Southwest Medical University Completes $140K Exosome Patent Equity Investment for ECRG4 mRNA Delivery Technology

According to the official website of Southwest Medical University, this achievement was valued at RMB 1 million and contributed as equity investment in Luzhou Zhongzhi Plant Research Institute Technology Co., Ltd.To further stimulate the innovative drive of researchers, the university has granted co-ownership of job-related scientific and technological achievements to their creators. In terms of specific distribution, the university retains a 20% equity stake to support subsequent research, while Dang Xitong and Mao Liang, as core contributors, each receive a 36% equity stake, and Zhou Rui receives an 8% equity stake.

Exosomes, as gene delivery vectors, possess a series of unique advantages. For instance, exosomes exhibit favorable biodistribution and biocompatibility; they are natural, stable, nanosized, capable of penetrating biological barriers, and have low immunogenicity. Furthermore, they can carry single or arbitrarily combined therapeutic agents.

However, since exosomes are secreted by cells themselves and selectively encapsulate signaling molecules from the cytoplasm during their formation, the underlying selective mechanism remains unclear. Therefore, loading therapeutically valuable genes into exosomes has always been a technical challenge.

Currently, researchers primarily employ four methods to load exogenous genes into exosomes: electroporation (introducing in vitro-synthesized exogenous genes into exosomes via electroporation), the freeze-thaw method (packaging exogenous genes into exosomes by repeatedly freezing and thawing a mixture of exosomes and the genes), direct transfection (using transfection reagents such as Lipofectamine to directly transfect in vitro-synthesized exogenous genes into exosomes), and indirect transfection (cloning exogenous genes into expression vectors, transfecting exosome-producing cells to promote overexpression of the target gene, and encapsulating the cytoplasm-enriched exogenous genes during exosome formation).

The first three methods primarily alter the physical structure of exosomes through specific stimulating factors, thereby enabling the passive loading of exogenous genes. However, this approach carries a significant risk of altering the morphological structure of exosomes and is limited by low packaging efficiency. In contrast, the fourth method requires targeted selection based on the type of gene, the cell type of origin, culture methods, and culture conditions to obtain exosomes with high gene loading capacity, stable expression, good biocompatibility, and broad applicability.

Based on this, Dang Xitong’s team focused on the fourth approach and developed, through a three-step innovative process, an exosome loaded with abundant ECRG4 mRNA:

First, the team constructed the pLVX-IRES-ZsGreen1-ECRG4 plasmid: total RNA was extracted, the ECRG4 gene was amplified by reverse transcription PCR (RT-PCR), and the ECRG4 gene was cloned into the pLVX-IRES-ZsGreen1 vector to obtain the pLVX-IRES-ZsGreen1-ECRG4 plasmid;

In fact, the team completed the preparation of lentivirus: HEK293T cells were transfected with a first mixture containing three plasmids, namely pMD2.G, psPAX2, and pLVX-IRES-ZsGreen1-ECRG4; the transfected HEK293T cells were cultured, the culture medium was collected, and the culture medium was processed to obtain lentivirus packaged with the ECRG4 gene.

Finally, the team completed the establishment of the ECRG4-HEK293 cell line: HEK293 cells were infected with a second mixture containing ECRG4 gene lentivirus, DMEM medium, and polybrene; the infected HEK293 cells were then cultured, and the ECRG4-HEK293 cell line was obtained through cell sorting.

It is understood that,The amount of ECRG4 mRNA loaded in these exosomes is at least 1,000 times higher than that in conventional exosomes. A higher content of ECRG4 mRNA in the exosomes leads to a greater enhancement of ECRG4 expression levels in recipient cells, thereby exerting a stronger inhibitory effect on tumor cells, particularly by significantly suppressing the proliferation and growth of oral squamous cell carcinoma.Furthermore, these exosomes can also be used to inhibit the growth of tumor cells in esophageal cancer, colon cancer, breast cancer, lung cancer, renal cancer, gastric cancer, colon cancer, esophageal cancer, liver cancer, and glioma.

In living organisms, since most cells secrete exosomes, these vesicles are present in various biological fluids—capable not only of penetrating tissues but also of disseminating into the bloodstream and even crossing the blood-brain barrier (BBB).

By carrying proteins, nucleic acids, lipids, and metabolites, exosomes not only facilitate intercellular communication but also participate in various physiological and pathological processes, including immune responses, viral infections, metabolic and cardiovascular diseases, neurodegenerative disorders, and tumor growth and progression. Consequently, exosomes hold multifaceted clinical application prospects: they can serve as drug delivery vehicles, therapeutic agents, novel biomarkers for disease diagnosis, or tools for injury repair in regenerative medicine and aesthetic restoration.

Given the broad application scenarios of exosomes, startups have sprung up like mushrooms after rain, flocking into this sector.According to incomplete statistics from VCBeat, as of 2021, there were 46 companies worldwide engaged in exosome-related research. Among them, nearly one-third (14 companies) focused on exosome diagnostics, while more than two-thirds (32 companies) were primarily conducting research on exosome-based therapies.

In the field of exosome-based diagnostics, Exosome Diagnostics launched ExoDX Lung (ALK) in January 2016, the world’s first liquid biopsy product capable of isolating and analyzing exosomal RNA from blood samples. This test enables sensitive, accurate, and real-time detection of EML4-ALK mutations in patients with non-small cell lung cancer (NSCLC). ExoDX Lung (ALK) was not only Exosome Diagnostics’ inaugural product but also the first commercial offering in the exosome diagnostics industry. In China, Berger Biopharmaceuticals focuses on in vitro diagnostic solutions based on blood-derived exosomes, aiming to reduce testing costs and facilitate the diagnosis, treatment, and health management of Alzheimer’s disease for small and medium-sized hospitals and medical laboratories.

In the field of exosome therapy, companies are primarily focusing on four major areas: oncology, neurological disorders, vaccine development, and gene therapy/rare diseases. This has attracted pharmaceutical giants such as Roche, Takeda, and Eli Lilly to enter the space. For example, on June 9, 2020, Eli Lilly entered into a $1.23 billion collaboration agreement with Evox Therapeutics, aiming to leverage Evox’s DeliverEX exosome delivery technology to develop exosome-based therapeutics loaded with siRNA and antisense oligonucleotides (AONs) for the treatment of neurological disorders.

From exosome-based diagnostics to exosome therapeutics, Chinese companies such as Wiscon, Enze Kangtai, and Aisai Biotech have increasingly made their presence felt in the exosome market.In 2024, the Viscon team developed a novel exosome-based siRNA drug targeting KRAS, achieving proof of concept in vivo by inhibiting the growth of KRAS-mutant tumors via both intratumoral (i.t.) and systemic intravenous (i.v.) administration.