Physical and biological properties of barium cross-linked alginate membranes

Evaluation of polymers for the liquid rhizobial formulation and their influence in the Rhizobium-Cowpea interaction

“…In contrast, Bashan et al (2002) demonstrated benefits of alginates to immobilize plant growth promoting bacteria (PGPB) and its benefits to agriculture, highlighting it as one the most compatible polymers with this bacteria, with the ability to protect them against adverse environmental conditions (Yabur et al 2007). The alginates used in our study (sodium alginate 1 and 2) markedly differ in terms of the block conformation of their chemical structures (Zimmermann et al 2007) ( Figure 1e and f); however, this effect depended on the type of bacterial species assessed. Therefore, prior to polymer utilization, it is important to perform a physicochemical characterization to obtain information that contributes to the correct use of these materials and their compatibility with PGPR.…”

“…Thus, the symbiosis was not interrupted despite the presence of these materials. The previous may be attributed to accelerated metabolic activities involved in the nodulation process, which requires the expression of specific nodulation genes (nod), leading to the synthesis of signaling molecules that induce nodule morphogenesis and the nutrient accumulation necessary for those processes (Zimmermann et al 2007). …”

Impact of alginate type and bead diameter on mass transfers and the metabolic activities of encapsulated C3A cells in bioartificial liver applications

“…Alginate is an unbranched natural copolymer composed of β-D-mannuronate (M) and α-L-guluronate (G), linked together by 1,4 bonds (Garbayo et al, 2002;Bajpai and Sharma, 2004). Due to its relative stability, biocompatibility, adjustable porosity and simplicity of use, alginate is thus a biomaterial of choice when it comes to entrapping cells (Garbayo et al, 2002;Zmora et al, 2002;David et al, 2004a;De Vos et al, 2006;Zimmermann et al, 2007;Wikstrom et al, 2008), to cell therapy (Chang, 2005;Paul et al, 2009) or to being used in medical devices (Ueyama et al, 2002;Orive et al, 2004;Gao et al, 2005;De Vos et al, 2006;Orive et al, 2006;Wikstrom et al, 2008). Some of these studies were conducted with hepatocytes that were either encapsulated within alginate beads (Selden et al, 1999;David et al, 2004b;Gao et al, 2005;Kinasiewicz et al, 2007;Kinasiewicz et al, 2008) or capsules (Canaple et al, 2001;Orive et al, 2004;Haque et al, 2005), or seeded within alginate scaffolds (Zmora et al, 2002;Seo et al, 2006).…”

Poloxamer 188 as a Supplement to Barium Cross-Linked Ultra-High Viscosity Alginate for Immunoisolation of Transplanted Islet Cells

“…Therefore, the M:G ratio, length of polymeric chains, and ratio of homologous to heterologous chains must be carefully tuned to optimize the microcapsules [6].A lack of standardization and information from manufacturers about the composition of the alginate (e.g., molecular weight, content, and ratio of D-mannuronic acid and L-guluronic acid) is a major problem for encapsulation experiments; this knowledge is of enormous importance for understanding the physico-chemical characteristics and hence biocompatibility of the alginate. Ba 2+ -gelled capsules comprised of 1:1 mixtures of UHV alginates from the closely related species Lessonia nigrescens and Lessonia trabeculata meet the demands of high stability and flexibility (UHV: 35% M and 65% G) [7].…”

“…Therefore, the M:G ratio, length of polymeric chains, and ratio of homologous to heterologous chains must be carefully tuned to optimize the microcapsules [6].…”