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In recent times, organelle-targeted drug delivery systems have gained tremendous attention due to the site-specific delivery of active drug molecules, resulting in enhanced bioefficacy. In this context, a phototriggered drug delivery system (DDS) for releasing an active molecule is superior, as it provides spatial and temporal control over the release. So far, a near-infrared (NIR) light-responsive organelle-targeted DDS has not yet been developed. Hence, we introduced a two-photon NIR light-responsive lysosome-targeted "AIE + ESIPT" active single-component DDS based on the naphthalene chromophore. The two-photon absorption cross section of our DDS is 142 GM at 850 nm. The DDS was converted into pure organic nanoparticles for biological applications. Our nano-DDS is capable of selective targeting, AIE luminogenic imaging, and drug release within the lysosome.

Controlled release of hydrogen sulfide (H2S), an important gasotransmitter that plays a significant role in the regulation of various physiological activities.

In recent times, organelle-targeted drug delivery systems gained tremendous attention due to the site specific delivery of active drug molecules resulting in enhanced bioefficacy. In this context, the phototriggered drug delivery system (DDS) for releasing an active molecule is superior as it provides spatial and temporal control over the release. So far, near infrared (NIR) light responsive organelle targeted DDS has not yet been developed. Hence, we introduced a two-photon NIR-light responsive lysosome targeted ʽAIE + ESIPTʼ active single component DDS based on naphthalene chromophore. The Two-photon absorption cross-section of our DDS is 142 GM at 850 nm. The DDS was converted into pure organic nanoparticles for biological applications. Our nano-DDS is capable of selective targeting, AIE-luminogenic imaging, and drug release within the lysosome. In vitro studies using cancerous cell lines showed that our single component photoresponsive nanocarrier exhibited enhanced cytotoxicity and real-time monitoring ability of the drug release.

The development of Photoremovable protecting groups (PRPGs), which can be activated in the ʽphototherapeutic windowʼ for biological applications, is highly challenging. Only PRPGs based on BODIPY dye have been developed so far, which can be excited ≥600 nm. Herein, we developed for the first time NIR dye hydroxystyryl dicyanomethylene-4H-pyran (DCM) as a PRPG that can be operated in the phototherapeutic window. Ours easily synthesized DCM photocages efficiently released aromatic and aliphatic carboxylic acids in an aqueous solution on irradiation using the light of wavelength ≥600 nm and 650 nm, separately. As an application, we used our DCM-PRPG as a single component nanocarrier drug delivery system (DDS) to uncage valproic acid (a known histone deacetylase inhibitor) for cancer treatment. In vitro studies revealed that our DDS, hydroxystyryl dicyanomethylene-4H-pyran valproic acid conjugate nanoparticles (DCM-VPA-NPs) exhibited good cellular internalization, biocompatibility, and enhanced cytotoxicity upon irradiation.

The development of Photoremovable protecting groups (PRPGs), which can be activated in the ʽphototherapeutic windowʼ for biological applications, is highly challenging. Only PRPGs based on BODIPY dye have been developed so far, which can be excited ≥600 nm. Herein, we developed for the first time NIR dye hydroxystyryl dicyanomethylene-4H-pyran (DCM) as a PRPG that can be operated in the phototherapeutic window. Ours easily synthesized DCM photocages efficiently released aromatic and aliphatic carboxylic acids in an aqueous solution on irradiation using the light of wavelength ≥600 nm and 650 nm, separately. As an application, we used our DCM-PRPG as a single component nanocarrier drug delivery system (DDS) to uncage valproic acid (a known histone deacetylase inhibitor) for cancer treatment. In vitro studies revealed that our DDS, hydroxystyryl dicyanomethylene-4H-pyran valproic acid conjugate nanoparticles (DCM-VPA-NPs) exhibited good cellular internalization, biocompatibility, and enhanced cytotoxicity upon irradiation.

