A historical overview of the activation and porosity of MOFs including strategies to design and preserve permanent porosity in MOFs.

Tissue engineering is a rapidly-growing approach to replace and repair damaged and defective tissues in the human body. Every year, a large number of people require bone replacements for skeletal defects caused by accident or disease that cannot heal on their own. In the last decades, tissue engineering of bone has attracted much attention from biomedical scientists in academic and commercial laboratories. A vast range of biocompatible advanced materials has been used to form scaffolds upon which new bone can form. Carbon nanomaterial-based scaffolds are a key example, with the advantages of being biologically compatible, mechanically stable, and commercially available. They show remarkable ability to affect bone tissue regeneration, efficient cell proliferation and osteogenic differentiation. Basically, scaffolds are templates for growth, proliferation, regeneration, adhesion, and differentiation processes of bone stem cells that play a truly critical role in bone tissue engineering. The appropriate scaffold should supply a microenvironment for bone cells that is most similar to natural bone in the human body. A variety of carbon nanomaterials, such as graphene oxide (GO), carbon nanotubes (CNTs), fullerenes, carbon dots (CDs), nanodiamonds and their derivatives that are able to act as scaffolds for bone tissue engineering, are covered in this review. Broadly, the ability of the family of carbon nanomaterial-based scaffolds and their critical role in bone tissue engineering research are discussed. The significant stimulating effects on cell growth, low cytotoxicity, efficient nutrient delivery in the scaffold microenvironment, suitable functionalized chemical structures to facilitate cell-cell communication, and improvement in cell spreading are the main advantages of carbon nanomaterial-based scaffolds for bone tissue engineering.

In this work, design and development of a new economically-efficient and environmentally-benign sonochemical-assisted oxidation protocol by using multiwall carbon nanotubes (MWCNTs) and TiO2 hybrid nanostructure catalyst is reported. The structure, morphology and particle size of the nanostructure catalyst and the products were characterized by various methods such as FT-IR, FE-SEM, EDX, XRD, DTA, GC and GC-MS analyses. The selective oxidations of alcohols to aldehydes, ketones and epoxidation were studied in the presence of MWCNTs/TiO2 at room temperature under ultrasonic irradiation conditions in excellent conversions. This is the first design, preparation, characterization and application of the present nanomaterial and also the first ultrasound-irradiated green oxidation. This novel protocol offers several advantages such as environmentally-benign, high yields, selective oxidations, short reaction times, easily isolation of the products, simple preparation, recoverability and reusability of the nanocatalyst without significant decrease in its activity.