New locally
injectable biomaterials that are suitable for use as soft tissue fillers are needed to address a significant unmet medical need. In this study, we used
pullulan and human-like
collagen (HLC) based
hydrogels with various molecular weights (MWs) in combination
therapy against tissue defects. Briefly,
pullulan was crosslinked with NaIO4 to form a
pullulan hydrogel and then may coupled with HLC using the reaction between the -NH2 end-group of HLC and the -CHO group present on the
aldehyde pullulan to form the HLC/
pullulan hydrogel, wherein the NaIO4 acted as the crosslinking and
oxidizing agent. The good miscibility of
pullulan and HLC in the
hydrogels was confirmed via Fourier transform infrared spectroscopy, scanning electron microscopy, compression testing,
enzyme degradation testing, cell adhesions, live/dead staining and subcutaneous filling assays. Here,
pullulan hydrogels with various MWs were fabricated and physicochemically characterized. Limitations of the
pullulan hydrogels included
inflammation, poor mechanical strength, and degradation. By contrast, the properties of the HLC/
pullulan hydrogels strongly enhanced. The efficacy of these
hydrogels was evaluated both in vitro and in vivo. Our results indicate that HLC/
pullulan hydrogels may have therapeutic value as efficient soft tissue fillers, with reduced
inflammation, improved cell adhesion and delayed
hydrogel degradation.