Journal: International Journal of Molecular Sciences

Article Title: Functionalization of Two-Component Gelatinous Peptide/Reactive Oligomer Hydrogels with Small Molecular Amines for Enhanced Cellular Interaction

doi: 10.3390/ijms26115316

Figure Lengend Snippet: Outline of reactive building blocks and cross-linking with gelatinous peptides. ( a ) Oligomeric building block oligo(PEDAS- co -NiPAAm- co -MA) (oPNMA, left) with four different anhydride contents indicated by x, ( b ) block oligo(PEDAS- co -DAAm- co -MA) (oPDMA, right) with two different MA contents (x), semi-transparent schematic illustrations of oPNMA-x and oPDMA-x depict the branched structure of NiPAAm (blue)/DAAm (turquois) and MA (red) along the PEDAS core (black/yellow). ( c ) Cross-linking step ✤: oPNMA-x and oPDMA-x react with free amines in gelatinous peptides Collagel ® (COL) or gelatin (G160) under neutral pH to yield cross-linked cGEL and cGEL(D); ‡ washing and hydration in phosphate-buffered saline (PBS), anhydride cleavage and dissociation increase negative charge density. ( d ) Pre-derivatization #: covalent binding of 2.5 equivalents of intact anhydride groups in oPNMA-x or oPDMA-x to small molecular primary amines via amidation, formation of oPNMA-x +amine or oPDMA-x +amine ; cross-linking to cGEL_amine and cGEL(D)_amine: (1) ✤ residual anhydride group cross-linking with COL, (2) ‡ hydration in PBS leads to dissociation, residual anhydride cleavage and protonation of tertiary amines of incorporated amine. ( c , d ) Schematic illustrations of oligomers, primary amine, and COL in cGEL do not reflect actual dimensions (exemplarily shown for oPNMA); COL and G schematic: amino residues with primary amine (green bullet), any other amino acid (brown bullet); primary amine: residual aliphatic, aromatic, or heterocyclic compound (blue hexagon); triangles with minus marks depict negative charges, hexagons with positive marks depict partial cationic moieties.

Article Snippet: Fractions of partially hydrolyzed gelatinous protein, Collagel ® (type B, 11.5 kDa, viscosity (10% ( w / v ), 25 °C): 3.58 mPas, Lot # 895046, COL) and Gelatin type B bloom 160 (G160) (batch #630253MI00) were kindly provided by Gelita AG (Eberbach, Germany).

Techniques: Blocking Assay, Saline, Binding Assay

Journal: International Journal of Molecular Sciences

Article Title: Functionalization of Two-Component Gelatinous Peptide/Reactive Oligomer Hydrogels with Small Molecular Amines for Enhanced Cellular Interaction

doi: 10.3390/ijms26115316

Figure Lengend Snippet: Direct cell contact of human adipose tissue-derived stem cells (hASCs) on cGEL matrices. ( a ) Number of hASCs on hydrogel discs derived from G160 cross-linked with oPNMA-1.75 and COL cross-linked with oPNMA-5, oPNMA-10 and oPDMA-7.5 on day three (white columns) and ten (grey columns), cell numbers were determined by viability measurements (Alamar Blue ® ); storage moduli G’ of cGEL discs rehydrated for 24 h (in PBS, at room temperature) (empty circles). Columns and circles with error bars represent means + standard deviation (columns: n = 4; circles: n = 5). Means with different letters are statistically significantly different ( p < 0.05). ( b ) Laser scanning microscopy images (z-stacks of at least 20 micrographs) with Calcein-AM staining on day ten and corresponding view of hydrogel frontal plane. Scale bars in z-stacks represent 100 µm.

Article Snippet: Fractions of partially hydrolyzed gelatinous protein, Collagel ® (type B, 11.5 kDa, viscosity (10% ( w / v ), 25 °C): 3.58 mPas, Lot # 895046, COL) and Gelatin type B bloom 160 (G160) (batch #630253MI00) were kindly provided by Gelita AG (Eberbach, Germany).

Techniques: Derivative Assay, Standard Deviation, Laser-Scanning Microscopy, Staining