Efficient photoacoustic imaging using indocyanine green (ICG) loaded functionalized mesoporous silica nanoparticles

A Facile Approach to Producing Liposomal J-Aggregates of Indocyanine Green with Diagnostic and Therapeutic Potential

Liposomal J-Aggregates of Indocyanine Green (L-JA) can serve as a biocompatible and biodegradable nanoparticle for photoacoustic imaging and photothermal therapy. When compared to monomeric IcG, L-JA are characterized by longer circulation, improved photostability, elevated absorption at longer wavelengths, and increased photoacoustic signal generation. However, the documented methods for production of L-JA vary widely. We developed an approach to efficiently form IcG J-aggregates (IcG-JA) directly in liposomes at elevated temperatures. Aggregating within fully formed liposomes ensures particle uniformity and allows for control of J-aggregate size. L-JA have unique properties compared to IcG. L-JA provide significant contrast enhancement in photoacoustic images for up to 24 hours after injection, while IcG and unencapsulated IcG-JA are cleared within an hour. L-JA allow for more accurate photoacoustic-based sO2 estimation and particle tracking compared to IcG. Furthermore, photothermal heating of L-JA with an 852nm laser is demonstrated to be more effective at lower laser powers than conventional 808nm lasers for the first time. The presented technique offers an avenue for formulating a multi-faceted contrast agent for photoacoustic imaging and photothermal therapy that offers significant advantages over other conventional agents.

Evaluation of the tumor-targeting specific imaging and killing effect of a CEA-targeting nanoparticle in colorectal cancer

INTRODUCTION

Colorectal cancer (CRC) is a prevalent digestive malignancy with significant global mortality and morbidity rates. Improving diagnostic capabilities for CRC and investigating novel therapeutic approaches are pressing clinical imperatives. Additionally, carcinoembryonic antigen (CEA) has emerged as a highly promising candidate for both colorectal tumor imaging and treatment.

METHODS

A novel active CEA-targeting nanoparticle, CEA(Ab)-MSNs-ICG-Pt, was designed and synthesized, which served as a tumor-specific fluorescence agent to help in CRC near-infrared (NIR) fluorescence imaging. In cell studies, CEA(Ab)-MSNs-ICG-Pt exhibited specific targeting to RKO cells through specific antibody-antigen binding of CEA, resulting in distribution both within and around these cells. The tumor-targeting-specific imaging capabilities of the nanoparticle were determined through in vivo fluorescence imaging experiments. Furthermore, the efficacy of the nanoparticle in delivering chemotherapeutics and its killing effect were evaluated both in vitro and in vivo.

RESULTS

The CEA(Ab)-MSNs-ICG-Pt nanoparticle, designed as a novel targeting agent for carcinoembryonic antigen (CEA), exhibited dual functionality as a targeting fluorescent agent. This CEA-targeting nanoparticle showed exceptional efficacy in eradicating CRC cells in comparison to individual treatment modalities. Furthermore, it exhibits exceptional biosafety and biocompatibility properties. CEA(Ab)-MSNs-ICG-Pt exhibits significant promise due to its ability to selectively target tumors through NIR fluorescence imaging and effectively eradicate CRC cells with minimal adverse effects in both laboratory and in vivo environments.

CONCLUSION

The favorable characteristics of CEA(Ab)-MSNs-ICG-Pt offer opportunities for its application in chemotherapeutic interventions, tumor-specific NIR fluorescence imaging, and fluorescence-guided surgical procedures.

Supramolecular dye nanoassemblies for advanced diagnostics and therapies

Dyes have conventionally been used in medicine for staining cells, tissues, and organelles. Since these compounds are also known as photosensitizers (PSs) which exhibit photoresponsivity upon photon illumination, there is a high desire towards formulating these molecules into nanoparticles (NPs) to achieve improved delivery efficiency and enhanced stability for novel imaging and therapeutic applications. Furthermore, it has been shown that some of the photophysical properties of these molecules can be altered upon NP formation thereby playing a major role in the outcome of their application. In this review, we primarily focus on introducing dye categories, their formulation strategies and how these strategies affect their photophysical properties in the context of photothermal and non-photothermal applications. More specifically, the most recent progress showing the potential of dye supramolecular assemblies in modalities such as photoacoustic and fluorescence imaging, photothermal and photodynamic therapies as well as their employment in photoablation as a novel modality will be outlined. Aside from their photophysical activity, we delve shortly into the emerging application of dyes as drug stabilizing agents where these molecules are used together with aggregator molecules to form stable nanoparticles.

