will be responded to within one to two business days.

Pharmaceutical, chemical, and cosmetic companies are responsible for knowing that their products are safe for human use and in the event of misuse that any adverse systemic effects are known. A challenge facing these industries is the immediate need to reduce or replace animal testing. This means new in vitro alternatives must be found to test new drug candidates, chemical ingredients, or finished products.

In the past, companies could evaluate the safety of new drugs, chemicals, or finished products in animal studies. Although, some animal studies are still done on a routine basis there is real regulatory, consumer, and corporate pressure to reduce, refine, and even replace animal toxicity testing.

Current in vitro models for kidney testing focuses mainly on immortalized cell lines (e.g. HK-2). These models are useful for identifying intracellular mechanisms of toxicity and for toxicity screening studies that can be used to rank order a group of new molecular entities. In order to produce scientifically valid in vitro toxicity data for kidney, the cell model should be physiologically similar to its in vivo counterpart.

To give your company the most accurate in vivo prediction, IONTOX employs human renal proximal tubule epithelial cells with functional transporter systems combined with concentration response, specific biomarkers for kidney, estimated plasma concentrations, and reference compounds, which make predicting in vivo kidney toxicity possible.

To request a quote for an in vitro kidney toxicity study fill out the contact form on iontox.com or email info@iontox.com. All contact requests will be responded to within one to two business days.