Schistosomiasis is one of the major public health problems worldwide. Even though this is a common illness among preschool children in poor countries, treatment is carried out mainly through the administration of praziquantel tablets, which has some disadvantages, such as the strong bitter taste. As an alternative to overcome this problem, the development of new encapsulated praziquantel formulations is demanded. For this reason, suspension polymerizations are carried out for the in situ encapsulation of praziquantel into polymer microparticles, using methyl methacrylate (MMA) and cationic compounds (diethylaminoethyl methacrylate, DEAEMA, and dimethylaminoethyl methacrylate, DMAEMA) as comonomers. This technique allows for the preparation of polymer microparticles with high encapsulation efficiencies (>90%) with characteristic sizes ranging from 0.5 to 1500 µm. Drug release profiles show that praziquantel is released from poly(methyl methacrylate) microparticles slowly due to the existence of strong diffusional resistance. On the other hand, the addition of cationic comonomers renders polymer particles sensitive to pH variations, allowing for faster release of praziquantel in acidic environments, as found in the stomach.

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.

Polymer nanoparticles have been widely used in many biomedical applications, constituting a major incentive for immobilization of proteins. Poly(methyl methacrylate) nanoparticles were synthesized through miniemulsion polymerizations and used as supports for bovine serum albumin immobilization. Particularly, the effects of surfactant type (anionic sodium dodecyl sulfate and cationic cetyl trimethyl ammonium bromide) surfactant concentration and monomer holdup on some of the final nanoparticle properties (particle sizes, zeta potential and protein load) were characterized with help of statistical experimental designs for the first time. Results showed that the characteristics of the surfactant controlled the BSA adsorption efficiency, with enhanced rates of adsorption on the anionic particle surfaces, showing that the surfactant exerts fundamental effect on functionalization of emulsified polymer particles, which must be explicitly acknowledged in studies of polymer particle functionalization with proteins. Finally, BSA adsorption was shown to follow a multilayer process, given the better fitting with the Freundlich model.