Automated long-term mapping and climate niche modeling are important for developing adaptation and management strategies for rubber plantations (RP). Landsat imageries at the defoliation and refoliation stages were employed for RP mapping in the Indian state of Tripura. A decision tree classifier was applied to Landsat image-derived vegetation indices (Normalized Difference Vegetation Index and Difference Vegetation Index) for mapping RPs at two-three years intervals from 1990 to 2017. A comparison with actual plantation data indicated more than 91% mapping accuracy, with most RPs able to be identified within six years of plantation, while several patches were detected after six years of plantations. The RP patches identified in 1990 and before 2000 were used for training the Maxent species distribution model, wherein bioclimatic variables for 1960–1990 and 1970–2000 were used as predictor variables, respectively. The model-estimated suitability maps were validated using the successive plantation sites. Moreover, the RPs identified before 2017 and the Shared Socioeconomic Pathways (SSP) climate projections (SSP126 and SSP245) were used to predict the habitat suitability for 2041–2060. The past climatic changes (decrease in temperature and a minor reduction in precipitation) and identified RP patches indicated an eastward expansion in the Indian state of Tripura. The projected increase in temperature and a minor reduction in the driest quarter precipitation will contribute to more energy and sufficient water availability, which may facilitate the further eastward expansion of RPs. Systematic multi-temporal stand age mapping would help to identify less productive RP patches, and accurate monitoring could help to develop improved management practices. In addition, the existing RP patches, their expansion, and the projected habitat suitability maps could benefit resource managers in adapting climate change measures and better landscape management.

In this work, we have developed a rhodamine dye based water-soluble, mitochondria-indicating photocage, which gets activated in the mitochondria producing a fluorescent signal and on-demand releases the caged anticancer drug, chlorambucil, in the cancer cells selectively upon irradiation of green light.

Recently, photoresponsive nanoparticles have been widely used to develop drug delivery systems (DDSs) wherein light is used as an external stimulus to trigger drug release in a spatially and temporally controlled fashion. Real time monitoring DDSs are also gaining much interest due to their capability of monitoring drug release in situ. In this context we designed a new photoresponsive real time monitoring nanoparticle based on photoluminescent silicon quantum dots (SiQDs) using the o-nitrobenzyl (ONB) derivative as a phototrigger for the controlled release of anticancer drug chlorambucil (Cbl). The strong fluorescence of SiQDs was initially quenched by ONB. Upon irradiation ONB triggered the release of the drug switching on the fluorescence of SiQDs to monitor the drug release. We reported a new and simple strategy to synthesise amine functionalised silicon quantum dots and covalently conjugated phototrigger ONB with caged anticancer drug Cbl onto it. Newly designed photoresponsive theranostic ONBCbl–SiQDs performed three important functions: (i) nanocarriers for drug delivery, (ii) controlled drug release under both one photon and two-photon excitation, and (iii) photoswitchable fluorescent nanoparticles for real-time monitoring of drug release based on the photoinduced electron transfer (PET) process. In vitro biological studies revealed the efficient cellular internalisation and cancer cell destruction ability of ONBCbl–SiQDs upon photoirradiation. ONBCbl–SiQDs exhibit a successful example of combining multiple functions into a single system for drug delivery systems.

The anti-tumor activity of Cu complexes is well established in cancer research. We developed a biotin-tagged Cu-chelating prodrug that is activated by one-photon and two-photon irradiation for the target-specific and spatio-temporally controlled in situ generation of a Cu complex. In this way, we transform copper from a "cancer-promoting" agent to an anticancer agent.

Fe filled carbon nanotubes were synthesized by atmospheric pressure chemical vapor deposition using a simple mixture of iron acetylacetonate with a conventional photoresist and the effect of growth temperature from 550 to 950 {\deg}C on Fe filled nanotubes has been studied. Scanning electron microscopy results show that, as the growth temperature increases from 550 to 950 {\deg}C, the average diameter of the nanotubes increases while their number density decreases. High resolution transmission electron microscopy along with energy dispersive X-ray investigation shows that the nanotubes have a multi-walled structure with partial Fe filling for all growth temperatures. The graphitic nature of the nanotubes was observed via X-ray diffraction pattern. Raman analysis demonstrates that the degree of graphitization of the carbon nanotubes depends upon the growth temperature., Comment: A. Nanostructures B. Vapor deposition C. Electron microscopy C. Raman spectroscopy C. X-ray diffraction

Near-infrared (NIR) fluorescent probes have been developed as potential bio-materials having profound applications in diagnosis and clinical practice. Herein, we wish to disclose a highly photostable ultra-bright NIR probe for the specific detection of lysosomes in numerous cell lines. Furthermore, the applicability of the developed NIR probe was evaluated for in vivo imaging.

‘Aggregation Induced Emission + Excited State Intramolecular Proton Transfer (AIE + ESIPT)’-assisted photorelease of an anticancer drug by a p-hydroxyphenacyl (pHP) phototrigger with real-time monitoring has been demonstrated.

