Narrow Results

Technetium and Rhenium are the two lower elements in the manganese triad. Whereas rhenium is known as an important part of high resistance alloys, technetium is mostly known as a cumbersome product of nuclear fission. It is less known that its metastable isotope ^99mTc is of utmost importance in nuclear medicine diagnosis. The technical application of elemental rhenium is currently complemented by investigations of its isotope ¹⁸⁸Re, which could play a central role in the future for internal, targeted radiotherapy. This article will briefly describe the basic principles behind diagnostic methods with radionuclides for molecular imaging, review the ^99mTc-based radiopharmaceuticals currently in clinical routine and focus on the chemical challenges and current developments towards improved, radiolabeled compounds for diagnosis and therapy in nuclear medicine.

The synthesis of a series of new fluorinated phthalocyanines and porphyrins as potential bimodal probes is evaluated. In these complexes, zinc phthalocyanine functions as a fluorescence imaging moiety while attachment of an aliphatic chain of different lengths bearing a tosylate group permits introduction of fluorine via nucleophilic substitution of the tosylate group. Using short-lived [¹⁸F]fluoride gives the analogous ¹⁸F-radiolabelled tracer rendering the bimodal probe suitable for both fluorescence and PET imaging.

This review article briefly describes: (a) the advantages in developing multifunctional nanoparticles for cancer-imaging and therapy, (b) the advantages and limitations of most of the porphyrin-based compounds in fluorescence imaging and photodynamic therapy (PDT), (c) problems associated with current Food and Drug Administration (FDA) approved photosensitizers, (d) challenges in developing in vivo target-specific PDT agents, (e) development of porphyrin-based nuclear-imaging agents (PET, SPECT) with an option of PDT, (f) the importance of light dosimetry in PDT, (g) the role of whole body or local hyperthermia in enhancing tumor-uptake, tumor-imaging and phototherapy and finally, (h) the advantages of photosensitizer-gold nanocages (Ps-Au NC) in photoacoustic and PDT.

Porphyrin-based molecules are actively studied as dual function theranostics: fluorescence-based imaging for diagnostics and fluorescence-guided therapeutic treatment of cancers. The intrinsic fluorescent and photodynamic properties of the bimodal molecules allows for these theranostic approaches. Several porphyrinoids bearing both hydrophilic and/or hydrophobic units at their periphery have been developed for the aforementioned applications, but better tumor selectivity and high efficacy to destroy tumor cells is always a key setback for their use. Another issue related to their effective clinical use is that, most of these chromophores form aggregates under physiological conditions. Nanomaterials that are known to possess incredible properties that cannot be achieved from their bulk systems can serve as carriers for these chromophores. Porphyrinoids, when conjugated with nanomaterials, can be enabled to perform as multifunctional nanomedicine devices. The integrated properties of these porphyrinoid-nanomaterial conjugated systems make them useful for selective drug delivery, theranostic capabilities, and multimodal bioimaging. This review highlights the use of porphyrins, chlorins, bacteriochlorins, phthalocyanines and naphthalocyanines as well as their multifunctional nanodevices in various biomedical theranostic platforms.

In an attempt to investigate its potential as a PDT ${}^{19}$F MRI molecular theranostic, a Zn phthalocyanine with 24 pseudo-equivalent fluorine atoms was designed and prepared. Compared to its H analogues, the fluorinated derivative has a much higher generation of singlet oxygen. ${}^{19}$F NMR signals in CDCl₃ showed that all the fluorine atoms are magnetically pseudo-equivalent with only two close fluorine signals. Formulation in PVP (polyvinylpyrrolidone), a FDA-approved additive, enabled water-solubilization of the phthalocyanines but no satisfying ${}^{19}$F NMR signal could be obtained, probably due to self-quenching caused by aggregation.

