Mid Sweden University

Polymeric multilayers capsules constructed using the layer-by-layer (LbL) technique are interesting candidates for the purposes of storage, encapsulation and release in a wide range of biomedical applications. In the current study, cellulose-based nanocapsules were produced via the LbL technique. In this procedure, alternating deposition of the two biocompatible polymers anionic cellulose, carboxymethylcellulose (CMC), and cationic cellulose, quaternized hydroxyethylcellulose ethoxylate (QHECE), on a cationic vesicular template made of didodecyldimethylammonium bromide (DDAB), was performed. The obtained nanocapsules, were characterized by dynamic light scattering (DLS), ⇣ potential measurements, and field-emission scanning electron microscopy (FE-SEM). DLS measurements revealed that the size of the spheres is about hundreds of nanometer with polydispersity index (PDI) values between 0.2 and 0.3, indicating a relatively homogeneous size distribution. In addition, FESEM characterization also indicated the shape and size of obtained material. The surface charge analysis of the nanocapsules by ⇣ potential measurements indicated the presence of electrostatically stabilized nanoparticles. The values of diameter, PDI and surface charge for cationic vesicles coated by CMC were 204 nm, 0.26 and –38 mV, respectively. After deposition of QHECE, the diameter, PDI, and surface charge were about 265 nm, 0.36 and +32.5 mV, respectively. Figure 1 shows FE-SEM images of cellulose nanoparticles fabricated via LbL deposition of polyelectrolyte layers. As seen in the microscopy images, the shape of the core-shell particles are not fully spherical which could be due to drying e↵ects of the sample before FE-SEM characterization. The construction of cellulose nanocontainers by using an alternating deposition of oppositely charged biobased polyelectrolytes on vesicles o↵ers several advantages such as simplicity, reproducibility, biocompatibility, low-cost, mild reaction conditions, and high controllability over the thickness and composition of the shell.