Highly sensitive hypoxia (H2O2)-activated photoresponsive polymeric nanoparticles for cocktail delivery of anticancer drugs doxorubicin (Dox) and chlorambucil (Cbl) were developed. The photoresponsive polymer conjugate was constructed by ring-opening polymerization (ROP) of caprolactone (as the tail) with 7-hydroxycoumarin chlorambucil (as the head). During nanoprecipitation, the polycaprolactone chain wrapped around the hydrophobic core (coumarin chlorambucil) to form a "shell". Interestingly, the polycaprolactone-tagged coumarin-chlorambucil (PCL-CC) NPs provided sufficient space for co-encapsulation of another hydrophobic anticancer drug Dox with a loading efficiency of 13 wt%. The controlled release of Dox and Cbl from Dox-PCL-CC NPs was investigated under three different conditions: (i) in the presence of H2O2 (tumor microenvironment), (ii) photoirradiation using UV light of ≥365 nm for 60 min, and (iii) photoirradiation using UV light of ≥365 nm for 15 min in the presence of H2O2. Results showed that photoirradiation in the presence of H2O2 results in generation of reactive oxygen species (HOO-, OH-), which assist hydrolysis of the ester group in the polymeric backbone of Dox-PCL-CC NPs and UV irradiation leads to cleavage of the coumarin-chlorambucil ester linkage, leading to burst release of Dox and Cbl. The drug release profile from the NPs under three different conditions was monitored by different instrumental techniques, e.g. emission spectroscopy, MALDI-Tof mass spectrometry, DLS and HPLC analysis. In vitro biological studies revealed that the present system can efficiently deliver the cocktail anticancer drugs with full control over release into the tumor cells by means of H2O2 and light activation.

Herein, we report an efficient synthesis of N-substituted pyrrole derivatives and their application to construct macrocyclic oxazocinone via a two-component coupling reaction followed by base mediated intramolecular cyclization. This methodology provides an easy two-step approach to constitute a library of fused pyrrolo-oxazocinone derivatives in good yields under mild reaction conditions. The present methodology offers an easy access to the synthesis of a library of fluorescent pyrole derivatives. Among them, tert-butyl 2-(2-(3-hydroxypropyl)-7-methoxy-4,5-dihydro-2H-benzo[e]isoindol-1-yl)acetate has been employed in bio-analytical imaging which shows efficient cellular internalization along with no obvious cellular toxicity.

Although increasing attention has been focused on gold nanoparticles (AuNPs) as operational catalysts for chemical conversion and pollutant degradation due to their unique reactivity, it is a challenging task to prepare highly active hybrid materials and stabilize their reactivity by preventing serious aggregation of AuNPs along with effective separation. Herein, a two-dimensional nanostructured hybrid material (RGS@AuNPs, ∼1 μm) is developed, which consists of AuNPs (∼10 nm in diameter) immobilized on the surface of sandwich-like periodic mesoporous silica (PMS) coated reduced graphene oxide (RGO). Transmission electron microscopy, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy and N2 adsorption/desorption are employed to characterize the obtained hybrid. The hybrid material (RGS@AuNPs) shows superior catalytic activity in the reduction of 4-nitrophenol (4-NP) and methylene blue (MB) dye in the presence of sodium borohydride (NaBH4). In addition, excellent photocatalytic activity is also achieved by the hybrid, as demonstrated through the decomposition of MB dye under visible light irradiation. The rate constants are calculated by considering the pseudo-first-order reaction equation, which shows that the constants are quite impressive compared with that of previous reports. Thus, the present hybrid material is a promising catalyst for the synthesis of some organic chemicals and wastewater management.

Photodynamic therapy (PDT) is a non-invasive cancer treatment. For target-specific PDT, targeting “overexpression” of some specific cellular markers will be highly beneficial. As CuII content is higher in cancer cells than in normal cells, selective binding with CuII can be the most effective mode for intracellular heterogeneity-responsive targeted PDT. Thus, a photosensitizer showing competent PDT activity only after CuII chelation is important for tumor-targeted PDT. Herein, we report a new ratiometric fluorescent chemosensor based on anthracene-N-phenylethylenediamine nanoparticles (ANT-pen NPs), which showed fluorescence color change from green to red upon CuII chelation. Only the CuII-bound state showed selective PDT activity; hence, this color change was used for real-time monitoring of targeted PDT. Cellular images in cancerous HeLa and non-cancerous NIH 3T3 cell lines showed the change in fluorescence of ANT-pen NPs on selective binding with CuII in HeLa cells only. MTT assay in both cells suggested massive cell destruction by ANT-pen-CuII NPs only in HeLa cells upon visible light exposure, whereas NPs remained non-toxic to NIH 3T3 cells.

