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Sustainable food production is a grand challenge facing the global economy. Traditional agricultural practice requires numerous interventions, such as application of nutrients and pesticides, of which only a fraction are utilized by the target crop plants. Controlled release systems (CRSs) designed for agriculture could improve targeting of agrochemicals, reducing costs and improving environmental sustainability. CRSs have been extensively used in biomedical applications to generate spatiotemporal release patterns of targeted compounds. Such systems protect encapsulant molecules from the external environment and off-target uptake, increasing their biodistribution and pharmacokinetic profiles. Advanced ‘smart’ release designs enable on-demand release in response to environmental cues, and theranostic systems combine sensing and release for real-time monitoring of therapeutic interventions. This review examines the history of biomedical CRSs, highlighting opportunities to translate biomedical designs to agricultural applications. Common encapsulants and targets of agricultural CRSs are discussed, as well as additional demands of these systems, such as need for high volume, low cost, environmentally friendly materials and manufacturing processes. Existing agricultural CRSs are reviewed, and opportunities in emerging systems, such as nanoparticle, ‘smart’ release, and theranostic formulations are highlighted. This review is designed to provide a guide to researchers in the biomedical controlled release field for translating their knowledge to agricultural applications, and to provide a brief introduction of biomedical CRSs to experts in soil ecology, microbiology, horticulture, and crop sciences. 

Most high-quality quantum dots (QDs) are synthesized in the organic phase, and are often coated with polymers for use in aqueous biological environments. QDs can exhibit fluorescence losses during phase transfer, but evaluating underlying mechanisms ( e.g. , oxidation, surface etching, loss of colloidal stability) can be challenging because of variation in synthesis methods. Here, fluorescence stability of QDs encapsulated in block co-polymer (BCP) micelles was investigated as a function of BCP terminal functionalization ( i.e. , –OH, –COOH, and –NH 2 groups) and synthesis method ( i.e. , electrohydrodynamic emulsification-mediated selfassembly (EE-SA), sonication, and manual shaking). Fluorescence losses, fluorescence intensity, energy spectra, and surface composition were assessed using spectrofluorometry and cathodoluminescence spectroscopy (CL) with integrated X-ray photoemission spectroscopy (XPS). QDs passivated using charged BCPs exhibited 50–80% lower fluorescence intensity than those displaying neutral groups ( e.g. , –OH), which CL/XPS revealed to result from oxidation of surface Cd to CdO. Fluorescence losses were higher for processes with slow formation speed, but minimized in the presence of poly(vinyl alcohol) (PVA) surfactant. These data suggest slower BCP aggregation kinetics rather than electrostatic chain repulsion facilitated QD oxidation. Thus, polymer coating method and BCP structure influence QD oxidation during phase transfer and should be selected to maximize fast aggregation kinetics. 

Glioblastoma (GBM) is an astrocytic brain tumor with median survival times of <15 months, primarily as a result of high infiltrative potential and development of resistance to therapy (i.e., surgical resection, chemoradiotherapy). A prominent feature of the GBM microenvironment is compressive solid stress (CSS) caused by uninhibited tumor growth within the confined skull. Here, we utilized a mechanical compression model to apply CSS (<115 Pa) to well-characterized LN229 and U251 GBM cell lines and measured their motility, morphology, and transcriptomic response. Whereas both cell lines displayed a peak in migration at 23 Pa, cells displayed differential response to CSS with either minimal (i.e., U251) or large changes in motility (i.e., LN229). Increased migration of LN229 cells was also correlated to increased cell elongation. These changes were tied to epigenetic signaling associated with increased migration and decreases in proliferation predicted via Ingenuity® Pathway Analysis (IPA), characteristics associated with tumor aggressiveness. miRNA-mRNA interaction analysis revealed strong influence of the miR548 family (i.e., mir-548aj, mir-548az, mir-548t) on differential signaling induced by CSS, suggesting potential targets for pharmaceutical intervention that may improve patient outcomes.

 

The microtubule (MT)‐kinesin system has been extensively studied because of its role in cellular processes, as well as its potential use for controllably transporting objects at the nanoscale. Thus, there is substantial interest in methods to evaluate MT properties, including bending radius and the binding energy of kinesin motor proteins to MT tracks. Current methods to identify these properties include optical tweezers, microfluidic devices, and magnetic fields. Here, the use of magnetic quantum dots (i.e., MagDots) is evaluated as a method to study MT‐kinesin interactions via applied magnetic forces. Magnetic fields are generated using a magnetic needle whose field gradient is quantified by finite element modeling (FEM). Magnetic force is applied to MagDot‐labeled MTs and demonstrated sufficient to steer and detach MTs from kinesin‐coated surfaces. Taking advantage of the dual‐functionality of MagDots, the magnetic force experienced by a single MagDot and the number of MagDots on MTs are determined. The total force exerted on MTs by MagDots is estimated to be ≈0.94–2.47 pN. This approach could potentially be used to interrogate MT properties and MT‐kinesin interactions, enhancing our biological understanding of this system and enabling further development of MT shuttles for nanotransport.