Tumor Cell-Targeting and Tumor Microenvironment-Responsive Nanoplatforms for the Multimodal Imaging-Guided Photodynamic/Photothermal/Chemodynamic Treatment of Cervical Cancer

Purpose

Phototherapy, known for its high selectivity, few side effects, strong controllability, and synergistic enhancement of combined treatments, is widely used in treating diseases like cervical cancer.

Methods

In this study, hollow mesoporous manganese dioxide was used as a carrier to construct positively charged, poly(allylamine hydrochloride)-modified nanoparticles (NPs). The NP was efficiently loaded with the photosensitizer indocyanine green (ICG) via the addition of hydrogen phosphate ions to produce a counterion aggregation effect. HeLa cell membrane encapsulation was performed to achieve the final M-HMnO2@ICG NP. In this structure, the HMnO2 carrier responsively degrades to release ICG in the tumor microenvironment, self-generates O2 for sensitization to ICG-mediated photodynamic therapy (PDT), and consumes GSH to expand the oxidative stress therapeutic effect [chemodynamic therapy (CDT) + PDT]. The ICG accumulated in tumor tissues exerts a synergistic PDT/photothermal therapy (PTT) effect through single laser irradiation, improving efficiency and reducing side effects. The cell membrane encapsulation increases nanomedicine accumulation in tumor tissues and confers an immune evasion ability. In addition, high local temperatures induced by PTT can enhance CDT. These properties of the NP enable full achievement of PTT/PDT/CDT and targeted effects.

Results

Mn2+ can serve as a magnetic resonance imaging agent to guide therapy, and ICG can be used for photothermal and fluorescence imaging. After its intravenous injection, M-HMnO2@ICG accumulated effectively at mouse tumor sites; the optimal timing of in-vivo laser treatment could be verified by near-infrared fluorescence, magnetic resonance, and photothermal imaging. The M-HMnO2@ICG NPs had the best antitumor effects among treatment groups under near-infrared light conditions, and showed good biocompatibility.

Conclusion

In this study, we designed a nano-biomimetic delivery system that improves hypoxia, responds to the tumor microenvironment, and efficiently loads ICG. It provides a new economical and convenient strategy for synergistic phototherapy and CDT for cervical cancer.

Injectable Thermogelling Nanostructured Ink as Simultaneous Optical and Magnetic Resonance Imaging Contrast Agent for Image-Guided Surgery

The development of efficient and biocompatible contrast agents is particularly urgent for modern clinical surgery. Nanostructured materials raised great interest as contrast agents for different imaging techniques, for which essential features are high contrasts, and in the case of precise clinical surgery, minimization of the signal spatial dispersion when embedded in biological tissues. This study deals with the development of a multimodal contrast agent based on an injectable hydrogel nanocomposite containing a lanthanide-activated layered double hydroxide coupled to a biocompatible dye (indocyanine green), emitting in the first biological window. This novel nanostructured thermogelling hydrogel behaves as an efficient tissue marker for optical and magnetic resonance imaging because the particular formulation strongly limits its spatial diffusion in biological tissue by exploiting a simple injection. The synergistic combination of these properties permits to employ the hydrogel ink simultaneously for both optical and magnetic resonance imaging, easy monitoring of the biological target, and, at the same time, increasing the spatial resolution during a clinical surgery. The biocompatibility and excellent performance as contrast agents are very promising for possible use in image-guided surgery, which is currently one of the most challenging topics in clinical research.