Since their discovery in 1968, the BODIPYs dyes (4,4-difluoro-4-bora-3a, 4a diaza-s-indacene) have found an exponentially increasing number of applications in a large variety of scientific fields. In particular, studies reporting bioapplications of BODIPYs have increased dramatically. However, most of the time, only in vitro investigations have been reported. The in vivo potential of BODIPYs and aza-BODIPYs is more recent, but considering the number of in vivo studies with BODIPY and aza-BODIPY which have been reported in the last five years, we can now affirm that this family of fluorophores can be considered important as cyanine dyes for future in vivo and even clinical applications. This review aims to present representative examples of recent in vivo applications of BODIPYs or aza-BODIPYs, and to highlight the potential of these dyes for optical molecular imaging.

Starting from simplex drug delivery system, the graphene oxide (GO) and reduced GO (rGO) materials have been developed to be “combo” nanoplatforms containing multiple therapeutic modalities, such as the targeted drug delivery, imaging, as well as photothermal therapy (PTT) due to their distinctive physical/chemical and optical properties including excellent biocompatibility, modifiable active groups, ultra-large surface area, and intense photothermal effect. The graphene-based nanoplatforms were used for the stimuli-responsive nanocarriers, showing excellent therapeutic effects activated by endogenous stimuli including low pH, overexpressed enzymes, biomolecules, elevated glutathione, and exogenous stimuli including light, magnetic/electric field, and ultrasound. More importantly, for multimodal synergistic therapy originated from the enhanced collaborative interactions among several monotherapy types, the obtained remarkable super-additive effects were not the results just through single therapy or their theoretical combination. In this review, the recent progresses of smart graphene-based nanoplatforms for integrated cancer therapy and bio-imaging are presented. Current challenges and future perspectives of graphene-based nanoplatforms in the biomedical field are also discussed.

The use of nanomedicine in the war on cancer diseases has progressed significantly in the recent past. Liposomal- and albumin-based chemotherapeutic agents as well as tumor contrast agents (e.g. Gd-DTPA, ferumoxides) have received FDA approval for human clinical use, while many other agents are in different phases of pre-clinical investigation and clinical trials. Plasmonic gold nanoparticles hold great promise as potential theranostic devices for detection and ablation of cancer diseases. This review discusses recent progress in the imaging, photothermal therapy, and nucleic acid/drug delivery using gold nanoparticles (spheres, shells, rods, cages) in vitro and in vivo. Issues relating to toxicity, biocompatibility, biodistribution, cellular uptake, and targeting efficiency are also discussed.

Effective design of nanoparticle systems can have a significant impact on therapeutic delivery. Physicochemical factors including size, shape and surface chemistry of nanoparticles can play a significant role in determining the efficacy of drug and gene delivery to cells. Polymeric as well as inorganic nanoparticle systems have been investigated as vehicles for nonviral gene delivery of transgenes. However, a head-to-head comparison of these different systems is largely lacking. In this study, we compare three related delivery systems, polymer, polymer-templated gold nanospheres and polymer-coated gold nanorods, for their respective in vitro transgene expression efficacies. Significant differences were seen in the hydrodynamic diameter and zeta potential for each of these different vehicles. Nevertheless, transgene (luciferase) expression efficacies and cytotoxicities were found to be similar for these three vehicles under different conditions. Our results indicate that polymeric systems can be used for synthesis or modification of nanoparticle systems with negligible variations in their transgene expression efficacies. This can have significant implications for generating polymer-nanoparticle theranostic systems that maintain therapeutic (e.g., nucleic acid) delivery efficacies, while also possessing additional functionalities, including

With the rise of graphene, there is growing attention on two-dimensional (2D) materials in the physical science community during the last decade. Most studies to date focus on the rich set of their superior electrical, optical, catalytic and electrochemical properties and highlight the encouraging opportunities for developing next generation electronics, optoelectronics, catalysis, and energy storage technologies. On the contrary, the biomedicine community has barely recognized the potential of these materials other than graphene. There are very limited published studies on these materials’ biological effects and biomedical applications. Here, we present a brief overview of 2D materials and discuss their potential for biomedical applications in hope of raising biomedical researchers’ awareness of the great opportunities associated with these materials. We first discuss the emergence of 2D materials and review two most important prerequisites for 2D materials’ biomedical applications, synthesis and biocompatibility. We then categorize the existing studies on 2D materials’ biomedical applications into biosensing, drug/gene delivery, antimicrobial, bioimaging and multimode therapeutic applications. We would put special emphasis on the great flexibility of various rational combinations of 2D material superior properties for the design and construction of assorted forms of reagents or devices with highly effective simultaneous diagnostic and therapeutic functions (or theranostics functions). At last, the newly emerging 2D black phosphorous with very rare and interesting properties is introduced as the next promising and important 2D materials to study in the upcoming years.

