What is an Ultrasonic Drug Coated Stent?

Drug coated stent:

In the treatment of arterial diseases, stent implantation has gained considerable popularity in clinical practice because it is relatively non-invasive. The alternative method for stent implantation is bypass surgery, which is a highly invasive and complex surgery.

Nowadays, stent therapy has become a feasible alternative to multiple bypass surgeries. At a 25% restenosis level, implanting a stent significantly reduces the risk of using drug-eluting stents.

A stent is a method of inserting a tubular mesh metal structure into an affected artery to relieve obstruction. The implantation of bare metal stents usually leads to restenosis, as the accumulation of scar tissue around the stent can cause re occlusion. To solve this problem, some protein surface polymers that can be slowly released need to be coated on the scaffold. The use of ultrasonic spraying technology has been proven to be effective in achieving continuous and uniform coating on supports.

 

 

Drug coated stents are a challenging spray application. Strict requirements have been placed on the manufacturing processes used to produce them. Ultrasonic spraying is very suitable for this application because it uses piezoelectric ceramics to generate vibrations of tens to hundreds of kilohertz, forming particles of tens or even a few micrometers without the need for high-pressure air pressure. It accurately and efficiently sprays the support, and the production environment is easily controlled, without pollutants entering.

 

There are two types of ultrasonic nozzles that can be used for spraying ultrasonic drug eluting stents: linear spray and convergent spray (as shown in the following figure). Both types of nozzles can be used for precise spraying of drug stents, which increases the difficulty of spraying due to the complexity and small size of drug stents. Line spray and convergent spray nozzles can produce droplets with small size and very tight and uniform distribution, which adhere well to the surface. The morphological characteristics of the coating can be adjusted by modifying process parameters, without rebounding or overspray. The use of linear or convergent nozzle coatings is thin and uniform, saving spraying materials, and free from defects such as blockages, adhesions, pinholes, and bubbles, ensuring that the spraying quality of drug stents does not decrease due to reduced working time.

 

Support types using ultrasonic spray coating (metal or bioabsorbable materials):

 

Arteries, peripherals, sinuses, bifurcated, naked, biodegradable, covered stents

 

Advantages of ultrasonic spraying bracket coating:

 

1. Highly controllable and repeatable spraying.

2. Non clogging ultrasonic spraying technology.

3. Able to perform precision spraying operations at a flow rate of microliters per hour.

4. The minimum droplet size can be designed to 12 μ m (above 150KHz), and the droplet distribution is very tight and uniform.

5. The flow rate of spray is very low, and it drops on the support almost at the speed of free fall, without rebound or overspray.

6. The drug coating is dense and not easy to peel off during use.