The pitch sounds almost too audacious: fundamentally reimagine how neurosurgeons stop bleeding during cranial procedures. But Endomedix, a pre-clinical medtech startup working out of Montclair State University's New Jersey campus, has convinced more than just venture capitalists. Eighteen neurosurgeons and physicians—people who actually operate inside human skulls—put their own money into the company's seed round.
That ought to tell you something.
By mid-2024, Endomedix had raised north of $4 million, initially targeting $4.2 million before extending the round to $4.9 million to accelerate manufacturing timelines and preclinical work, according to investor materials on Spark XYZ. The backers include angel networks and small funds, but it's the physician investors who lend the venture a certain credibility. They've seen the problem firsthand.
Gelatin, Swelling, and 80 Years of Improvisation
Walk into a modern operating room during a neurosurgical procedure, and you'll find surgeons reaching for the same basic technology their predecessors used when Harry Truman occupied the White House. Gelatin-based hemostats—Pfizer's Gelfoam debuted in 1945—remain the standard for controlling bleeding in the brain. Contemporary products from Baxter (FLOSEAL) and Johnson & Johnson (SURGIFLO) refine the formula. But they all share an inconvenient trait: they swell.
Up to 20 percent expansion, in fact. Inside the rigid confines of a skull, that's not trivial. The swelling creates pressure against delicate brain tissue. Product labels carry explicit warnings about use "in areas of bony confine, the spinal cord, the brain and/or cranial nerves." Surgeons are instructed to irrigate away excess material—a workaround, not a solution.
For a field that prides itself on precision, it's a crude compromise.
Endomedix's answer is PlexiClot, a device built on what the company calls its PLEXimine chemistry platform. Natural polysaccharides—dextran and chitosan—form a three-dimensional hydrogel in situ. The material gels in two to nine seconds, achieves hemostatic tamponade in roughly 20 seconds, and here's the key differentiator: it claims to gently shrink rather than expand. No swelling risk, at least in theory.
The technology is also transparent, which matters more than you might think. Surgeons can visualize the bleeding site in real time during application, rather than working blind beneath an opaque barrier. It's that kind of operational detail that apparently resonated with the neurosurgeons who became investors.
Angel Money, SBIR Grants, and the Slow Build

Central Texas Angel Network led the seed round in April 2024 with over $500,000. Golden Seeds' New Jersey chapter followed with north of $200,000. In July, the New Jersey Commission on Science, Innovation, and Technology kicked in a $74,344 small business grant—modest, but helpful for a team operating on startup economics.
The company has also leaned heavily on non-dilutive capital. Endomedix has secured somewhere between $3.1 million and $3.2 million in cumulative NIH SBIR awards over several years, funding the foundational science underpinning PLEXimine. That federal support bought runway without surrendering equity, always a smart play for early-stage medtech companies navigating lengthy regulatory timelines.
The seed terms, per the company's March 2024 executive summary: preferred stock with warrants, a 1x liquidation preference, and a $7 million pre-money valuation. Straightforward, if not particularly generous.
The Regulatory Gauntlet Ahead

Endomedix plans to funnel the capital into manufacturing scale-up, preclinical studies supporting a Breakthrough Device designation pathway with the FDA, and internal hiring. The team remains lean—four full-time employees plus consultants as of early 2024—though that headcount may have shifted since.
The company has completed bench testing and three large animal model studies. It's held two pre-submission meetings with the FDA's Center for Devices and Radiological Health to map out requirements for a PMA submission with superiority claims. That's the regulatory gold standard, but it's also the longest, most expensive path. Expect years, not quarters.
President and CEO Richard Russo and VP of R&D Piyush Modak, a co-founder, lead the venture. The IP portfolio includes seven granted patents and two published applications spanning the U.S. and Europe—enough to protect the core technology, though not so comprehensive as to guarantee market dominance if a well-funded competitor emerges.
A $1.9 Billion Market, If They Can Crack It

The addressable market, per a September 2024 profile by the University City Science Center: $1.9 billion in neurosurgery absorbable hemostats. Post-operative hemorrhage drives costly 30-day reoperations in cranial procedures, leaving hospitals absorbing hundreds of millions in unreimbursed expenses annually. Any device that reduces reoperation rates would find a receptive audience among hospital procurement teams and risk management departments.
But PlexiClot remains firmly pre-clinical. No FDA clearance. No approval. No human trials yet. The company is still proving the technology works in animal models, a necessary step but hardly a guarantee of clinical success.
If—and it's a meaningful if—the device delivers on its non-swelling promise and navigates the PMA process, it would represent the first fundamental shift in the chemistry of surgical bleeding control in the brain since 1945. That's nearly eight decades of incremental tweaks.
For a four-person team working out of a university campus in Montclair, it's the kind of moonshot that either changes a field or quietly folds after burning through its runway. The neurosurgeon-investors, at least, seem to think the odds are worth taking.
