N-(2-mercaptoethyl) acrylamide (MEAM) monomer was synthesized by acrylation of cysteamine and was cross-linked with ethylene glycol dimethacrylate (EGDMA) via dispersion polymerization forming poly(N-(2-mercaptoethyl) acrylamide) (p(MEAM)) microgel. Then, the prepared microgels were tested for potential biomedical use, eg, antioxidant capacity and blood compatibility, cytotoxicity, apoptotic, and necrotic cell death; drug delivery properties were determined. Antioxidant studies of p(MEAM) microgels revealed a super antioxidant capability with total phenol content and trolox equivalent antioxidant capacity as 6.05 ± 1.15 mg/L gallic acid equivalency and 40.96 ± 2.40 mM trolox/g, respectively. Moreover, the blood compatibility of p(MEAM) microgels on fresh blood was resulted in lower than 1.0% hemolysis ratios for all the studied concentration range, and the blood clotting index was determined as 60.66% at 2.0 mg/mL at microgel concentration. The biocompatibility studies employing WST-1 test on L929 fibroblast cells and DLD-1 colon cancer cells have shown that p(MEAM) microgel was biocompatible up to 200 μg/mL concentration with the cell viability values of 84.54% and 86.15% on L929 fibroblast and DLD-1 colon cancer cells, respectively. Using Captopril was used as model drug to test p(MEAM) microgel as drug delivery device for in vitro release studies at different pHs. Release profile of Captopril was found linear up to 5 hours with the released amounts of 9.81, 12.24, and 13.78 mg g -1 microgel at the pH 1.5, 7.4, and 9.0, respectively. KEYWORDS acrylamidebiocompatibility, acrylation of cysteamine, antioxidant material, drug delivery/release, microgel/nanogel, N-(2-mercaptoethyl) hemocompatibility 1 | INTRODUCTION There is great interest on functional vinyl group-containing monomers and to generate polymers bearing reactive electrophilic, nucleophilic, and click chemistry groups that can be prepared employing different synthesis/polymerization techniques. 1-3 Allylation and/or (meth) acrylation are the most commonly used reactions with ─COOH, ─NH 2 , ─SH, and ─OH to form polymerizable new side for linear, cross-linked, and branched polymer preparation with different physicochemical properties, and morphologies. 4-7Micro-and nano-sized polymeric particles composed of hydrophilic, hydrophobic, or amphiphilic monomers have immense interest in biological applications due to high stability, high loading capacity, and stimuli-responsive properties. 8-10 Depending on the sizes, these materials are sometimes called microgel and nanogels. For materials needed to be used in biological applications should perform their functions on without causing any damage, reaction, immune response, and so on on/in the applied areas, eg, body and tissue. Therefore, these materials need to be tested for biocompatibility, 11 and in many biological applications, these biomaterials are also required to contact with