A new fluorescent photoremovable protecting group (FPRPG) based on acetylcarbazole framework has been explored for the first time release of single and dual (similar or different) substrates from single chromophore. Mechanistic studies of the photorelease process revealed that photorelease of two (similar or different) substrates from acetyl carbazole proceeds via a stepwise pathway. Further, we constructed photoresponsive dual drug delivery system (DDS) to release two different anticancer drugs (caffeic acid and chlorambucil, 1 equiv each). In vitro study reveals that our DDS exhibit excellent properties like biocompatibility, cellular uptake, and photoregulated dual drug release.

Organic near-infrared (NIR) fluorescent probes have been recognized as an emerging class of materials exhibiting a great potential in advanced bioanalytical applications. However, synthesizing such organic probes that could simultaneously work in the NIR spectral range and have large Stokes shift, high stability in biological systems, and high photostability have been proven challenging. In this work, aggregation induced excimeric NIR emission in aqueous media was observed from a suitably substituted perylene monoimide (PeIm) dye. Controlled entrapment of the dye into pluronic F127 micellar system to preserve its monomeric green emission in aqueous media was also established. The aggregation process of the PeIm dye to form organic nanoparticles (NPs) was evaluated experimentally by the means of transmission electron microscope imaging as well as theoretically by the molecular dynamics simulation studies. Tuning the morphology along with the formation of colloidosomes by the controlled self-aggregation of PeIm NPs in aqueous suspension was demonstrated successfully. Finally, both excimeric and monomeric emissive PeIm NPs as well as PeIm colloidosomes were employed for the bioimaging in vitro.

A versatile heterogeneous photocatalysis protocol was developed by using ruthenium bipyridyl tethered porous organosilica (Ru-POS). The versatility of the Ru-POS catalyst in organo-photocatalysis was explored by (i) oxidative aromatization of Hantzsch ester, (ii) reductive dehalogenation of alkyl halides, and (iii) functional group interconversion (FGI) of alcohols to alkyl halides. NRF (Natl Research Foundation, S’pore) Accepted version

o-Hydroxycinnamate derivatives are well-known phototriggers for fast and direct release of alcohols and amines without proceeding through the cleavage of carbonate or carbamate linkages. Despite these unique features, o-hydroxycinnamates lack extensive applications in biological systems mainly because of their non-fluorescent nature. To overcome this limitation, we have attached a 2-(2'-hydroxyphenyl) benzothiazole (HBT) moiety, capable of rapid excited-state intramolecular proton transfer (ESIPT) to the o-hydroxycinnamate group. The ESIPT effect induced two major advantages to the o-hydroxycinnamate group: (i) large Stokes' shifted fluorescence (orange colour) properties and (ii) distinct fluorescence colour change upon photorelease. In vitro studies exhibited an image guided, photoregulated release of bioactive molecules by the o-hydroxycinnamate-benzothiazole-methyl salicylate conjugate and real-time monitoring of the release action.

We developed excellent charge reversal photoresponsive nanoparticles for targeted delivery of the anticancer drug chlorambucil. The charge reversal photoresponsive nanoparticles were constructed using two main ingredients, namely folic acid decorated mesoporous silica and quinoline chromophore. The newly synthesized quinoline chromophore performed three important roles, i.e., (i) fluorescent chromophore for cell imaging, (ii) phototrigger for regulated release of anticancer drug, and (iii) charge reversal based on its zeta potential for nuclear localization. Furthermore, folic acid decorated mesoporous silica facilitated active internalization of the drug inside the cancer cells. In vitro biological studies reveal that our photoresponsive DDS could deliver the anticancer drug chlorambucil into the tumor cells, killing the cancer cells by both one photon (≥365 nm) and two photon (675 nm) irradiation.

An efficient synthetic protocol of pyrroles and isoquinolines through NaN3/NH4Cl promoted intramolecular aza-annulation of formyl group with suitable alkenes or alkynes is described in high yield and regioselectivities. The metal free exo-trig and endo-dig aza-cyclisation has been extended for the synthesis of bicyclic or tricyclic pyrroles along with environment sensitive fluorescent isoquinoline derivatives. Reactions occur in excellent yields, broad scope and high tolerance of functional groups. The synthetic utility of this methodology was demonstrated in the short synthesis of the core structure of lamellarin Q.

