A: When blood vessel stenosis causes ischemia and hypoxia of tissues and organs, stents can be used to open and support the narrowed blood vessels. Stent implantation is a minimally invasive interventional surgery that does not require general anesthesia. When the patient is awake, a thin needle is inserted into the blood vessel at the wrist or thigh root, and a very thin guide wire and catheter are inserted. The stent is transported from the catheter to the narrowed blood vessel and opened to restore blood supply to the tissues. Usually, the patient can walk after the operation without affecting normal life.

A: When treating diseases caused by vascular stenosis, stent implantation is the first choice internationally. Only when the patient is not suitable for stent implantation will bypass surgery or other surgical procedures be considered. Heart bypass surgery was a technology that existed 20 years before stent implantation . As for which surgical method is more suitable, the doctor will fully evaluate the patient's actual situation.

A: Stent implantation is to open narrowed or blocked blood vessels and end the patient's diseased state, but the disease is cured and the stent remains in the body. The long-term presence of foreign matter in the body will bring at least two negative effects. First, in order to prevent the stent from growing thrombus, it is necessary to take antithrombotic drugs such as aspirin for a long time, which increases the risk of bleeding; second, after the coronary stent (commonly known as the heart stent) is implanted, due to long-term foreign body stimulation, there is a probability of about 2-3% per year that the stent position will be restenosis; the restenosis rate of below-knee vascular stents is higher, and the treatment of restenosis in the stent is more difficult. If it is a child's blood vessel, the implantation of a non-degradable stent will limit the growth of the blood vessel and hinder growth and development. In addition, the presence of the stent as a foreign body will affect the image quality in later medical examinations such as MRI and CT. If it is a degradable stent, the stent will be completely absorbed after the disease is cured , and the above problems can be avoided.

A: Currently, the biodegradable scaffolds that are on the market or have been clinically studied are classified according to the materials into plastic biodegradable scaffolds (polymer stents) and metal biodegradable scaffolds (magnesium alloy and iron alloy stents). Polymer stents were studied the earliest, and the representative polymer stent is the ABSORB stent of Abbott Laboratories in the United States. It obtained CE certification in 2011 and was registered by the US FDA in 2016. However, in 2017, it was withdrawn from the global market 14 months after its launch because the incidence of adverse events was higher than that of permanent metal drug stents in the same period. The reason is that the strength of polymer materials is not as good as that of metal stents, and the stents must be made hypertrophic, which leads to clinical problems; while the mechanical properties of metal (magnesium alloy and iron alloy) biodegradable scaffolds are stronger than those of polymer stents, and both magnesium alloy stents and iron alloy stents have entered the clinic. The magnesium alloy stent ( Magmaris ) of Biotronik of Germany is the first biodegradable metal stent to enter the clinic. It obtained CE certification in 2017 and is currently in the post-market clinical stage. Biotyx Technology is the only company in the world that is developing ferroalloy biodegradable scaffolds . The first human clinical trial began in March 2018, and all Phase III clinical trials were completed in July 2023. A total of more than 1,300 patients were implanted, with a 100% success rate. Among all biodegradable stent materials, only ferroalloy mechanical properties are comparable to the cobalt-chromium alloy materials of the current mainstream permanent stents. The performance of zinc alloys and magnesium alloys is only half of that of permanent stent materials, and the performance of polymer materials is only one-tenth of that of permanent stents. As for which stent is the best, clinical results are needed to confirm.

A: Of course, all vascular stenosis can be treated with biodegradable scaffolds, and in theory, the long-term benefits are better than permanent stents. There are two groups of people who benefit the most: young patients; and patients with high bleeding risk or who cannot take antithrombotic drugs for a long time for various reasons. In addition, there are currently no pulmonary artery stents and below-the-knee stents for infants and young children in the world. Biodegradable scaffolds bring new treatment methods to these patients, and naturally the benefits are also great.

Q: Why is Biotyx the only one in the world that develops iron scaffolds?

