We previously reported an attenuated cationic amphiphilic lytic (ACAL) peptide, engineered from a natural hemolytic peptide, named L17E [1]. Substantial cytosolic delivery of biomacromolecules, including immunoglobulin G (IgG), was attained in the presence of this peptide. Fc region binding peptide conjugated with L17E trimer [FcB(L17E)3] was designed for more efficient IgG delivery into cells [2]. Particle-like liquid droplets were generated by mixing Alexa Fluor 488 labeled IgG (Alexa488-IgG) with FcB(L17E)3. Droplet contact with the cellular membrane led to spontaneous influx and distribution of Alexa488-IgG throughout cells in serum containing medium. Involvement of cellular machinery accompanied by actin polymerization and membrane ruffling was suggested for the translocation. Alexa488-IgG negative charges were crucial in liquid droplet formation with positively charged FcB(L17E)3. Successful intracellular delivery of Alexa Fluor 594-labeled anti-nuclear pore complex antibody allowed binding to cellular targets in the presence of FcB(L17E)3. Conjugation of L17E to hydrophilic polymers was also found to provide a similar mode of cytosolic IgG delivery, suggesting design flexibility for intracellular delivery via liquid droplet (or coacervate).