Multifunctional nanocarriers for cell imaging, drug delivery, and near-IR photothermal therapy

Nanotechnology-based Nose-to-brain Delivery in Epilepsy: A NovelApproach to Diagnosis and Treatment

Epilepsy is a serious neurological disease, and scientists have a significant challenge in developing a noninvasive treatment for the treatment of epilepsy. The goal is to provide novel ideas for improving existing and future anti-epileptic medications. The injection of nano treatment via the nose to the brain is being considered as a possible seizure control method. Various nasal medicine nanoformulations have the potential to cure epilepsy. Investigations with a variety of nose-to-brain dosing methods for epilepsy treatment have yielded promising results. After examining global literature on nanotechnology and studies, the authors propose nasal administration with nanoformulations as a means to successfully treat epilepsy. The goal of this review is to look at the innovative application of nanomedicine for epilepsy treatment via nose-to-brain transfer, with a focus on the use of nanoparticles for load medicines. When nanotechnology is combined with the nose to brain approach, treatment efficacy can be improved through site specific delivery. Furthermore, this technique of administration decreases adverse effects and patient noncompliance encountered with more traditional procedures.

New Frontiers in Colorectal Cancer Treatment Combining Nanotechnology with Photo- and Radiotherapy

Colorectal cancer is the third most common cancer worldwide. Despite recent advances in the treatment of this pathology, which include a personalized approach using radio- and chemotherapies in combination with advanced surgical techniques, it is imperative to enhance the performance of these treatments and decrease their detrimental side effects on patients' health. Nanomedicine is likely the pathway towards solving this challenge by enhancing both the therapeutic and diagnostic capabilities. In particular, plasmonic nanoparticles show remarkable potential due to their dual therapeutic functionalities as photothermal therapy agents and as radiosensitizers in radiotherapy. Their dual functionality, high biocompatibility, easy functionalization, and targeting capabilities make them potential agents for inducing efficient cancer cell death with minimal side effects. This review aims to identify the main challenges in the diagnosis and treatment of colorectal cancer. The heterogeneous nature of this cancer is also discussed from a single-cell point of view. The most relevant works in photo- and radiotherapy using nanotechnology-based therapies for colorectal cancer are addressed, ranging from in vitro studies (2D and 3D cell cultures) to in vivo studies and clinical trials. Although the results using nanoparticles as a photo- and radiosensitizers in photo- and radiotherapy are promising, preliminary studies showed that the possibility of combining both therapies must be explored to improve the treatment efficiency.

Synthesis of Carbon-Encapsulated Magnetic Iron Oxide Nanocomposites for Bioapplication

Carbon-encapsulated Fe3O4 nanoparticles (NPs) were successfully synthesized from a single precursor using one-step solvothermal methods. X-ray diffraction and transmission electron microscopy were used to characterize the as-prepared NPs, and UV-visible absorbance spectroscopy was used to check their optical properties. The morphological results revealed that Fe3O4@C, quasi-spherical Fe3O4 particles encapsulated by carbon. In addition, the carbon-encapsulated Fe3O4 NPs were conjugated with folic acid (FA) to be used as biomarkers in the diagnosis and treatment of tumour cells. Fourier transform infrared spectroscopy and UV-visible spectroscopic techniques were used to confirm the conjugation process.

Polymeric nanocarriers: A promising tool for early diagnosis and efficient treatment of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third most prevalent type of cancer for incidence and second for mortality worldwide. Late diagnosis and inconvenient and expensive current diagnostic tools largely contribute to the progress of the disease. The use of chemotherapy in the management of CRC significantly reduces tumor growth, metastasis, and morbidity rates. However, poor solubility, low cellular uptake, nonspecific distribution, multiple drug resistance and unwanted adverse effects are still among the major drawbacks of chemotherapy that limit its clinical significance in the treatment of CRC. Owing to their remarkable advantages over conventional therapies, the use of nanotechnology-based delivery systems especially polymeric nanocarriers (PNCs) has revolutionized many fields including disease diagnosis and drug delivery.

AIM OF REVIEW

In this review, we shed the light on the current status of using PNCs in the diagnosis and treatment of CRC with a special focus on targeting strategies, surface modifications and safety concerns for different types of PNCs in colonic cancer delivery.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review explores the current progress on the use of PNCs in the diagnosis and treatment of CRC with a special focus on the role of PNCs in improvement of cellular uptake, drug targeting and co-delivery of chemotherapeutic agents. Possible toxicity and biocompatibility issues related to the use of PNCs and imitations and future recommendation for the use of those smart carriers in the diagnosis and treatment of CRC are also discussed.

Preparation and application of chitosan-based fluorescent probes

Biomass materials have abundant natural resources, renewability and good biochemical compatibility, so biomass-based fluorescent materials prepared from biomass materials have gradually become a research hotspot.

