With the rapid development of the economy, in recent years, the world has put forward higher requirements for promoting environmental governance technologies, methods, and paths such as carbon reduction, pollution reduction, green expansion, and growth. It is urgent to rely on technological innovation to solve the problems of green development. In response, Unilong actively promotes its subsidiaries to seek green opportunities, strengthen technological innovation, and promote carbon reduction and efficiency enhancement. Unilong has broken through technological innovation and achieved significant results in the field of biopolymer materials, with PCL, PGA, and PLGA having significant advantages. It has also opened up overseas markets and sold to Europe, the Americas, Southeast Asia, Africa, and other places.
We all know that there are many polymers, and today I will share an article about the differences between PGA and PLGA.
Polyhydroxyacetic acid (PGA)
Polyglycolide is a simple polyester with excellent biodegradability and biocompatibility. Its final degradation products are carbon dioxide and water, which are excreted from the body through normal metabolism. It is an important medical polymer material. Widely used in internal fixation of human or animal fractures, repair of bone defects, repair of tendons, and suturing of blood vessels, muscles, and other tissues in humans or animals.
There are two classic preparation methods for polyglycolic acid: direct condensation polymerization and glycolide ring opening polymerization. The direct condensation polymerization method, in general, involves the direct dehydration and condensation of hydroxyacetic acid. The process is short, the operation is simple, the instruments and equipment are few, and the consumption of raw materials and reagents is low. However, generally, only oligomers with relative molecular weights ranging from tens to thousands can be obtained, resulting in poor product performance and easy decomposition. Its mechanical strength is far from meeting the requirements for the use of surgical sutures and surgical implant materials. The ring-opening polymerization of glycolide is a method of preparing polyhydroxyacetic acid through the ring-opening polymerization of glycolide. High molecular weight polyhydroxyacetic acid can be synthesized through this method, but it requires high purity of glycolide, a long synthesis process, low product yield, and high synthesis cost.
Polylactic acid hydroxyacetic acid copolymer (PLGA)
Poly(D,L-Lactide-Co- Glycolide) (PLGA) is a biodegradable functional polymer organic compound that is randomly polymerized from two monomers – lactic acid and glycolic acid. It has good biocompatibility, non-toxic properties, and excellent encapsulation and film forming properties, and is widely used in pharmaceutical, medical engineering materials, and modern industrial fields. Our PLGA has passed FDA certification and has been officially included as a medicinal excipient in the US Pharmacopoeia.
Different types of PLGA can be prepared with different monomer ratios. For example, PLGA 75:25 indicates that the polymer is composed of 75% lactic acid and 25% hydroxyacetic acid. All PLGAs are amorphous, with a glass transition temperature between 40 and 60 ° C. Pure lactic acid or hydroxyacetic acid polymers are relatively insoluble. Unlike PLGA, which exhibits a wider range of solubility, it can dissolve in more general solvents such as chlorinated solvents, tetrahydrofuran, acetone, or ethyl acetate.
Breaking ester bonds can lead to the degradation of PLGA, and the degree of degradation varies with the monomer ratio. The higher the proportion of glycolide, the easier it is to degrade. There are also special cases where when the ratio of the two monomers is 50:50, the degradation rate will be faster, which takes about two months.
There are many applications of biodegradable materials in the human body. Among them, the most well-known one is suture. Absorbable sutures have been widely used in the medical field, achieving the goal of no need to remove the suture.
In recent years, many related products have also emerged, which generally have some advantages: they can be excreted through metabolism, are non-toxic, safe and reliable, have good biocompatibility, and have controllable degradation performance. Therefore, these products are widely used as biomedical materials. For example, surgical sutures, drug controlled release systems, orthopedic fixation (bone plates, etc.) and tissue repair materials (seamless repair, etc.), cardiac stents, vascular containers, hemostatic clips, artificial blood vessels, neural conduits, etc. The biodegradable materials used mainly include polyhydroxyacetic acid (PGA), polylactic acid hydroxyacetic acid copolymer (PLGA), etc.
At present, PLA and PLGA are the most widely used materials that have been certified to be implanted into the human body. We need to conduct a large number of animal experiments to make different products based on the characteristics of each material. Due to the need for many materials to act as scaffolds in the human body, there are high requirements for strength; The length of degradation time is also related to medical intensity. Overall, in the field of medical materials, the most important factors are degradation time and medical strength.