Fig 2: Comparison of antiviral activity of sulfated (A) ulvans against HSV-1 [45], (B) glucans against HCMV [47], (C) pectins against HSV-1 [259] and (D) arabinogalactans against HSV-1 [44], having different molecular masses (MSs). Antiviral activity was performed by plaque reduction assay in HEp-2 cells (human larynx epithelial cells carcinoma, ATCC CCL-23) (A,C), in Vero cells (ATCC CCL-81) (D) and by GFP-based replication assay in primary human fibroblasts (B).

Fig 3: Infection of human BRON and ALV organoid by two clinical isolates (WA-1 and hCoV-19/Norway/Bergen-01/2020) of SARS-CoV-2 virus. (A) RT-qPCR was used to detect the expression of the SARS-CoV-2 N gene in bronchiolar organoids infected with a clinical isolate of SARS-CoV-2-WA1 (Washington strain), using the SYBR green method. Data is shown as 2 ^ -(avg Ct SARS-CoV-2 N – avg Ct GAPDH), n.d., not detected. (B) Replication of SARS-CoV-2 in organoids of BRON and ALV differentiation was assessed by infection of organoid cultures at multiplicity of infection (MOI) of 0 (Neg.Ctrl), 0.005 or 0.5. Titration of harvested supernatants were performed by TCID50 assay on Vero cells (CCL-81, ATCC). Bar-charts display the quantification of organoid supernatants harvested 72 h post infection (left) and 96 h post infection (right). For each condition the mean +-SD of four biological replicates is shown, n.d., not detected. (C) Histopathology of bronchiolar (BRON) and alveolar (ALV) organoid cultures, mock infected (Neg.Ctrl.) or SARS-CoV-2 infected at MOI of 0.5. Samples were harvested 72 hours post infection, and FFPE sections stained by H&E. Formation of multinucleated cells (syncytia, black filled arrowheads) characteristic of SARS-CoV-2 infection in human patient samples were observed in the infected samples. Scale bar in all images equals 100 µm, except zoomed inserts (20 µm). (D) In situ detection of bronchiolar (BRON, left panel) and alveolar (ALV, right panel) organoid tissue cells infected by mock (Neg.Ctrl.) or 0.5 MOI SARS-CoV-2 virus (hCoV-19/Norway/Bergen-01/2020), was done by immunostaining of FFPE sections to detect SARS-CoV-2 nucleocapsid (red) and pan-cytokeratin (Pan-CK, green). DAPI (blue) nuclear stain. Scale bar in all images equals 50 µm, except lower panel (10 µm). Samples were harvested 72 hours post infection for BRON and 96 hours post infection for ALV. (E) Immunofluorescent staining of formalin fixed paraffin embedded (FFPE) sections of bronchiolar (BRON, left panel) and alveolar (ALV, right panel) organoids mock infected (Neg.Ctrl) or infected by SARS-CoV-2 virus (hCoV-19/Norway/Bergen-01/2020), MOI 0.5, (samples were harvested 72 hours post infection for BRON and 96 hours post infection for ALV) display the expression of dsRNA (green) and E-cadherin (red). DAPI (blue) nuclear stain. Scale bar equals 50 µm in all images, except lower panel (10 µm).

Fig 4: Viability percentage extracted from MTT data of tests performed by directly exposing (A) VERO cell cultures (ATCC CCL81.4) and (B) THP-1 Cell cultures (ATCC TIB-202) to film’s fragments for 24 h and 72 h. (C) Hemolytic behavior after an incubation time of 1 h. Triton X-100 and PBS were used as positive and negative controls respectively. Data compared to PC (PC) (Mean ± SD) where, ns = no significant *p ≤ 0.05 **p ≤ 0.01 ***p ≤ 0.001 ****p ≤ 0.0001.

Fig 5: Biocompatibility testing of PC. Viability percentage extracted from MTT data of tests performed by directly exposing (A) VERO cell cultures (ATCC CCL81.4) and (B) THP-1 Cell cultures (ATCC TIB-202) to film’s fragments for 24 h and 72 h. (C) Hemolysis percentage of films exposed to only erythrocytes. (D) Contact Angle of type II H2O on the surface of the polymers before and after sterilization with ethylene oxide. (E) Adsorbed serum protein on the film surface. (F) Platelet aggregation percentage of PRP exposed to films. (G)) Number of platelets adhered to the surface of the film by LDH activation analysis. Data compared to PEUU. Mean ± SD) where, ns = no significant *p ≤ 0.05 **p ≤ 0.01 ***p ≤ 0.001 ****p ≤ 0.0001.