Bifunctional nanomaterials for simultaneously improving cell adhesion and affecting bacterial biofilm formation on silicon-based surfaces.

In the biomedical field, silicon-based materials are widely used as implants, biomedical devices, and drug delivery systems. Although these materials show promise for implant technologies and clinical applications, many of them fail to simultaneously possess key properties, such as mechanical stability, biostability, stretchability, cell adhesiveness, biofilm inhibition, and drug delivery ability. Therefore, there is considerable need for the development and improvement of new biomaterials with improved properties. In this context, we describe the synthesis of a new hybrid nanocomposite material that is prepared by incorporating bifunctional nanomaterials onto glass and polydimethylsiloxane surfaces. The results show that our hybrid nanocomposite material is elastic, stretchable, injectable, biostable, has pH-controlled drug delivery ability, and display improved cell adhesion and proliferation and, at the same time, impacted bacterial biofilm formation on the respective surfaces.

Injectable polymer/nanomaterial composites for the fabrication of three-dimensional biomaterial scaffolds.

Current tissue engineering techniques have been intensively focused on creating injectable systems that can be used in minimally invasive surgery and controlled local drug delivery applications. The materials developed so far are based on natural and synthetic polymers and their nanocomposites, but many of them fail to simultaneously provide mechanical stability, stretchability and enhanced cell adhesiveness. In this context, to generate advanced injectable nanocomposite polymers that concurrently possess several properties, we used nanomaterials as well as nanomaterials that are chemically functionalized with bioactive molecules. Our 3D-printed polymer/nanomaterial composites (nanocomposite polymers) displayed enhanced mechanical properties, good shape fidelity, non-toxicity, stretchability, biostability and cell adhesiveness.

3D bioprinting of triphasic nanocomposite hydrogels and scaffolds for cell adhesion and migration.

In this study we describe the first example of 3D bioprinted triphasic chiral nanocomposite (NC) hydrogels/scaffolds to simulate the complex 3D architecture, nano/micro scale topography, and chiral nature of extracellular matrix. These multifunctional constructs are prepared using a 3D bioprinting technique and are composed of three connected hydrogels/scaffolds, two of which are loaded with nanomaterials functionalized with opposite enantiomers of a biomolecule. With these constructs, we direct the migration of cells toward the part of the triphasic chiral NC hydrogels/scaffolds containing the cells' preferred biomolecule enantiomer.

Self-assembled monolayers of chiral periodic mesoporous organosilica as a stimuli responsive local drug delivery system.

We present the preparation of self-assembled monolayers (SAMs) of pH responsive chiral periodic mesoporous organosilicas (PMOs) as model implants with drug delivery ability. SAMs of pH responsive PMOs were prepared by layer-by-layer coating of PMOs with polyelectrolytes (e.g. the enantiomers of a polycation biopolymer), for delivering organic molecules and anticancer drug molecules locally in a controlled manner to the adhered cells. We demonstrate that the amount of primary fibroblast, immortal NIH 3T3, and malignant Colo 818 cells adhered to the SAM of the d-enantiomer of polycation-functionalized PMOs was higher in comparison to that of the l-enantiomer of the polycation-functionalized PMO monolayer. In addition, we observe that the 3T3 and Colo cells internalized more of the organic and anticancer drug molecules (released from pH responsive PMOs) than the primary cells did due to the local acidic environment of them. Therefore, as the chirality of the PMOs influenced the amount of cells that adhered, the released molecules interacted with different amounts of cells which allowed us to tune the extent of local drug delivery.