Recent advances and trends in nanoparticles based photothermal and photodynamic therapy

Light-mediated therapies, including photodynamic therapy (PDT) and photothermal therapy (PTT) have been exploited as minimally invasive techniques for ablation of various tumors., Both modalities may eradicate tumors with minimal side effects to normal tissues and organs. Moreover, developments of light-mediated approaches using nanoparticles (NPs) and photosensitizer (PS) as diagnostic and therapeutic agents may have a crucial role in achieving successful cancer treatment. In recent years, novel nanoplatforms and strategies have been investigated to boost the therapeutic effect.. In this regard, gold, iron oxide, graphene oxide nanoparticles and hybrid nanocomposites have attracted attention.. Moreover, the combination of these materials with PS, in the form of hybrid NPs, reduces in vitro and in vivo normal tissue cytotoxicity, improves their solubility property in the biological environment and enhances the therapeutic effects. In this review, we look into the basic principles of PTT and PDT with their strengths and limitations to treat cancers. We also will discuss light-based nanoparticles and their PTT and PDT applications in the preclinical and clinical translation. Also, recent advances and trends in this field will be discussed along with the clinical challenges of PTT and PDT.

A novel CT contrast agent for intestinal-targeted imaging through rectal administration

In this study, a novel CT contrast agent used by rectal administration is developed for targeting intestinal imaging. Iopamidol, an iodinated contrast agent, is loaded in chitosan (CS) nanospheres modified by Anti-5-HT3R (AH) antibody. The obtained AH-CS-I nanospheres (AH-CS-I Ns) would combine to 5-HT3 receptors highly expressed on the gastrointestinal mucosal, enhancing the intestinal-targeting ability of the contrast agent. The AH-CS-I Ns were administered by the rectal route for intestinal CT imaging, and FITC-labeled AH-CS-I Ns were prepared for investigating the in vivo distribution of the contrast agent. As a result, obvious contrast enhancement could still be observed at 6 h post administration because of the poorly absorption of enteral AH-CS-I Ns. Unlike the intravascularly administered agents, AH-CS-I Ns would not accumulate in the kidney and induce adverse reactions. Therefore, this technology has potential applications in the examination of intestinal diseases and could reduce the side effect of commercial iopamidol.

Advances in Functionalized Photosensitive Polymeric Nanocarriers

The synthesis of light-responsive nanocarriers (LRNs) with a variety of surface functional groups and/or ligands has been intensively explored for space-temporal controlled cargo release. LRNs have been designed on demand for photodynamic-, photothermal-, chemo-, and radiotherapy, protected delivery of bioactive molecules, such as smart drug delivery systems and for theranostic duties. LRNs trigger the release of cargo by a light stimulus. The idea of modifying LRNs with different moieties and ligands search for site-specific cargo delivery imparting stealth effects and/or eliciting specific cellular interactions to improve the nanosystems’ safety and efficacy. This work reviews photoresponsive polymeric nanocarriers and photo-stimulation mechanisms, surface chemistry to link ligands and characterization of the resultant nanosystems. It summarizes the interesting biomedical applications of functionalized photo-controlled nanocarriers, highlighting the current challenges and opportunities of such high-performance photo-triggered delivery systems.

Controlled Synthesis and Surface Engineering of Janus Chitosan-Gold Nanoparticles for Photoacoustic Imaging-Guided Synergistic Gene/Photothermal Therapy

The unsymmetrical morphology and unique properties of Janus nanoparticles (JNPs) provide superior performances for biomedical applications. In this work, a general and facile strategy is developed to construct a series of symmetrical and unsymmetrical chitosan/gold nanoparticles. Taking advantage of the active motion derived from Janus structure, selective surface functionalization of polysaccharide domain, and photothermal effect of gold nanorods, Janus chitosan/gold nanoparticles (J-Au-CS) are selected as a model system to construct Janus-structured chitosan/gold nanohybrids (J-ACP). Near-infrared (NIR)-responsive J-ACP composed of polycationic chitosan nanospheres and PEGylated gold nanorods hold great potential to realize photoacoustic (PA) imaging-guided complementary photothermal therapy (PTT)/gene therapy for breast cancer. The morphology effect of chitosan/gold nanostructures on enhanced PTT, cellular uptake, and gene transfection is investigated. The feasibility of PA imaging to track the accumulation of J-ACP and guide PTT is also explored. Notably, synergistic therapy is achieved based on PTT-enhanced gene therapy. In addition, the loading function of chitosan/gold nanoparticles for fluorescence imaging is demonstrated. The current work extends the application of JNPs for imaging-guided synergistic cancer therapy and provides flexible candidates with distinct structures for diverse biomedical applications.

Polysaccharides-based bio-nanostructures and their potential food applications

Polysaccharides are omnipresent biomolecules that hold great potential as promising biomaterials for a myriad of applications in various biotechnological and industrial sectors. The presence of diverse functional groups renders them tailorable functionalities for preparing a multitude of novel bio-nanostructures. Further, they are biocompatible and biodegradable, hence, considered as environmentally friendly biopolymers. Application of nanotechnology in food science has shown many advantages in improving food quality and enhancing its shelf life. Recently, considerable efforts have been made to develop polysaccharide-based nanostructures for possible food applications. Therefore, it is of immense importance to explore literature on polysaccharide-based nanostructures delineating their food application potentialities. Herein, we reviewed the developments in polysaccharide-based bio-nanostructures and highlighted their potential applications in food preservation and bioactive "smart" food packaging. We categorized these bio-nanostructures into polysaccharide-based nanoparticles, nanocapsules, nanocomposites, dendrimeric nanostructures, and metallo-polysaccharide hybrids. This review demonstrates that the polysaccharides are emerging biopolymers, gaining much attention as robust biomaterials with excellent tuneable properties.

