Covalently Functionalized Halloysite-Calixarene Nanotubes for Injectable Hydrogels: A Multicavity Platform for...

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Poor water solubility limits the therapeutic application of many anticancer drugs.
• Halloysite nanotubes (HNTs) offer potential as drug carriers due to their structure and biocompatibility.
• Hydrophobic and positively charged drugs present significant delivery challenges.

Purpose of the Study:

• To design and develop novel halloysite-based hybrid nanomaterials for enhanced drug delivery.
• To create injectable and biocompatible systems for hydrophobic anticancer drugs.
• To investigate the impact of calixarene functionalization on drug release profiles.

Main Methods:

• Covalently grafting calix[5]arene macrocycles onto halloysite nanotubes (HNTs) to create a multicavity platform.
• Encapsulating a model hydrophobic drug, PB4, into pristine HNTs (HNTs/PB4) and calixarene-functionalized HNTs (HNTs-Calix/PB4).
• Incorporating drug-loaded HNTs into Laponite-based thixotropic hydrogels for injectable delivery.

Main Results:

• Successful characterization of the hybrid nanomaterials, demonstrating good loading efficiency and aqueous dispersibility.
• Evaluation of drug release kinetics, showing faster release from pristine HNTs and sustained release from calixarene-functionalized HNTs.
• Antiproliferative activity of the drug-loaded hydrogels against MCF-7 cells was maintained, confirming drug efficacy.

Conclusions:

• This study presents the first example of covalently calixarene-functionalized halloysite.
• The developed halloysite-based hybrid nanomaterials offer a versatile platform for drug delivery.
• The tunable release profiles make these systems adaptable for various therapeutic strategies and combination therapies.