Novel biocompatible homo and co-polymeric microparticles were synthesized from maleic acid (MA) and citric acid (CA) for uptake/release thiamine as a model drug. Surfactant-free self-emulsion polymerization technique was accomplished to synthesize the microparticles in a single step. The antimicrobial, antioxidant properties of those microparticles and their thiamine uptake/release capacities were investigated. Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyzer (TGA), particle-size/zeta-potential (Zeta/DLS) and scanning electron microscopy (SEM) instruments were utilized for the characterizations of microparticles. FTIR revealed the existence of bonding interaction between the carboxylic acid groups of CA and MA. TGA results represented that thermal decomposition of microparticles was gradually continuing up to 1000 degrees C. The hydrodynamic diameters of poly (CA), poly (MA), poly (CA-co-MA) microparticles were found to be in the range of 681 nm, 1273 nm, 1604 nm, respectively. The zeta potential of those microparticles was in the range of - 5.69 mV, - 16.90 mV and - 7.73 mV, respectively. The studies demonstrated that all microparticles have superior properties to absorb and release thiamine compared with similar candidates. Furthermore, controlled release behavior of thiamine was examined using zero sequence, first-order, Higuchi and Korsmeyer-Peppas models in PBS solutions at pH 7.4. Thiamine release from all microparticles exhibits a very high correlation with the Korsmeyer-Peppas semiempirical model and could be interpreted by the superposition of both Fickian diffusion and non-Fickian diffusion based on Peppas' semiempirical equation. Superior capacities of microparticles, synthesized in one step without formation of toxic by-products, to absorb and release thiamine, aside from their biocompatible, antioxidant and antimicrobial properties make them valuable materials in nanotechnology and biomedical applications.