Fabrication of Human Genomic DNA Encapsulated Supermacroporous Alginate (SMPA) Beads

In this study, human genomic DNA (hDNA) encapsulated alginate cryogel beads (SMPA) and normal alginate beads were fabricated via freeze-thawing cryogelation and microinjection procedures respectively. The fabricated beads were characterized by scanning electron microscopy (SEM) and fluorescent microscope. The characterization results showed that both beads exhibited smooth surfaces with obvious pores and burgled topologies, however, a bug-like sprout is visibly seen on the surface of SMPA beads. Also, the encapsulated hDNA showed brilliant green fluorescence when visualized with fluorescence microscopy. The encapsulation efficiency of 89.1−96.7% was achieved when the concentration of hDNA and alginate varied within 0.05−0.075% and 0.5−0.75 wt%, respectively in the presence of 0.1 M CaCl2 crosslinking agent. ~80% hDNA was released over an extended period of 80 h when SMPA was immersed in a 0.5 M Na2HPO4 solution diluted with 10 mM Tris buffer (pH 7). The SMPA cryobeads demonstrated a higher swelling capability when compared with the normal beads. In the first 3 h, SMPA cryobeads achieved 225% swelling ratio compared with the normal beads that attained 155%. Beyond 3 h, the normal beads did not show significant swelling ratio while SMPA increased obviously to 315% before reaching equilibrium at the tenth hour. iv Results and trends here demonstrated that the fabricated supermacroporous alginate-based cryogel beads have great potential to be used as a biocompatible vehicle for transporting biomacromolecules. Keywords: controlled release systems; human genomic DNA; alginate polymeric cryobeads; supermacroporous; gene therapy.