This work was undertaken to determine the structural characteristics of polysaccharides extracted from CO2-enriched Arthrospiraplatensis (Spirulina Water Soluble Polysaccharide: SWSP), as well as its antioxidant activities, cytotoxic effects and laser burn wound healing in rats. This SWSP was structurally characterized by Scanning Electron Microscopy (SEM), Fourier-transformed infrared (FT-IR), X-ray diffraction (XRD), high-performance liquid chromatography (HPLC), and thin layer chromatography (TLC). This novel polysaccharide was found to have an average molecular weight of 6.21 kDa. It is a hetero-polysaccharide composed of rhamnose, xylose, glucose and mannose. According to XRD and FT-IR spectra, the SWSP showed a semi-crystalline structure. It is composed of 100 to 500 µm geometric shaped units with flat surfaces and it was found to inhibit the proliferation of human colon (HCT-116) and breast (MCF-7) cancers. This polysaccharide display potential antioxidant activities determined through three different assays: scavenging activity against 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) scavenging assay and ferric reducing antioxidant power assay (FRAP). Results strongly support the beneficial effects of the SWSP to accelerate wound healing in rats. Indeed, its application significantly increased tissue re-epithelization and remodeling phases, after 8 days of the experiment. Findings herein demonstrated that SWSP could be a novel auspicious source of natural wound healing closure and/or cytotoxic remedy.