Decellularized Green and Brown Macroalgae as Cellulose Matrices for Tissue Engineering

Abstract

Scaffolds resembling the extracellular matrix (ECM) provide structural support for cells in the engineering of tissue constructs. Various material sources and fabrication techniques have been employed in scaffold production. Cellulose-based matrices are of interest due to their abundant supply, hydrophilicity, mechanical strength, and biological inertness. Terrestrial and marine plants offer diverse morphologies that can replicate the ECM of various tissues and be isolated through decellularization protocols. In this study, three marine macroalgae species-namely Durvillaea poha, Ulva lactuca, and Ecklonia radiata-were selected for their morphological variation. Low-intensity, chemical treatments were developed for each species to maintain native cellulose structures within the matrices while facilitating the clearance of DNA and pigment. Scaffolds generated from each seaweed species were non-toxic for human dermal fibroblasts but only the fibrous inner layer of those derived from E. radiata supported cell attachment and maturation over the seven days of culture. These findings demonstrate the potential of E. radiata-derived cellulose scaffolds for skin tissue engineering and highlight the influence of macroalgae ECM structures on decellularization efficiency, cellulose matrix properties, and scaffold utility.

Keywords: cellulose; decellularization; fibroblast; macroalgae; matrix; scaffold; seaweed; skin; tissue engineering.

Figure 1

Morphological differences between macroalgae: (A) macroscopic images of Durvillaea poha (i), Ulva lactuca (ii), and Ecklonia radiata (iii) illustrate differences in size and morphology; (B) H&E staining of paraffin-embedded sections; and (C) SEM imaging reveals their porous versus fibrous structural composition. Scale bars are as indicated.

Figure 2

Structural differences between macroalgae matrices: (A) Images of Durvillaea poha (i), Ulva lactuca (ii), and Ecklonia radiata (iii) matrices demonstrate macrostructure after chemical treatment. (B) H&E staining of paraffin-embedded sections, (C) SEM imaging, and (D) calcofluor white staining of paraffin-embedded sections show porous and/or fibrous compositions. Scale bars are as indicated.

Figure 3

Human dermal fibroblasts attach to and distribute through the fibrous layers of Ecklonia radiata but not Ulva lactuca and Durvillaea poha scaffolds. Representative two-dimensional optical slices (i,iii) and three-dimensional confocal Z-stacks (ii,iv) showing BJ/5Ta cells cultured on Durvillaea poha (A), Ulva lactuca (B), and Ecklonia radiata (C) matrices for two (i,ii) or seven (iii,iv) days, after fixation and staining with wheat germ agglutinin (WGA; red) and calcofluor white (CW; blue) to visualize cell membrane glycans and cellulose fibers, respectively. Gold arrows show cells and spheroids that have failed to attach to cellulose fibers. Red arrows show acellular punctate staining. Scale bars are as indicated.

Figure 4

Fibroblasts differ in their attachment to and morphology on macroalgae scaffolds. Scanning electron microscopy images showing BJ/5Ta cells cultured on Durvillaea poha (A), Ulva lactuca (B), and Ecklonia radiata (C) matrices for two (i) or seven (ii) days. Gold arrows show cells and spheroids lacking fibroblastic morphology. Scale bars are as indicated.