Hybrid Hydrogel Loaded with Chlorhexidine⊂ß-CD-MSN Composites as Wound Dressing.

Background: Much attention has been paid to sustained drug release and anti-infection in wound management. Hydrogels, which are biocompatible materials, are promising tools for controlled drug release and infective protection during wound healing. However, hydrogels also demonstrate limitations in the highly efficient treatment of wounds because of the diffusion rate. In this work, we explored pH-sensitive hydrogels that enable ultra-long-acting drug release and sustained antibacterial properties. Methods: We constructed a hybrid gelatin methacrylate (GelMA) system with sustainable antibacterial properties combining hyaluronic acid (HA)-coated mesoporous silica nanoparticles (MSN), which loaded host-guest complexes of chlorhexidine (CHX) with ß-cyclodextrins (ß-CD) (CHX⊂CD-MSN@HA@GelMA). The release mechanism of CHX was explored using UV-vis spectra after intermittent diffusion of CHX. The hybrid hydrogels were characterized, and the drug content in terms of the release profile, bacterial inhibition, and in vivo experiments were investigated. Results: Except for dual protection from both hydrogels, MSN in the HA improved the drug loading efficiency to promote the local drug concentration. It showed that complicated CHX-loaded MSN releases CHX more gradually and over a longer duration than CHX-loaded MSNs. This demonstrated a 12-day CHX release time and antibacterial activity, primarily attributable to the capacity of ß-CD to form an inclusion complex with CHX. Meanwhile, in vivo experiments revealed that the hydrogels safely promote skin wound healing and enhance therapeutic efficacy. Conclusion: We constructed pH-sensitive CHX⊂CD-MSN@HA@GelMA hydrogels that enable ultra-long-acting drug release and sustained antibacterial properties. The combination of ß-CD and MSN would be better suited to release a reduced rate of active molecules over time (slow delivery), making them great candidates for wound dressing anti-infection materials.

[The effect of insulin-like growth factor-I on the proliferation and alkaline phosphatase activity of human periodontal ligament cells under three-dimensional culture system].

OBJECTIVE: To investigate the effect of insulin-like growth factor- I (IGF- I) on the proliferation and alkaline phosphatase (ALP) activity of human periodontal ligament cells (hPDLCs) under three-dimensional (3D) culture system. METHODS: The hPDLCs were cultured from periodontium of human teeth by the outgrowth method. Rotary cell culture system (RCCS) was enrolled to set 3D culture system. Samples were set to four groups: Negative control group, positive control group (3D group, IGF-I group), and experimental group (3D with IGF- I group). Proliferation was tested with methylthiazolyl tetrazolium (MTT), and ALP activity was assayed by spectrophotometer at 1, 3, 5, 7 d respectively. RESULTS: Compared with that of negative control group, cell proliferation increased significantly in 3D with IGF-I group since 3 d (P < 0.05). Besides, the cell proliferation of 3D with IGF-I group was significantly higher than that of 3D group (P < 0.05). ALP activity of 3D with IGF- I group was significantly higher than that of negative control group, and 3D group at 3, 5, 7 d (P < 0.05). CONCLUSION: IGF-I significantly promotes the proliferation and ALP activity of hPDLCs under 3D culture system.