Limenbio’s HIPPER Technology Achieves Breakthrough in Rat Heart Preservation

In 2024, over 100,000 individuals in the United States alone are on the national transplant waiting list, a number that stretches into the millions globally. The primary bottleneck in modern transplant medicine is the supply-demand organ disparity. This crisis is exacerbated by the inability to efficiently transport organs over long distances. The current gold standard, Static Cold Storage (SCS), has remained largely unchanged for decades, offering a narrow preservation window of typically 4–6 hours for hearts. It's estimated that for every 10 donor hearts recovered, up to 4 are discarded due to the inability to transport them to a matching recipient in time. This is not just a logistical problem; it is a fatal one.

Limenbio Inc. is determined to meet this challenge head-on. Building on its expertise in cell and tissue cryopreservation, the company has developed a groundbreaking approach called High-Pressure Gaseous Perfusion (HIPPER). This technology represents a significant leap forward, moving beyond conventional liquid-based methods to harness the immense potential of gaseous perfusion for organ preservation.

To validate the effectiveness of HIPPER technology for whole organs, Limenbio conducted a series of three preclinical studies focused on preserving rat hearts. This was a crucial first step, demonstrating the technology's ability to transition successfully from cellular applications to a more complex organ system. These studies were conducted in strict adherence to the 3Rs principles (Replacement, Reduction, and Refinement), underscoring a commitment to minimizing animal use and ensuring the highest standards of animal welfare.

The first experiment, conducted over three days at the National Medical Research Center for Transplantation and Artificial Organs, served as a crucial proof-of-concept. The goal was to demonstrate that HIPPER could successfully preserve whole organs. The study compared HIPPER-preserved hearts to a control group preserved using the standard SCS method with HTK solution (Custodiol).

The results were impressive both visually and functionally. After 10 hours of preservation and subsequent rewarming, HIPPER-treated hearts spontaneously began beating and showed strong contractions without electrical stimulation. In contrast, the control group exhibited no beating, even with electrical stimulation. The HIPPER hearts were also a healthy color, with a stable heart rate. Histological analysis further confirmed these observations, revealing significantly less tissue damage, necrosis, and infarction zones in the HIPPER group compared to the control hearts.

In a video recording of our preclinical study, a rat heart preserved for 10 hours in Custodiol solution at +4°C showed no signs of activity or response to electrical cardio-stimulation (ECS).

This initial successful outcome garnered enthusiastic responses from the participating surgeons and medical professionals.

Following the initial success, the second experiment was designed to obtain objective, quantifiable data to support the qualitative observations from the first study. Hearts were preserved using the same HIPPER technology, but their performance was assessed using a Langendorff apparatus, which allows for precise measurement of heart function, including pressure and contractility.

Initially, this experiment proved unsuccessful, as the data did not suggest the HIPPER hearts were performing significantly better than the standard preservation group. This led to a critical period of analysis, revealing that equipment malfunctions and procedural deviations had compromised the results.

Instead of a failure, this "unsuccessful" experiment became an invaluable learning experience. It provided critical information about key technological parameters and highlighted the need for strict, standardized assessment procedures. The team used this data to improve the process and minimize the impact of human error in future studies.

The third and most extensive experiment, which took over twelve months and two rounds to complete, was conducted at the Ural Branch of the Academy of Sciences.

The primary objective was to replicate the evaluation from the second study but with a completely standardized and controlled procedure to generate statistically significant data. A major part of this long-term effort was to enhance all the technological aspects of the Langendorff apparatus, sensor usage, and the evaluation protocol itself. This meticulous preparation, which took more than four months, ensured the data collected was precise and reliable.

The results of this final study provided compelling, objective evidence of the HIPPER technology's superiority. Wistar rat hearts were divided into five groups: a control group using SCS and four experimental groups using HIPPER with different gas mixtures. Hearts were preserved for six hours and then evaluated.

The results showed superior quality in HIPPER hearts as measured by resuscitation ratios, heart rates, and left ventricular developed pressure. Notably, the HIPPER group fueled by air demonstrated intermediate results, falling in between the HIPPER group fueled by proprietary Xe-Oxygen mixtures and the control (HTK solution). Ultimately, transversal sections of HIPPER hearts showed dramatically smaller infarct areas compared to the controls. The collective data from this study confirmed the overall superiority of the Limenbio technology over conventional static cold storage.

The successful completion of the rat heart experiments marks a pivotal moment for Limenbio. The team has demonstrated not only the functional potential of the HIPPER technology but also the ability to generate statistically validated data to support its claims. The technology and the developed device have been successfully patented.

The positive feedback from partnering scientific centers and the compelling results from these studies highlight the significant potential for scaling the technology. The company is now advancing its preclinical studies to larger animal models. Limenbio's research has laid a strong foundation for future development, positioning the company to revolutionize the field of organ preservation and transplantation.