Biomaterials are the cornerstone to promote the rapid changes in the field of biomedicine. Biohydrogel

as an important member

has shown a vigorous development trend in recent years. A new injectable poly(γ-glutamic) acid (PGA)/hyaluronic acid (HA) composite hydrogel crosslinked by biocompatible method was introduced in this study. Firstly

the PGA-Ty precursor and the HA-CA precursor were synthesized by EDC/NHS protocol. The structures of both precursors were confirmed by nuclear magnetic resonance (NMR) and infrared spectroscopy (IR). The two precursors were crosslinked in aqueous phase under the combined action of low concentration hydrogen peroxide (10 mM) and horseradish peroxidase (HRP

10U·mL

-1

) to obtain interpenetrating network (IPN) hydrogels. The properties of series IPN hydrogels

such as equilibrium water content

morphology

enzymatic degradation profile and mechanical properties were tested. Mechanical strength of I3 and I3' hydrogels were 8113Pa and 9629Pa

respectively. Equilibrium water content could be varied from 13.3~21. Porous scaffolds

whose pore size of internal structure was in the range of 10~100

μ

m

could be obtained after IPN hydrogel be lyophilized. The drug release behavior and antibacterial effect

in vitro

were evaluated by using tetracycline hydrochloride as a drug model. Under physiological conditions

both of the drug loaded hydrogels showed regular drug release profiles and a certain pH sensitivity. After 5 days release

the cumulative release rate of the drug was 77.74%

while the drug loaded hydrogel in acidic environment had released 92%. The cytotoxicity of gel materials and the effect of cell 3D culture showed that its biocompatibility was good. The cells embedded

in vitro

did not show obvious cytotoxicity through 72h culture. Series of data show that these IPN hydrogels can be designed as a pHsensitive drug delivery carrier. And because of its good biocompatibility

it also has potential as a cell scaffold

trauma excipient or other biomedical materials.