The present work evaluated the effects of different ionic and nonionic stabilizers and respective concentrations on methyl methacrylate (MMA) miniemulsion polymerizations. The stabilities of the prepared miniemulsions are characterized through sedimentation and phase separation analyses and afterwards polymerizations are performed at the most stable conditions for each analyzed stabilizer. Monomer conversion profiles and final product properties are determined for comparative purposes. Obtained results indicated that the performances of the stabilizers during the polymerizations are not necessarily related to the stabilizing performances observed during preparation of the miniemulsions and that polymer latexes produced with the nonionic surfactant Tween80 presented the most suitable properties for applications in the biomedical field, as this stabilizer presented good stabilizing performances both during miniemulsion preparation and miniemulsion polymerization.

Schistosomiasis is a parasitic disease that affects millions of people, especially low‐income people, and is considered a major public health problem in underdeveloped countries. The drug used most often for the treatment of the disease is praziquantel (PZQ), which has a strong and characteristic bitter taste that makes treatment of children inconvenient. For this reason, the present work investigates the development of smart pH‐sensitive polymer microparticles produced through suspension polymerizations to be used as vehicles for the controlled release of praziquantel in the body. The microparticles are produced through copolymerization of methyl methacrylate and the cationic comonomers diethylaminoethyl methacrylate or dimethylaminoethyl methacrylate. The obtained results indicate that microparticles with sizes in the range of 10–1100 µm can be formed successfully, allowing high PZQ encapsulation efficiencies (>80%). Zeta potential analyses and drug release assays confirm the pH‐sensitive responses of the cationic copolymers, leading to effective release of PZQ (around 80% in pH 1.2) in acidic media that simulate the organic fluids present in the stomach.

Schistosomiasis is a neglected tropical disease that affects primarily the poorest and most vulnerable populations. Although praziquantel (PZQ) is the drug used most frequently for treatment of schistosomiasis, PZQ presents unpleasant bitter taste and low solubility in water, which prejudice the implementation of pediatric treatments. For this reason, the main purpose of the present work was the production of stable nanoparticles loaded with PZQ through in situ miniemulsion copolymerizations of methyl methacrylate (MMA) with diethylaminoethyl methacrylate (DEAEMA) or dimethylaminoethyl methacrylate (DMAEMA). Due to the cationic nature of the comonomers, the use of different ionic surfactants was also investigated. Nanoparticles with narrow particle size distributions, characteristic average diameters ranging from 50 nm to 110 nm, and loaded with 20 wt% of PZQ were manufactured successfully PZQ encapsulation efficiencies were higher than 97 wt% and PZQ was homogeneously dispersed in the final polymer matrix. Finally, the use of a cationic surfactant with DEAEMA cationic comonomer led to more stable latexes because of the high absolute value of the zeta potential.

Front Cover: Smart drug delivery based on cationic polymer microparticles is developed via free‐radical suspension polymerizations of MMA, DMAEMA and DEAEMA. The microparticles show high incorporation of the drug praziquantel (mainly used in schistosomiasis treatment) and efficient releases in acidic pHs, showing great potential as a new oral formulation. This is reported by Thamiris Franckini Paiva, Jéssica Bentes Alves, Príamo Albuquerque Melo, and José Carlos Pinto in article 1900028.

Polyisobutylenes (PIB) constitute a versatile family of polymer materials that have been used mainly as fuel and lubricant additives. Particularly, the current commercial demand for highly reactive polyisobutylene (HR-PIB) products motivates the development of new processes and procedures to produce PIBs with high polymer yields, narrow molar mass distributions and high vinyl contents. For this reason, a bibliometric survey is presented here to map and discuss important technical aspects and technological trends in the field of solution cationic polymerization of isobutylenes. It is shown that investigations in this field are concentrated mainly on developed countries and that industrial initiatives indicate high commercial interest and significant investments in the field. It is also shown that use of catalyst systems based on AlCl3 and ether cocatalysts can be very beneficial for PIB and HR-PIB manufacture. Finally, it is shown that investigations search for cheaper and environmentally friendly catalysts and solvents that can be employed at moderate temperatures, particularly for the production of HR-PIB.