Cytocompatibility is related to the behavior of biomaterials in various contexts. The term refers to the ability of a material to perform with an appropriate host response in a specific situation. The term’s ambiguity reflects the ongoing development of insights into how biomaterials interact with the human body and, eventually, how those interactions determine the clinical success of a medical device (such as a pacemaker, hip replacement, or stent). Modern medical devices and prostheses are often made of more than one material, so discussing the biocompatibility of a specific material is not always sufficient.

What Are Cytocompatibility Tests?

Since the body’s immune response and repair functions are so complicated, it is not adequate to describe the biocompatibility of a single material in relation to a single cell type or tissue. Cytocompatibility tests are sometimes composed of large batteries of in vitro tests to determine if a certain surface is biocompatible. These tests do not determine the cytocompatibility of material, but they constitute an important step towards animal testing and clinical trials that will determine the biocompatibility of the material in a given application, and thus medical devices such as implants or drug delivery devices.

When Is a Material Considered Cytocompatible?

The material will be considered cytocompatible if both structure and functions of the tissue in direct contact with it remain unchanged. The maintenance of these functions depends directly upon the quality of the material surface. Thus, a material may induce reorganization of tissue without exhibiting cellular damage, but the previous (original) structure and functions will be lost. Therefore, research and development of biomaterials may provide surface properties of the material which satisfy these requirements. Most research on blood-contacting material is concerned with this aspect.