Dynamic Titania Nanotube Surface Achieves UV-Triggered Charge Reversal and Enhances Cell Differentiation

Abstract

Stimuli-responsive biomaterials supply a promising solution to adapt to the complex physiological environment for different biomedical applications. In this study, a dynamic UV-triggered pH-responsive biosurface was constructed on titania nanotubes (TNTs) by loading photoacid generators, diphenyliodonium chloride, into the nanotubes, and grafting 2,3-dimethyl maleic anhydride (DMMA)-modified hyperbranched poly(L-lysine) (HBPLL) onto the surface. The local acidity was dramatically enhanced by UV irradiation for only 30 s, leading to the dissociation of DMMA and thereby the transformation of surface chemistry from negatively charged caboxyl groups to positively charged amino groups. The TNTs−HBPLL−DMMA substrate could better promote proliferation and spreading of rat bone mesenchymal stem cells (rBMSCs) after UV irradiation. The osteogenic differentiation of rBMSCs was enhanced because of the charge reversal in combination with the titania-based substrates.

Smart stimuli-responsive strategies for titanium implant functionalization in bone regeneration and therapeutics

“…148,149 Some studies also explored the application of UV light as an in situ stimulus to improve the biological performance of titanium implants. Bai et al 104 reported an UV light-triggered dynamic titanium surface by loading photoacid generators (diphenyliodonium chloride, DPIC) in titania nanotubes (TNTs). Upon UV light irradiation for 30 seconds, enhanced local acidity by DPIC decomposed 2,3-dimethylmaleic anhydride (DMMA)-modified hyperbranched poly(L-lysine) (HBPLL), and consequently transformed surface chemistry from negatively charged caboxyl groups to positively charged amino groups.…”

“…(1) Triggered antibacterial or anti-tumor drug release 25,97,98,[100][101][102][103][107][108][109][110][111][112][113] (1) Natural biomolecules (chitosan and silk fibroin) [97][98][99][100][101][102][103] (2) Conformation change of molecules (2) Surface potential changes promoting cell adhesion and osteogenesis [104][105][106] (2) Synthetic polymers (PMAA, DMMA and etc.) 25,104,105 (3) Cleavage of bonds/linkers (3) Inorganic molecules (MOFs, ZnO and etc.) [106][107][108] (4) pH-sensitive bonds/linkers 101,[108][109][110][111][112][113]…”

“…And this system also displayed satisfying biocompatibilities and pro-osteogenic activity. In another study, Zhang et al 104 utilized positively-charged carboxyl groups to shield cationic quaternary ammonium salts (QAs) from toxicity and constructed a pH-sensitive antibacterial copolymer coating on titanium surfaces via an LBL method. When bacterial infection occurred, the acidic environment could deionize carboxyl groups which led to invalidation of the shielding effect of positive charges, and as a result, the bactericidal activity of cationic QAs was emancipated.…”

Nanoparticles in Polyelectrolyte Multilayer Layer-by-Layer (LbL) Films and Capsules—Key Enabling Components of Hybrid Coatings

“…Choosing proper aggregation state of nanoparticles and laser wavelength corresponding to the maximum absorption of NPs, one can locally cross-link the surface of films exposed to laser, Figure 2 (right). Even more drastic action of laser-nanoparticle interaction has been implemented in cell detachment [54], differentiation [55], and cell death induction [56]. However, this is not the only functionality of the nanoparticles in the coatings-they can be also used to control the masking for fabricating Janus particles.…”

Electrostatic Repulsive Features of Free-Standing Titanium Dioxide Nanotube-Based Membranes in Biofiltration Applications

“…Within aforementioned techniques, it is possible to produce thin polymeric membranes of large size and controllable fiber thickness, but although the fiber orientations can be adjusted, the tortuosity feature of the pores cannot be fully controlled. Electrochemical anodic oxidation is one of the cost- and time-efficient methods to fabricate highly orientated porous or/and nanotubular metal oxides such as titania, alumina, and zirconia surface arrays and membranes, even though it is not a lithographic fabrication technique. − Due to their biocompatibility, photocatalytic activity, and antibacterial characteristic, anodic titanium dioxide (TiO 2 ) nanotubes (NTs) and their polymeric composites exhibit a reasonable potential in biological applications. − …”