Microspheres Drive a Massive Market: WeiMu Medical's Drug-Eluting Microspheres Receive Ethical Approval and Clinical Trial Authorization

Medical-grade polymer materials are the most widely used biomedical materials in clinical applications, yet they remain a sector heavily reliant on imports and characterized by monopolistic dominance.

The technology and product quality of the polymer materials industry directly determine the R&D progress and product performance of downstream medical enterprises. Those who master the materials hold the autonomy over innovation and production.

Shanghai Weimu Medical is a domestic interventional medical device platform based on innovative polymer materials.The company focuses on oncology, medical aesthetics, and pan-vascular intervention. Its two core products—drug-eluting embolic microspheres and varicose vein closure adhesive—are about to enter clinical trials.Previously, the clinical trial of polyvinyl alcohol (PVA) drug-loaded embolization microspheres has obtained clinical approval.

Xie Dang, founder of Weimu Medical, is a native of Changsha, Hunan Province, and holds a Ph.D. in Polymer Materials Science. After graduating from Fudan University in 2007, he did not initially enter the medical device industry. However, an unexpected incident altered the course of his life.

“In 2011, my father passed away from liver cancer, which had a profound impact on me. I suddenly felt that my work had lost its meaning. Because of my father, I came to understand every individual suffering from illness. Therefore, I resolved to apply my expertise to pursue a career in the medical field, specifically to develop therapies for liver cancer and help cancer patients like my father.”

Since 2012, Xie Dang has been deeply engaged in the medical device industry.Developed products such as varicose vein ablation catheters and liquid embolic agents (for intracranial arteriovenous malformations).。

Armed with innovative technologies, fueled by passion, and staying true to his original aspiration of entering the healthcare industry, Xie Dang founded his own company in 2020—Weimu Medical, an interventional medical device company based on innovative polymer materials.

Currently,The company has assembled an elite founding team integrating R&D, quality assurance, clinical affairs, and regulatory registration. The team includes several PhDs and Master’s degree holders specializing in polymer materials, as well as professionals with medical backgrounds.. They have cultivated deep expertise in the medical device sector, accumulating extensive experience.

The founder’s original aspiration reflects the company’s core values and sense of social responsibility. Drawing on Xie Dang’s unique life experiences, Weimu Medical possesses a deeper understanding of the healthcare industry and holds itself to higher standards for corporate development. Although the company was recently established, all of Weimu Medical’s product initiatives are guided by its philosophy: “Devotedly safeguarding health, letting life bask in sunshine.”

As the founder requires of Weimu Medical team members: “Our products must not only withstand the test of the market, but also give patients and doctors greater confidence in their use. In terms of safety and efficacy, our standards are nothing short of excellence.”

Weimu Medical has established three major technology platforms, collectively known as “MBA,” in the fields of “oncology intervention,” “pan-vascular intervention,” and “medical aesthetics,” based on innovative polymer materials.

“M”, which stands for Membrane, mainly includesHeart ValveCurrently, most available heart valves are bioprosthetic valves made from bovine or porcine pericardium, which entail high costs. Shanghai Weimu Medical Technology Co., Ltd. plans to develop a heart valve using synthetic polymer materials, aiming to reduce costs while maintaining therapeutic efficacy.

“B”, i.e., Beads microspheres, whereinDrug-eluting embolic microspheres for TACE (transarterial chemoembolization) treatment of liver cancer are the core products of Weimu Medical.，The synthesis process of microspheres is the company's key technical barrier.The synthesis of drug-loaded microspheres is the result of combining multiple technical modules, including polymer material modification, reshaping, and spheroidization.. Leveraging a team of polymer materials experts, Weimu Medical modularizes technologies and combines them to drive product innovation, with “a single product potentially backed by seven or eight patents.”

Currently, the drug-eluting embolic microspheres independently developed by Weimu Medical have obtained clinical trial approval. In addition, the company is leveraging its proprietary microsphere technology to develop polylactic acid (PLA) microsphere products tailored for the medical aesthetics market.

