Protecting metal-organic framework crystals from hydrolytic degradation by spray-dry encapsulating them into polystyrene microspheres

A one-step, alternative, rapid, and scalable spray-drying (SD) synthesis of metal-organic frameworks (MOF)@polymer composites with enhanced hydrolytic stabilities was reported. SD was used to encapsulate preformed MOF crystals in a polymeric matrix to generate microscale MOF@polymer spheres. For proof-of-concept Hong-Kong University of Science and Technology-1 (HKUST-1) was chosen as the water-sensitive MOF, and polystyrene (PS) as the organic polymer. The synthesis of HKUST-1@PS began with preparation of a stable colloidal suspension of HKUST-1 crystals and a solution of PS in dichloromethane (DCM). This mixture was atomized using a two-fluid nozzle. After 40 min of continuous spraying, 1.7 g of a blue powder was recovered. The sample was then washed with ethanol and dried at 120°C under vacuum. This product was analyzed through field-emission scanning electron microscopy (FESEM), which indicated that it comprised smooth microspheres of HKUST-1@PS composites and did not contain any free HKUST-1. X-ray powder diffraction (XRPD) analysis of these spheres revealed a perfect match with the HKUST-1 pattern. The exclusive presence of microspheres and the match in XRPD patterns evidenced that HKUST-1 crystals were indeed entrapped within the polymeric matrix of PS

Multifunctional Magnetic-fluorescent Nanocomposites for Biomedical Applications

Nanotechnology is a fast-growing area, involving the fabrication and use of nano-sized materials and devices. Various nanocomposite materials play a number of important roles in modern science and technology. Magnetic and fluorescent inorganic nanoparticles are of particular importance due to their broad range of potential applications. It is expected that the combination of magnetic and fluorescent properties in one nanocomposite would enable the engineering of unique multifunctional nanoscale devices, which could be manipulated using external magnetic fields. The aim of this review is to present an overview of bimodal “two-in-one” magnetic-fluorescent nanocomposite materials which combine both magnetic and fluorescent properties in one entity, in particular those with potential applications in biotechnology and nanomedicine. There is a great necessity for the development of these multifunctional nanocomposites, but there are some difficulties and challenges to overcome in their fabrication such as quenching of the fluorescent entity by the magnetic core. Fluorescent-magnetic nanocomposites include a variety of materials including silica-based, dye-functionalised magnetic nanoparticles and quantum dots-magnetic nanoparticle composites. The classification and main synthesis strategies, along with approaches for the fabrication of fluorescent-magnetic nanocomposites, are considered. The current and potential biomedical uses, including biological imaging, cell tracking, magnetic bioseparation, nanomedicine and bio- and chemo-sensoring, of magnetic-fluorescent nanocomposites are also discussed

Current trend in synthesis, Post-Synthetic modifications and biological applications of Nanometal-Organic frameworks (NMOFs)

Since the early reports of MOFs and their interesting properties, research involving these materials has grown wide in scope and applications. Various synthetic approaches have ensued in view of obtaining materials with optimised properties, the extensive scope of application spanning from energy, gas sorption, catalysis biological applications has meant exponentially evolved over the years. The far‐reaching synthetic and PSM approaches and porosity control possibilities have continued to serve as a motivation for research on these materials. With respect to the biological applications, MOFs have shown promise as good candidates in applications involving drug delivery, BioMOFs, sensing, imaging amongst others. Despite being a while away from successful entry into the market, observed results in sensing, drug delivery, and imaging put these materials on the spot light as candidates poised to usher in a revolution in biology. In this regard, this review article focuses current approaches in synthesis, post functionalization and biological applications of these materials with particular attention on drug delivery, imaging, sensing and BioMOFs