Hyaluronic Acid/Type I Collagen Hydrogels with Tunable Physicochemical
Properties using Diels-Alder Click Chemistry
Rabia Fatima, M.S.
Abstract
Osteoarthritis (OA) is a debilitating joint disorder that affects over 32.5 million adults in the United States.
Current OA treatments are constrained by short-term efficacy and the inability to facilitate the repair of
large cartilage defects. Consequently, the limited regenerative capacity of articular cartilage remains a
significant clinical challenge. Tissue engineering strategies employing biomimetic hydrogels and
mesenchymal stem cells (MSCs) present a promising approach by mimicking the physicochemical cues of
the native cartilage extracellular matrix (ECM). However, existing hydrogel and MSC-based therapies face
limitations, including insufficient mechanical robustness, poor cytocompatibility, mismatched
biodegradation rates relative to cellular remodeling, and compromised long-term stability under
physiological conditions.
In this study, we present a novel strategy to overcome these limitations by using a bioorthogonal Diels-
Alder click chemistry-based hydrogel platform composed of hyaluronic acid (HA) and type I collagen (Col
I), designed to replicate key structural and biochemical features of the cartilage ECM. The hydrogels were
synthesized using furan-functionalized HA (HA-furan), furan-functionalized type I collagen (Col-furan),
and bis-maleimide-functionalized polyethylene glycol (mal-PEG-mal). Hydrogels were fabricated at
furan:maleimide molar ratios of 1:0.5, 1:1, and 1:2.5, followed by gelation under physiological conditions
at 37 °C for 24 hours without the need for catalysts or initiators. Material characterization revealed that this
approach predominantly yielded elastic hydrogels, with the 1:1 molar ratio formulation exhibiting high
mechanical properties and stability. Specifically, the 1:1 hydrogel demonstrated a Young’s modulus 2.1-
fold and 4.7-fold greater than the 1:0.5 and 1:2.5 hydrogels, respectively. Further analysis indicated that
hydrogel stability and mechanical performance were primarily influenced by microstructural organization
(amorphous vs crystalline domains) and crosslinking density. Notably, the incorporation of Col introduced
native Arg-Gly-Asp (RGD) motifs, enhancing bioactivity and promoting cell-matrix interactions.
Collectively, this bioactive, biodegradable, and mechanically tunable hydrogel platform provides a
promising avenue for the fabrication of ECM-inspired biomaterials for articular cartilage repair, soft tissue
engineering, and regenerative medicine applications.
Wednesday, Oct 1st, 2025, at 4:30 pm
CAMP 176
Rabia Fatima is a Ph.D. candidate in Chemical & Biomolecular Engineering at Clarkson University,
working in the Biomaterials and Stem Cell Engineering Lab with Dr. Bethany Almeida. She earned a BS
in Biochemistry from Kinnaird College and an MS in Industrial Biotechnology from the National
University of Science and Technology, Pakistan. Her research develops biocompatible hydrogels and drug-
delivery nanoparticles for regenerative therapies targeting degenerative joint diseases.