Peptide 'Passport' Fools Macrophages to Aid Drug Delivery

Researchers say a synthetic ‘passport’ peptide may allow drugs to function with greater efficacy by evading the body’s immune system.

The University of Pennsylvania has been developing the technology - presently in pre-clinical animal models – and believes the technology will lengthen the time therapeutic and drug delivery devices can function in the body and avoid inflammatory responses from the immune system treating them as foreign objects.

Speaking with in-Pharmatechnologist.com, research leader Professor Dennis Discher said: “Many implanted and injected materials and particles are 'attacked' or even removed by innate immune cells, particularly macrophages.” He continued, adding:

The approach is based on earlier work by Discher’s team in which the human protein CD47 - which can be found on nearly all cell membranes – was replicated by a peptide.

According to Discher “the peptide we made helps macrophages recognize things as 'Self' rather than foreign” and is thus not destroyed by the macrophages. The peptide is thus designated a ‘passport’ whilst the macrophage acts as ‘border patrol.’

The researchers detail the potential benefits of combining these passport proteins with nanoparticle-based drug formulations or devices such as pacemakers and artificial limbs in a report in the journal Science.

One of the main advantages of evading the immune system in this way is - according to Discher - that “bioavailability is greatly increased" which is likely to be of interest to the increasing number of drugmakers developing poorly soluble compounds for pharmaceutical applications.

The technology is presently in early stage of development and although discussions with several interested parties in the pharma industry are ongoing, Discher declined to name any of the firms involved.