pH-controlled degradation and thermal stability of a porous poly(γ-glutamic acid) monolith crosslinked with an oxazoline-functionalized polymer

A monolithic porous material designed for cell scaffolding applications has been introduced. A raw monolith with high surface area was prepared from a solution of poly(γ-glutamic acid) (PGA) by phase separation. The monolith was then crosslinked by using a low-toxic polymer that could be cleaved off from the monolith hydrolytically. The resultant monolith maintained the original porosity during the crosslinking process. It was also thermally stable up to decomposition temperature of PGA. The monolith was found to be low-cytotoxic and degradable in aqueous media at the rate controlled by the pH. The monolith was also found to adsorb/desorb a calcium salt by pH control, which may open up the possibility to change the surface nature of the monolith to promote cell adhesion and proliferation.