Nano- to microscale liquid coacervate particles are provided. The liquid coacervate particles are produced by a process including stimulating a population of liquid droplets containing one or a mixture of components to induce a phase separation point of a first component, and maintaining stimulation at the phase separation point to form a coacervate domain of the first component within each of the droplets to form the liquid coacervate particles. The self-assembled nano, meso, micro and macro liquid coacervate particles and related coated substrates can have utility in drug delivery, bioanalytical systems, controlled cell culture, tissue engineering, biomanufacturing and drug discovery.