  L-DOPA has been the gold standard treatment for Parkinson's disease since 50
years. Being the direct biochemical precursor of dopamine, L-DOPA is
effectively converted in the brain, but two major phenomena reduce its
therapeutic action: i) competition with amino acids in the gut wall and in the
blood brain barrier and ii) its fast kinetics (absorption, distribution,
metabolism, and elimination). Continuous administration of L-DOPA, such as
jejunal pumps, have addressed the issue of fast absorption. Considering a
subcutaneous delivery of L-DOPA allows to bypass the gastrointestinal tract and
avoid competition with dietary amino acids. Remains the competition at the
blood barrier between amino acids and L-DOPA, which we address by proposing a
closed-loop controlled, continuous subcutaneous delivery pump. In the
proof-of-concept format, the delivery strategy evaluated on comprehensive model
of L-DOPA kinetics, holds the promise of improving the treatment of late-stage
Parkinson's disease patients.
