Guiding Fibroblast Activation Using an RGD‐Mutated Heparin Binding II Fragment of Fibronectin for Gingival Titanium Integration

Abstract

The formation of a biological seal around the neck of titanium (Ti) implants is critical for ensuring integration at the gingival site and for preventing bacterial colonization that may lead to periimplantitis. This process is guided by activated fibroblasts, named myofibroblasts, which secrete extracellular matrix (ECM) proteins and ECM‐degrading enzymes resolving the wound. However, in some cases, Ti is not able to attract and activate fibroblasts to a sufficient extent, which may compromise the success of the implant. Fibronectin (FN) is an ECM component found in wounds that is able to guide soft tissue healing through the adhesion of cells and attraction of growth factors (GFs). However, clinical use of FN functionalized Ti implants is problematic because FN is difficult to obtain, and is sensitive to degradation. Herein, functionalizing Ti with a modified recombinant heparin binding II (HBII) domain of FN, mutated to include an Arg‐Gly‐Asp (RGD) sequence for promoting both fibroblast adhesion and GF attraction, is aimed at. The HBII‐RGD domain is able to stimulate fibroblast adhesion, spreading, proliferation, migration, and activation to a greater extent than the native HBII, reaching values closer to those of full‐length FN suggesting that it might induce the formation of a biological sealing.

Effect of Functionalization of Texturized Polypropylene Surface by Silanization and HBII-RGD Attachment on Response of Primary Abdominal and Vaginal Fibroblasts

“…Consequently, functionalized PP surfaces provided stronger adhesion to human fibroblasts compared to untreated surfaces where adhesion relied on weaker and non-specific interactions such as van der Waals forces and electrostatic interactions. These results support our previous observations that HBII-RGD functionalization similarly promotes cellularity and spreading of human mesenchymal cells and foreskin fibroblasts cultured on titanium surfaces [ 43 , 44 ]. Furthermore, the effects of HBII-RGD on cellularity appeared to have a threshold below which these effects were nearly undetectable in our model.…”

“…The HBII-RGD fragment was produced by standard recombinant DNA methods as previously described [ 43 , 44 ]. Briefly, the DNA fragment of HBII was inserted into the pGEX-6-P1 plasmid (GE Healthcare, Buckinghamshire, UK) and transformed into DH5α cells (Invitrogen, Carlsbad, CA, USA).…”

“…The HBII-RGD fragment was covalently attached to PP discs by silanization as carefully described in previous studies [ 43 , 44 ]. Briefly, PP discs were cleaned and activated by oxygen plasma for 2 min at 12 MHz in a Femto low-pressure plasma system (Diener Electronic, Germany).…”

“…Among the various possible ECM molecules, in previous studies we generated a recombinant fragment spanning the type III12-14 (heparin-binding II, HBII) repetitions of fibronectin (a protein strongly involved in tissue regeneration), which has been shown to induce bone differentiation in mesenchymal stem cells due to its ability to bind growth factors [ 42 ]. The fragment has been mutated to include an RGD sequence (HBII-RGD), which promotes both cell adhesion and differentiation/activation properties when osteoblasts [ 43 ] or fibroblasts [ 44 ] are applied to solid materials.…”

Enhancing osseointegration of titanium implants through MC3T3‐E1 protein‐gelatin polyelectrolyte multilayers

“…Studies have shown that the modification of titanium implants with bioactive substance can greatly facilitate the adhesion of cells to the surface of titanium implants. [31][32][33][34][35][36] Figure 5 demonstrates that on day 1 and 3 of incubation, the TiOH surface exhibited the highest cell adhesion and viability, while after 5 days of incubation, no significant difference in cell number was observed among the groups. This indicates that both surface roughness and wettability influence cell proliferation on material surfaces, and the microenvironment in which the cells grow also plays a crucial role in regulating cell proliferation and differentiation.…”