Graphene oxide - biopolymers hydrogel nanocarriers for the evaluation of controlled release of anticancer drugs / Abdullah Ali Ghawanmeh

Faculty of Industrial Sciences and Technology

Thesis (Doctor of Philosophy) -- Universiti Malaysia Pahang – 2021

Includes bibliographical references

Cancer is the most dangerous disease that leads to death. Various traditional methods are involved in cancer treatment, including surgery, radiation therapy, and chemotherapy. However, limitations have been reported, including the lack of target site, toxicity issue, and the method efficiency. The present work aims to formulate a graphene oxide-based biopolymers nanocomposite system as nanocarriers for 5-fluorouracil (5-FU) and colchicine (COL) anticancer drugs delivery, that offers controlled release for colorectal cancer cells. The system also displays biological interfaces for easy access to tumor cells. The nanocomposite system was formulated via the ionotropic gelation method in hydrogel beads that consist of graphene oxide, carboxymethyl cellulose, and gum Arab, with Fe ions as a crosslinker to develop nanocarriers. The use of graphene oxide was due to its excellent structural and physicochemical properties, non-toxicity, and biodegradability which are capable to interact with drugs and polymers. Carboxymethyl cellulose and gum Arab have been used as pH-stimuli response biopolymers. The composition of graphene oxide, carboxymethyl cellulose, and gum Arab were optimized and examined by using central composite design and response surface methodology. The increase in drug encapsulation efficiency and decrease in drug release were found with the increasing amount of graphene oxide, carboxymethyl cellulose, and gum Arab. Accordingly, the optimized nanocomposite hydrogel beads showed improvement in drug encapsulation efficiency of 5-FU (61.80%) and COL (77.66%) with a good sustainable drug release pattern over a prolonged period of 8 h (R8h = 59.8% for 5-FU and R8h = 60.33% for COL). Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and field-emission scanning electron microscopy (FE-SEM) characterizations confirmed the successful hydrogel beads preparation with biopolymer and drug by electrostatic interactions, amorphization and fully drug dispersion within the hydrogel beads matrix, and smooth surface morphology with little wrinkles and nanopores. The specific surface area for these nanocomposite beads was calculated as 13.72 m2/g with an average pore diameter of 4.21 nm, revealing the existence of a mesoporous structure in these nanocomposites. The swelling behavior of these beads was triggered by pH media and the cumulative drug release profile for 5-FU and COL at different pH showed prolonged sustainable drug release which follows the Higuchi model. The type of diffusion mechanism is a non-Fickian mechanism, except for colchicine release at pH 7.4, where the type of diffusion mechanism is a Fickian mechanism (release exponent, n = 0.281). The results showed that the optimized graphene oxide-based biopolymers nanocomposite hydrogel beads are pH sensitive and could be a promising nanocarrier and sustainable release for anticancer drug delivery for cancer therapy.