Unlike conventional blood, haemoglobin vesicles do not require blood-type matching and can be stored for extended periods, making them a potential option for emergencies, disasters and military operations.
What happens when a soldier is critically wounded on the battlefield but donated blood cannot reach them in time? Japan is exploring artificial red blood cells that could help bridge this gap by providing temporary oxygen-carrying support until a conventional blood transfusion becomes available.
The technology, known as haemoglobin vesicles, is being developed by researchers at Nara Medical University in Japan. It involves extracting haemoglobin — the protein responsible for carrying oxygen in red blood cells — and enclosing it within tiny artificial structures called liposomes.
Presenting the research at the International Congress of Military Medicine in Abu Dhabi, Dr Eiji Hinoshita, director-general for health and medicine at Japan’s Ministry of Defence, said conventional blood transfusions remained essential to treating combat casualties. However, delivering sufficient supplies to the point of injury can be challenging.
Logistical constraints, limited transport options and difficult frontline conditions can delay blood deliveries to severely wounded personnel, creating a potentially fatal gap between injury and definitive treatment.
Japan is therefore exploring artificial blood as an additional capability to support conventional donated blood, rather than as a replacement for it.
The research was presented at the 46th World Congress of Military Medicine, which is being held at the ADNEC Centre in Abu Dhabi until November 13.
Organised in the UAE under the supervision of the International Committee of Military Medicine, the congress has brought together military medical professionals, researchers and defence health experts from more than 120 countries. Discussions cover a range of issues, including battlefield trauma, emergency surgery, mental health and medical preparedness.
Unlike conventional blood, haemoglobin vesicles do not require blood-type matching. Their potential for longer-term storage could also make them suitable for stockpiling and use during military operations, natural disasters and other emergencies when regular blood supplies are disrupted.
Hinoshita said the product is designed to reduce the toxicity associated with free haemoglobin while preserving its ability to transport oxygen.
Animal experiments have produced encouraging results. In one study involving rabbits with severe haemorrhagic shock, eight of the 10 animals treated with the artificial blood survived. By comparison, none of the 10 animals given only a plasma expander survived, while all 10 animals that received conventional red blood cells and plasma components survived.
The findings offer preliminary evidence that the artificial product could provide temporary oxygen-carrying support when conventional blood is unavailable. However, they do not establish that it is as effective as donated blood or that it is ready for use in treating wounded soldiers.
The technology has also progressed to early-stage human safety testing. A Phase Ib clinical trial registered in Japan is evaluating haemoglobin vesicles in healthy adult volunteers, with planned doses of up to 400ml. The study is designed to assess safety and how the product behaves in the body, rather than evaluate its effectiveness in treating patients with severe bleeding.
Japan’s interest in the technology forms part of a broader effort to strengthen military medical preparedness. Hinoshita said the country’s 2022 National Security Strategy identified the need to secure blood and other essential medical supplies for treating combat casualties.
An expert panel on transfusion in combat casualty care was subsequently established in August 2023 to advance the development of a system for producing, securing and stockpiling blood supplies.
The artificial blood research aims to address a challenge that stockpiling conventional blood alone cannot necessarily resolve: ensuring the right medical product reaches an injured person at the right time.
If further testing establishes its safety and effectiveness, haemoglobin vesicles could eventually give military medical teams another option when access to conventional blood transfusions is delayed.
