Thermally Solvent-Free Cross-Linked pH/Thermosensitive Hydrogels as Smart Drug Delivery Systems.

Bucatariu, Sanda; Cosman, Bogdan; Constantin, Marieta; Ailiesei, Gabriela Liliana; Rusu, Daniela; Fundueanu, Gheorghe

An imbalance in the body's pH or temperature may modify the immune response and result in ailments such as autoimmune disorders, infectious diseases, cancer, or diabetes. Dual pH- and thermo-responsive carriers are being evaluated as advanced drug delivery microdevices designed to release pharmaceuticals in response to external or internal stimuli. A novel drug delivery system formulated as hydrogel was developed by combining a pH-sensitive polymer (the "biosensor") with a thermosensitive polymer (the delivery component). Thus, the hydrogel was created by cross-linking, using a solvent-free thermal approach, of poly(N-isopropylacrylamide-co-N-hydroyethyl acrylamide), P(NIPAAm-co-HEAAm), and poly(methylvinylether-alt-maleic acid), P(MVE/MA). The chemical structure of the polymers and hydrogels was analyzed using Fourier-transform infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopies. The pH/thermosensitive hydrogel loses its thermosensitivity under physiological conditions but, remarkably, can recover the thermosensitive capabilities when certain physiologically active biomolecules, acting as triggering agents, electrostatically interact with pH-sensitive units. Our research aimed to develop a drug delivery system that could identify the disturbance of normal physiological parameters and instantaneously send a signal to thermosensitive units, which would collapse and modulate the release profiles of the drug.

TARGETED drug delivery; CROSSLINKED polymers; DRUG delivery systems; PROTON magnetic resonance; NUCLEAR magnetic resonance

Gels (2310-2861), 2024, Vol 10, Issue 12, p834

2310-2861

Academic Journal

10.3390/gels10120834