Clay nanoparticles for regenerative medicine and biomaterial design: A review of clay bioactivity

Abstract

Clay nanoparticles, composites and hydrogels are emerging as a new class of biomaterial with exciting potential for tissue engineering and regenerative medicine applications. Clay particles have been extensively explored in polymeric nanocomposites for self-assembly and enhanced mechanical properties as well as for their potential as drug delivery modifiers. In recent years, a cluster of studies have explored cellular interactions with clay nanoparticles alone or in combination with polymeric matrices. These pioneering studies have suggested new and unforeseen utility for certain clays as bioactive additives able to enhance cellular functions including adhesion, proliferation and differentiation, most notably for osteogenesis. This review examines the recent literature describing the potential effects of clay-based nanomaterials on cell function and examines the potential role of key clay physicochemical properties in influencing such interactions and their exciting possibilities for regenerative medicine.

Growth‐Factor Free Multicomponent Nanocomposite Hydrogels That Stimulate Bone Formation

“…In particular, Lap ‐containing hydrogels exhibited a significant decrease in degradation rate, which correlates with previous studies also reporting an enhanced Lap‐induced stability in polymers60 and biopolymers 45. We speculate that the suppressed hydrogel susceptibility to rapid enzymatic degradation observed in HA‐Tyr‐Lap and HA‐Tyr‐Lap‐GHK‐Cu 2+ may be attributed to the strong affinity of Lap discs to proteins and enzymes through physical adsorption,41 which would consequently limit hyaluronidase access to the HA backbone.…”

“…However, self‐assembling materials typically provide limited structural integrity, which has hindered their wide spread applicability. Lap is a 2D nanosilicate with anisotropic charge distribution, which has been exploited as an effective cross‐linker and rheology modifier for hydrogels39 for the delivery of drugs, growth factors, and antibodies 40,41. Lap has been reported to promote cell adhesion and proliferation and can exert osteogenic effects on cells in vitro 42.…”

Copolymer/Clay Nanocomposites for Biomedical Applications

“…Polymer/clay nanocomposites including their 3D bioprinting have been reviewed recently for different biomedical applications. [ 19 ] Gaharwar et al [ 20 ] reviewed the potential of laponite nanoclay and its nanocomposites for additive manufacturing and regenerative medicine. Liu et al [ 21 ] reported an overview of halloysite nanotubes and respective nanocomposites for various biomedical applications such as drug delivery, biosensing, and bone regeneration.…”

Nanoparticle–Polymer Synergies in Nanocomposite Hydrogels: From Design to Application

“…Clays, a series of minerals with diverse dimensions, such as SiO 2 (0D), halloysite‐nanotubes (1D), montmorillonite (2D), and synthetic hectorite (2D), are extensively used as nanofillers in NC gels . One frequently used material is clay nanoplatelets, such as montmorillonite (MMT) and synthetic hectorite (laponite).…”

“…Each layer of the clay nanoplatelets consists of one octahedral sheet sandwiched by two tetrahedral sheets. The octahedral sheets usually contain cations, such as aluminum (Al) ions and magnesium (Mg) ions, which are octahedrally coordinated by oxygen, while the tetrahedral sheets consist of silicon dioxide with negative charges due to partial isomorphous substitution, typically of Al 3+ by Mg 2+ in montmorillonite and of Mg 2+ by Li + in laponite . The basal plane of these clay minerals has a permanent negative charge due to the isomorphous substitution of cations within the octahedral and/or tetrahedral layers by cations with lower valence.…”