Efficient functionalization of alginate biomaterials

Peptide coupled alginates obtained by chemical functionalization of alginates are commonly used as scaffold materials for cells in regenerative medicine and tissue engineering. We here present an alternative to the commonly used carbodiimide chemistry, using partial periodate oxidation followed by reductive amination. High and precise degrees of substitution were obtained with high reproducibility, and without formation of by-products. A protocol was established using l-Tyrosine methyl ester as a model compound and the non-toxic pic-BH3 as the reducing agent. DOSY was used to indirectly verify covalent binding and the structure of the product was further elucidated using NMR spectroscopy. The coupling efficiency was to some extent dependent on alginate composition, being most efficient on mannuronan. Three different bioactive peptide sequences (GRGDYP, GRGDSP and KHIFSDDSSE) were coupled to 8% periodate oxidized alginate resulting in degrees of substitution between 3.9 and 6.9%. Cell adhesion studies of mouse myoblasts (C2C12) and human dental stem cells (RP89) to gels containing various amounts of GRGDSP coupled alginate demonstrated the bioactivity of the material where RP89 cells needed higher peptide concentrations to adhere

Efficient functionalization of alginate biomaterials

Peptide coupled alginates obtained by chemical functionalization of alginates are commonly used as scaffold materials for cells in regenerative medicine and tissue engineering. We here present an alternative to the commonly used carbodiimide chemistry, using partial periodate oxidation followed by reductive amination. High and precise degrees of substitution were obtained with high reproducibility, and without formation of by-products. A protocol was established using l-Tyrosine methyl ester as a model compound and the non-toxic pic-BH3 as the reducing agent. DOSY was used to indirectly verify covalent binding and the structure of the product was further elucidated using NMR spectroscopy. The coupling efficiency was to some extent dependent on alginate composition, being most efficient on mannuronan. Three different bioactive peptide sequences (GRGDYP, GRGDSP and KHIFSDDSSE) were coupled to 8% periodate oxidized alginate resulting in degrees of substitution between 3.9 and 6.9%. Cell adhesion studies of mouse myoblasts (C2C12) and human dental stem cells (RP89) to gels containing various amounts of GRGDSP coupled alginate demonstrated the bioactivity of the material where RP89 cells needed higher peptide concentrations to adhere

Oral language supports early literacy: A pilot cluster randomizedtrial in disadvantaged schools

This study examined the impact of teacher professional development aimed at improving the capacity of primary teachers in disadvantaged schools to strengthen children's expressive and receptive oral language skills and early literacy success in the first 2 years of school. Fourteen low-SES schools in Victoria, Australia were randomly allocated to a research (n = 8) or control arm (n = 6), resulting in an initial sample of 1254 students, (n = 602 in research arm and n = 652 in control arm). The intervention comprised 6 days of teacher and principal professional development (delivered by language and literacy experts), school-based continuing contact with the research team and completion by one staff member of each research school of a postgraduate unit on early language and literacy. Schools in the control arm received standard teaching according to state auspiced curriculum guidelines. Full data were available on 979 students at follow-up (time 2). Students in the research arm performed significantly better on Test of Language Development: Primary (Fourth Edition) sub-tests (p ≤ .002) and the Reading Progress Test (F = 10.4(1); p = .001) than students in the control arm at time 2. Narrative scores were not significantly different at time 2, although students in research schools showed greater gains. Findings provide “proof of concept” for this approach, and are discussed with respect to implications for teacher professional development and pre-service education concerning the psycholinguistic competencies that underpin the transition to literacy.