A series of carboxylic acids including amino acids were protected as their corresponding fluorescent ester conjugates by coupling with an environment sensitive fluorophore 9-methylacridine. Photophysical properties of all the ester conjugates along with the protecting group have been investigated. Interestingly, the emission properties of the ester conjugates and 9-methylacridine were found to be highly sensitive to polarity, H-bonding and pH of the environment. Photolysis of all the ester conjugates was carried out using UV light above 360 nm and it was found that in every case the corresponding carboxylic acids were released in high chemical yield. Further, intercalation and the preferred binding mode of acridine-9-methanol and its ester conjugates with DNA were studied. In vitro biological studies revealed that acridine-9-methanol has good biocompatibility, cellular uptake property and cell imaging ability.

The design, synthesis, and in vitro biological studies of a biotin-carbazole-dicyanovinyl-chlorambucil conjugate (Bio-CBZ-DCV-CBL; 6) are reported. This conjugate (6) is a multifunctional single-molecule appliance composed of a thiol-sensor DCV functionality, a CBZ-derived phototrigger as well as fluorescent reporter, and CBL as the anticancer drug, and Bio as the cancer-targeting ligand. In conjugate 6, the DCV bond undergoes a thiol-ene click reaction at pH

Ultrafine palladium nanoparticles (Pd NPs) with 8 and 3 nm sizes were effectively fabricated in triazine functionalized porous organic polymer (POP) TRIA that was developed by nonaqueous polymerization of 2,4,6-triallyoxy-1,3,5-triazine. The Pd NPs encapsulated POP (Pd-POP) was fully characterized using several techniques. Further studies revealed an excellent capability of Pd-POP for catalytic transfer hydrogenation of alkenes at room temperature with superior catalytic performance and high selectivity of desired products. Highly flammable H2 gas balloon at high pressure and temperature used in conventional hydrogenation reactions was not needed in the present synthetic system. Catalytic activity is strongly dependent on the size of encapsulated Pd NPs in the POP. The Pd-POP catalyst with Pd NPs of 8 nm in diameter exhibited higher catalytic activity for alkene hydrogenation as compared with the Pd-POP catalyst encapsulating 3 nm Pd NPs. Computational studies were undertaken to gain insights into different catalytic activities of these two Pd-POP catalysts. High reusability and stability as well as no Pd leaching of these Pd-POP catalysts make them highly applicable for hydrogenation reactions at room temperature.

Structural diversity and uniformity of nanomaterials are usually prerequisites for many practical applications involving the oriented fabrication of various devices with full control over their desired physiochemical properties. Particularly in the optoelectronic field, ordered assembly inside cells is required not only for obtaining attractive configurations but also for playing an important role in the characteristics of photoconduction and conductivity. Here, we present a synergetic self-assembly driven by coordination and intermolecular interactions for the construction of organic-inorganic hybrids with multi-morphologies and tunable physical properties. 3,4,9,10-Perylenetetracarboxylic dianhydride was treated with base to produce various assemblies by coordination with metal ions, showing morphologies of nanowires, nanosheets, nanoribbons and nanorods. The organic π-spacer affords an extension in different directions through the suitable incorporation of metal ions with different coordination modes for the formation of metal-ligand complexes. Interestingly, the obtained nanorods were twisted rods with obvious screw threads on the rod wall, supporting the synergetic self-assembly. Then, anisotropic mobility measurements of the obtained Cu(2+)-ligand assembly were carried out to show the importance of the size- and shape-confined synthesis of the hybrids. By presenting a series of ordered metal-ligand complex superstructures driven by synergetic self-assembly, this work is expected to pave the way for future anisotropic measurements of complex assemblies.

Two porous covalent organic frameworks (COFs) with good biocompatibility were employed as drug nanocarriers, where three different drugs were loaded for subsequent drug release in vitro. The present work demonstrates that COFs are applicable in drug delivery for therapeutic applications.