Engineered nanoparticles for imaging and drug delivery in colorectal cancer

Colorectal cancer (CRC) is one of the deadliest diseases worldwide due to a lack of early detection methods and appropriate drug delivery strategies. Conventional imaging techniques cannot accurately distinguish benign from malignant tissue, leading to frequent misdiagnosis or diagnosis at late stages of the disease. Novel screening tools with improved accuracy and diagnostic precision are thus required to reduce the mortality burden of this malignancy. Additionally, current therapeutic strategies, including radio- and chemotherapies carry adverse side effects and are limited by the development of drug resistance. Recent advances in nanotechnology have rendered it an attractive approach for designing novel clinical solutions for CRC. Nanoparticle-based formulations could assist early tumor detection and help to overcome the limitations of conventional therapies including poor aqueous solubility, nonspecific biodistribution and limited bioavailability. In this review, we shed light on various types of nanoparticles used for diagnosis and drug delivery in CRC. In addition, we will explore how these nanoparticles can improve diagnostic accuracy and promote selective drug targeting to tumor sites with increased efficiency and reduced cytotoxicity against healthy colon tissue.

Active targeting of gold nanoparticles as cancer therapeutics

Gold nanoparticles (AuNPs) are of increasing interest for their unique properties and their biocompatability, minimal toxicity, multivalency and size tunability make them exciting drug carriers. The functionalisaton of AuNPs with targeting moieties allows for their selective delivery to cancers, with antibodies, proteins, peptides, aptamers, carbohydrates and small molecules all exploited. Here, we review the recent advances in targeted-AuNPs for the treatment of cancer, with a particular focus on these classes of targeting ligands. We highlight the benefits and potential drawbacks of each ligand class and propose directions in which the field could grow.

Role of gold nanoparticles in advanced biomedical applications

Gold nanoparticles (GNPs) have generated keen interest among researchers in recent years due to their excellent physicochemical properties. In general, GNPs are biocompatible, amenable to desired functionalization, non-corroding, and exhibit size and shape dependent optical and electronic properties. These excellent properties of GNPs exhibit their tremendous potential for use in diverse biomedical applications. Herein, we have evaluated the recent advancements of GNPs to highlight their exceptional potential in the biomedical field. Special focus has been given to emerging biomedical applications including bio-imaging, site specific drug/gene delivery, nano-sensing, diagnostics, photon induced therapeutics, and theranostics. We have also elaborated on the basics, presented a historical preview, and discussed the synthesis strategies, functionalization methods, stabilization techniques, and key properties of GNPs. Lastly, we have concluded this article with key findings and unaddressed challenges. Overall, this review is a complete package to understand the importance and achievements of GNPs in the biomedical field.

Metal-derived nanoparticles in tumor theranostics: Potential and limitations

Initially, metal derived nanoparticles have been used exclusively as contrasting agents in magnetic resonance imaging. Today, green routes of chemical synthesis together with numerous modifications of the core and surface gave rise to a plethora of biomedical applications of metal derived nanoparticles including tumor imaging, diagnostics, and therapy. These materials are an emerging class of tools for tumor theranostics. Nevertheless, the spectrum of clinically approved metal nanoparticles remains narrow, as the safety, specificity and efficiency still have to be improved. In this review we summarize the major directions for development and biomedical applications of metal based nanoparticles and analyze their effects on tumor cells and microenvironment. We discuss the advantages and possible limitations of metal nanoparticle-based tumor theranostics, as well as the potential strategies to improve the in vivo performance of these unique materials.

Magnetic nanoparticles double wrapped into cross-linked salep/PEGylated carboxymethyl cellulose; a biocompatible nanocarrier for pH-triggered release of doxorubicin

A magnetic nanocarrier was synthesized in which Fe3O4 nanoparticles were encapsulated into double layers of polysaccharide shells. The first shell, which was composed of cross-linked salep polysaccharide, contained multiple nitrogen atoms in its structure and provided numerous sites for multiple functionalization. A fluorescence dye and doxorubicin, as widely used chemotherapy agent, were easily attached to the first shell and then a second shell of PEGylated carboxymethyl cellulose enveloped the drug loaded carrier to enhance its biocompatibility and regulates the drug release behavior. The results of drug loading and release behavior showed that the resulting nanocarrier can carry large amounts of drug molecules and a remarkable pH-sensitive release was observed in vitro. The hemolysis and coagulation assays proved the biocompatibility of nanocarrier toward red blood cells and the MTT experiments confirmed that the drug loaded nanocarrier is highly toxic for MCF-7 cancer cells while the unloaded nanocarrier was almost nontoxic. Further flow cytometry experiments and confocal microscopy demonstrated that the double layered magnetic nanocarrier can penetrate into the cells and efficiently release the drug molecules into the cell nucleus. Moreover, the results of MRI experiments performed on the nanocarrier showed that it can be serve as a negative MRI contrast agent.