A: The biggest challenge for iron alloy materials used in vascular stents is that iron degrades slowly in the human environment and the absorption of degradation products takes a long time. Biotyx Medical spent nearly 20years to find a suitable technical solution, which effectively solved the problems of slow iron degradation and long absorption time. The principle is to use the degradation of polylactic acid coating to generate an acidic microenvironment, so that iron can be degraded into soluble ions and easily absorbed. At the same time, nitrogen is infiltrated into the iron to significantly improve the mechanical properties of the iron. Sufficient support can be achieved with very little iron, and the stent rod can be made thinner than a hair. The less iron is used, the better it will degrade naturally. And absorption is faster. For example, the iron content of a commonly used iron scaffold is less than 8 mg, which is equivalent to the iron intake required by a normal person in less than a week. We began to develop ferroalloy degradable stents in 2006. Over the past 10 years, we have been constantly discovering and solving problems. We have applied for patents to protect related technologies.

A: Yes, all absorbable scaffolds cannot degrade uniformly in the body. The clinical requirements for the degradation of absorbable scaffolds are: 1. The support time must be guaranteed, that is, the stent must be able to support the blood vessel to maintain smooth blood flow before the vascular remodeling is completed; 2. Before the stent is covered by the neointima, no degradation products can fall into the bloodstream due to degradation, otherwise thrombosis may form. After the vascular remodeling is completed, the stent is covered by tissue, and the degradation of the stent will not cause restenosis, thrombosis, etc., which leads to re-treatment (target vessel revascularization), so any degradation is acceptable, that is, uniform degradation is not a clinical requirement .

A: Iron degrades into iron ions in an acidic microenvironment. A portion of it is directly bound by blood proteins and enters the human iron circulation system for use by the body, while a portion forms hemosiderin in the tissues and is deposited in the blood vessel walls for temporary storage. The macrophages in the human body (the body's scavengers) will clean up these hemosiderin, enter the body's lymphatic system (the body's sewer), and eventually return to the body's iron circulation. The iron absorption of the iron scaffold is the same as the iron absorption left in the subcutaneous blood when our bodies are injured, and eventually returns to the iron circulation through this path. The iron content of a commonly used iron scaffold is only equivalent to the iron in 20 ml of blood, and 20 ml is equivalent to the volume of a thumb.

A: The iron alloy stent contains about 94% iron, about 6% zinc and less than 0.1% nitrogen. The drug coated on the outside of the stent is the same as that of the permanent drug stent. Iron and zinc are essential trace elements in the human body, and nitrogen is a non-toxic element. The materials used in the iron alloy stent are all non-toxic and harmless substances, without any heavy metals or toxic elements. After the iron scaffold is implanted in the human body, the trace amount of polylactic acid drug-loaded coating will degrade into non-toxic carbon dioxide and water, and the iron and zinc will degrade into iron and zinc ions that can be used by the human body, respectively, so it has good biocompatibility. There are 4-5 grams of total iron in our human body, and about 1-2 mg of iron is ingested and enters the blood every day, and 10-20 mg of zinc is ingested and enters the blood every day. A conventional iron scaffold contains ~8 mg of iron and less than 1 mg of zinc. Iron is equivalent to the iron intake of a normal person in less than a week, and zinc is only equivalent to the intake of an adult for a few hours. Therefore, the iron and zinc ions that the stent degrades and releases into the blood every day are basically negligible, and it is impossible to cause systemic toxicity risks. A large number of animal experiments and human trials have proved that iron scaffolds have good biocompatibility and are non-toxic.