“A,” referring to Adhesive glue, currently under development by Weimu MedicalVenous Closure Adhesive, directly benchmarking Medtronic's VenaSeal product. In addition, the company's adhesive products under development also includeIntracranial Liquid Coil、Valve Edge-to-Edge Repair Adhesiveetc. Currently, mitral valve clips are commonly used in clinical practice for valve repair, but they carry risks of thrombosis or clip detachment; the use of valve repair adhesive can reduce these treatment risks.

All three technology platforms are built upon Weimu Medical’s polymer material technology, its unwavering “ace,” includingModification, polymerization, and formulation optimization of polymeric materials, as well as process standardization for medical devices。

“Mass production of medical devices requires standardization of manufacturing processes to ensure consistent product performance. As end users, physicians place great emphasis on the quality and stability of medical devices, as any product defect could potentially harm patients.”

Leveraging the technological advantages of innovative materials, supported by MBA’s three major technology platforms and built upon two core technologies—microspheres and hydrogels,Shanghai Weimu Medical Technology Co., Ltd. has chosen blue-ocean markets characterized by limited competition and high barriers to entry.。

The company’s initial target market was interventional oncology, with a current focus on the liver cancer market.

China is the country with the highest burden of liver cancer, accounting for half of the global cases, with approximately 600,000 TACE procedures performed annually.

Liver cancer has an insidious onset, with most patients being asymptomatic in the early stages; by the time they seek medical examination, the disease has often progressed to the intermediate or advanced stages. Currently,TACE is internationally recognized as the first-line treatment for patients with unresectable intermediate-to-advanced hepatocellular carcinoma., and can also serve as an adjunct to pharmacological, radiofrequency, and other therapies. Drug-eluting bead transarterial chemoembolization (D-TACE) can increase the local drug concentration in the tumor region, thereby achieving favorable therapeutic outcomes while reducing the systemic toxic side effects of chemotherapeutic agents.

Drug-loaded microspheres are micron-sized, crystal-clear hydrogel beads that appear identical to the naked eye. The true differences lie at the molecular level. The raw material of the microspheres, polyvinyl alcohol (PVA), does not inherently possess drug-loading capacity. Manufacturers must chemically modify the material to introduce negatively charged groups onto the PVA polymer chains, enabling them to load cationic drugs. Based on the principle of electrostatic adsorption, a higher density of negatively charged groups results in greater drug-loading capacity and faster drug-loading kinetics.

However, an increase in negatively charged ion groups compromises the elasticity of drug-loaded microspheres, necessitating optimization of the material formulation and molecular-level structural design. Microspheres with poor elasticity may fracture during injection into the human body; the resulting small fragments can penetrate hepatic sinusoidal tissue, enter the hepatic venous return, and thereby cause pulmonary embolism. Furthermore, these small fragments are prone to obstructing the delivery catheter, impeding the physician’s treatment progress.

Therefore,Drug-loaded microspheres must achieve a balance between chemical and physical properties。

Weimu Medical’s drug-eluting microsphere products use PVA as the base material, enablingLoad 90% of the chemotherapy drugs onto microspheres within 15 minutes, whereas imported brands require 90 minutes to achieve the same result. In addition, the unique internal structure of Weimu Medical’s drug-eluting microspheres endows them with excellent mechanical properties,The company's drug-loaded microspheres can be compressed by over 70% in volume.. Currently, Weimu Medical's drug-eluting microspheres have obtained clinical trial approval.

“Drug-loaded microspheres are a market-validated sector with high returns, but currently, there are not many microsphere products approved in China. Medical device R&D is a long-cycle, high-risk process that relies heavily on the capital market. If we can obtain approval as soon as possible to generate revenue, the company will enter a virtuous development phase.”

In the field of neurointervention, coil embolization for the treatment of intracranial aneurysms has become highly prevalent. However, the acceleration of centralized volume-based procurement has inevitably cast a shadow over the metallic coil market.

Generally, a coil embolization system comprises framing coils, filling coils, and finishing coils. To achieve adequate embolization density, an aneurysm may require the packing of six or seven coils. Each coil detachment necessitates the application of a certain force, which may cause the microcatheter to be dislodged from the aneurysm sac due to interactive forces. This can significantly prolong procedural time and increase surgical risks. Furthermore, the presence of coils within the patient’s body carries additional risks, such as coil migration and thrombus formation.

