3D Printable Poly(-isopropylacrylamide) Microgel Suspensions with Temperature-Dependent Rheological Responses.

Microgel suspensions have garnered significant interest in fundamental research due to their phase transition between liquid-like to paste-like behaviors stemming from tunable interparticle and particle-solvent interactions. Particularly, stimuli-responsive microgels undergo faster volume changes in response to external stimuli in comparison to their bulk counterparts, while maintaining their structural integrity. Here, concentrated and diluted suspensions of poly(-isopropylacrylamide) (PNIPAm) microgels are dispersed to different packing fractions in water for the characterizations of temperature-responsive rheological responses.

Paramagnetic MnFe--Polystyrene Nanobeads as a Potential T-T Multimodal Magnetic Resonance Imaging Contrast Agent with Studies.

In developing a cluster-nanocarrier design, as a magnetic resonance imaging contrast agent, we have investigated the enhanced relaxivity of a manganese and iron-oxo cluster grafted within a porous polystyrene nanobead with increased relaxivity due to a higher surface area. The synthesis of the cluster-nanocarrier for the cluster MnFeO(OCCHCH═CH)(HO), cross-linked with polystyrene (the nanocarrier), under miniemulsion conditions is described. By including a branched hydrophobe, -octane, the resulting nanobeads are porous and ∼70 nm in diameter.

Paramagnetic Clusters of Mn(OCCH)(Bpy) in Polyacrylamide Nanobeads as a New Design Approach to a T- T Multimodal Magnetic Resonance Imaging Contrast Agent.

There is an increasing need for gadolinium-free magnetic resonance imaging (MRI) contrast agents, particularly for patients suffering from chronic kidney disease. Using a cluster-nanocarrier combination, we have identified a novel approach to the design of biomedical nanomaterials and report here the criteria for the cluster and the nanocarrier and the advantages of this combination. We have investigated the relaxivity of the following manganese oxo clusters: the parent cluster Mn(OCCH)(Bpy) (1) where Bpy = 2,2'-bipyridine and three new analogs, Mn(OCCHCH═CH)(Bpy) (2), Mn(OCC(CH)═CH)(Bpy) (3), and MnO(OCCH)(Pyr) (4) where Pyr = pyridine.