PLANTNER Secures Pre-Series A Funding to Scale Korean Marine Biomaterial Production

PLANTNER, a South Korean marine biomaterial startup developing locally sourced alginate—the world’s second most-traded marine biopolymer—has secured a pre-Series A round of undisclosed size.

Coolidge Corner Investment led the round, with new participation from Impact Square, Hana Financial Group–QNEST, Yuhan-Kimberly–MYSC, and AI Angel Club–CNTTech.

Founded in 2024, PLANTNER extracts and refines valuable compounds from discarded and underutilized seaweed, then formulates and polymerizes them into customized materials for bio, medical device, and beauty applications. The company is working with large corporations, mid-tier firms, public institutions, and startups to develop enhanced alginate materials and composite biopolymers tailored to specific industrial needs. Its technical and commercial progress has been recognized with a 2026 Edison Award Silver and other domestic and international honors.

PLANTNER has also expanded its natural-material expertise into agriculture, running an organic fertilizer business in Vietnam focused on soil improvement. The company leverages local underutilized resources and agri-food byproducts to build a circular farming value chain—an ESG approach that earned it a first-ever foreign-team prize at Techfest Vietnam, organized by Vietnam’s Ministry of Science and Technology. Other milestones in the market include coverage in a VTV2 documentary and selection for the 2026 KOICA CTS SEED 2 program.

The fresh capital will fund PLANTNER’s domestic alginate mass-production facility and expand its custom-formulation R&D for target industries. The company aims to accelerate both localization and commercialization of alginate materials and to pursue phased entry into global markets, including the United States.

“Even as an early-stage company, PLANTNER is driving domestic production of biomaterials while conducting R&D with diverse partners to raise material utility. We expect rapid growth ahead,” an investor in the round said.

“South Korea possesses world-class seaweed cultivation infrastructure, yet our marine biomaterial industry remains heavily import-dependent,” said PLANTNER CEO Jeong-woo Shin. “We will advance alginate localization using high-quality domestic seaweed, grow as a quality-focused material company, and bring eco-friendly innovation to global bio and beauty markets.”

The South Korean climate tech and resource-circulation sector has seen a string of early-stage raises this year. In June, UPROOTY secured seed investment to scale micro-hydropower and carbon-credit infrastructure, and INOBUS raised approximately $1.3M (KRW 2 billion) through the Korea Credit Guarantee Fund’s First Penguin program to build PET sorting infrastructure.