Genipin-Cross-Linked Layer-by-Layer Assemblies: Biocompatible Microenvironments To Direct Bone Cell Fate

Abstract

The design of biomimetic coatings capable of improving the osseointegration of bone biomaterials is a current challenge in the field of bone repair. Toward this end, layer-by-layer (LbL) films composed of natural components are suitable candidates. Chondroitin sulfate A (CSA), a natural glycosaminoglycan (GAG), was used as the polyanionic component because it promotes osteoblast maturation in vivo. In their native state, GAG-containing LbL films are generally cytophobic because of their low stiffness. To stiffen our CSA-based LbL films, genipin (GnP) was used as a natural cross-linking agent, which is much less cytotoxic than conventional chemical cross-linkers. GnP-cross-linked films display an original combination of microscale topography and tunable mechanical properties. Structural characterization was partly based on a novel donor/acceptor Förster resonance energy transfer (FRET) couple, namely, FITC/GnP, which is a promising approach for further inspection of any GnP-cross-linked system. GnP-cross-linked films significantly promote adhesion, proliferation, and early and late differentiation of preosteoblasts.

Controlling cell adhesion using layer-by-layer approaches for biomedical applications

“…Different covalent cross-linking methods have been developed, such as photo cross-linking via benzophenone [123] or vinylbenzene [124,125] groups and other cross-linking agents [98]. For example, photo cross-linking films constructed from PLL and hyaluronan (HA) derivatives modified by photo-reactive vinylbenzyl groups were studied by Pozos-Vasquez et al [96].…”

“…Gaudiere et al [98] explored the use of natural cross-linking agent genipin to induce film cross-linking. The Young's modulus of the film could experience a tenfold increase for cross-linked films as compared to native ones.…”

Tuning cell adhesive properties via layer-by-layer assembly of chitosan and alginate

“…Multilayers based on these polysaccharides are stable over a pH range of 3–9, but exhibit high hydration levels and low mechanical strength, which impair cell adhesion. [27–29] Post-assembly modifications can be used to tune these properties, namely adsorption or immobilization of extracellular matrix (ECM) proteins such as laminin (LM) and fibronectin (FN) as well as chemical cross-linking of the films.…”

“…Different approaches can be used to tune mechanical properties including the incorporation of nanocolloids [32], assembly pH [33], or by using covalent cross-linkers such as glutaraldehyde, [34, 35] 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) in combination with sulfo-N-hydroxysulfo-succinimide (EDC/s-NHS) [36–38] and genipin [29, 39]. Genipin is a naturally derived chemical from the gardenia fruit that has been extensively investigated due to its ability to cross-link amine-containing polymers [40, 41] in diverse systems, including multilayered films [39, 42].…”

Osteoblast biocompatibility of premineralized, hexamethylene-1,6-diaminocarboxysulfonate crosslinked chitosan fibers

“…Recently, we reported the novel crosslinking of electrospun chitosan fibers with the crosslinkers genipin and hexamethylene-1,6-diaminocarboxysulfonate (HDACS) [30]. Genipin is a natural crosslinker that has demonstrated success in a variety of scaffolds and tissue cultures including bone tissue engineering applications [34–37]. Both crosslinkers have been previously utilized for chitosan gels and films [31].…”