Vapochromic behavior is employed to selectively monitor the vapor changes in surrounding environment, particularly for toxic gas leaking and floating detection. Thus, sensitive trapping and accurate response to different toxic vapors are critical factors in vapochromic sensing. In this work, a self-assembled hybrid that consists of fluorescent organic octahedron encapsulated by metal–organic polyhedron (MOP) is reported. The fluorescent octahedron is used as a responsive sensor to probe various solvent vapors, while the MOP is employed as a protector to prevent the corrosion of solvents to the organic octahedron. The hybrid exhibits remarkable vapochromic behavior to different solvents, and shows the highest selectivity and sensitivity specifically to acetone. In addition, acetone vapor under different conditions is utilized for further studying the response mechanism of the hybrid. This work presents a promising vapochromic sensor with good stability, selectivity, and sensitivity. The study is expected to open up the applicability of MOP-based hybrids for specific molecular capture, interim storage, controlled release, and advanced sensing.

Simple and efficient photoacid generators (PAGs) for carboxylic and sulfonic acids based on N-acyl-N-phenylhydroxylamines have been demonstrated. Irradiation of o-carboxylates and thermally rearranged o-arenesulfonates of N-acyl-N-phenylhydroxylamines using UV light (≥254 nm) in aqueous methanolic solution resulted in efficient generation of carboxylic and sulfonic acids, respectively. The carboxylic acid generation ability of N-acyl-N-phenylhydroxylamines was found to be dependent on their N-acyl substituents. Further, polymer bearing o-arenesulfonates of N-acyl-N-phenylhydroxylamine was synthesized and demonstrated as PAG for sulfonic acids.

A series of new fluorescent ester conjugates of carboxylic acids including amino acids was synthesized by coupling with an environment-sensitive fluorophore 1-acetylpyrene. Interestingly, the fluorescence properties of the ester conjugates and 1-acetylpyrene were found to be highly sensitive to its surrounding environment. The results obtained from the photolysis of the ester conjugates indicated that various factors like solvent, irradiation wavelength, and the structure of the conjugates govern the rate of the photocleavage.

A novel controlled-release formulation (CRF) of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was developed to reduce its negative environmental impacts by improving its herbicidal efficacy. The 2,4-D was chemically caged by coupling with photoremovable protecting groups (PRPGs) of coumarin derivatives. Photophysical studies of caged compounds showed that they all exhibited strong fluorescence properties. Controlled release of 2,4-D was achieved by irradiating the caged compounds using UV-vis light (310, 350, and 410 nm). The effect of various factors such as pH, solvent, and different substituents at the seventh position of coumarin moiety on the rate of photorelease was studied. The herbicidal activity of caged compounds and 4-(hydroxymethyl)-7-substituted coumarins was studied against Vigna radiata . The new formulation provided greater control over the release of 2,4-D by UV-vis light and also demonstrated the potential of the PRPGs not only to act as a delivery device but also to possess herbicidal activity after photorelease.

Partially Fe filled multi-walled carbon nanotubes (MWCNTs) were grown by chemical vapor deposition with propane at 850 {\deg}C using a simple mixture of iron (III) acetylacetonate (Fe(acac)3) powder and conventional photoresist. Scanning electron microscopy revealed that catalytic nanoparticles with an average diameter of 70 nm are formed on the Si substrate which governs the diameter of the MWCNTs. Transmission electron microscopy shows that the nanotubes have a multi-walled structure with partial Fe filling. A site-selective growth of partially Fe filled MWCNTs is achieved by a simple photolithographic route., Comment: Filled CNT, CVD, Partial filling, Photolithography

A novel silica-tethered ruthenium complex (RPOS) is prepared and successfully applied as a photocatalyst for the oxidative aromatization of Hantzsch esters [→ (III), (IV)], the reductive dehalogenation of halides (V) and (VII), and the halogenation of alcohols (IX).

Magnetic Fe3O4 nanoparticles embedded in graphene oxide (Fe3O4@GO) behave as a highly efficient and reusable heterogeneous nanocatalyst for alkene hydrogenation in EtOH at 80 °C temperature using hydrazine hydrate as the hydrogen source to deliver the corresponding alkanes in good to excellent yields together with high TOF (4500 h(-1)) within a 4-20 h reaction time.

