Search

We report the identification of a photocleavable anionic surfactant, 4-hexylphenylazosulfonate (Azo), which can be rapidly degraded by ultraviolet irradiation, for top-down proteomics. Azo can effectively solubilize proteins with performance comparable to that of sodium dodecyl sulfate (SDS) and is compatible with mass spectrometry. Azo-aided top-down proteomics enables the solubilization of membrane proteins for comprehensive characterization of post-translational modifications. Moreover, Azo is simple to synthesize and can be used as a general SDS replacement in SDS-polyacrylamide gel electrophoresis.

Top-down mass spectrometry (MS)-based proteomics provides a comprehensive analysis of proteoforms to achieve a proteome-wide understanding of protein functions. However, the MS detection of low-abundance proteins from blood remains an unsolved challenge due to the extraordinary dynamic range of the blood proteome. Here, we develop an integrated nanoproteomics method coupling peptide-functionalized superparamagnetic nanoparticles (NPs) with top-down MS for the enrichment and comprehensive analysis of cardiac troponin I (cTnI), a gold-standard cardiac biomarker, directly from serum. These NPs enable the sensitive enrichment of cTnI (1010 more abundant than cTnI). We demonstrate that top-down nanoproteomics can provide high-resolution proteoform-resolved molecular fingerprints of diverse cTnI proteoforms to establish proteoform-pathophysiology relationships. This scalable and reproducible antibody-free strategy can generally enable the proteoform-resolved analysis of low-abundance proteins directly from serum to reveal previously unachievable molecular details., Top-down proteomics can provide unique insights into the biological variations of protein biomarkers but detecting low-abundance proteins in body fluids remains challenging. Here, the authors develop a nanoparticle-based top-down proteomics approach enabling enrichment and detailed analysis of cardiac troponin I in human serum.

The degradation of bionanomaterials is essential for medical applications of nanoformulations, but most inorganic-based delivery agents do not biodegrade at controllable rates. In this contribution, we describe the controllable plasmonic photocracking of gold@silica nanoparticles by tuning the power and wavelength of the laser irradiation, or by tuning the size of the encapsulated gold cores. Particles were literally broken to pieces or dissolved from the inside out upon laser excitation of the plasmonic cores. The photothermal cracking of silica, probably analogous to thermal fracturing in glass, was then harnessed to release cargo molecules from gold@silica@polycaprolactone nanovectors. This unique and controllable plasmonic photodegradation has implications for nanomedicine, photopatterning, and sensing applications.

An integrated top-down phosphoproteomics strategy enabled by functionalized cobalt ferrite nanoparticle enrichment and online LC/MS/MS for identification, quantification, and characterization of low abundance phosphoproteins is presented., Phosphorylation plays pivotal roles in cellular processes and dysregulated phosphorylation is considered as an underlying mechanism in many human diseases. Top-down mass spectrometry (MS) analyzes intact proteins and provides a comprehensive analysis of protein phosphorylation. However, top-down MS-based phosphoproteomics is challenging due to the difficulty in enriching low abundance intact phosphoproteins as well as separating and detecting the enriched phosphoproteins from complex mixtures. Herein, we have designed and synthesized the next generation functionalized superparamagnetic cobalt ferrite (CoFe2O4) nanoparticles (NPs), and have further developed a top-down phosphoproteomics strategy coupling phosphoprotein enrichment enabled by the functionalized CoFe2O4 NPs with online liquid chromatography (LC)/MS/MS for comprehensive characterization of phosphoproteins. We have demonstrated the highly specific enrichment of a minimal amount of spike-in β-casein from a complex tissue lysate as well as effective separation and quantification of its phosphorylated genetic variants. More importantly, this integrated top-down phosphoproteomics strategy allows for enrichment, identification, quantification, and comprehensive characterization of low abundance endogenous phosphoproteins from complex tissue extracts on a chromatographic time scale.

A multifunctional nanoparticle with designed selectivity was made using hollow mesoporous silica, ship-in-a-bottle synthesis of a crystalline solid-state detector, and protection of the crystal by acid-responsive nanogates. The system demonstrates the inverse application of the usual trapping of contents by the gate followed by their release. Instead, the gate protects the contents followed by selective exposure. Crystallization of [Pt(tpy)Cl](PF6) (tpy = 2,2':6',2''-terpyridine) inside the cavity of hollow mesoporous silica created the unique core/shell nanoparticle. The crystalline core becomes fluorescent in the presence of perchlorate. By condensing an acid-sensitive gate onto the particle, access to the pores is blocked and the crystal is protected. The new nanomaterial obeys Boolean AND logic; only the presence of both the analyte (ClO4-) and acid results in the optical response.

Materials that utilize the micropatterned structure of a mesoporous silica film to successfully load and release cargo using a thermal sensitive polymer are presented in this paper. Films with pore sizes of ~2 nm and ~5 nm aligned in the pulling direction were synthesized using evaporation induced self-assembly techniques. The pores are exposed using a new method of stamping micropatterns without the use hydrofluoric acid. A well studied temperature dependent polymer (poly(N-isopropylacrylamide-co-Acrylamide)) was grafted onto the surface of these films to act as a temperature activated gatekeeper. Below the lower critical solution temperature (LCST) the polymer is erect and can block the pore openings, trapping cargo inside the pores. When the temperature is above the LCST the polymer collapses and unblocks the pores, allowing cargo to escape. The loading capacities as well as the reusability of these films were studied.

