Search for: All records

Focal therapies such as hyperthermia have been successfully used to treat solid localized tumors; however, they are not easily applied to cancers that may present in a disseminated form such as ovarian cancer. To address this need, iron oxide (IO) particles were incorporated into microporous poly(caprolactone) scaffolds previously shown to recruit disseminating cancer cells. Under an alternating magnetic field, IO‐loaded scaffolds exhibited heating and killed ID8 ovarian cancer cells in vitro. After implantation in the intraperitoneal cavity of mice, IO‐loaded scaffolds became infiltrated with tissue after 6–7 weeks, and infiltrated cells were successfully treated ex vivo. Finally, IO‐loaded scaffolds noninvasively killed infiltrated cells in vivo as evidenced by decreases in number of nuclei. These studies demonstrate the promising use of IO‐loaded scaffolds as a tool for noninvasive hyperthermia, which could be an innovative modality for treatment of disseminated cancers.

 

Polyelectrolyte-driven flocculation of suspended particulate in solution is an important process in a variety of industrial processes such as drinking water treatment and composite material synthesis. Flocculation depends on a wide variety of physicochemical and hydrodynamic properties, which affect floc size, growth rate, and floc morphology. Floc formation and growth behavior is explored here using two different molecular weights of a cationic polyacrylamide flocculant and anisotropic Na-bentonite clay particles under a variety of solution ionic strengths. A Taylor–Couette cell with radial injection capabilities was used to study the effects of solution ionic strength and polyelectrolyte molecular weight on floc size, growth rate, and floc morphology during the flocculation process with a constant global velocity gradient. The floc size generally decreased with increasing ionic strength whereas the floc growth rate initially increased then decreased. This likely occurred due to charge screening effects, where increased bentonite aggregate size and a less expanded polyelectrolyte conformation at higher ionic strengths results in a decreased ability for the polyelectrolyte to bridge multiple bentonite aggregates. The densification of bentonite aggregates at higher ionic strengths resulted in floc morphologies that were more resistant to shear-induced breakage. With the exceptions of optimal dose concentration and dispersion coefficients, there were no clear differences in the floc growth rate behaviors for the two molecular weights studied. This work contributes to an improved understanding of the physicochemical complexities of polyelectrolyte-driven flocculation that can inform dosing requirements for more efficient industrial operations.