Polydopamine Nanoparticles as an Organic and Biodegradable Multitasking Tool for Neuroprotection and Remote Neuronal Stimulation.

Oxidative stress represents a common issue in most neurological diseases, causing severe impairments of neuronal cell physiological activity that ultimately lead to neuron loss of function and cellular death. In this work, lipid-coated polydopamine nanoparticles (L-PDNPs) are proposed both as antioxidant and neuroprotective agents, and as a photothermal conversion platform able to stimulate neuronal activity. L-PDNPs showed the ability to counteract reactive oxygen species (ROS) accumulation in differentiated SH-SY5Y, prevented mitochondrial ROS-induced dysfunctions and stimulated neurite outgrowth. Moreover, for the first time in the literature, the photothermal conversion capacity of L-PDNPs was used to increase the intracellular temperature of neuron-like cells through near-infrared (NIR) laser stimulation, and this phenomenon was thoroughly investigated using a fluorescent temperature-sensitive dye and modeled from a mathematical point of view. It was also demonstrated that the increment in temperature caused by the NIR stimulation of L-PDNPs was able to produce a Ca2+ influx in differentiated SH-SY5Y, being, to the best of our knowledge, the first example of organic nanostructures used in such an approach. This work could pave the way to new and exciting applications of polydopamine-based and of other NIR-responsive antioxidant nanomaterials in neuronal research.

Multimodal Decorations of Mesoporous Silica Nanoparticles for Improved Cancer Therapy.

The presence of leaky vasculature and the lack of lymphatic drainage of small structures by the solid tumors formulate nanoparticles as promising delivery vehicles in cancer therapy. In particular, among various nanoparticles, the mesoporous silica nanoparticles (MSN) exhibit numerous outstanding features, including mechanical thermal and chemical stability, huge surface area and ordered porous interior to store different anti-cancer therapeutics with high loading capacity and tunable release mechanisms. Furthermore, one can easily decorate the surface of MSN by attaching ligands for active targeting specifically to the cancer region exploiting overexpressed receptors. The controlled release of drugs to the disease site without any leakage to healthy tissues can be achieved by employing environment responsive gatekeepers for the end-capping of MSN. To achieve precise cancer chemotherapy, the most desired delivery system should possess high loading efficiency, site-specificity and capacity of controlled release. In this review we will focus on multimodal decorations of MSN, which is the most demanding ongoing approach related to MSN application in cancer therapy. Herein, we will report about the recently tried efforts for multimodal modifications of MSN, exploiting both the active targeting and stimuli responsive behavior simultaneously, along with individual targeted delivery and stimuli responsive cancer therapy using MSN.

The urgent need for integrated science to fight COVID-19 pandemic and beyond.

The COVID-19 pandemic has become the leading societal concern. The pandemic has shown that the public health concern is not only a medical problem, but also affects society as a whole; so, it has also become the leading scientific concern. We discuss in this treatise the importance of bringing the world's scientists together to find effective solutions for controlling the pandemic. By applying novel research frameworks, interdisciplinary collaboration promises to manage the pandemic's consequences and prevent recurrences of similar pandemics.

Multiple core-shell functionalized colloidal mesoporous silica nanoparticles.

The selective functionalization of the inner and outer surfaces of colloidal mesoporous silica (CMS) nanoparticles with different trialkoxysilanes, following a newly developed delayed co-condensation approach, results in bifunctional CMS. Complementary CMS nanoparticles were prepared with two different functional groups located either on the outer shell or in the inner core of the particle. The identification and localization of the functional groups was achieved by means of different techniques including zeta potential, nitrogen sorption measurements, and fluorescence spectroscopy. This last technique was applied to fluorescein isothiocyanate (FITC)-labeled CMS featuring aminopropyl functional groups on the periphery or the internal pore surface of the particles. Fluorescence quenching experiments were carried out with dodecanethiolate-stabilized gold nanoparticles having a diameter greater than the pore size of the CMS. It could be shown that fluorescence quenching occurs only when the FITC is positioned on the outer surface of the CMS nanoparticles, whereas no quenching was observed for FITC located in the inner core of the nanoparticle. These results clearly confirm the controlled localization of the aminopropyl groups in the nanometer space of the CMS particles. Our approach thus offers the opportunity to synthesize, in a novel multistep co-condensation strategy, various bifunctional mesoporous nanoparticles with controlled localization of different functional groups in the inner core or on the outer shell of the nanoparticle.