Engineered photonic near-infrared light activated photothermal theranostic nanovaccine induced targeted remodeling of tumor microenvironment

Tumor recurrence, which happens as a result of persisting tumor cells and minor lesions after treatments like surgery and chemotherapy, is a major problem in oncology. Herein, a strategy to combat this issue by utilize a theranostic nanovaccine composed of photonic HCuS. This nanovaccine aims to eradicate cancer cells and their traces while also preventing tumor recurrence via optimizing the photothermal immune impact. Successful membrane targeting allows for the introduction of new therapeutic agents into the tumor cells. Together with co-encapsulated Toll-Like Receptors (TLR7/8) agonist R848 for activating T cells and maturing DCs, the combined effects of HCuS and ICG function as photothermal agents that generate heat in the presence of NIR light. Photothermal-mediated immunotherapy with therapeutic modalities proved successful in killing tumor cells. By activating the immune system, this new photonic nanovaccine greatly increases immunogenic cell death (ICD), kills tumor cells, and prevents their recurrence.

Calcium-enriched carbon nanoparticles loaded with indocyanine green for near-infrared fluorescence imaging-guided synergistic calcium overload, photothermal therapy, and glutathione-depletion-enhanced photodynamic therapy

Combining phototherapy with other treatments has significantly advanced cancer therapy. Here, we designed and fabricated calcium-enriched carbon nanoparticles (Ca-CNPs) that could effectively deplete glutathione (GSH) and release calcium ions in tumors, thereby enhancing the efficacy of photodynamic therapy (PDT) and the calcium overload effect that leads to mitochondrial dysfunction. Due to the electrostatic interaction, π-π stacking interaction, multiple hydrogen bonds, and microporous structures, indocyanine green (ICG) was loaded onto the surface of Ca-CNPs with a high loading efficiency of 44.7 wt%. The obtained Ca-CNPs@ICG can effectively improve the photostability of ICG while retaining its ability to generate singlet oxygen (1O2) and undergo photothermal conversion (Ca-CNPs@ICG vs. ICG, 45.1% vs. 39.5%). In vitro and in vivo experiments demonstrated that Ca-CNPs@ICG could be used for near-infrared fluorescence imaging-guided synergistic calcium overload, photothermal therapy, and GSH depletion-enhanced PDT. This study sheds light on the improvement of 1O2 utilization efficiency and calcium overload-induced mitochondrial membrane potential imbalance in tumor cells.

Silicon-containing nanomedicine and biomaterials: materials chemistry, multi-dimensional design, and biomedical application

The invention of silica-based bioactive glass in the late 1960s has sparked significant interest in exploring a wide range of silicon-containing biomaterials from the macroscale to the nanoscale. Over the past few decades, these biomaterials have been extensively explored for their potential in diverse biomedical applications, considering their remarkable bioactivity, excellent biocompatibility, facile surface functionalization, controllable synthesis, etc. However, to expedite the clinical translation and the unexpected utilization of silicon-composed nanomedicine and biomaterials, it is highly desirable to achieve a thorough comprehension of their characteristics and biological effects from an overall perspective. In this review, we provide a comprehensive discussion on the state-of-the-art progress of silicon-composed biomaterials, including their classification, characteristics, fabrication methods, and versatile biomedical applications. Additionally, we highlight the multi-dimensional design of both pure and hybrid silicon-composed nanomedicine and biomaterials and their intrinsic biological effects and interactions with biological systems. Their extensive biomedical applications span from drug delivery and bioimaging to therapeutic interventions and regenerative medicine, showcasing the significance of their rational design and fabrication to meet specific requirements and optimize their theranostic performance. Additionally, we offer insights into the future prospects and potential challenges regarding silicon-composed nanomedicine and biomaterials. By shedding light on these exciting research advances, we aspire to foster further progress in the biomedical field and drive the development of innovative silicon-composed nanomedicine and biomaterials with transformative applications in biomedicine.

