Development of an Insulin‐Permeable Hydrogel Membrane Based on Photocrosslinkable Poly(2‐Alkyl‐2‐Oxazoline)s

This study presents the development of insulin‐permeable hydrogel‐based composite membranes from photocrosslinkable poly(2‐alkyl‐2‐oxazoline)s. The membrane design addresses the challenge of maintaining protein structural integrity during delivery through polymeric systems, leveraging the antifouling and biocompatible properties of poly(2‐oxazoline)s to minimize protein denaturation. 2‐Methyl‐2‐oxazoline and 2‐ethyl‐2‐oxazoline were copolymerized with benzophenone‐containing monomer 2‐[3‐(4‐benzoylphenoxy)propyl]‐2‐oxazoline via microwave‐assisted cationic ring‐opening polymerization to yield photocrosslinkable polymers. Thin films of these polymers were crosslinked and attached to a medical‐grade PET mesh substrate under UV irradiation in a multi‐layer manner to form water‐permeable hydrogel membranes after swelling with water. Comprehensive membrane characterization includes optical and ESEM microscopy and permeation tests. The results demonstrate that copolymers fully embed the PET mesh, forming smooth, coherent polymer layers with 10‐fold swelling upon water addition (from ∼67 to ∼695 µm thickness). The hydrogel membrane allows for flow‐controlled permeation of insulin solutions with a rate of approximately 25 µL h −1 over a membrane area of 1.77 cm 2 , acting as a flow‐regulating barrier for potential reservoir‐based delivery systems. DLS, UV–vis, and CD spectroscopic analyses confirm that insulin maintains its structural integrity after permeation.