Discerning the self-healing, shear-thinning characteristics and therapeutic efficacy of hydrogel drug carriers migrating through constricted microchannel resembling blood microcapillary

Abstract Margination of nanodrug carriers towards the wall of the microcapillaries during movement is an important issue in therapeutics. The drug encapsulation and release efficiency of such nanocarriers that undergo high shear flow inside a constricted microenvironment are the major aspects of a drug delivery system. In this context, migration of hydrogel drug carriers through a 7 µm constricted microchannel, designed to mimic microcapillaries in the human body, was examined. Interestingly, the carriers could withstand the adverse constriction and migrate without having drifted towards the channel walls. Therapeutic efficacy of the drug carrier was determined by drug encapsulation and drug release studies. Loading efficiency of anti-cancer drug doxorubicin on hydrogel carriers was found to be 68.6%, while its release was 60.6% in twelve hours. A shear thinning viscoelastic FENE-P drop model was adopted to delineate migration behavior of the drug carriers numerically. The hydrogel drug carriers regained their original shape and structure after migration. This provided a remarkable insight into the self-healing property of the hydrogel particles. Validation of results averred the significance of FENE-P drop model in reflecting the shear thinning nature of the hydrogel carriers. A relaxation time of 850 ms is suggested for better migration prediction of the carriers. Overall, the present study affirmed hydrogel nanocarriers as a potent drug carrier for cancer therapy.