Micellized α-Cyclodextrin-Based Supramolecular Hydrogel Exhibiting pH-Responsive Sustained Release and Corresponding...

Area of Science:

• Polymer Science and Engineering
• Biomaterials Science
• Drug Delivery Systems

Background:

• Supramolecular hydrogels offer tunable properties for controlled release applications.
• Injectable formulations are desirable for minimally invasive drug delivery.
• Poly(L-lactic acid) (PLLA), poly(2-(dimethylamino)ethyl methacrylate) (DMAEMA), and poly(poly(ethylene glycol) methyl ether acrylate) (PEGMA) are biocompatible polymers.

Purpose of the Study:

• To fabricate injectable supramolecular hydrogels for sustained protein release.
• To investigate the influence of pH on hydrogel properties and drug release kinetics.
• To elucidate the mechanisms governing protein release from the hydrogel network.

Main Methods:

• Fabrication of tricomponent hydrogels using PLLA/DMAEMA/PEGMA polymers and alpha-cyclodextrin (α-CD).
• Rheological analysis to assess hydrogel behavior under shear and varying pH.
• Protein release studies using Bovine Serum Albumin (BSA) and lysozyme at pH 3, 7, and 10.
• Analysis of release mechanisms using Lissajous-Bowditch curves and Power Law.

Main Results:

• The hydrogels sustained protein release for 60-120 hours.
• pH significantly influenced hydrogel rheology and protein release profiles.
• Protein release was governed by complex interactions including protein properties, polymer pKa, and hydrogel pore size.
• Lissajous-Bowditch curves revealed pH-dependent microstructural changes affecting network integrity.
• The release mechanism was a combination of diffusion and erosion (non-Fickian and super case II transport).

Conclusions:

• PLLA/DMAEMA/PEGMA/α-CD supramolecular hydrogels are effective for sustained protein delivery.
• pH is a critical parameter for controlling hydrogel network structure and drug release.
• Understanding the interplay between hydrogel properties and protein characteristics is key for optimizing drug delivery systems.