Production of highly crosslinked microspheres by the precipitation polymerization of 2-(diethylamino)ethyl methacrylate with two or three functional crosslinkers

Microcapsules Containing pH-Responsive, Fluorescent Polymer-Integrated MoS2: An Effective Platform for in Situ pH Sensing and Photothermal Heating

We report the design of a novel microcapsule platform for in situ pH sensing and photothermal heating, which involves the encapsulation of pH-responsive polymer-coated molybdenum disulfide (MoS₂) nanosheets (NSs) in microcapsules with an aqueous core and a semipermeable polymeric shell. The MoS₂ NSs were functionalized with pH-responsive polymers having fluorescent groups at the distal end to provide pH-sensitive Förster resonance energy transfer (FRET) effect. The pH-responsive polymers were carefully designed to produce a dramatic change in the polymer conformation, which translated to a change in the FRET efficiency near pH 7.0 in response to subtle pH changes, enabling the detection of cancer cells. The pH-sensitive MoS₂ NSs were microfluidically encapsulated within semipermeable membranes to yield microcapsules with a uniform size and composition. The microcapsules retained the MoS₂ NSs without leakage while allowing the diffusion of small ions and water through the membrane. At the same time, the membranes excluded adhesive proteins and lipids in the surrounding media, protecting the encapsulated MoS₂ NSs from deactivation and enabling in situ pH monitoring. Moreover, the encapsulated MoS₂ NSs showed high-performance photothermal heating, rendering the dual-functional microcapsules highly suitable for cancer diagnosis and treatment.

Aerogel microspheres from natural cellulose nanofibrils and their application as cell culture scaffold

We demonstrated that ultralight pure natural aerogel microspheres can be fabricated using cellulose nanofibrials (CNF) directly. Experimentally, the CNF aqueous gel droplets, produced by spraying and atomizing through a steel nozzle, were collected into liquid nitrogen for instant freezing followed by freeze-drying. The aerogel microspheres are highly porous with bulk density as low as 0.0018 g cm(-3). The pore size of the cellulose aeogel microspheres ranges from nano- to macrometers. The unique ultralight and high porous structure ensured high moisture (~90 g g(-1)) and water uptake capacity (~100 g g(-1)) of the aerogel microspheres. Covalent cross-linking between the native nanofibrils and cross-linkers made the aerogel microspheres very stable even in a harsh environment. The present study also confirmed this kind of aerogel microspheres from native cellulose fibers can be used as cell culture scaffold.