Cancer is a global disease that is considered as one of the leading causes of death worldwide. The developed resistance toward chemotherapy and radiotherapy, the low degree of selectivity and the accumulation are motivating the efforts to find innovative bio-active systems. The utilization of cellulosic substrates is highly favorable to be used as bio-composites due to their biocompatibility and bioavailability. Two composites with different molar ratios of cellulosic substrates and poly(amidoamine) (PAMAM) hyperbranched polymer have been prepared using a solvent exchange method. The resultant composites were assigned as Comp E and Comp T that prepared by using ethyl cellulose and TEMPO-oxidized cellulose, respectively. The prepared composites were characterized via measurement of overall zeta charge and FTIR. The topography of the composites was investigated using a scanning electron microscope. The evaluation of cytotoxicity and anticancer activity was also studied. The IC50 values from the results of cell viability assays were calculated to investigate the sensitivity of MCF-7, HCT-116, HepG-2, and WI-38 to different types of composites and starting materials. The morphological changes of cancer cell lines were studied using an inverted microscope after different treatments compared to control cells. Higher antitumor activity of polyamidoamine was recorded against tested carcinoma cell lines and lower cytotoxicity was observed against normal cell lines. Also, after a combination of PAMAM with two types of cellulose, the antitumor activity of liver carcinoma cell line was increased for Comp E and Comp T followed by breast and colon carcinoma cells. The biocompatibility of the two types of cellulose was observed against normal cell lines. The cytotoxicity of PAMAM was decreased after combination of two types of cellulose. [ABSTRACT FROM AUTHOR]