Cancer is one of the most prevalent diseases with mortality rate considerably increasing every year. Conventional treatment strategies for cancer like chemotherapy suffer from the drawbacks of multiple-dose requirements and non-specificity of drug action. Moreover, the cost involved in the diagnosis and treatment is very high. Recently, the application of nanotechnology in the field of cancer has witnessed tremendous significance due to the unique size, shape, and surface properties of nanomaterials. With the intention to utilize biocompatible and biodegradable nanomaterials in cancer and reduce the non-specificity, approaches such as targeted nanotherapeutics came into existence. Besides having therapeutic potential, some materials demonstrate their applicability in bioimaging forecasting distinct optical properties. In this review, we have discussed the basics and principles guiding the design of different photo-triggered nanotheranostic materials used in cancer. Additionally, recent developments and advantages offered by the NIR-responsive photodynamic and photothermal agents along with their future scope have been presented. An overview of the toxicity and clinical prospect of photosensitive agents is also summarized. Overall, the field of photo-triggered cancer nanotheranostics has huge potential that can be clinically translated into an affordable and safe treatment approach.

Cancer threatens the life and well-being of human beings. Millions of newly diagnosed cancer cases and a large number of deaths caused by cancer are reported each year in the world. Early detection and effective treatment are key to reduce cancer mortality, which can be potentially realized by using “theranostics”. Theranostics are a group of hybrid nanoparticles that perform in cancer patients to provide both diagnostic and therapeutic functions through a single nano-sized structure. In particular, core-shell structured theranostics have shown unique physicochemical properties, allowing them to facilitate molecular/cell targeting, bio-imaging, and drug delivery functions. This review, therefore, aims to present and discuss the recent development of research on core-shell structured theranostics. Specifically, it focuses on core-shell structured theranostics made of metals, silica and polymers. Different aspects, such as synthesis and structure, of core-shell structured theranostics are discussed in this review. This review helps readers to have a good understanding of the design and fabrication of core-shell structured theranostics.

Superparamagnetic iron oxide (SPIO) has been used as a contrast agent for magnetic resonance imaging (MRI) since the late 20th century. With the development of SPIO, cellular MRI has been recognized as a suitable and highly sensitive noninvasive modality with great potential to benefit translational research. In addition to its traditional diagnostic property, latest advances have conferred SPIO with multifunctionality. Several SPIO-based theranostic probes with targeting, therapeutic and diagnosis components have been successfully developed. The objective of this brief review is to summarize the characteristics, synthesizing methods, labeling approaches and current applications of SPIO-based cellular MRI in oncology. Herein, we first depict the history, classification and advantages of and the differences between T1- and T2/T2*-based SPIO contrast agents for cancer treatment. Second, we outline current coating materials that render SPIO less toxic and more biocompatible to mammalian cells. Finally, the cell labeling techniques and applications of SPIO-based MRI for tracking mesenchymal stem cell tumor–homing in preclinical models are introduced.

Graphene and graphene-based nanomaterials such as graphene oxide (GO), reduced graphene oxide (rGO) and graphene quantum dots (GQDs) have gained a lot of attention from diverse scientific fields for applications in sensing, catalysis, nanoelectronics, material engineering, energy storage and biomedicine due to its unique structural, optical, electrical and mechanical properties. Graphene-based nanomaterials emerge as a novel class of nanomedicine for cancer therapy for several reasons. Firstly, its structural properties like high surface area and aromaticity enables easy loading of hydrophobic drugs. Secondly, presence of oxygen containing functional groups improve its physiological stability and also act as site for biofunctionalization. Thirdly, its optical absorption in the NIR region enable them to act as photoagents for photothermal and photodynamic therapies of cancer, both in vitro and in vivo. Finally, its intrinsic fluorescence property helps in bioimaging of cancer cells. Overall, graphene-based nanomaterials can act as agents for developing multifunctional theranostic platforms for carrying out more efficient detection and treatment of cancers. This review provides a detailed summary of the different applications of graphene-based nanomaterials in drug delivery, nucleic acid delivery, phototherapy, bioimaging and theranostics.

