Organs on a chip

RASHMI MADDA

LIFE SCIENCES DEPARTMENT

Topics of Talk

Introduction 3D Cell Culture Microfluidics Drug responsiveness in 3D Tumor cell culture Lung Functions on a Chip Organs on a Chip Drug toxicity induced model of Pulmonary Edema Discussion Conclusion

R&D Production is on decline

Cells in DishesAnimal Testing

Methods for Clinical Testing

Animal Testing

Introduction

Drug Testing in animal models is time consuming, costly and often does not predict the adverse effects in humans and also 60% of animal models are not able to predict the toxicity .(Hamelton et al 2011)

3D Culture models have recently garnered great attention .

They promote levels of cell differentiation not possible in conventional 2D Culture systems.

3D Culture systems is a large microfabrication technologies from the microchip industry and microfluidics.

It approaches to create cell culture microenvironments

This technology supports both tissue differentiation and recapitulate the tissue-tissue interfaces, spatiotemporal micro gradients and mechanical microenvironments of living organs.

This organs on chips permit the study of human physiology in an organ specific context, enable novel in vitro disease models, and could potentially serve as replacements of animals used in drug development and toxin testing

Failure to predict human drug toxicity

50% of Drug Candidates are failed in clinical trails due to the toxicity. Post marketing with draw or limited use of drugs to adverse drug effects

Drug metabolism as a key determinant of species-species differences in drug toxicology.

The development of safe and effective drugs is currently hampered by the poor predictive power of existing preclinical animals that often lead to failure of drug compounds and late development after they enter in to the human clinical trials.

Huh et al 2011

Cell Architects

Cells feel Human body is the best home for them

Organ on a Chip

Highlights Miniature human organs made by 3D printing could create a "body on a chip" that enables better

drug testing. That futuristic idea has become a new bioprinting project.

The 2-inch "body on a chip" would represent a realistic testing ground for understanding how the human body might react to dangerous diseases, chemical warfare agents and new drugs intended to defend against biological or chemical attacks.

Such technology could speed up drug development by replacing less-ideal animal testing or the simpler testing done on human cells in petri dishes — and perhaps save millions or even billions of dollars from being wasted on dead-end drug candidates that fail in human clinical trials.

Microscale engineering technologies are combined with cultured living human cells to create microfluidic devices that replicate the physiological and mechanical microenvironment of whole living organs.

3D Cell Culture

It is defined as the culture of living cells within the microfabricated devices having 3D structures that mimic tissue and organ specific microarchitechture.

Cell cultures in 3D matrix gels are referred to as 3D ECM gel cultures, 3D gel cultures or conventional 3D cultures.

Microengineering techniques such as Photolithography, replica modeling and microcontact printing are well suited to create structures with defined shapes and positions on the micrometer scale .

That can be used to position cells and tissues control cell shape and function, and create highly structured 3D culture microenvironments.

Organs on a Chip

An Organ-on-a-Chip (OC) is a multi-channel 3-D microfluidic cell culture chip that simulates the activities, mechanics and physiological response of entire organs and organ systems.

It constitutes the subject matter of significant biomedical engineering research, more precisely in bio-MEMS.

The convergence of Lab-on-Chips (LOCs) and cell biology has permitted the study of human physiology in an organ-specific context, introducing a novel model of in vitro multicellular human organisms.

One day, they will perhaps abolish the need for animals in drug development and toxin testing.

Nevertheless, building valid artificial organs requires not only a precise cellular manipulation, but a detailed understanding of the human body’s fundamental intricate response to any event.

A common concern with Organs-on-Chips lies in the isolation of organs during testing. “If you don’t use as close to the total physiological system that you can, you’re likely to run into troubles” says William Haseltine, founder of Rockville, MD. Microfabrication, microelectronics and microfluidics offer the prospect of modeling sophisticated in vitro physiological responses under accurately simulated conditions.