An organic nanoparticle-based drug delivery system with high drug loading efficacy (∼79 wt %) was developed using a perylene-derived photoremovable protecting group, namely, perylene-3,4,9,10-tetrayltetramethanol (Pe(OH)4). The anticancer drug chlorambucil was protected by coupling with Pe(OH)4 to form photocaged nanoparticles (Pe(Cbl)4). The photorelease mechanism of chlorambucil from the Pe(Cbl)4 conjugate was investigated experimentally by high-resolution mass spectrometry and theoretically by density functional theory calculations. The Pe(Cbl)4 nanoparticles perform four important roles: (i) a nanocarrier for drug delivery, (ii) a phototrigger for drug release, (iii) a fluorescent chromophore for cell imaging, and (iv) a photoswitchable fluorophore for real-time monitoring of drug release. Tunable emission of the perylene-derived nanoparticles was demonstrated by comparing the emission properties of the Pe(OH)4 and Pe(Cbl)4 nanoparticles with perylene-3-ylmethanol. These nanoparticles were subsequently employed in cell imaging for investigating their intracellular localization. Furthermore, the in vivo toxicity of the Pe(OH)4 nanoparticles was investigated using the mouse model. Histological tissue analysis of five major organs, i.e., heart, kidney, spleen, liver, and lung, indicates that the nanoparticles did not show any obvious damage to these major organs under the experimental conditions. The current research presents a successful example of integrating multiple functions into single-component organic nanoparticles for drug delivery.

We report for the first time an organic nanoparticle based nuclear-targeted photoresponsive drug delivery system (DDS) for regulated anticancer drug release. Acridin-9-methanol fluorescent organic nanoparticles used in this DDS performed three important roles: (i) ″nuclear-targeted nanocarrier″ for drug delivery, (ii) ″phototrigger″ for regulated drug release, and (iii) fluorescent chromophore for cell imaging. In vitro biological studies reveal acridin-9-methanol nanoparticles of ∼60 nm size to be very efficient in delivering the anticancer drug chlorambucil into the target nucleus, killing the cancer cells upon irradiation. Such targeted organic nanoparticles with good biocompatibility, cellular uptake property, and efficient photoregulated drug release ability will be of great benefit in the field of targeted intracellular controlled drug release.

We report for the first time the use of perylene-3-ylmethanol fluorescent organic nanoparticles as a drug delivery system. In the present system, perylene-3-ylmethanol nanoparticles performed four important roles: (i) “nanocarriers” for drug delivery; (ii) “phototriggers” for the drug release; (iii) fluorescent chromophores for cell imaging; and (iv) detectors for real time-monitoring of drug release. In vitro biological studies revealed that the newly developed perylene-3-ylmethanol nanoparticles exhibit good biocompatibility and cellular uptake as well as efficient photoregulated anticancer drug release ability. Such fluorescent organic nanoparticles may open up new perspectives for designing a new class of promising photoresponsive nanocarriers for drug delivery.

A new class of carboxylate and sulfonate esters of 1-hydroxy- 2(1H)-quinolone has been demonstrat- ed as nonionic photoacid generators (PAGs). Irradiation of carboxylates and sulfonates of 1-hydroxy-2(1H)-qui- nolone by UV light (l 310 nm) result- ed in homolysis of weak NO bond leading to efficient generation of car- boxylic and sulfonic acids, respectively. The mechanism for the homolytic NO bond cleavage was supported by time- dependent DFT calculations. Photores- ponsive 1-(p-styrenesulfonyloxy)-2-qui- nolone-methyl methacrylate (SSQL- MMA) and 1-(p-styrenesulfonyloxy)-2- quinolone-lauryl acrylate (SSQL-LA) copolymers were synthesized from PAG monomer 1-(p-styrenesulfony- loxy)-2-quinolone, and subsequently controlled surface wettability was dem- onstrated for the above-mentioned photoresponsive polymers.

By irradiation of substrates such as (III) or (VI), a cleavage of the N—O bond occurs to give the corresponding carboxylic acids.

The synthesis of Ni filled multiwalled carbon nanotubes was performed by atmospheric pressure chemical vapor deposition with propane on Si at 850 C using a simple mixture of Ni(salen), and a conventional photoresist. Analysis of the carbon nanotubes using scanning electron microscopy together with high resolution transmission electron microscopy show that the nanotubes have grown by a tip growth mechanism and exhibit a multi walled structure with partial Ni filling. The high quality of the Ni filled nanotubes is evidenced by Raman spectroscopy. The magnetic properties of Ni filled nanotubes were analyzed using a superconducting quantum interference device which revealed their ferromagnetic behavior with large coercivity. A scalable as well as site selective growth of high quality Ni filled carbon nanotubes is achieved by a simple photolithographic method., Comment: multiwalled carbon nanotubes,chemical vapor deposition,Ni(salen),photoresist,magnetic properties,coercivity