Protein corona

Layer of biomolecules that forms around nanoparticles in a biological environment

Protein Corona

The protein corona is a layer of biomolecules, primarily proteins, that forms on the surface of nanoparticles when they are introduced into a biological environment, such as blood plasma. This phenomenon is critical in determining the biological identity and behavior of nanoparticles, influencing their biodistribution, cellular uptake, and immune system response.

Formation of protein corona on nanoparticles

Formation

When nanoparticles enter a biological fluid, they are immediately surrounded by a complex mixture of proteins and other biomolecules. This interaction leads to the formation of a protein corona, which can be divided into two distinct layers: the "hard" corona and the "soft" corona. The hard corona consists of proteins that are tightly bound to the nanoparticle surface, while the soft corona is composed of loosely associated proteins that can exchange with the surrounding environment.

Composition

The composition of the protein corona is influenced by several factors, including the physicochemical properties of the nanoparticles, such as size, shape, surface charge, and hydrophobicity. The biological environment, including the type of fluid and its protein content, also plays a significant role. Common proteins found in the corona include albumin, immunoglobulins, and fibrinogen.

Impact on Nanoparticle Behavior

The presence of a protein corona can significantly alter the properties of nanoparticles. It affects their colloidal stability, cellular uptake, and biodistribution. The protein corona can also mask the surface properties of nanoparticles, potentially reducing their targeting efficiency and altering their interaction with cell membranes.

Biological Implications

The formation of a protein corona is a critical consideration in the design of nanoparticle-based drug delivery systems and diagnostic tools. Understanding the protein corona is essential for predicting the pharmacokinetics and toxicity of nanoparticles. It also plays a role in the immune response, as the corona can either enhance or reduce the recognition of nanoparticles by the immune system.

Research and Applications

Research into the protein corona is ongoing, with studies focusing on its dynamic nature and the development of strategies to control its formation. Applications include the design of "stealth" nanoparticles that evade the immune system and the use of protein corona profiles as biomarkers for disease diagnosis.

Related pages

• Nanoparticle
• Biomolecule
• Drug delivery
• Immune system