Cationic amphiphilic dextran hydrogels with potential biomedical applications

Dextran microparticles were chemically modified for the attachment of quaternary ammonium groups carrying substituents with different hydrophobicity, in order to obtain amphiphilic cationic hydrogels with different hydrophilic/lipophilic balance. These hydrogels retain various amounts of dyes: Rose Bengal, Brilliant Blue and Vitamin B12, used as models for hydrophobic, amphiphilic and hydrophilic drugs, as a function of their hydrophilic/hydrophobic properties. Bovine serum albumin (BSA) retention by hydrogels occurs in higher amounts at pH 6.9, and is influenced by electrostatic, hydrophobic forces and the swelling of the supports. Tetanus anatoxin is retained by the supports through electrostatic and/or hydrophobic forces, in amounts varying between 110 and 200 mg/g. Both proteins are gradually released, through increasing of the eluent ionic strengths. Alpha-tocopherol is retained by the hydrogels preponderantly through hydrophobic forces, in amounts varying between 130 and 300 mg/g. Measurement of the scavenging effect proved the antioxidant properties of the included drug. Based on the obtained results, one can appreciate the potential of the synthesized cationic hydrogels as supports for biomolecules or as vaccine adjuvants.