A: Iron is one of the essential nutrients for the human body and the most abundant trace element in the human body. It participates in various metabolic processes of living organisms, including oxygen transport, DNA synthesis and electron transport. An adult has a total of 4-5 grams of iron in the body, 1-2 mg of which is taken in through food every day, and 1-2 mg of iron is lost from the body through sweating, exfoliation and bleeding. When the iron balance in the body is disrupted, excess iron ions accumulate in the cells to form an unstable iron pool. The free divalent iron in the iron pool participates in the Fenton reaction, generating reactive oxygen species (ROS) represented by hydroxyl free radicals (HO•) and producing harmful effects. We have fully evaluated the possibility of iron scaffolds participating in the Fenton reaction . First, the results of animal experiments showed that after the iron scaffold was implanted in the animal, it was completely degraded in ~1 year. During the degradation of the stent, the iron ion concentration in the blood remained unchanged, and there was no effect on the systemic iron concentration. No systemic toxicity caused by iron overload was found. After rigorous pathological analysis, the tissues around the iron scaffold implantation had no local toxicity and carcinogenicity, and the blood vessels implanted with the iron scaffold had no atherosclerotic plaque formation. The inflammatory response was the lowest among all absorbable scaffolds, comparable to permanent stents. Secondly, it is worth mentioning that iron is an essential transition metal element for all living organisms. It plays a variety of important physiological roles based on its redox activity. The destruction of iron balance can cause oxidative damage. Therefore, human cells have evolved an extremely complete set of oxidation and antioxidant balance mechanisms to maintain a reasonable ROS concentration and protect cells from uncontrolled oxidative damage during the absorption of iron. Finally, an iron scaffold weighs only a few milligrams and is completely degraded within one year after implantation in the body. The iron ions released by the stent every day are at most tens of micrograms, which is far lower than the daily intake of the human body. Therefore, the impact on the iron balance in the human body can be ignored. In summary, our research results show that iron-based stents will not trigger the Fenton reaction to cause atherosclerosis, and are not toxic or carcinogenic!

A: Iron is a magnetic material, and in theory it seems to be MR incompatible. However, our laboratory and animal experimental tests have shown that its MR compatibility is comparable to that of current permanent stents. Our labels indicate that it is "MR conditionally safe", which means that it is MR safe under certain conditions, and this safety boundary condition is exactly the same as that of permanent stents. This is because the amount of iron used in iron scaffolds is very small, even less than the amount of iron in stainless steel stents. After the stent degrades, it becomes "MR safe".

A: Preliminary clinical results show that the drug degrades by about 60% in human coronary arteries in six months and by about 80% in one year. It is completely absorbed in 2-3 years. More clinical data in the future will provide more accurate and comprehensive degradation data.

A: After our test, it can pass and the security inspection machine will not beep. The reason is that the scaffold is very small and the amount of iron is below the detection limit of the machine.

A: The endothelialization time of iron scaffolds (the tissue completely wraps the stent, separating it from the blood, and no longer allowing thrombosis) is shorter than that of permanent stents. Therefore, the dual-antibody time of iron scaffolds is currently the same as that of permanent stents, which is one year. More clinical data will provide more references in the future . The dual-antibody time of polylactic acid biodegradable scaffolds is generally more than 3 years.

A: The surgical procedure for iron scaffolds is the same as that for permanent stents currently used. There is no need to emphasize the PSP operation for polylactic acid stents and the 4P operation for magnesium alloy stents. The key points of PSP/4P operation are: pre-dilate the narrowed blood vessels with a balloon before stent placement, accurately measure the blood vessel diameter with an OCT (intravascular optical coherence imaging) catheter, and re-dilate the stent with a high-pressure balloon after stent implantation. These additional operations will bring additional costs.

A: The product has not yet been approved by the China Food and Drug Administration and cannot be sold for the time being. However, several clinical trials have been conducted in China, including 1. IBS® TitanTM clinical trial of below-the-knee stents chaired by Professor Guo Wei of the PLA General Hospital (301 Hospital); 2. IBS® AngelTM clinical trial of pediatric pulmonary artery stents chaired by Professor Zhang Zhiwei of Guangdong Provincial People's Hospital ; 3. IBS® clinical trial of coronary stents chaired by Academician Gao Runlin of Beijing Fuwai Hospital. Our absorbable iron-based coronary stent IBS® was first implanted in March 2018, and all three phases of implantation were completed in July 2023. A total of more than 1,300 patients were implanted, with a 100% success rate. Academician Gao published the 3-year clinical results of the first clinical trial in EuroIntervention magazine, which preliminarily proved the safety and effectiveness of the iron scaffold. More clinical trial results will be published in the future. Interested patients can contact the doctors of the relevant clinical trials and evaluate if they meet the conditions to join our clinical trials.

We have obtained the CE registration certificate for IBS Angel™ Scaffold, and we have also submitted CE applications for IBS™ and IBS Titan™. They are currently under review. Please pay attention to the information on our website for the specific progress.