The COVID-19 pandemic has caused an unprecedented health and economic crisis, highlighting the importance of developing new molecular tools to monitor and detect SARS-CoV-2. Hence, this study proposed to employ the carrageenan extracted from Gigartina skottsbergii algae as a probe for SARS-CoV-2 virus binding capacity and potential use in molecular methods. G. skottsbergii specimens were collected in the Chilean subantarctic ecoregion, and the carrageenan was extracted —using a modified version of Webber’s method—, characterized, and quantified. After 24 h of incubation with an inactivated viral suspension, the carrageenan’s capacity to bind SARS-CoV-2 was tested. The probe-bound viral RNA was quantified using the reverse transcription and reverse transcription loop-mediated isothermal amplification (RT-LAMP) methods. Our findings showed that carrageenan extraction from seaweed has a similar spectrum to commercial carrageenan, achieving an excellent proportion of binding to SARS-CoV-2, with a yield of 8.3%. Viral RNA was also detected in the RT-LAMP assay. This study shows, for the first time, the binding capacity of carrageenan extracted from G. skottsbergii, which proved to be a low-cost and highly efficient method of binding to SARS-CoV-2 viral particles.

This study describes the development of β-cyclodextrin (β-CD) inclusion complexes of curcumin (CUR) and a synthetic curcuminoid analogue (CN56), which were incorporated into poly(vinyl alcohol)/κ-carrageenan hydrogel films to create a multifunctional system capable of sustained drug release and effective antimicrobial action. Carrageenan was extracted from Gigartina skottsbergii, and hydrogels were prepared using a freeze–thaw crosslinking method. The inclusion complexes were formed at a 1:6 molar ratio, achieving loading efficiencies of 75.62% for CUR and 79.00% for CN56. FTIR confirmed molecular interactions between the complexes and the polymeric matrix, accompanied by reduced crystallinity and increased amorphous character. Thermogravimetric analysis revealed enhanced thermal stability, with degradation onset temperatures above 239 °C, while DSC analysis indicated irreversible amorphization after the first heating cycle. SEM analysis showed improved surface uniformity in complex-loaded films compared with those containing free compounds. Swelling experiments demonstrated significantly greater fluid uptake in complex-loaded hydrogels, particularly for CN56 (1080% after 45 min). Controlled release studies revealed sustained drug release profiles, with 76.49% of CUR and 56.02% of CN56 released over 36 h, following Fickian diffusion mechanisms. In vitro antimicrobial assays confirmed marked activity of CUR and CN56 against Gardnerella vaginalis, a key pathogen associated with bacterial vaginosis. Biocompatibility tests, including hemolysis and MTT reduction assays, indicated low cytotoxicity and satisfactory hemocompatibility. Rheological analysis further demonstrated increased viscosity and potential mucoadhesive behavior. Collectively, these findings highlight the potential of carrageenan-based PVA hydrogels as innovative pharmaceutical platforms for the prevention and treatment of recurrent bacterial vaginosis, offering a promising alternative to conventional therapies.