Abstract:Nanoclays have generated interest in biomaterial design for their ability to enhance the mechanics of polymeric materials and impart biological function. As well as their utility as physical cross-linkers, clays have been explored for sustained localization of biomolecules to promote in vivo tissue regeneration. To date, both biomolecule-clay and polymer-clay nanocomposite strategies have utilised the negatively charged clay particle surface. As such, biomolecule-clay and polymer-clay interactions are set in c… Show more
“…For example, the ability of clay to take up and bind bioactive molecules has been used to initiate the formation of new vessels in a wound with the help of vascular endothelial growth factor localization and to stimulate osteogenesis at notably reduced bone morphogenetic protein (BMP) doses ( Gibbs et al., 2016 ). Another example showed that stable Laponite@BMP-2 complexes can be formed by the strong static binding between Laponite nanoplatelets and BMP-2 to effectively preserve the intrinsic bioactivity of BMP-2 and prolong the release period ( Kim et al., 2020 ; Zhang et al., 2020 ). Figure 2 Possible Models Illustrating How Clay May Promote Osteogenesis (A) Ionic dissolution behavior of Laponite inside cells, and the subsequent enhancement in the intracellular concentration of ions and minerals such as lithium, magnesium, and silicate and all degradation products that are known to affect osteogenic cell function.…”
Section: Classification Of Nanocomposite Hydrogelsmentioning
Summary
Bone defects caused by trauma and surgery are common clinical problems encountered by orthopedic surgeons. Thus, a hard-textured, natural-like biomaterial that enables encapsulated cells to obtain the much-needed biophysical stimulation and produce functional bone tissue is needed. Incorporating nanomaterials into cell-laden hydrogels is a straightforward tactic for producing tissue engineering structures that integrate perfectly with the body and for tailoring the material characteristics of hydrogels without hindering nutrient exchange with the surroundings. In this review, recent developments in inorganic nanocomposite hydrogels for bone tissue engineering that are of vital importance but have not yet been comprehensively reviewed are summarized.
“…For example, the ability of clay to take up and bind bioactive molecules has been used to initiate the formation of new vessels in a wound with the help of vascular endothelial growth factor localization and to stimulate osteogenesis at notably reduced bone morphogenetic protein (BMP) doses ( Gibbs et al., 2016 ). Another example showed that stable Laponite@BMP-2 complexes can be formed by the strong static binding between Laponite nanoplatelets and BMP-2 to effectively preserve the intrinsic bioactivity of BMP-2 and prolong the release period ( Kim et al., 2020 ; Zhang et al., 2020 ). Figure 2 Possible Models Illustrating How Clay May Promote Osteogenesis (A) Ionic dissolution behavior of Laponite inside cells, and the subsequent enhancement in the intracellular concentration of ions and minerals such as lithium, magnesium, and silicate and all degradation products that are known to affect osteogenic cell function.…”
Section: Classification Of Nanocomposite Hydrogelsmentioning
Summary
Bone defects caused by trauma and surgery are common clinical problems encountered by orthopedic surgeons. Thus, a hard-textured, natural-like biomaterial that enables encapsulated cells to obtain the much-needed biophysical stimulation and produce functional bone tissue is needed. Incorporating nanomaterials into cell-laden hydrogels is a straightforward tactic for producing tissue engineering structures that integrate perfectly with the body and for tailoring the material characteristics of hydrogels without hindering nutrient exchange with the surroundings. In this review, recent developments in inorganic nanocomposite hydrogels for bone tissue engineering that are of vital importance but have not yet been comprehensively reviewed are summarized.
“…On the other hand, the positively charged nanoclay edges compete with Ca 2+ for alginate junction sites. [ 41 ] Chemically crosslinked PNIPAAm chains bind to clay surfaces through hydrogen, ionic, and polar interactions. All these interactions lead to the formation of the 3D nanocomposite hydrogels with mutually interpenetrating and interacting inorganic and organic networks of ALG, PNIPAAm, and LAP with unique thermal and mechanical properties.…”
4D printing has emerged as an important technique for fabricating 3D objects from programmable materials capable of time‐dependent reshaping. In the present investigation, novel 4D thermoinks composed of laponite (LAP), an interpenetrating network of poly(N‐isopropylacrylamide) (PNIPAAm), and alginate (ALG) are developed for direct printing of shape‐morphing structures. This approach consists of the design and fabrication of 3D honeycomb‐patterned hydrogel discs self‐rolling into tubular constructs under the stimulus of temperature. The shape morphing behavior of hydrogels is due to shear‐induced anisotropy generated via 3D printing. The compositionally tunable hydrogel discs can be programmed to exhibit different actuation behaviors at different temperatures. Upon immersion in 12 °C water, singly crosslinked sheets roll up into a tubular construct. When transferred to 42 °C water, the tubes first rapidly unfold and then slightly curve up in the opposite direction. Through a dual photocrosslinking of PNIPAAm, it is possible to inverse temperature‐dependent shape morphing and induce self‐folding at higher and unrolling at lower temperatures. The extensive self‐assembling motion is essential to developing thermal actuators with broad applications in, e.g., soft robotics and active implantology, whereas controllable self‐rolling of planar hydrogels is of the highest interest to biomedical engineering as it allows for effective fabrication of hollow tubes.
“…Previously, we prepared hyaluronan (HA) derivatives in which aminobisphosphonates were permanently attached to HA backbone through stable chemical bonds, thereby excluding possibility for the release of aminobisphosphonates as intact drugs [ 29 , 30 ]. It was also demonstrated that these HA-BP derivatives formed shear-thinning and self-healing hydrogels upon interaction with either hydrated metal ions such as Ca 2+ [ 31 ], Mg 2+ [ 32 ], Ag + [ 33 ], or nanoparticles of inorganic salts such as calcium phosphate [ 30 ], magnesium silicate [ 32 ], calcium sodium phosphosilicate (bioglass) [ 34 ], and clay [ 35 ].…”
Due to its unique properties resembling living tissues, hydrogels are attractive carriers for the localized and targeted delivery of various drugs. Drug release kinetics from hydrogels are commonly controlled by network properties and the drug-network interactions. However, and simultaneously, the programmable delivery of multiple drugs with opposing properties (hydrophilicity, molecular weight, etc.) from hydrogels with determined network properties is still challenging. Herein, we describe the preparation of injectable self-healing hyaluronic acid (HA) hydrogels that release hydrophobic simvastatin and hydrophilic aminobisphosphonate (BP) drugs independently in response to acidic and thiol-containing microenvironments, respectively. We apply a prodrug strategy to BP by conjugating it to HA via a self-immolative disulfide linker that is stable in the blood plasma and is cleavable in the cytoplasm. Moreover, we utilize HA-linked BP ligands to reversibly bind Ca2+ ions and form coordination hydrogels. Hydrazone coupling of hydrophobic ligands to HA permits the encapsulation of simvastatin molecules in the resulting amphiphilic HA derivative and the subsequent acid-triggered release of the drug. The conjugation of BP and hydrophobic ligands to HA enables preparation of both bulk self-healing hydrogels and nanogels. Moreover, the developed hydrogel system is shown to be multi-responsive by applying orthogonally cleavable linkers. The presented hydrogel is a potential candidate for the combination treatment of osteoporosis and bone cancers as well as for bone tissue regeneration since it can deliver bone anabolic and anti-catabolic agents in response to bone diseases microenvironments.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