Photoactivation of “snap-top” stoppers over the pore openings of mesoporous silica nanoparticles releases intact cargo molecules from the pores. The on-command release can be stimulated by either one UV photon or two coherent near-IR photons. Two-photon activation is particularly desirable for use in biological systems because it enables good tissue penetration and precise spatial control. Stoppers were assembled by first binding photolabile coumarin-based molecules to the nanoparticle surface. Then, after loading the particles with cargo, bulky β-cyclodextrin molecules were noncovalently associated with the substituted coumarin molecule, blocking the pores and preventing the cargo from escaping. One-photon excitation at 376 nm or two-photon excitation at 800 nm cleaves the bond holding the coumarin to the nanopore, releasing both the cyclodextrin cap and the cargo. The dynamics of both the cleavage of the cap and the cargo release was monitored using fluorescence spectroscopy. This system traps intact cargo molecules without the necessity of chemical modification, releases them with tissue penetrating near-IR light and have possible applications in photo-stimulated drug delivery.

Here we report the synthesis and characterization of a family of photolabile nitroveratryl-based surfactants that form different types of supramolecular structures depending on the alkyl chain lengths ranging from eight to twelve carbon atoms. By incorporating a photocleavable α-methyl-o-nitroveratryl moiety, the surfactants can be degraded, along with their corresponding supramolecular structures, by light irradiation in a controlled manner. The self-assembly of the amphiphilic surfactants was characterized by conductometry to determine the critical concentration for the formation of the supramolecular structures, transmission electron microscopy to determine the size and shape of the supramolecular structures, and dynamic light scattering (DLS) to determine the hydrodynamic diameter of the structures in aqueous solutions. The photodegradation of the surfactants and the supramolecular structures was confirmed using UV-Vis spectroscopy, mass spectrometry, and DLS. This surfactant family could be potentially useful in drug delivery, organic synthesis, and other applications.

Proton transfer caused by excitation of a photoacid attached to the surface of a mesoporous silica nanoparticle activates a nanovalve and causes release of trapped molecules. The protonation of an aniline- based stalk releases a noncovalently bound cyclodextrin molecule that blocked a pore. The results show that pH-responsive molecular delivery systems can be externally controlled using light.

We report the design and synthesis of a nano-container consisting of mesoporous silica nanoparticles with the pore openings covered by "snap-top" caps that are opened by near-IR light. A photo transducer molecule that is a reducing agent in an excited electronic state is covalently attached to the system. Near IR two-photon excitation causes inter-molecular electron transfer that reduces a disulfide bond holding the cap in place, thus allowing the cargo molecules to escape. We describe the operation of the "snap-top" release mechanism by both one- and two-photon activation. This system presents a proof of concept of a near-IR photoredox-induced nanoparticle delivery system that may lead to a new type of photodynamic drug release therapy. © 2014 the Partner Organisations.

International audience; A therapy of cancer cells: Two-photon-triggered camptothecin delivery (see picture) with nanoimpellers was studied in MCF-7 breast cancer cells. A fluorophore with a high two-photon absorption cross-section was first incorporated in the nanoimpellers. Fluorescence resonance energy transfer (FRET) from the fluorophore to the azobenzene moiety was demonstrated.

Throughout this Communication, the aromatic structure wasincorrectly drawn with the double bonds in the wrongpositions. The correct aromatic structure is as follows:This correction applies to the structures shown in Scheme 1,Figures 1, 3, 4, and 5, and the Table of Contents graphic. Thecorrect molecules were used for all of the experiments in thepaper, and none of the results in the paper are affected by thischange.

Controllable drug delivery is urgently pursued for cancer therapy, because conventional chemotherapy is associated with serious toxic side effects. Precisely controlled external stimuli-activated nanoparticles are promising, as selective activation of the system takes place only upon stimulation of trigger signals and only in the area of interest. Silica nanoparticles have a number of advantages such as well established synthesis methods, chemical and thermal stability, large drug loading capacity, and the ease to carry out various surface modifications. We previously showed that our mesoporous silica nanoparticle-based nanoimpellers are effective for photo-activated drug delivery. However, like other light activating nanoparticles, our nanoimpeller also employed UV/Vis light, thus limiting its medical applications due to its short wavelength and inability for deep tissue penetration. Here we report our new generation of nanoimpellers functionalized with two-photon fluorophore that has a high two photon absorption cross-section, suitable for fluorescence resonance energy transfer (FRET) to photoisomerize azobenzene moieties in the NIR region. The azobenzene residing in the porous framework allows physical entrapment of the anticancer drug camptothecin, which is then propelled out of the pores by two-photon-triggered photoisomerization, resulting in on-demand intracellular drug release. Intracellular release of molecules is dependent on light excitation powers and wavelengths, and the anticancer drug delivery inside of cells can be regulated with light excitation. TPE fluorescence imaging was performed to demonstrate the cellular uptake of the nanoimpellers. Nanoimpeller with a high energy transfer quantum yield from the fluorophore to the azobenzene moiety was able to induce cancer cell death under these TPE conditions and did not show toxicity to control cells that were shielded from light. In a similar but different design, we also synthesized nanoparticles that have nanovalves placed at the pore openings. These results suggest that our newly synthesized two-photon-activated nanoimpellers could be useful for cancer therapy because of deep tissue penetrating ability and controllability. Actual application of such light-triggered delivery system in animal models remains to be proven, but we believe this two-photon light-activated mesoporous silica nanoparticles have a broad application prospects for biomedicine. Citation Format: Jie lu, Jonas Croissant, Jean-Olivier Jean-Olivier Durand, Tania Guardado-Alvarez, Jeffrey I. Zink, Fuyuhiko Tamanoi. Light-controllable nano-drug delivery system with deep tissue penetrating ability for cancer therapy with two-photon-triggered nanoimpellers. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-9. doi:10.1158/1538-7445.AM2014-LB-9