Intranasal Delivery of Nanoformulations: A Potential Way of Treatment for Neurological Disorders

Although the global prevalence of neurological disorders such as Parkinson’s disease, Alzheimer’s disease, glioblastoma, epilepsy, and multiple sclerosis is steadily increasing, effective delivery of drug molecules in therapeutic quantities to the central nervous system (CNS) is still lacking. The blood brain barrier (BBB) is the major obstacle for the entry of drugs into the brain, as it comprises a tight layer of endothelial cells surrounded by astrocyte foot processes that limit drugs’ entry. In recent times, intranasal drug delivery has emerged as a reliable method to bypass the BBB and treat neurological diseases. The intranasal route for drug delivery to the brain with both solution and particulate formulations has been demonstrated repeatedly in preclinical models, including in human trials. The key features determining the efficacy of drug delivery via the intranasal route include delivery to the olfactory area of the nares, a longer retention time at the nasal mucosal surface, enhanced penetration of the drugs through the nasal epithelia, and reduced drug metabolism in the nasal cavity. This review describes important neurological disorders, challenges in drug delivery to the disordered CNS, and new nasal delivery techniques designed to overcome these challenges and facilitate more efficient and targeted drug delivery. The potential for treatment possibilities with intranasal transfer of drugs will increase with the development of more effective formulations and delivery devices.

Accurate and Real-Time Temperature Monitoring during MR Imaging Guided PTT

Photothermal therapy (PTT) is an efficient approach for cancer treatment. However, accurately monitoring the spatial distribution of photothermal transducing agents (PTAs) and mapping the real-time temperature change in tumor and peritumoral normal tissue remain a huge challenge. Here, we propose an innovative strategy to integrate T₁-MRI for precisely tracking PTAs with magnetic resonance temperature imaging (MRTI) for real-time monitoring temperature change in vivo during PTT. NaBiF₄: Gd@PDA@PEG nanomaterials were synthesized with favorable T₁-weighted performance to target tumor and localize PTAs. The extremely weak susceptibility (1.04 × 10^-6 emu g^-1 Oe^1-) of NaBiF₄: Gd@PDA@PEG interferes with the local phase marginally, which maintains the capability of MRTI to dynamically record real-time temperature change in tumor and peritumoral normal tissue. The time resolution is 19 s per frame, and the detection precision of temperature change is approximately 0.1 K. The approach achieving PTT guided by multimode MRI holds significant potential for the clinical application.

Photothermally Enhanced Molecular Delivery and Cellular Positioning on Patterned Plasmonic Interfaces

Photothermal conversion effect of plasmonic nanostructures is considered as a promising technique for cellular and molecular manipulations owing to controllability of local temperature. Therefore, this technique has been extensively applied to biological studies such as controlling cellular behavior, delivery of biologics, and biomolecular detection. Herein, we propose a novel method for directed cell positioning and photothermally modulated molecular delivery to the cells using patterned plasmonic interfaces. Plasmonic substrates with gold nanorods (GNRs) and cell adhesion molecules fabricated by microcontact printing are optimized for cellular positioning on designated patterns. Through the photothermal conversion effect of GNRs on the pattern, we further demonstrate on-demand, light-induced delivery of drug molecules to the target cells. We expect that this approach will provide a new way to study single cellular behaviors and enhance molecular delivery to the target cells.

Next-generation of targeted AAVP vectors for systemic transgene delivery against cancer

Bacteriophage (phage) have attractive advantages as delivery systems compared with mammalian viruses, but have been considered poor vectors because they lack evolved strategies to confront and overcome mammalian cell barriers to infective agents. We reasoned that improved efficacy of delivery might be achieved through structural modification of the viral capsid to avoid pre- and postinternalization barriers to mammalian cell transduction. We generated multifunctional hybrid adeno-associated virus/phage (AAVP) particles to enable simultaneous display of targeting ligands on the phage's minor pIII proteins and also degradation-resistance motifs on the very numerous pVIII coat proteins. This genetic strategy of directed evolution bestows a next-generation of AAVP particles that feature resistance to fibrinogen adsorption or neutralizing antibodies and ability to escape endolysosomal degradation. This results in superior gene transfer efficacy in vitro and also in preclinical mouse models of rodent and human solid tumors. Thus, the unique functions of our next-generation AAVP particles enable improved targeted gene delivery to tumor cells.

Surface modification of gold nanoparticles with neuron-targeted exosome for enhanced blood-brain barrier penetration

Gold nanoparticles (AuNPs) have been extensively used as nanomaterials for theranostic applications due to their multifunctional characteristics in therapeutics, imaging, and surface modification. In this study, the unique functionalities of exosome-derived membranes were combined with synthetic AuNPs for targeted delivery to brain cells. Here, we report the surface modification of AuNPs with brain-targeted exosomes derived from genetically engineered mammalian cells by using the mechanical method or extrusion to create these novel nanomaterials. The unique targeting properties of the AuNPs after fabrication with the brain-targeted exosomes was demonstrated by their binding to brain cells under laminar flow conditions as well as their enhanced transport across the blood brain barrier. In a further demonstration of their ability to target brain cells, in vivo bioluminescence imaging revealed that targeted-exosome coated AuNPs accumulated in the mouse brain after intravenous injection. The surface modification of synthetic AuNPs with the brain-targeted exosome demonstrated in this work represents a highly novel and effective strategy to provide efficient brain targeting and shows promise for the future in using modified AuNPs to penetrate the brain.

