**1. Introduction**

Biocompatibility testing is a crucial aspect of the development and evaluation of medical devices and pharmaceutical agents. Ensuring that these products are safe and effective for human use is of paramount importance, as they can directly interact with the body's tissues and cells. The primary goal of biocompatibility testing is to assess the safety and effectiveness of medical devices and pharmaceutical agents before they come into contact with the human body. These products may possess a variety of mechanical, physical, and chemical properties that can potentially impact their interactions with biological systems. Biocompatibility testing helps identify any potential risks associated with these interactions, allowing for the optimization of product design and formulation to minimize the likelihood of adverse effects. The components of biocompatibility or the tissue response of the clinically relevant performance of biomaterials are cytotoxicity, genotoxicity, mutagenicity, carcinogenicity, and immunogenicity. Medical devices and pharmaceutical agents must undergo a series of tests to determine their cytotoxic effects and acute systemic toxicity. These tests are essential in ensuring that the products are safe for clinical use and do not pose any undue risks to patients.

#### **1.1 Cell viability and cytotoxicity assessments**

A key component of biocompatibility testing involves the evaluation of cell viability and cytotoxicity. Cell viability refers to the number of healthy, functioning cells in a sample, while cytotoxicity measures the potential of a substance to cause cell damage or death. By assessing these parameters, researchers can gain insights into how medical devices and pharmaceutical agents may affect the body at the cellular level [1]. Various assays can be employed to measure cell viability and cytotoxicity, including dye exclusion methods, metabolic activity-based methods, ATP assays, and DNA synthesis cell proliferation assays, among others. These tests can help determine whether a substance exhibits direct cytotoxic effects or impacts cell proliferation, providing valuable information on its safety profile.

#### **1.2 Biocompatibility testing for medical devices**

Medical devices, which encompass a wide range of products used in various clinical disciplines, must demonstrate good biocompatibility to be deemed safe for use. This is particularly important for devices that come into direct contact with the body's tissues and cells, such as implants, prosthetics, and surgical instruments. Biocompatibility testing for medical devices involves assessing the compatibility of these products with the biological systems they will encounter during use. This includes evaluating the interaction between the device and the living tissues and cells it will come into contact with, as well as examining the potential for adverse reactions, such as inflammation, infection, or rejection. By thoroughly evaluating the biocompatibility of medical devices, researchers can develop products that are more likely to integrate successfully with the body and promote positive patient outcomes.
