Solution for thickness measurement of drug coatings on cardiac stents Unikang Technology Co., LTD
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| Background introduction of cardiac stents |
| Coating materials for heart stents |
| Characteristics of drug-coated stents |
| Customer and market situation of heart stents |
| Solution for measuring the thickness of heart stent coatings |
Background introduction of cardiac stents
Background of Heart Stents
According to the annual statistics on human disease mortality rates, approximately 17 million people die from cardiovascular diseases worldwide each year, accounting for one-third of global deaths. Coronary heart disease is the leading cause of death.
Coronary heart disease, also known as ischemic heart disease, is a type of heart disease caused by atherosclerosis of the coronary arteries, which leads to narrowing or blockage of blood vessels, resulting in coronary circulation disorders and causing myocardial ischemia, hypoxia or necrosis.
In 1987, Sigwart applied coronary stent implantation in clinical practice. Subsequently, during the development of coronary heart disease intervention, there were two historic leaps: the implantation of Bare metal stents (BMS) and the implantation of Drug eluting stents (DES) within the coronary arteries.
The main function of DES is to prevent the occurrence of cardiovascular restenosis. Drug-eluting stents (DES) that reduce neointimal hyperplasia within the stent during the chronic phase are stents that carry (load) anti-vascular intimal hyperplasia drugs on a bare metal stent platform, which are eluted and released locally in the blood vessel, effectively inhibiting intimal hyperplasia within the stent to prevent restenosis within the stent. The effective application of drug-eluting stents can reduce the incidence of restenosis and re-interventional surgery. It is usually composed of three parts: a platform made of metal scaffolds, a drug carrier, and the drug.
Coating materials for heart stents
Cardiac Stent Coating Materials
The common coating materials for heart stents are generally the following three types
Inorganic material coated scaffoldIncluding coated stents such as diamond-like stents (DLC), silicon carbide (Sic), ceramics, and carbon molecules. | Polymer materialsIn recent years, the research on vascular stents made entirely of polymer materials has received much attention from researchers and is regarded as a very promising material for vascular stent fabrication. | ProteinGelatin, 32P colloidal chromium phosphate, plasma, etc. have been reported as carriers for drugs, radioactive substances or genetically modified organisms, but they are only found in animal experiments. |
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Characteristics of DES drug-coated stents
Drug eluting stent characteristics
Characteristics and mechanism of action of DES drug-coated stents
The drug comes into contact with and covers the area of the blood vessel wall evenly, with a polymer coating as the carrier and a stent as the drug release platform, carrying the drug dose < In the coverage area where the drug distribution mainly covers the steel beam position of the scaffold coating, the drug release kinetics is carried out slowly and controllably at 100-200 μ g, effectively reducing the occurrence of restenosis.
Drug sustained-release characteristics: The combination of drug molecules and sustained-release high-molecular coating materials inhibits the growth of scar tissue around the stent, effectively reducing the incidence of restenosis in patients.
Anti-rejection characteristics: Reduce the immune rejection phenomenon in patients' bodies, enhance the effectiveness of treatment and the recovery experience of patients throughout the entire course of the disease.
Customer and market situation of heart stents
Cardiac stent customers and market
Microport Medical, Lepu Medical, Jiwei Medical, Sinuo Medical, Kangdelai Medical and others have gone public one after another. In the next two years, cardiovascular enterprises such as Huitai, Xintong and Bomai will also go public one after another. There will be more than ten listed companies in the cardiovascular field, and funds will continue to gather in the leading enterprises.
With the development of China's medical device industry, the Pearl River Delta mainly relies on Guangdong for the import and export of medical devices, while the Yangtze River Delta has the largest number of registered medical device products in Jiangsu Province. Beijing, Tianjin, Liaoning and Shandong, which belong to the Beijing-Tianjin-Hebei Bohai Rim region, have become the three major medical device industry clusters in China.
Leading industry clients such as Sino and Kangdelai, which mainly focus on product application research and development, have driven the product quality inspection demands of other clients in the entire industry. This has radiated to medical device testing system-related units in the entire industry, such as medical device testing centers in Tianjin and Suzhou, for different requirements for the inspection of stents and stent-related medical system film layers.
Solution for measuring the thickness of heart stent coatings
Measurement of Stent Coating Thickness
The thickness and uniformity of the drug-loaded polymer coating will affect the release rate and duration of the drug as well as the coverage rate of the drug on the surface of the lesion site. Therefore, efficient and precise measurement of the surface coating is required.
The commonly used measurement methods for the thickness and surface distribution of drug coatings at present 1The thickness of the drug coating is roughly calculated by controlling the number of sprays and the duration. 2The film thickness is measured and the distribution is confirmed with the help of the scanning electron microscope scale. The sample preparation of the above two methods is rather complicated and the measurement efficiency is relatively low. 3. Use the Filmetrics optical film measuring instrument It can achieve rapid measurement of film thickness and optical constants. By analyzing the reflection spectrum between the upper and lower interfaces of the film layer to be measured, the measurement results can be obtained within a few seconds.The unique measurement system enables automatic thickness mapping of the entire surface of the support simply by rotating the support during measurement. High efficiency and fast speed. |
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When measurement needs to be carried out in certain tiny and specific areas on the surface of the sample to be tested, or when other applications require a spot size as small as 1 micron, F40 can obtain precise thickness and optical parameter values by gradually correcting each objective lens and then conducting the measurement. |
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Light of different wavelengths will be reflected at the top and bottom of the film, and the total amount of reflected light is the superposition of the reflected light from these two parts. Due to the wave-like nature of light, these two parts of reflected light may interfere with each other to be complementary (adding intensity) or cancel each other out (subtracting intensity), depending on their phase relationship. The phase relationship depends on the optical path difference of the reflected light from these two parts, which is determined by the thickness of the film, the optical constant, and the wavelength of the light. When the phase difference is an integer multiple of the wavelength. When constructive superposition occurs, the reflectivity is at its maximum. When the phase difference is half a wavelength, destructive superposition occurs, and the reflectivity; The superposition between integer multiples and half wavelengths, with a reflectance between the maximum and minimum reflections, thus forms an interference pattern. |
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Installation of the equipment and actual test data
The author of the article
| Sales Manager of North China Region With nearly 10 years of industry background in scientific research and analysis instruments, I focus on applications related to the properties and morphology of thin films. With professional and friendly communication, we explore and understand the actual applications and demands of our clients, and provide accurate solutions. We have been serving major research institutes and enterprises in the north for a long time.
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