Synthesis of Polyphosphate‐Loaded Nanoparticles Using Inverse Miniemulsion Polymerization for Sustained Delivery to the Gastrointestinal Tract

Polyphosphate salts, such as sodium hexametaphosphate (PPi), are effective in the attenuation of collagenase and biofilm production and prevention of anastomotic leak in mice models. However, systemic administration of polyphosphate solutions to the gut presents a series of difficulties such as uncontrolled delivery to target and off‐site tissues. In this article a process to produce PPi‐loaded poly(ethylene glycol) diacrylate (PEGDA) hydrogel nanoparticles through miniemulsion polymerization is developed. The effects of using a polyphosphate salt, as compared to a monophosphate salt, is investigated through cloud point measurements, which is then translated to a change in the required HLB of the miniemulsion system. A parametric study is developed and yields a way to control particle swelling ratio and mean diameter based on the surfactant and/or initiator concentration, among other parameters. Finally, release kinetics of two different crosslink density particles shows a sustained and tunable release of the encapsulated polyphosphate.     

Calculation of Molecular Weight Distributions in Non‐Linear Free‐Radical Polymerization Using the Numerical Fractionation Technique

Mathematical Modeling of non‐linear polymerization systems subject to gel formation is a challenging endeavor. At the gel point, the second and higher molecular weight moments diverge to infinity making it impossible to obtain the molecular weight distribution (MWD). The numerical fractionation (NF) technique utilizes a refinement of the method of moments to model non‐linear polymerization systems that form gel. Since the method of moments yields results in terms of average quantities, some information is lost when reconstructing the MWD using NF. As a consequence, a broad shoulder appears at the high chain length end of the MWD tail. This study demonstrates that the validity of the gamma distribution deteriorates for the broader branched polymer generations and evaluates the performance of various alternative model distributions. Proper selection of the model distribution enhances the NF‐reconstructed MWD.     

Correction to: Parallel and distributed computing for stochastic dual dynamic programming

Computational Management Science -