Nanomaterial Applications in Photothermal Therapy for Cancer

As a result of their unique compositions and properties, nanomaterials have recently seen a tremendous increase in use for novel cancer therapies. By taking advantage of the optical absorption of near-infrared light, researchers have utilized nanostructures such as carbon nanotubes, gold nanorods, and graphene oxide sheets to enhance photothermal therapies and target the effect on the tumor tissue. However, new uses for nanomaterials in targeted cancer therapy are coming to light, and the efficacy of photothermal therapy has increased dramatically. In this work, we review some of the current applications of nanomaterials to enhance photothermal therapy, specifically as photothermal absorbers, drug delivery vehicles, photoimmunological agents, and theranostic tools.

A Review on the Scope of Photothermal Therapy-Based Nanomedicines in Preclinical Models of Colorectal Cancer

Oncologic thermal ablation involves the use of hyperthermic temperatures to damage and treat solid cancers. Thermal ablation is being investigated as a method of treatment in colorectal cancers and has the potential to complement conventional anticancer treatments in managing local recurrence and metastatic disease. Photothermal therapy utilizes photosensitive agents to generate local heat and induce thermal ablation. There is growing interest in developing nanotechnology platforms to deliver such photosensitive agents. An advantage of nanomedicines is their multifunctionality, with the capability to deliver combinations of chemotherapeutics and cancer-imaging agents. To date, there have been no clinical studies evaluating photothermal therapy-based nanomedicines in colorectal cancers. This review presents the current scope of preclinical studies, investigating nanomedicines that have been developed for delivering multimodal photothermal therapy to colorectal cancers, with an emphasis on potential clinical applications.

Core–shell noble-metal@zeolitic-imidazolate-framework nanocarriers with high cancer treatment efficiency in vitro

Core–shell Au@zeolitic-imidazolate-framework nanocarriers with high drug-loading, controlled drug release properties, and high cancer treatment efficiency.

Nitroxide-radicals-modified gold nanorods for in vivo CT/MRI-guided photothermal cancer therapy

Purpose

This article presents a report of the synthesis, characterization, and biomedical application of nitroxide-radicals-modified gold nanorods (Au-TEMPO NRs) for imaging-guided photothermal cancer therapy.

Patients and methods

Au nanorods were synthesized through seed-mediated growth method, 4-Amino-TEMPO was added and the reaction proceeded under magnetic stirring.

Results

With a mean length of 39.2 nm and an average aspect ratio of approximately 3.85, Au-TEMPO NRs showed good photothermal ability when they were irradiated by 808-nm laser. Au-TEMPO NRs could be stored in PBS for more than 1 month, showed no cytotoxicity against both tumor and normal cells at a concentration of up to 3 mg/mL, and functioned as a dual-mode contrast agent for CT/magnetic resonance (MR) imaging in vitro and in vivo, due to their high X-ray attenuation of Au and good r1 relaxivity of nitroxide radicals. Further, they had a long retention time (~4 hours) in the main organs, which enabled a long CT/MR imaging time window for diagnosis. Bio-distribution results revealed that these Au-TEMPO NRs passively aggregated in the liver and spleen. After irradiation by 808-nm laser, Au-TEMPO NRs could ablate the solid tumor in 4T1 tumor-bearing mice, which implied they were a potential theranostic agent for dual-mode imaging and photothermal cancer therapy.

Conclusion

This type of Au-TEMPO NRs with the abilities of CT/MR imaging and photothermal therapy, can play an active role in imaging-guided photothermal cancer therapy.

Developing Hollow-Channel Gold Nanoflowers as Trimodal Intracellular Nanoprobes

Gold nanoparticles-enabled intracellular surface-enhanced Raman spectroscopy (SERS) provides a sensitive and promising technique for single cell analysis. Compared with spherical gold nanoparticles, gold nanoflowers, i.e., flower-shaped gold nanostructures, can produce a stronger SERS signal. Current exploration of gold nanoflowers for intracellular SERS has been considerably limited by the difficulties in preparation, as well as background signal and cytotoxicity arising from the surfactant capping layer. Recently, we have developed a facile and surfactant-free method for fabricating hollow-channel gold nanoflowers (HAuNFs) with great single-particle SERS activity. In this paper, we investigate the cellular uptake and cytotoxicity of our HAuNFs using a RAW 264.7 macrophage cell line, and have observed effective cellular internalization and low cytotoxicity. We have further engineered our HAuNFs into SERS-active tags, and demonstrated the functionality of the obtained tags as trimodal nanoprobes for dark-field and fluorescence microscopy imaging, together with intracellular SERS.

Highly Biocompatible Chlorin e6-Loaded Chitosan Nanoparticles for Improved Photodynamic Cancer Therapy

The photosensitizer Chlorin e6 (Ce6) has been frequently employed for photodynamic therapy (PDT) of cancer; however, its nonspecific toxicity has limited its clinical applications. In this study, we prepared chitosan nanoparticles (CNPs), with a mean diameter of approximately 130 nm, by a nonsolvent-aided counterion complexation method in an aqueous solution, into which Ce6 could be physically entrapped during the preparation process. These CNPs and Ce6-loaded CNPs (CNPs-Ce6) were fully characterized by UV-vis, photoluminescence, and Fourier transform infrared spectroscopic analysis, as well as dynamic light scattering and transmission electron microscopy measurements. More importantly, the biocompatibility of the otherwise toxic Ce6 was significantly improved upon its loading into the CNPs, as demonstrated by both confocal laser scanning microscopy analysis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Furthermore, the PDT efficiency of Ce6-loaded CNPs was dramatically enhanced, in comparison with that of the free Ce6, as shown by both MTT and flow cytometry assays. This discovery provides a novel strategy for improving the biocompatibility and therapeutic efficacy of PDT agents by using a natural, biocompatible polysaccharide carrier.

