A new bimetallic coordination polymer [In2Na(H2O)2(ddca)3](NO3)·4H2O (1, H2ddca = 6,6′-dithiodinicotinic acid) is produced via a hydrothermal reaction of In(NO3)3, H2ddca with NaOH as the pH modulator. Various characterization methods, such as thermogravimetric analysis (TGA), elemental analysis (EA), single crystal and powder X-ray diffraction measurements, are used. Furthermore, a process of sonochemistry with oleic acid at 453 K is used to produce nanoparticles of 1 (nano-1). In terms of the biological function of the synthesized complex, the real-time reverse transcription-polymerase chain reaction is carried out to explore the relative mRNA expression of miR-181 in MGC-803, BGC-823, and SGC-7901 gastric cancer cell lines, and the western blot is used to explore the protein expression of apoptotic protein Bcl-2.