Rheological modulation and drug delivery efficiency of carbon nanotube-integrated guar gum hydrogels

Guar gum–based hydrogels are attractive candidates for drug delivery due to their biocompatibility and high swelling capacity; however, their poor mechanical strength and uncontrolled burst release limit their practical applicability. To overcome these limitations, the present study investigates the effect of incorporating unmodified multi-walled carbon nanotubes MWCNTs on the rheological properties and drug release behavior of guar gum (GG) hydrogels. The addition of MWCNTs significantly enhanced the viscoelastic and mechanical characteristics of the hydrogel network, with the storage modulus (G′) increasing from 0.2 MPa for pristine GG to 2.2 MPa for the GG/MWCNT composite containing 0.2 wt% nanotubes, indicating increased crosslinking density and network stability. Drug release studies demonstrated a marked modulation in release kinetics upon nanotube incorporation. While the pristine GG hydrogel exhibited a burst release, delivering nearly 96% of the encapsulated drug within 4 h, the GG/MWCNT (0.2 wt%) hydrogel achieved approximately 97% release in a sustained and controlled manner over 28 h. This delayed release behavior is attributed to the improved structural integrity and stronger polymer–nanotube interactions, which restrict molecular diffusion. Overall, the incorporation of MWCNTs provides a rheology-modulated hydrogel platform with enhanced mechanical strength and prolonged therapeutic efficacy, making it a promising system for advanced controlled drug delivery applications.