Multifunctional Photonic Nanomaterials for Diagnostic, Therapeutic, and Theranostic Applications

The last decade has seen dramatic progress in the principle, design, and fabrication of photonic nanomaterials with various optical properties and functionalities. Light-emitting and light-responsive nanomaterials, such as semiconductor quantum dots, plasmonic metal nanoparticles, organic carbon, and polymeric nanomaterials, offer promising approaches to low-cost and effective diagnostic, therapeutic, and theranostic applications. Reasonable endeavors have begun to translate some of the promising photonic nanomaterials to the clinic. Here, current research on the state-of-the-art and emerging photonic nanomaterials for diverse biomedical applications is reviewed, and the remaining challenges and future perspectives are discussed.

Photothermal lysis of pathogenic bacteria by platinum nanodots decorated gold nanorods under near infrared irradiation

Photothermal lysis is an effective method for fast removal of pathogenic bacteria from bacterial contaminated environments and human body, irrespective of bacterial drug resistance. In the present work, a highly effective photothermal agent, Au@Pt nanorods (NRs), was prepared by modification of Pt nanodots with particle size of 5nm on the surface of Au NRs with a length of ca. 41nm and a width of ca. 13nm. The LSPR absorbance band of Au@Pt NRs could be tuned from 755 to 845nm by changing the Pt loading from 0.05 to 0.2, as compared to Au NRs. The photothermal conversion efficiency of Au@Pt NRs depended on the Pt loading, Au@Pt NRs concentration, and power density. Under NIR irradiation, the Au@Pt_0.1 NRs exhibited the highest efficiency in photothermal lysis of both gram-positive and gram-negative bacteria. The introduction of Pt nanodots on the surface of Au@Pt NRs not only enhanced their photothermal conversions but also enhanced their affinity to bacteria and significantly decreased their cytotoxicity. The photothermal lysis of bacteria over Au@Pt NRs caused the damage onto the cell walls of bacteria, implying that the killing of bacteria probably went through the thermal ablation mechanism.

Stabilisation of small mono- and bimetallic gold–silver nanoparticles using calix[8]arene derivatives

We report a facile approach to synthesise small Au–Ag alloyed nanoparticles using a new cali[8]arene derivative as a stabiliser.

Polydopamine Nanoparticles for Combined Chemo- and Photothermal Cancer Therapy

Cancer therapy with two different modalities can enhance treatment efficacy and reduce side effects. This paper describes a new method for combined chemo- and photothermal therapy of cancer using poly dopamine nanoparticles (PDA-NPs), where PDA-NPs serve not only as a photothermal agent with strong near infrared absorbance and high energy conversion efficiency, but also as a carrier to deliver cisplatin via interaction between cisplatin and catechol groups on PDA-NPs. Polyethylene glycol (PEG) was introduced through Michael addition reaction to improve the stability of PDA-NPs in physiological condition. A remarkable synergistic therapeutic effect has been achieved compared with respective single treatments. This work suggests that the PDA-based nanoplatform can be a universal scaffold for combined chemo- and photothermal therapy of cancer.

Alkali-etching growth of nest-like Ag@mTiO2 hierarchical nanostructures and their potential applications

Porous nanomaterials have attracted extensive interests in adsorption, catalysis, biosensors, and biomedicine due to their high surface area, well-defined pore structure and tunable pore size. However, how to obtain porous nanomaterials of desirable component and unique structure with multifunctionalities and synergetic properties is still a great challenge. In this work, a novel nest-like Ag@mTiO₂ hierarchical nanostructure with Ag nanoparticle as the core and a mesoporous crystalline TiO₂ as the protective shell was successfully prepared by layer-by-layer assembly technique and alkali-etching hydrothermal route. By simply changing the conditions of alkali etching, different nanostructures could be obtained, such as core-shell or rattle type. In the process, the thickness of coating silica layer and TiO₂ shell both played important roles for the formation of desired nanostructures. The as-prepared products had a large specific surface area of 301m²/g and a tailored TiO₂ outer shell. Raman spectra results showed perfect SERS signal of the tags enhanced and remained good stability even after one month. Doxycycline (Doxy) was chosen to evaluate their drug loading and controlled release properties. The results indicated that the obtained Ag@mTiO₂ nanoparticles exhibited good biocompatibility and excellent drug-loading capacity. Consequently, they are also expected to serve as ideal candidates for more potential applications including photocatalysis, drug controlled release, biosensor and cell imaging, etc.

Nanoparticles for bone tissue engineering

Tissue engineering (TE) envisions the creation of functional substitutes for damaged tissues through integrated solutions, where medical, biological, and engineering principles are combined. Bone regeneration is one of the areas in which designing a model that mimics all tissue properties is still a challenge. The hierarchical structure and high vascularization of bone hampers a TE approach, especially in large bone defects. Nanotechnology can open up a new era for TE, allowing the creation of nanostructures that are comparable in size to those appearing in natural bone. Therefore, nanoengineered systems are now able to more closely mimic the structures observed in naturally occurring systems, and it is also possible to combine several approaches - such as drug delivery and cell labeling - within a single system. This review aims to cover the most recent developments on the use of different nanoparticles for bone TE, with emphasis on their application for scaffolds improvement; drug and gene delivery carriers, and labeling techniques. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:590-611, 2017.

