Yet, it remains unknown what nanoparticles (NPs) can be a good candidate for insulin delivery, and there is, however, still little research on chitosan nanoparticles (ChNs) for insulin delivery. The aim is to shed light on the efficacy of hairy cellulose nanocrystals (HCNs) in insulin delivery and compare it with ChNs. NPs were synthesized and assessed through using SEM, DLS, Zeta potential, FTIR, and MTT. Insulin was loaded on both NPs and the insulin loading and encapsulation efficacy were measured. The release kinetic model was also studied using zero order, First order, Korsmeyer-Peppas, and Higuchi models. The analysis revealed that HCNS were in a rod shape while ChNS were spherical. HCNs had a size of 100-150 nm with a zeta potential of +34.2 mV, while ChNs were 100-200 nm and had a surface charge of +40.7 mV. Insulin loading reduced the zeta potential to -26.08 mV and +19.47 mV in HCNs and ChNs respectively. HCNs showed higher cell viability than ChNs. Insulin release was more stable in HCNs compared to the ChNs. Korsmeyer-Peppas (R2=0.99, n=0.741, K=0.004 ) was the most fitted model for ChNs, while for HCNs, both Korsmeyer-Peppas (R2=0.97) and Higuchi models (R2=0.95) were the most fitted model. To sum up, HCNs showed higher potential in insulin loading and release compared to ChNs.