Amino Payments, the Philadelphia-based, blockchain-centered advertising-tech developer that says it will help publishers regain control of advertising revenues diverted by giant middlemen such as Google and Facebook, has raised another $4.5 million from its investors, led by First Round Capital of Philadelphia, according to this SEC filing.

UPDATE: Other investors include You & Mr. Jones, NYCA, Tessera, SafeGraph CEO Auren Hoffman and BrightRoll founder Tod Sacerdoti, Amino founder Will Luttrell said in an emailed statement Wednesday. "Amino will use this funding to expand its footprint through the digital advertising ecosystem," he added. Luttrell says Amino users include big advertisers such as AT&T and Bayer. "Soon, our partners like [online ad platforms] AppNexus and Dstillery will enjoy faster payment cycles and reporting accuracy that comes from a shared blockchain-based transaction system," he concluded.

Amino will use the money to add staff in Philadelphia, Luttrell told Roberto Torres, who first reported the investment at Technical.ly

Last summer, Amino raised $1.85 million from investors led by First Round, which has backed Uber and hundreds of smartphone- and cloud-era software companies, and including Philadelphia-based bank-marketing mogul Richard Vague. First Round chief Josh Kopelman has since joined Amino's board. Kopelman also chairs the board of the company that owns the Inquirer and Philly.com

Luttrell's past companies include Integral Ad Science (AdSafe Media). His partner is David Bookspan, founder of West Conshohocken-based Monetate.