Chitosan supraparticles with fluorescent silica nanoparticle shells and nanodiamond-loaded cores

Supraparticles with a biopolymer chitosan core and templated with (ultra)small nanoparticles are reported. Nanoparticle density on the template surface could be controlled and the template core could be loaded with nanodiamonds.

NIR light-triggered shrinkable thermoresponsive PNVCL nanoshells for cancer theranostics

NIR light-responsive gold coated shrinkable thermoresponsive nanoshells as preliminary step to ablate large and deep-seated tumors using combined chemo-photothermal therapy.

A Multifunctional Platform for Tumor Angiogenesis-Targeted Chemo-Thermal Therapy Using Polydopamine-Coated Gold Nanorods

Image-guided combined chemo-thermal therapy assists in optimizing treatment time, enhancing therapeutic efficiency, and circumventing side effects. In the present study, we developed a chemo-photothermal theranostic platform based on polydopamine (PDA)-coated gold nanorods (GNRs). The PDA coating was thin; however, it significantly suppressed the cytotoxicity of the cetyltrimethylammonium bromide template and allowed high cisplatin loading efficiency, arginine-glycine-aspartic acid (RGD) peptide (c(RGDyC)) conjugation, and chelator-free iodine-125 labeling (RGD-¹²⁵IPt-PDA@GNRs). While loaded cisplatin was released in a pH-sensitive manner, labeled ¹²⁵I was outstandingly stable under biological conditions. RGD-¹²⁵IPt-PDA@GNRs had a high specificity for αvβ₃ integrin, and consequently, they could selectively accumulate in tumors, as revealed by single photon emission computed tomography/CT imaging, and in target tumor angiogenic vessels, as shown by high-resolution photoacoustic imaging. As RGD-¹²⁵IPt-PDA@GNRs targets tumor angiogenesis, it is a highly potent tumor therapy. Combined chemo-photothermal therapy with probes could thoroughly ablate tumors and inhibit tumor relapse via a synergistic antitumor effect. Our studies demonstrated that RGD-¹²⁵IPt-PDA@GNRs is a robust platform for image-guided, chemo-thermal tumor therapy with outstanding synergistic tumor killing and relapse inhibition effects.

TiO2 nanotube platforms for smart drug delivery: a review

Titania nanotube (TNT) arrays are recognized as promising materials for localized drug delivery implants because of their excellent properties and facile preparation process. This review highlights the concept of localized drug delivery systems based on TNTs, considering their outstanding biocompatibility in a series of ex vivo and in vivo studies. Considering the safety of TNT implants in the host body, studies of the biocompatibility present significant importance for the clinical application of TNT implants. Toward smart TNT platforms for sustainable drug delivery, several advanced approaches were presented in this review, including controlled release triggered by temperature, light, radiofrequency magnetism, and ultrasonic stimulation. Moreover, TNT implants used in medical therapy have been demonstrated by various examples including dentistry, orthopedic implants, cardiovascular stents, and so on. Finally, a future perspective of TNTs for clinical applications is provided.

Effect of Molecular Structure on Stability of Organic Nanoparticles Formed by Bodipy Dimers

The objective was to evaluate the stability of organic nanoparticles made from Bodipy dimers. Bodipy dimers with different length of linkers were synthesized via multicomponent Passerini reaction, and could form the fluorescent nanoparticles (FNPs) through nanoprecipitation. Bodipy-dimers FNPs with long chain linker indicated better stability in biological condition than those with short one as revealed by changes of diameter and size distribution. The FNPs possessed high physical homogeneity and low cytotoxicity. The molecular structure dependent stability was also validated by confocal laser scanning microscope based on the dissociation-induced fluorescence recovering. Importantly, stable FNPs also could be used to load hydrophobic cargoes and deliver them into cytoplasm. We believe this systematic study between structure and stability might open new opportunities for designing stable nanoparticles for various applications.

Reducing Both Pgp Overexpression and Drug Efflux with Anti-Cancer Gold-Paclitaxel Nanoconjugates

Repeated administrations of anti-cancer drugs to patients often induce drug resistance. P-glycoprotein (Pgp) facilitates an efficient drug efflux, preventing cellular accumulation of drugs and causing multi-drug resistance (MDR). In this study, we developed a gold-paclitaxel nanoconjugate system to overcome MDR. Gold nanoparticles (GNPs) were conjugated with β-cyclodextrin enclosing paclitaxel (PTX) molecules and PEG molecules. GNP conjugates were effectively endocytosed by both drug-sensitive human lung cancer H460 cells and Pgp-overexpressed drug-resistant H460_PTX cells. Compared with PTX, PGNPs did not induce the Pgp overexpression in drug-sensitive H460 cells after long-term treatment and also avoided being pumped out of cells by overexpressed Pgp molecules in H460_PTX with a 17-fold lower EC₅₀ compared to PTX. Fluorescent microscopy and flow cytometry further confirmed that fluorescent labeled PGNPs (f-PGNPs) maintained a high cellular PTX level in both H460 and H460_PTX cells. These results demonstrated that nano-drug conjugates were able to avoid the development of drug resistance in sensitive cells and evade Pgp-mediated drug resistance and to maintain a high cytotoxicity in drug-resistant cancer cells. These findings exemplify a powerful nanotechnological approach to the long-lasting issue of chemotherapy-induced drug resistance.

