Plasma treatment is a surface modification technique that can significantly alter the surface properties of polymeric biomaterials, thereby affecting their biocompatibility. Plasma is an ionized gas containing ions, electrons, free radicals, and neutral species. When a polymeric biomaterial is exposed to plasma, various physical and chemical processes occur on its surface, leading to changes in surface properties such as wettability, surface chemistry, and topography. These changes can influence the interaction of the biomaterial with biological systems, thus affecting its biocompatibility.1. Wettability: Plasma treatment can increase the wettability of polymeric biomaterials by introducing polar functional groups e.g., hydroxyl, carboxyl, and amine groups onto their surface. This improves the surface's ability to absorb water, which is essential for cell adhesion, spreading, and proliferation. Enhanced wettability can lead to better biocompatibility, as cells can interact more effectively with the biomaterial surface.2. Surface chemistry: Plasma treatment can introduce various functional groups onto the surface of polymeric biomaterials, depending on the type of gas used in the plasma process. For example, oxygen plasma can create oxygen-containing functional groups, while ammonia plasma can introduce amine groups. These functional groups can alter the surface chemistry, enabling the biomaterial to interact more effectively with proteins, cells, and other biological components. This can result in improved biocompatibility, as the biomaterial can better integrate with the surrounding tissue.3. Surface topography: Plasma treatment can also modify the surface topography of polymeric biomaterials by etching or cross-linking the polymer chains. This can create a rougher or smoother surface, depending on the plasma conditions and the type of polymer. Changes in surface topography can influence cell adhesion, spreading, and proliferation, as cells respond differently to various surface textures. A suitable surface topography can enhance biocompatibility by promoting cell attachment and growth.4. Sterilization: Plasma treatment can also serve as a sterilization method for polymeric biomaterials. The reactive species in the plasma can effectively inactivate microorganisms, ensuring that the biomaterial is free from contamination. This is crucial for biocompatibility, as the presence of microorganisms can lead to infection and inflammation, compromising the performance of the biomaterial.In summary, plasma treatment can modify the surface properties of polymeric biomaterials, such as wettability, surface chemistry, and topography, which can significantly affect their biocompatibility. By tailoring these properties, plasma treatment can improve the interaction between the biomaterial and the biological environment, leading to better integration and performance in biomedical applications.