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Principal Investigator: Connie Manz
Organization: BACKSTOP NEURAL, INC.
Fiscal Year: 2024
Award: $485,026
Funding agency: National Institute of Neurological Disorders and Stroke
Project Summary
BackStop Neural proposes to demonstrate the feasibility of a novel paddle-type epidural stimulation lead to
relieve chronic arm and neck pain. To date, spinal cord stimulation (SCS) has been used primarily to treat
chronic back and leg pain, which require placement of electrodes in the thoracic region of the spine. Although
a few studies have also shown that SCS is effective in treating chronic arm and neck pain, current
commercial leads are not well suited to placement in the cervical spine. Percutaneous leads suffer from high
lead migration rates, a key issue for cervical placement. Paddle leads offer lower risk of migration but are ~2
mm thick, making placement in the narrow cervical epidural space difficult. In this Phase I SBIR project,
BackStop Neural will scale our softening electrode arrays validated in rats to human-sized epidural leads that
are 10× thinner than commercially available leads yet stiff enough for established surgical implantation
techniques. These leads are capable of softening and conforming to the spinal cord once implanted in the
body providing positional stability that limits migration and provides chronic, effective stimulation. We build on
preliminary data showing effective cervical stimulation in rats for 4 months using softening electrode arrays,
conformation of paddles to rat and human cadaver spinal cords, hydrolytic stability of newly developed
softening polymer chemistries, and preliminary biocompatibility and electrode fabrication on these re-
formulated softening polymers. The first aim of this grant is to design and fabricate a 16-channel, 0.2 mm
thick human-sized softening paddle lead. The main outcomes are a 10× change in modulus from dry, 25 °C
conditions to wet, 37 °C conditions, electrode charge storage capacities of at least 2 mC/cm2, and fully
packaged lead resistance of < 20 ohms. The second aim will demonstrate the mechanical and electrical
stability of the epidural leads using tensile, lead body flex, connector flex, and current pulsing testing. The
metrics of success will be a < 20% change in electrode impedance following tensile testing to the earlier of
5N or 20% elongation, 100,000 cycles of lead body bending 90° (+0° / -5°) in each direction, and 100,000
cycles of connector bending 45° ±2° in each direction, and < 20% change in charge injection capacity over a
billion stimulation pulses. The third aim will demonstrate the biocompatibility and surgical feasibility of the
epidural leads using ISO 10993 cytotoxicity, intracutaneous, systemic toxicity, and ASTM hemolysis studies
and a pilot sheep study (n=2) conducted at NAMSA. The main outcomes are passing all ISO biocompatibility
tests, minimal inflammation and fibrous capsule formation at 21 days, and confirmation of the mechanical and
electrical integrity of leads via visual inspection, cyclic voltammetry, and electrical impedance spectroscopy
after explant. Successful completion of Phase I aims will enable Phase II efforts in full SCS system testing
with implantable pulse generators, advancing regulatory efforts with the FDA, and full biocompatibility and
large animal study testing to demonstrate safety and efficacy for our regulatory submission.
Terms: <21+ years old><Acceleration><Address><Adult><Adult Human><Affect><Animals><Arm Pain><Back><CPRS Type I><CPRS Type Is><CRPS Type I><CRPS Type II><Cadaver><Capsules><Causalgia><Cervical><Cervical Pain><Cervical Portion of Spinal Cord><Cervical Spinal Cord><Cervical Vertebrae><Cervical spinal cord structure><Cervical spine><Cervicalgia><Cervicalgias><Cervicodynia><Cervicodynias><Charge><Chest><Chronic><Common Rat Strains><Complex Regional Pain Syndrome Type II><Complex Regional Pain Syndromes><Cyclicity><Data><Deafferentation Pain><Diabetic Neuralgia><Dorsum><Dryness><Electrical Impedance><Electrodes><Ensure><Ethylene Oxide><Euthanasia><Extremities><FDA approved><Film><Future><Grant><Hemolysis><Histopathology><Human><Image><Impedance><Implant><Inflammation><Injections><Intractable Pain><Lead><Leanness><Leg Pain><Limb structure><Limbs><Low Back Ache><Low Back Pain><Low Backache><Lumbago><Lytotoxicity><Measurement><Mechanics><Medulla Spinalis><Mercy Killing><Microfabrication><Modern Man><Modulus><Molecular Configuration><Molecular Conformation><Molecular Stereochemistry><NINDS><National Institute of Neurological Diseases and Stroke><National Institute of Neurological Disorders and Stroke><Neck><Neck Ache><Neck Pain><Neckache><Neurostimulation procedures of spinal cord tissue><Non-Trunk><Operative Procedures><Operative Surgical Procedures><Outcome><Ovine><Ovis><Oxirane><Pain Syndrome Type I, Regional, Complex><Pain in lower limb><Painful Diabetic Neuropathy><Pattern><Pb element><Periodicity><Phase><Physiologic pulse><Polymer Chemistry><Polymers><Property><Pulse><Rat><Rats Mammals><Rattus><Reflex Sympathetic Dystrophy><Reflex Sympathetic Dystrophy Syndrome><Refractory Pain><Research><Resistance><Rhythmicity><Risk><Rodent><Rodentia><Rodents Mammals><Running><SBIR><Safety><Sheep><Shoulder-Hand Syndrome><Site><Small Business Innovation Research><Small Business Innovation Research Grant><Spectroscopy><Spectrum Analyses><Spectrum Analysis><Spinal Column><Spinal Cord><Spinal Cord Stimulation><Spine><Sudek Atrophy><Surgical><Surgical Interventions><Surgical Procedure><Syndrome><System><Techniques><Testing><Thick><Thickness><Thinness><Thorace><Thoracic><Thorax><Vertebral column><Visual><adulthood><backbone><biocompatibility><biomaterial compatibility><cadaveric><cadavers><capsule><chronic back pain><chronic pain><commercialization><conformation><conformational><conformational state><conformationally><conformations><cytotoxicity><design><designing><effective therapy><effective treatment><electric impedance><electrical property><epidural space><erythrolysis><fabrication><heavy metal Pb><heavy metal lead><imaging><implantation><improved><in vivo><innovate><innovation><innovative><intractable pain syndrome><manufacturing process><materials science><mechanic><mechanical><migration><neural><novel><pain reduction><polymer><polymeric><reduce pain><resistant><scale up><seal><success><surgery><systemic toxicity><years lived with disability>