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Controllable release of multiple distinct cargoes from a nanomaterial is crucial to a variety of therapeutic and catalytic applications. In this study, we describe a DNA functionalized multi-layered surface crosslinked micelle (mlSCM) consisting of individually degradable layers. The DNA modified mlSCM has the ability to encapsulate separate small molecule cargo in distinct compartments within the nanocapsule, separated by chemical crosslinkers. Through a multistep self-assembly process, we show physical separation of internalized cargo as evidenced by electron microscopy, along with observation of chemical control over release, and chemical reaction conditions, as seen by fluorescence spectroscopy and a high-performance liquid chromatography mass spectrometry assay. Additionally, we evaluated the ability of these DNA crosslinked micelles to co-release two separate cargoes into the same cellular environment through an in vitro confocal microscopy assay. We show individualized targeting of two distinct but related dyes for the detection of ATP and mitochondria. The colocalization of these dyes indicates that unique locations and signals related to cellular respiration can be identified using a single mlSCM. Through these studies we ultimately show that the mlSCM has a tailorable design with the potential to be applied to numerous applications, ranging from sensing to drug delivery. 

Herein we report a thermoresponsive crosslinker that can be utilized to stabilize the surface of micelles through a “click” reaction and to trigger the disassembly via a retro Diels Alder (rDA) mechanism. The micelles generated were 100 nm in size and monodispersed. Above 60 °C, rDA dissociation of crosslinker occurs resulting to the degradation of the micelles and release of hydrophobic cargo. 

Intracellular trafficking and delivery of nucleic acids is an area of growing interest, particularly as it relates to therapeutic applications. Spectroscopic methods have been used to observe and quantitatively measure the delivery of oligonucleotides both in vitro and in vivo . Herein we demonstrate the use of a new fluorophore labeled surfactant presenting a solvatochromatic chromophore for tracking the assembly and degradation of a hybrid biomaterial we refer to as a nucleic acid nanocapsule (NAN). We show that the surfactant enables critical micelle concentration determination, monitoring of NAN disassembly in vitro , and the ability to track the cellular movement and activity of surfactant–oligonucleotide conjugates in cells when coupled with quantitative PCR analysis. 

The methylation of mercury is known to depend on the chemical forms of mercury (Hg) present in the environment and the methylating bacterial activity. In sulfidic sediments, under conditions of supersaturation with respect to metacinnabar, recent research has shown that mercury precipitates as β-HgS(s) nanoparticles (β-HgS(s) nano ). Few studies have examined the precipitation of β-HgS(s) nano in the presence of marine dissolved organic matter (DOM). In this work, we used dynamic light scattering (DLS) coupled with UV-Vis spectroscopy and transmission electron microscopy (TEM) to investigate the formation and fate of β-HgS(s) nano formed in association with marine DOM extracted from the east and west of Long Island Sound, and at the shelf break of the North Atlantic Ocean, as well as with low molecular weight thiols. We found that while the β-HgS(s) nano formed in the presence of oceanic DOM doubled in size after 5 weeks, those forming in solutions with coastal DOM did not grow over time. In addition, when the Hg II  : DOM ratio was varied, β-HgS(s) nano only rapidly aggregated at high ratios (>41 μmol Hg II per mg C) where the concentration of thiol groups was determined to be substantially low relative to Hg II . This suggests that functional groups other than thiols could be involved in the stabilization of β-HgS(s) nano . Furthermore, we showed that β-HgS(s) nano forming under anoxic conditions remained stable and could therefore persist in the environment sufficiently to impact the methylation potential. Exposure of β-HgS(s) nano to sunlit and oxic environments, however, caused rapid aggregation and sedimentation of the nanoparticles, suggesting that photo-induced changes or oxidation of organic matter adsorbed on the surface of β-HgS(s) nano affected their stability in surface waters.