In the present study, an application of cellulose nanofibers has been established for the controlled release of an anticancer drug, i.e., camptothecin. The camptothecin is known for its antitumor activity. However, it has certain limitations like instability, low solubility in aqueous solution, and biological fluids. Firstly, the camptothecin was encapsulated into the cellulose nanofiber complex by adjusting the composition ratio of cellulose nanofibers-camptothecin, i.e., 10:3, 10:5, and 10:7. In the 10:3 composition ratio of cellulose nanofibers, camptothecin showed the highest encapsulation efficiency, i.e., 65.28%. The binding of camptothecin with cellulose nanofibers was confirmed by FT-IR analysis. Also, the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm studies demonstrate physical adsorption of camptothecin onto the homogeneous as well as the heterogeneous surface of cellulose nanofibers. Further, the controlled and extended-release profile was observed at different physiological pH, and different kinetics models were used to understand the drug release mechanism. The highest correlation in all pH conditions was obtained in Korsmeyer-Peppas with R2 value = 0.93 (pH 1.2), 0.89 (pH 6.8), and 0.97 (pH 7.4), whereas in Higuchi model, R2 value = 0.89 (pH 1.2), 0.91 (pH 6.8), and 0.98 (pH 7.4), suggesting the release of a drug via a diffusion mechanism. Hence, the results established that enzyme-mediated cellulose nanofibers may also be an optimal carrier for the controlled drug release formulation without any chemical excipients.
Keywords: Camptothecin; Cellulose; Controlled release; Isotherm; Kinetic; Nanocarrier.
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