Hepatitis C

We designed a device for the therapy of hepatitis C, composed of microencapsulated mammalian cells that include a genetic bistable toggle switch with a positive feedback loop, where in one state the cells produce interferon alpha (IFN-α) as the antiviral effector and in the second state they produce hepatocyte growth factor (HGF) to promote liver regeneration.

A pharmacokinetic model demonstrated that if the device is implanted into the liver it results in higher levels of IFN-α within the liver than systemically. More importantly, this type of application avoids the spikes of high IFN-α concentration that occur in treatment with IFN-α injections. This should decrease the severity of side effects of IFN-α experienced by a high percentage of patients.

We estimated, based on the detection of IFN-α produced by HEK293 cells, that sufficient quantities of the therapeutic protein could be produced by the amount of microencapsulated cells feasible in a real therapeutic application.

Figure 1. Therapy of hepatitis C by microencapsulated cells which can be regulated to produce and release therapeutic proteins into the liver tissue.

Figure 2. Scheme of the constructs for the regulated therapy of hepatitis C with interferon alpha (IFN-α) and hepatocyte growth factor (HGF). Each of the therapeutic effector is released in equimolar amount to the autoactivator.

References

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