Development of multiple stimuli responsive magnetic polymer nanocontainers as efficient drug delivery systems

Magnetic nanodevices based on poly[(methacrylic acid)-co-(N- isopropylacrylamide)] [P(MAA-co-NIPAAm)] are prepared and used as drug delivery systems employing daunorubicin (DNR) as a model drug. The magnetic nanocontainers exploit the pH, temperature, and magnetic response of the polymeric shell constituents and magnetic nanoparticles, respectively, for controlled pH, temperature and alternating magnetic field triggered drug release. The in vitro cytotoxicity of both DNR-loaded and empty nanocontainers is examined on MCF-7 breast cancer cells along with the intracellular distribution of DNR. The results show that the DNR-loaded nanocontainers have an anti-tumor effect comparable to the free drug. The current observations provide important information for potent drug delivery and release systems. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Nanostructuring the Surface of Dual Responsive Hollow Polymer Microspheres for Versatile Utilization in Nanomedicine-Related Applications

The design and fabrication of hollow polymer microspheres responsive to various stimuli comprises a promising approach for the development of multifunctional and efficient systems for various nanomedicine-related applications. In this paper, we present the preparation of poly(methacrylic acid-co-N,N’-methylenebis-(acrylamide)-co-poly(ethylene glycol) methyl ether methacrylate-co-N,N’-bis(acryloyl)-cystamine) (PMAA(S-S)) hollow microspheres following a two-stage distillation precipitation polymerization procedure. Magnetic and silver nanocrystals were chemically grown on the surface of the hollow polymer microspheres, resulting in a composite system with, interesting properties. We evaluated the performance of the composite hollow microspheres as magnetic hyperthermia mediators and their surface-enhanced Raman spectroscopy activity. Assessment of Daunorubicin-loaded PMAA(S-S) hollow microspheres performance as effective drug carriers was carried out through drug release experiments upon application of different pH and reducing conditions. pH and redox responsiveness as well as basic mechanisms of release profiles are discussed. Furthermore, in vitro cytotoxicity of empty and drug-loaded PMAA(S-S) hollow microspheres against MCF-7 cancer cells was investigated in order to evaluate their performance as drug carriers

Radical social innovations and the spatialities of grassroots activism: navigating pathways for tackling inequality and reinventing the commons

In this article, by drawing on empirical evidence from twelve case studies from nine countries from across the Global South and North, we ask how radical grassroots social innovations that are part of social movements and struggles can offer pathways for tackling socio-spatial and socio-environmental inequality and for reinventing the commons. We define radical grassroots social innovations as a set of practices initiated by formal or informal community-led initiatives or/and social movements which aim to generate novel, democratic, socially, spatially and environmentally just solutions to address social needs that are otherwise ignored or marginalised. To address our research questions, we draw on the work of Cindi Katz to explore how grassroots innovations relate to practices of resilience, reworking and resistance. We identify possibilities and limitations as well as patterns of spatial practices and pathways of re-scaling and radical praxis, uncovering broadly-shared resemblances across different places. Through this analysis we aim to make a twofold contribution to political ecology and human geography scholarship on grassroots radical activism, social innovation and the spatialities of resistance. First, to reveal the connections between social-environmental struggles, emerging grassroots innovations and broader structural factors that cause, enable or limit them. Second, to explore how grassroots radical innovations stemming from place-based community struggles can relate to resistance practices that would not only successfully oppose inequality and the withering of the commons in the short-term, but would also open long-term pathways to alternative modes of social organization, and a new commons, based on social needs and social rights that are currently unaddressed