Sodium Alginate as a Potential Therapeutic Filler: An In Vivo Study in Rats

Abstract

Filler injection demand is increasing worldwide, but no ideal filler with safety and longevity currently exists. Sodium alginate (SA) is the sodium salt of alginic acid, which is a polymeric polysaccharide obtained by linear polymerization of two types of uronic acid, d-mannuronic acid (M) and l-guluronic acid (G). This study aimed to evaluate the therapeutic value of SA. Nine SA types with different M/G ratios and viscosities were tested and compared with a commercially available sodium hyaluronate (SH) filler. Three injection modes (onto the periosteum, intradermally, or subcutaneously) were used in six rats for each substance, and the animals were sacrificed at 4 or 24 weeks. Changes in the diameter and volume were measured macroscopically and by computed tomography, and histopathological evaluations were performed. SA with a low M/G ratio generally maintained skin uplift. The bulge gradually decreased over time but slightly increased at 4 weeks in some samples. No capsule formation was observed around SA. However, granulomatous reactions, including macrophage recruitment, were observed 4 weeks after SA implantation, although fewer macrophages and granulomatous reactions were observed at 24 weeks. The long-term volumizing effects and degree of granulomatous reactions differed depending on the M/G ratio and viscosity. By contrast, SH showed capsule formation but with minimal granulomatous reactions. The beneficial and adverse effects of SA as a filler differed according to the viscosity or M/G ratio, suggesting a better long-term volumizing effect than SH with relatively low immunogenicity

Osteoimmunity-regulating nanosilicate-reinforced hydrogels for enhancing osseointegration

“…36 It is worth mentioning that the SM hydrogel we prepared was more likely to induce M1 polarization of macrophages. This phenomenon was similar to the previous research, 37,38 probably ascribing to the lack of purification of SA, given that it has been reported that the effect of SA on macrophage activity differs depending on the degree of purification, the M/G ratio, and viscosity. 39,40 Our study indicated that loading HM may be a powerful method for regulating the macrophage response in SM-based hydrogels.…”

3D Printed Gene-Activated Sodium Alginate Hydrogel Scaffolds

“…The insignificant inflammatory reaction caused by gene-activated SA-based scaffolds during their intramuscular implantation, in our opinion, is due to the moderate toxic effect of the incorporated transfecting complexes when they are released into the surrounding tissues, as well as an increase in the local divalent ion concentration leading to the attraction of leukocytes from blood vessels to the implantation zone [ 37 ]. However, these results, in general, correspond to the standard foreign body reaction to gradually degrading biomaterials [ 38 ].…”

pH-Responsive Drug Delivery and Imaging Study of Hybrid Mesoporous Silica Nanoparticles

“…Sodium alginate (SA), an anion- and water-soluble linear polysaccharide, comprises 1-4-linked β-D-mannuronate (M) and α-L-guluronate (G) [ 32 ]. SA has been widely employed in pharmaceutical excipients for its fascinating advantages (including its safety, biocompatibility, and biodegradability [ 33 , 34 , 35 , 36 ]). SA is relatively low-cost and easily available via the isolation from cell walls of brown algae ( Ascophyllum nodosum and Laminaria digitate ) as compared with polymers and polyelectrolytes [ 33 , 37 ].…”