Porphyrin-based molecules are actively studied as dual function theranostics: fluorescence-based imaging for diagnostics and fluorescence-guided therapeutic treatment of cancers. The intrinsic fluorescent and photodynamic properties of the bimodal molecules allows for these theranostic approaches. Several porphyrinoids bearing both hydrophilic and/or hydrophobic units at their periphery have been developed for the aforementioned applications, but better tumor selectivity and high efficacy to destroy tumor cells is always a key setback for their use. Another issue related to their effective clinical use is that, most of these chromophores form aggregates under physiological conditions. Nanomaterials that are known to possess incredible properties that cannot be achieved from their bulk systems can serve as carriers for these chromophores. Porphyrinoids, when conjugated with nanomaterials, can be enabled to perform as multifunctional nanomedicine devices. The integrated properties of these porphyrinoid-nanomaterial conjugated systems make them useful for selective drug delivery, theranostic capabilities, and multimodal bioimaging. This review highlights the use of porphyrins, chlorins, bacteriochlorins, phthalocyanines and naphthalocyanines as well as their multifunctional nanodevices in various biomedical theranostic platforms.

Since their discovery in 1968, the BODIPYs dyes (4,4-difluoro-4-bora-3a, 4a diaza-s-indacene) have found an exponentially increasing number of applications in a large variety of scientific fields. In particular, studies reporting bioapplications of BODIPYs have increased dramatically. However, most of the time, only in vitro investigations have been reported. The in vivo potential of BODIPYs and aza-BODIPYs is more recent, but considering the number of in vivo studies with BODIPY and aza-BODIPY which have been reported in the last five years, we can now affirm that this family of fluorophores can be considered important as cyanine dyes for future in vivo and even clinical applications. This review aims to present representative examples of recent in vivo applications of BODIPYs or aza-BODIPYs, and to highlight the potential of these dyes for optical molecular imaging.

In an attempt to investigate its potential as a PDT ¹⁹F MRI molecular theranostic, a Zn phthalocyanine with 24 pseudo-equivalent fluorine atoms was designed and prepared. Compared to its H analogues, the fluorinated derivative has a much higher generation of singlet oxygen. ¹⁹F NMR signals in CDCl₃ showed that all the fluorine atoms are magnetically pseudo-equivalent with only two close fluorine signals. Formulation in PVP (polyvinylpyrrolidone), a FDA-approved additive, enabled water-solubilization of the phthalocyanines but no satisfying ¹⁹F NMR signal could be obtained, probably due to self-quenching caused by aggregation.

Nanomaterials with different morphologies and functions have been widely developed. Among them, the nanotheranostic systems designed and simultaneously used for therapeutics and diagnostics draw particular attention. To achieve the multifunctionality in one nanoformulation, typically four components are included: nanocarriers, targeting ligand, imaging domain and therapeutics. This review is aimed at introducing some examples of possibilities for the different components in a nanotheranostic system.

The use of nanomedicine in the war on cancer diseases has progressed significantly in the recent past. Liposomal- and albumin-based chemotherapeutic agents as well as tumor contrast agents (e.g. Gd-DTPA, ferumoxides) have received FDA approval for human clinical use, while many other agents are in different phases of pre-clinical investigation and clinical trials. Plasmonic gold nanoparticles hold great promise as potential theranostic devices for detection and ablation of cancer diseases. This review discusses recent progress in the imaging, photothermal therapy, and nucleic acid/drug delivery using gold nanoparticles (spheres, shells, rods, cages) in vitro and in vivo. Issues relating to toxicity, biocompatibility, biodistribution, cellular uptake, and targeting efficiency are also discussed.