Delivery and cytotoxicity of doxorubicin and temozolomide to primary glioblastoma cells using gold nanospheres and gold nanorods

Nanoparticles with coating entrapping a chemotherapeutic drug for delivery have not been tested for their cytotoxic effects in in-vitro glioblastoma cell cultures to increase treatment efficacy. Therefore, we synthesized silica-coated gold nanorods and gold nanospheres that were loaded with doxorubicin or temozolomide. The morphology of the nanoparticles was characterized using transmission electron microscopy (TEM), the molecular structure was characterized using infrared spectroscopy and in vitro efficacy was determined using glioblastoma cell cultures. TEM analysis showed that gold nanorods had a length of 49–65 nm and a diameter of 8.5–14 nm whereas gold nanospheres had a diameter of 9.5–37 nm. Infrared spectroscopy of doxorubicin and temozolomide and the silica coating revealed molecular fingerprints such as bending, stretching and vibrations of chemical bonds that confirmed the presence of silica coating and drug loading of the gold nanoparticles. In the biological assessment of the effects of drug-loaded gold nanoparticles on primary glioblastoma cell cultures, cytotoxicity, viability and the ratio of cyototoxicity and viability were used as parameters to analyze the effects on the cells of drug delivery via gold nanoparticles on the cells. Our data suggest that doxorubicin in the concentration range of 0.12–3.16 μM when delivered using both gold nanorods and nanospheres induced a 3.8–5.5-fold increased cytotoxicity in comparison to direct delivery. Temozolomide in the concentration range of 4.6–115 μM when delivered by either type of gold nanoparticles induced a 2–4-fold increased cytotoxicity in comparison to direct delivery. Nanospheres were more effective in delivery and cytotoxicity of doxorubicin and temozolomide to glioblastoma cells than gold nanorods. Our data suggest that gold nanoparticles and in particular gold nanospheres are more effective in delivery of doxorubicin and temozolomide to primary glioblastoma cells in culture than direct delivery.

Chitosan coated gold nanorod chelating gadolinium for MRI-visible photothermal therapy of cancer

The multifunctional nanoparticles synthesized via nonsolvent counterion complexation method are applied for in vivo MR imaging and photothermal therapy of cancer.

Nanoshell-mediated photothermal therapy can enhance chemotherapy in inflammatory breast cancer cells

Nanoshell-mediated photothermal therapy (PTT) is currently being investigated as a standalone therapy for the treatment of cancer. The cellular effects of PTT include loss of membrane integrity, so we hypothesized that nanoshell-mediated PTT could potentiate the cytotoxicity of chemotherapy by improving drug accumulation in cancer cells. In this work, we validated our hypothesis using doxorubicin as a model drug and SUM149 inflammatory breast cancer cells as a model cancer subtype. In initial studies, SUM149 cells were exposed to nano-shells and near-infrared light and then stained with ethidium homodimer-1, which is excluded from cells with an intact plasma membrane. The results confirmed that nanoshell-mediated PTT could increase membrane permeability in SUM149 cells. In complementary experiments, SUM149 cells treated with nanoshells, near-infrared light, or a combination of the two to yield low-dose PTT were exposed to fluorescent rhodamine 123. Analyzing rhodamine 123 fluorescence in cells via flow cytometry confirmed that increased membrane permeability caused by PTT could enhance drug accumulation in cells. This was validated using fluorescence microscopy to assess intracellular distribution of doxorubicin. In succeeding experiments, SUM149 cells were exposed to subtherapeutic levels of doxorubicin, low-dose PTT, or a combination of the two treatments to determine whether the additional drug uptake induced by PTT is sufficient to enhance cell death. Analysis revealed minimal loss of viability relative to controls in cells exposed to subtherapeutic levels of doxorubicin, 15% loss of viability in cells exposed to low-dose PTT, and 35% loss of viability in cells exposed to combination therapy. These data indicate that nanoshell-mediated PTT is a viable strategy to potentiate the effects of chemotherapy and warrant further investigation of this approach using other drugs and cancer subtypes.

Aptamer-conjugated, fluorescent gold nanorods as potential cancer theradiagnostic agents

GNRs are emerging as a new class of probes for theradiagnostic applications thanks to their unique optical properties. However, the achievement of proper nanoconstructs requires the synthesis of highly pure GNRs with well-defined aspect ratio (AR), in addition to extensive surface chemistry modification to provide them with active targeting and, possibly, multifunctionality. In this work, we refined the method of the seed mediated growth and developed a robust procedure for the fabrication of GNRs with specific AR. We also revealed and characterized unexplored aging phenomena that follow the synthesis and consistently alter GNRs' final AR. Such advances appreciably improved the feasibility of GNRs fabrication and offered useful insights on the growth mechanism. We next produced fluorescent, biocompatible, aptamer-conjugated GNRs by performing ligand exchange followed by bioconjugation to anti-cancer oligonucleotide AS1411. In vitro studies showed that our nanoconstructs selectively target cancer cells while showing negligible cytotoxicity. As a result, our aptamer-conjugated GNRs constitute ideal cancer-selective multifunctional probes and promising candidates as photothermal therapy agents.