Researchers have developed a novel composite hydrogel film that combines a polyacrylamide and calcium alginate polymer network with in-situ calcium carbonate mineralization. This innovative approach provides a new structural method for regulating film swelling and enabling the controlled release of phycocyanin, a bioactive pigment-protein complex known for its antioxidant and antibacterial properties. The findings, recently published by Frontiers of Materials Science, open promising avenues for advanced biomedical applications, including wound dressings and tissue engineering.
The core of this innovation lies in the mineralization strategy, which introduces an additional means of regulating hydrogel structure beyond conventional polymer-network and ionic-crosslinking approaches. By depositing calcium carbonate directly onto the film surface, researchers created a tunable barrier that influences both water absorption and the release kinetics of encapsulated bioactive compounds. This structural modification proved highly effective in achieving sustained, gradual release rather than rapid diffusion.
Key research findings are as follows: 1) Optimized Formulation: An acrylamide to sodium alginate mass ratio of 8:1, treated with 0.20 wt.% sodium carbonate, yielded the most balanced performance, combining relatively high swelling capacity with sustained phycocyanin release; 2) Strong Antibacterial Activity: The phycocyanin-loaded composite film demonstrated inhibition rates of 67.27% against Staphylococcus aureus and 52.45% against Escherichia coli; 3) Remarkable Antioxidant Capacity: ABTS radical-scavenging efficiency reached 98.29%, while DPPH scavenging efficiency achieved 79.68%; 4) Complex Release Mechanism: Release kinetics followed the Korsmeyer–Peppas model with an exponent of 0.5524, indicating that phycocyanin release involves both molecular diffusion and polymer network swelling-relaxation, rather than diffusion alone; 5) Confirmed Mineralization: Scanning electron microscopy revealed particulate calcium carbonate deposits on the film surface, X-ray diffraction confirmed crystalline calcite formation, and thermal analysis demonstrated that mineralization modified the film’s thermal response.
While the composite hydrogel film shows significant promise for biofunctional materials, researchers note that long-term stability and retention of phycocyanin bioactivity during prolonged release require further evaluation. Future work will focus on optimizing these parameters to translate this mineralization strategy into practical clinical and industrial applications, potentially advancing the development of next-generation drug delivery systems and bioactive wound care products.
DOI：10.1007/s11706-026-0783-y