Announcement PDF RNS Number : 5636Z BSF Enterprise PLC 20 October 2026 20 October 2026 BSF Enterprise PLC ("BSF" or the "Company") US Patent Allowance - Foundational Macromolecular Crowding Technology Foundational Patent Underpins Hub-and-Spoke Business Strategy BSF Enterprise PLC (LSE: BSFA | OTCQB: BSFAF), an operational life sciences platform focused on developing and commercialising biotechnologies across tissue engineering and cellular agriculture, is pleased to announce that its wholly owned subsidiary, 3D Bio-Tissues Limited ("3DBT"), has received a formal Notice of Allowance from the United States Patent and Trademark Office ("USPTO") for patent application number 18/578,286. The patent, entitled "Cell culture medium and supplements for corneal and skin cell culture," covers proprietary formulations utilising macromolecular crowding (MMC) agents within serum-free and reduced-serum media. Prosecution on the merits is officially closed, with all 17 examined claims (Claims 2-18) approved for issuance. On issuance, the patent will provide proprietary protection in the United States-the world's largest market for biotechnology and commercial biomanufacturing - and will support BSF's hub-and-spoke business strategy. Key Highlights: ● 17 Allowed US Claims: On issuance, provides exclusive rights across 17 claims covering defined serum-free media and supplement compositions incorporating 3DBT's proprietary macromolecular crowding technology. ● Upcoming Protection for milieu.bio: Strengthens the intellectual property supporting the Group's commercial consumables subsidiary, milieu.bio Limited, which markets and distributes CityMix® and CytoBoost™ media supplements to international life-science and bioprocessing partners, including Seawith Inc. As announced on 15 October 2026, milieu.bio sells these supplements under licence from 3DBT, which receives a royalty on external sales. ● Strategic Underpinning for Subsidiary Pipelines: ○ Lab-Grown Leather Ltd ("LGL"): Covers skin fibroblast culture and extracellular matrix (ECM) synthesis protocols used in LGL's production route. ○ Kerato Ltd: Complements Kerato's primary commercial focus - the cell-free biomaterial, LiQD Cornea™ - by providing proprietary protection over advanced cell-based tissue engineering pipelines that can be transferred into Kerato to expand its long-term ophthalmic and veterinary regenerative offerings. Strategic Impact: Supporting the Hub-and-Spoke Business Strategy Under BSF's hub-and-spoke model, foundational technologies developed within 3DBT act as the central "hub", with high- value applications deployed across commercial "spokes". This US patent allowance directly operationalises that strategy: 1. Commercial Media Sales (milieu.bio): Media costs represent a significant operational challenge in cell-based biomanufacturing.The Good Food Institute has projected that, at industrial scale, cell culture media could account for 55-95% of the marginal cost of cultivated meat production, making it a primary target for cost reduction. 3DBT's crowder combinations enhance cellular proliferation and extracellular matrix deposition under serum-free conditions while reducing reliance on expensive recombinant growth factors. The allowance strengthens milieu.bio's position as it scales B2B sampling and international commercial supply agreements. 2. Broader Applications: Stromal cells represent the biological foundation for tissue repair, cell therapy, and cultivated biomaterials. The allowed claims cover skin and corneal cell culture. milieu.bio's products address a wider set of markets, including biopharma, cell therapy and cellular agriculture. 3. Lab-Grown Leather Ltd: The allowed claims specifically encompass dermal fibroblast culture and matrix deposition, poised to protect LGL's cellular agriculture protocols upon formal issuance. 4. Kerato Ltd & Pipeline Optionality: Kerato's near-term clinical and commercial milestone remains the regulatory progress of LiQD Cornea™, an advanced acellular biomaterial that does not require cell culture. In parallel, this allowance supports long-term optionality: Kerato was established as BSF's dedicated corneal company to commercialise 3DBT's corneal intellectual property, providing a potential route to cellular regenerative therapies. Dr Che Connon, Chief Executive Officer of BSF Enterprise, commented: "The allowance of this patent in the United States represents an important commercial and legal milestone for BSF Enterprise. The US is the global epicentre for life sciences and bioprocessing, and these 17 allowed claims will, on issuance, provide enforceable protection for our proprietary formulations. Importantly, this outcome shows our hub-and-spoke model at work. 3D Bio-Tissues continues to act as an IP generator, developing defensible innovations that drive commercial revenue through milieu.bio and, once issued, shielding the specialised pipelines inside Lab-Grown Leather and Kerato. With third-party studies confirming media efficiency and cost being the most significant operational challenge in biomanufacturing, our platform represents an important enabler for commercial success in the sector. Our ambition is for milieu.bio to become a leading global provider of cell-culture media additives." Patent Details: ● Application Number: US 18/578,286 ● Filing Date: 10 January 2024 (claiming priority from PCT/GB2022/051811 and GB 2110035.9) ● Title: Cell Culture Medium and Supplements for Corneal and Skin Cell Culture ● Assignee: 3D Bio-Tissues Limited ● Inventors: Dr Che John Connon, Dr Ricardo Gouveia ● Allowed Claims: Claims 2 to 18 (17 claims encompassing culture methods, liquid and dry powder media supplements, and hermetically sealed media vessels). This announcement contains inside information for the purposes of Article 7 of Regulation 2014/596/EU which is part of domestic UK law pursuant to the Market Abuse (Amendment) (EU Exit) Regulations 2019 (SI 2019/310). Engage with the BSF Enterprise management team directly by asking questions, watching video summaries and seeing what other shareholders have to say. Navigate to our Interactive Investor website here: https://bsfenterprise.com/link/r6w15P For further enquiries, please visit www.bsfenterprise.com or contact: BSF Enterprise PLC Geoff Baker - Chairman Che Connon - CEO & Director We encourage all investors to share questions on this announcement via our investor website. https://bsfenterprise.com/s/a1f22b Bowsprit Partners (Financial Adviser & Broker) John Treacy James Sheehan +44 (0)203 883 4430 ISIN of the Ordinary Shares is GB00BHNBDQ51. SEDOL Code is BHNBDQ5. About BSF Enterprise PLC BSF Enterprise PLC (LSE: BSFA) is an operational life sciences platform committed to developing, acquiring, and commercialising high-potential biotechnology enterprises across cellular agriculture, sustainable biomaterials, and regenerative medicine. Through its hub-and-spoke operational model, BSF provides strategic leadership, central governance, and access to capital markets, translating laboratory innovations into commercial market opportunities. The Group's portfolio includes: ● 3D Bio-Tissues Limited: Core IP holding house, tissue engineering platform, and central manufacturing facility. ● Lab-Grown Leather Limited: Sustainable biomaterials company developing animal-free, tissue-engineered leather for luxury and automotive applications. ● Kerato Limited: Pre-clinical biotechnology venture developing advanced biomaterials and regenerative therapies for corneal repair and vision restoration. ● milieu.bio Limited: Dedicated consumables subsidiary supplying proprietary macromolecular crowding media supplements to biopharma, cell therapy, and cellular agriculture markets. This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions relating to the use and distribution of this information may apply. For further information, please contact rns@lseg.com or visit www.rns.com. 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