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Adsorption (not to be mistaken for ''absorption'') is the accumulation and adhesion of molecules, atoms, ions, or larger particles to a surface, but without surface penetration occurring. The adsorption of larger biomolecules such as proteins is of high physiological relevance, and as such they adsorb with different mechanisms than their molecular or atomic analogs. Some of the major driving forces behind protein adsorption include: surface energy, intermolecular forces, hydrophobicity, and ionic or electrostatic interaction. By knowing how these factors affect protein adsorption, they can then be manipulated by machining, alloying, and other engineering techniques to select for the most optimal performance in biomedical or physiological applications. ==Relevance== Many medical devices and products come into contact with the internal surfaces of the body, such as surgical tools and implants. When a non-native material enters the body, the first step of the immune response takes place and host extracellular matrix and plasma proteins aggregate to the material in attempts to contain, neutralize, or wall-off the injurious agent. These proteins can facilitate the attachment of various cell types such as osteoblasts and fibroblasts that can encourage tissue repair. Taking this a step further, implantable devices can be coated with a bioactive material to encourage adsorption of specific proteins, fibrous capsule formation, and wound healing. This would reduce the risk of implant rejection and accelerate recovery by selecting for the necessary proteins and cells necessary for endothelialization. After the formation of the endothelium, the body will no longer be exposed to the foreign material, and will stop the immune response. Proteins such as collagen or fibrin often serve as scaffolds for cell adhesion and cell growth. This is an integral part to the structural integrity of cell sheets and their differentiation into more complex tissue and organ structures. The adhesion properties of proteins to non-biological surfaces greatly influences whether or not cells can indirectly attach to them via scaffolds. An implant like a hip-stem replacement necessitates integration with the host tissues, and protein adsorption facilitates this integration. Surgical tools can be designed to be sterilized more easily so that proteins do not remain adsorbed to a surface, risking cross-contamination. Some diseases such as Creutzfeldt–Jakob disease and kuru (both related to mad cow disease) are caused by the transmission of prions, which are errant or improperly folded forms of a normally native protein. Surgical tools contaminated with prions require a special method of sterilization to completely eradicate all trace elements of the misfolded protein, as they are resistant to many of the normally used cleansing methods. However, in some cases, protein adsorption to biomaterials can be an extremely unfavorable event. The adhesion of clotting factors may induce thrombosis, which may lead to stroke or other blockages. Some devices are intended to interact with the internal body environment such as sensors or drug-delivery vehicles, and protein adsorption would hinder their effectiveness. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Protein adsorption」の詳細全文を読む スポンサード リンク
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