[PPS-O-5] Titanium surface functionalization with vinylphosphonic acid - glutathione coating for suppression of ROS-induced cell damage and improvement of osteogenesis
[Abstract]
Objective
Titanium surface functionalization is a potent and versatile method to enhance the biological reactions of implant biomaterials1. Beyond the fundamental necessity of biocompatibility, an advanced strategy for treating titanium surfaces must be capable of controlling the surrounding microenvironment effectively. Prior research has shown that titanium implants can lead to an overproduction of reactive oxygen species (ROS), thereby hindering the process of bone formation2.
To address this issue, the present work demonstrated the synthesis of vinylphosphonic acid (VPA)- glutathione (GSH) molecule via thiol-ene click reaction and its controlled-release when pH was elevated. Furthermore, Ti substrates modified with VPA-GSH coating exhibited high antioxidant activity.
Methods
The polished Ti discs were treated in UV-Ozone cleaner. The DPAP, as a photoinitiator, dissolved in tetrahydrofuran was added to the mixed solution of VPA and GSH under the UV light for 24h. Afterward, titanium discs were soaked in VPA/GSH/VPA-GSH solutions at 70℃ for 12h, respectively (named as TiV, TiG and TiVG groups). The surface morphology and chemical state were analyzed using FE-SEM and XPS. The hydrophilicity was measured. The release of GSH and H2O2-scavenging effects were evaluated. MC3T3-E1 cells were cultured on the Ti substrates. The intracellular ROS was stained with DCFH-DA. After treating cells with H2O2 to simulate oxidative stress, cell viability and residual H2O2 concentration were measured. ALP activity assay was evaluated for the differentiation of MC3T3-E1
Statistical analysis was performed by 1-way ANOVAs and followed by Tukey’s test as a post hoc evaluation. All data were expressed as mean ± SD.
Results
The present work demonstrated the synthesis of the VPA-GSH molecule via the thiol-ene click reaction and its reversibility. TiVG surface improved surface hydrophilicity, sequentially promoting MC3T3-E1 cell adhesion and impaired ROS generation. Furthermore, Ti substrates modified with synthetic VPA-GSH coating exhibited high antioxidant activity by releasing GSH. Thereby, osteogenesis of MC3T3-E1 cells was enhanced represented by ALP activity increasing.
References
(1)Chen W.; Shen X.; Hu Y. et al. Surface Functionalization of Titanium Implants with Chitosan-Catechol Conjugate for Suppression of ROS-Induced Cells Damage and Improvement of Osteogenesis. Biomaterials 2017, 114.
(2)Ueno T.; Ikeda T.; Tsukimura N. et al. Novel Antioxidant Capability of Titanium Induced by UV Light Treatment. Biomaterials 2016, 108.
Objective
Titanium surface functionalization is a potent and versatile method to enhance the biological reactions of implant biomaterials1. Beyond the fundamental necessity of biocompatibility, an advanced strategy for treating titanium surfaces must be capable of controlling the surrounding microenvironment effectively. Prior research has shown that titanium implants can lead to an overproduction of reactive oxygen species (ROS), thereby hindering the process of bone formation2.
To address this issue, the present work demonstrated the synthesis of vinylphosphonic acid (VPA)- glutathione (GSH) molecule via thiol-ene click reaction and its controlled-release when pH was elevated. Furthermore, Ti substrates modified with VPA-GSH coating exhibited high antioxidant activity.
Methods
The polished Ti discs were treated in UV-Ozone cleaner. The DPAP, as a photoinitiator, dissolved in tetrahydrofuran was added to the mixed solution of VPA and GSH under the UV light for 24h. Afterward, titanium discs were soaked in VPA/GSH/VPA-GSH solutions at 70℃ for 12h, respectively (named as TiV, TiG and TiVG groups). The surface morphology and chemical state were analyzed using FE-SEM and XPS. The hydrophilicity was measured. The release of GSH and H2O2-scavenging effects were evaluated. MC3T3-E1 cells were cultured on the Ti substrates. The intracellular ROS was stained with DCFH-DA. After treating cells with H2O2 to simulate oxidative stress, cell viability and residual H2O2 concentration were measured. ALP activity assay was evaluated for the differentiation of MC3T3-E1
Statistical analysis was performed by 1-way ANOVAs and followed by Tukey’s test as a post hoc evaluation. All data were expressed as mean ± SD.
Results
The present work demonstrated the synthesis of the VPA-GSH molecule via the thiol-ene click reaction and its reversibility. TiVG surface improved surface hydrophilicity, sequentially promoting MC3T3-E1 cell adhesion and impaired ROS generation. Furthermore, Ti substrates modified with synthetic VPA-GSH coating exhibited high antioxidant activity by releasing GSH. Thereby, osteogenesis of MC3T3-E1 cells was enhanced represented by ALP activity increasing.
References
(1)Chen W.; Shen X.; Hu Y. et al. Surface Functionalization of Titanium Implants with Chitosan-Catechol Conjugate for Suppression of ROS-Induced Cells Damage and Improvement of Osteogenesis. Biomaterials 2017, 114.
(2)Ueno T.; Ikeda T.; Tsukimura N. et al. Novel Antioxidant Capability of Titanium Induced by UV Light Treatment. Biomaterials 2016, 108.