SEMA4D-heparin Complexes Immobilized on Titanium Surfaces Have Anticoagulant, Cell-Migration-Promoting, and Immunoregulatory Effects

Abstract

Soluble semaphorin 4D (SEMA4D) is a 120 kDa transmembrane protein, which belongs to the semaphorin family of axon guidance molecules that act primarily axonal repellents. SEMA4D elicits its migration-promoting and immunomodulatory effects through activation of PLXNB1 and CD72, respectively. In this study, SEMA4D combined with heparin were adsorbed onto cationic surfaces. The biocompatibility evaluation results indicated that the SEMA4D-heparin-modified surfaces displayed less platelet adhesion and activation, prolonged activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) and reduced fibrinogen gamma chain (FGG) exposure and fibrinogen adhesion. Additionally, endothelial cells (ECs) showed improved adhesion density and proliferation activity on the SEMA4D-heparin-modified surfaces. Chemotactic and haptotaxis assays indicated a highly guided migration for ECs on the modified surfaces. The immunological tests revealed that the SEMA4D-heparin complexes had a positive immunomodulatory effect on macrophages and promoted macrophages polarization into M2 phenotypes. Overall, the results suggested that the SEMA4D-heparin complexes can be a potential therapeutic agent to promote tissue healing and accelerate in situ endothelialization with minimal side effects and positive immunomodulatory effect.

Blood biocompatibility enhancement of biomaterials by heparin immobilization: a review

“…EC migration and proliferation and in vivo implantation were also performed. All the results were favorable and further, SEMA4Dheparin complex could potentially be used as a therapeutic agent to help tissue healing and accelerate in-situ endothelialization with low side effects and a positive immunomodulatory effect [48]. Another research work carried for immobilization of heparin using polydopamine and PLL (poly-L-lysine); and incubated stainless steel sample.…”

Anti-inflammatory effects of the immobilization of SEMA4D on titanium surfaces in an endothelial cell/macrophage indirect coculture model

“…This forms a firm barrier, which effectively prevents peri-implantitis [79][80][81]. The proangiogenic properties and direct anti-inflammatory effects of SEMA4D have been reported [35,82,83]. However, to the best of our knowledge, no study has demonstrated the indirect inflammatory response of SEMA4D mediated by endothelial cells via quantitative and qualitative methods, especially for dental application.…”

“…The prepared titanium plates were activated in a 2 M NaOH solution at 80 • C for 12 h and denoted as the Ti-OH samples. Subsequently, the Ti-OH specimens were immersed in 2.5 mg ml −1 PLL solution (in PBS pH 7.4) and incubated overnight at 4 • C, denoted as Ti-PLL [35]. According to the instructions, SEMA4D was diluted into different concentrations (50, 100, and 200 ng ml −1 ) and mixed with the same volume of 10 mg ml −1 BSA solution (in PBS pH 7.4), and then the complexes were incubated at 37 • C for 1 h. Afterward, the Ti-PLL plates were immersed in the above SEMA4D-BSA solution at 37 • C for 3 h to combine with the SEMA4D-BSA complex, denoted as Ti-4D25, Ti-4D50, and Ti-4D100 corresponding to the SEMA4D concentrations of 25, 50, and 100 ng ml −1 , respectively.…”