Weimu Medical’s hydrogel coil product is a photo-crosslinked hydrogel that can rapidly cure under fiber-optic illumination.By injecting hydrogel, the aneurysm can be filled in a single session, which not only increases the packing density but also simplifies the surgical procedure for physicians.To navigate tortuous and fragile neurovascular structures, hydrogel products are administered in liquid form; however, they risk being dispersed by blood flow before reaching the target site, necessitating timely in situ solidification.

“We can conceptualize this as a 3D-printed coil, where the stiffness of the coil is controlled by adjusting the light intensity of the optical fiber. When the hydrogel is initially extruded, it is slightly stiffer, which facilitates wall apposition of the coil. Subsequently, we adjust the light intensity to soften the coil, thereby achieving a dense packing effect.”

In addition, Weimu Medical’s coil products exhibit favorable biocompatibility and are radiopaque under X-ray. Upon completion of filling, the hydrogel adheres via hydrogen bonding and hydrophobic interactions, achieving high packing density while resisting unwinding.

Currently,Weimu Medical’s Implantable Hydrogel Coil Product Has Been Finalized. Following the inclusion of metal coils in centralized procurement, innovative hydrogel coils may experience accelerated development.

Since entering the vascular intervention market, Dr. Xie Dang has mastered the core technologies of varicose vein-related products. “Venous closure adhesives are likely to replace radiofrequency ablation catheters in the future.” While developing radiofrequency ablation catheters at a foreign enterprise, Dr. Xie Dang recognized the development potential of venous closure adhesives.

Leveraging years of expertise in the field of varicose vein adhesives, Shanghai Weimu Medical Technology Co., Ltd. has developed a varicose vein closure adhesive based on material innovations, which is scheduled to enter clinical trials in 2022. The approval and clinical application of Medtronic’s VenaSeal Venous Closure System have already demonstrated the efficacy and commercial value of venous closure adhesives.

According to the "2021 White Paper on the Medical Aesthetics Industry" released by So-Young Data Research Institute, China's medical aesthetics market size is projected to reach RMB 184.6 billion in 2021. Hyaluronic acid (commonly known as HA) is considered one of the four key factors driving the rapid development of the medical aesthetics market.

Weimu Medical, leveraging microsphere technology,Development of PLLA (poly-L-lactic acid) andA new type of biostimulatory filler composed of hyaluronic acid provides immediate physical support to fill in depressions upon injection, while PLLA stimulates endogenous collagen regeneration.. Meanwhile, this hyaluronic acid microsphere product features a "watermelon-like" structure, with PLLA microspheres uniformly coated by hyaluronic acid, offering an optimal balance of firmness and flexibility while eliminating the risk of injection-related clogging.

Amid surging innovation enthusiasm in the medical device sector, domestic enterprises should prioritize investment in raw materials to secure genuine R&D autonomy. Weimu Medical is precisely such a company, dedicated to the technological translation of innovative biomedical materials.

Throughout its development, Weimu Medical has maintained close collaborations with major hospitals across China, leading a new frontier through “hospital-enterprise partnerships.” Currently, Weimu Medical is engaged in collaborative R&D of medical device products with several top-tier (Grade III Class A) hospitals in China, including Hunan Provincial People’s Hospital, Zhejiang Provincial People’s Hospital, Beijing Tiantan Hospital, the Department of Plastic and Reconstructive Surgery at Tongji Hospital, and the Third Xiangya Hospital of Central South University, thereby advancing patient-oriented research and development of new materials.

Furthermore, Weimu Medical has successively launched industry-academia collaboration projects with universities such as Xi’an Jiaotong University, Fudan University, Tongji University, East China Normal University, East China University of Science and Technology, and South China University of Technology, to jointly develop new materials in the field of medical devices.

At the outset of the venture, Xie Dang established a three-phase development model. In the first two years, the company aimed to secure one Class III medical device registration certificate; in the next two years, it targeted obtaining three to five such certificates. Sales revenue was projected to exceed RMB 10 million in 2024, RMB 20 million in 2025, and RMB 50 million in 2026, with the goal of listing on the STAR Market by 2027.

Currently, Weimu Medical is making steady progress toward its first two-year goal.