What is Organs on a Chip

Microfluidics Microfluidics: The use of microfabrication techniques from the IC

industry to fabricate channels, chambers, reactors, and active components on the size scale of the width of a human hair or smaller

Credit: Dr. Karen Cheung, UBC ECE

Sample savings – nL of enzyme, not mL Faster analyses – can heat, cool small volumes

quickly Integration – combine lots of steps onto a single

device Novel physics – diffusion, surface tension, and

surface effects dominate This can actually lead to faster reactions!

Why use microfluidics?

• Three PDMS layers are aligned and irreversibly bonded to form two sets of three parallel microchannels separated by a 10-mm-thick PDMS membrane containing an array of through-holes with an effective diameter of 10 mm. Scale bar, 200 mm.

• After permanent bonding, PDMS etchant is flowed through the side channels. Selective etching of the membrane layers in these channels produces two large side chambers to which vacuum is applied to cause mechanical stretching. Scale bar, 200 mm.

• Images of an actual lung- on-a-chip microfluidic device viewed from above.

Manufacturing

PDMS:Poly dimethylsiloxaneECM : Fibronectin, collagen

Cating PDMS

Membrane

Pre polymered the layers

Photolithography of

microchannels

Coat with the binding layer and incubate

at 65 c overnight

Bound irreversibly with

the two layers

Etching the membrane

with TBAF & NMP

Apply Hydrostatic

Pressure &Vacume

Run the etchant solution

Upper chamber is Alveolar chamber

Lower chamber Blood flow

Workflow

Manufacturing

• The microfabricated lung mimic device uses compart- mentalized PDMS microchannels to form an alveolar-capillary barrier on a thin, porous, flexible PDMS membrane coated with ECM.

• The device recreates physiological breathing movements by applying vacuum to the side chambers and causing mechanical stretching of the PDMS membrane forming the alveolar-capillary barrier.

• During inhalation in the living lung, contraction of the diaphragm causes a reduction in intrapleural pressure (Pip), leading to distension of the alveoli and physical stretching of the alveolar-capillary interface.

Biologically inspired design of a human breathing lung-on-a-chip microdevice.

A microengineered model of human pulmonary edema.

IL-2 therapy is associated with vascular leakage that causes excessive fluid accumulation (edema) and fibrin deposition in the alveolar air spaces.

Endothelial exposure to IL-2 (1000 U/ml) causes liquid in the lower microvascular channel to leakinto the alveolar chamber (days 1 to 3) and eventually fill the entire air space (day 4).• During IL-2 treatment, prothrombin (100 mg/ml) and fluorescently labeled fibrinogen (2 mg/ml) introducedinto the microvascular channel form fluorescent fibrin clots (white) over the course of 4 days.• A fluorescence confocal microscopic imageshows that the fibrin deposits (red) in (D) are found on the upper surface of the alveolar epithelium(green). (F) The clots in (D) and (E) are highly fibrous networks, as visualized at high image.

Quantitative analysis of pulmonary edema progression on-chip

Lung on a chip edema Model

Different Organs on a Chip

Organ Rationale Cell Lines Characteristics

Liver p450 activity Hep-G2/C3A hepatomaMarrow sensitive to chemo MEG-01 megakaryoblast line(Hematopoietic) dose limiting toxicity attachment/suspension

inducible attachmentTumor initial tumor primary MES-SA uteran sarcoma(Sensitive) type sensitive to doxorubicinTumor (MDR) resistant tumors can MES-SA/DX-5 variant(Resistant) selected for resistance

to doxorubicin

Human Cell Culture Analog

Sensitive Tumor Cells (MES-SA)

Resistant Tumor Cells (MES-SA/DX-5)

Bone Marrow Blood Cells (MEG-01)

Liver Cells (Hep-G2/C3-A)

Micro Cell Culture Analog

Device on peristaltic pump in incubator

All cells labeled with cell tracker green before experiment

Other Tissues/ Debubbler

Application to Study Multidrug Resistance Suppressors

Organ on a Chip in Clinical Trails

Different Industries also involved

Soft ware

Cell BiologyPhysiology

Engineering

Clinician

Virology

Mechanical ENGINEERING

Biologist

Microbiology

Personalized Medicine

Thank You