Study on the antibacterial property of EGCG/PLL phenolamine coating integrated chlorhexidine on porous titanium surface

Acta Universitatis Medicinalis Anhui 2025 01 v.60 109-116     font:big middle small

Found programs: Natural Science Foundation of Anhui Province (No. 2208085QE136)

Authors:Hong Huilei; Xu Jianguang; Qiu Hua

Keywords:porous titanium;surface modification;phenolamine cross-linked coating;antibacterial;chlorhexidine

DOI:10.19405/j.cnki.issn1000-1492.2025.01.015

〔Abstract〕 Objective To construct a phenolamine cross-linked coating composed of epigallocatechin gallate(EGCG) and poly-L-lysine(PLL) on the surface of the porous pure Ti integrated with the antibacterial substance chlorhexidine(CHX), and to study the antibacterial property and biosafety. Methods A porous structure(pTi group) was formed on the surface of titanium samples by alkaline heat treatment. Then the pTi group was immersed in the mixed solution of EGCG and PLL in an alkaline aerobic environment for 24 h to obtain the phenolamine group samples(EP group). Finally, the titanium tablets were further immersed in the aqueous solution of chlorhexidine(CHX) for 24 h to obtain the antibacterial groups(EPC group). Microstructure and properties of the surface were characterized by scanning electron microscopy(SEM), X-ray photoelectron spectrometer(XPS) and water contact angle measuring instrument. The antibacterial properties of coating were observed and evaluated by nephelometry, inhibition zone method and live/dead bacterial staining. The cytocompatibility of the coating was evaluated by MTT method and cell fluorescence staining, and the cell adhesion and proliferation ability in bacterial environment were evaluated by the co-culture of bacteria and cells. Results SEM results showed that the pore size of samples after alkali heat treatment decreased with the deposition of the phenolamine coating. The measurement of water contact angle showed that the contact angle increased significantly with the grafting of coating. The intensity of N1s and C1s peaks increased and Ti2p and O1s peaks decreased detected by XPS tests. The Cl2p peak appeared in EPC group referred to the control group. The antibacterial experimentsin vitroshowed that the antibacterial samples could perform effective antibacterial effects on Staphylococcus aureus and Aggregatibacter actinomycetem-comitans for at least 7 days. In the biocompatibility experiments, MTT and cell fluorescence staining results showed that the adherent cells had good morphology and proliferative activity. The bacteria-cell co-culture results showed that the EPC groups could provide a good environment for cell proliferation and growth with excellent antibacterial properties. Conclusion Chlorhexidine-grafted phenolamine deposited on porous titanium surface displays an effective antibacterial effect with good biosafety performance, which can play an antibacterial role in the bacterial environment while ensuring cell adhesion and proliferation.