Silica nanoparticles: A review of their safety and current strategies to overcome biological barriers

Silica nanoparticles (SNP) have gained tremendous attention in the recent decades. They have been used in many different biomedical fields including diagnosis, biosensing and drug delivery. Medical uses of SNP for anti-cancer, anti-microbial and theranostic applications are especially prominent due to their exceptional performance to deliver many different small molecules and recently biologics (mRNA, siRNA, antigens, antibodies, proteins, and peptides) at targeted sites. The physical and chemical properties of SNP such as large specific surface area, tuneable particle size and porosity, excellent biodegradability and biocompatibility make them an ideal drug delivery and diagnostic platform. Based on the available data and the pre-clinical performance of SNP, recent interest has driven these innovative materials towards clinical application with many of the formulations already in Phase I and Phase II trials. Herein, the progress of SNP in biomedical field is reviewed, and their safety aspects are analysed. Importantly, we critically evaluate the key structural characteristics of SNP to overcome different biological barriers including the blood-brain barrier (BBB), skin, tumour barrier and mucosal barrier. Future directions, potential pathways, and target areas towards rapid clinical translation of SNP are also recommended.

Acoustic platforms meet MXenes - a new paradigm shift in the palette of biomedical applications

The wide applicability of acoustics in the life of mankind spread over health, energy, environment, and others. These acoustic technologies rely on the properties of the materials with which they are made of. However, traditional devices have failed to develop into low-cost, portable devices and need to overcome issues like sensitivity, tunability, and applicability in biological in vivo studies. Nanomaterials, especially 2D materials, have already been proven to produce high optical contrast in photoacoustic applications. One such wonder kid in the materials family is MXenes, which are transition metal carbides, that are nowadays flourishing in the materials world. Recently, it has been demonstrated that MXene nanosheets and quantum dots can be synthesized by acoustic excitations. In addition, MXene can be used as a mechanical sensing material for building piezoresistive sensors to realize sound detection as it produces a sensitive response to pressure and vibration. It has also been demonstrated that MXene nanosheets show high photothermal conversion capability, which can be utilized in cancer treatment and photoacoustic imaging (PAI). In this review, we have rendered the role of acoustics in the palette of MXene, including acoustic synthetic strategies of MXenes, applications such as acoustic sensors, PAI, thermoacoustic devices, sonodynamic therapy, artificial ear drum, and others. The review also discusses the challenges and future prospects of using MXene in acoustic platforms in detail. To the best of our knowledge, this is the first review combining acoustic science in MXene research.

NIR-triggered thermosensitive polymer brush coating modified intraocular lens for smart prevention of posterior capsular opacification

Posterior capsule opacification (PCO) is the most common complication after cataract surgery. Drug-eluting intraocular lens (IOLs) is a promising concept of PCO treatment in modern cataract surgery. However, the large dose of drugs in IOL leads to uncontrollable and unpredictable drug release, which inevitably brings risks of overtreatment and ocular toxicity. Herein, a low-power NIR-triggered thermosensitive IOL named IDG@P(NIPAM-co-AA)-IOL is proposed to improve security and prevent PCO by synergetic controlled drug therapy and simultaneous photo-therapy. Thermosensitive polymer brushes Poly(N-isopropylacrylamide-co-Acrylic acid) (P(NIPAM-co-AA)) is prepared on IOL via surface-initiated reversible addition-fragmentation chain transfer (SI-RAFT) polymerization. Then, Doxorubicin (DOX) and Indocyanine green (ICG) co-loaded Gelatin NPs (IDG NPs) are loaded in P(NIPAM-co-AA) by temperature control. The IDG NPs perform in suit photodynamic & photothermal therapy (PTT&PDT), and the produced heat also provides a trigger for controllable drug therapy with a cascade effect. Such functional IOL shows excellent synergistic drug-phototherapy effect and NIR-triggered drug release behavior. And there is no obvious PCO occurrence in IDG@P(NIPAM-co-AA) IOL under NIR irradiation compared with control group. This proposed IDG@P(NIPAM-co-AA)-IOL serves as a promising platform that combines phototherapy and drug-therapy to enhance the therapeutic potential and medication safety for future clinical application of PCO treatment.

NIR-II Nanoprobes: A Review of Components-Based Approaches to Next-Generation Bioimaging Probes

Fluorescence and photoacoustic imaging techniques offer valuable insights into cell- and tissue-level processes. However, these optical imaging modalities are limited by scattering and absorption in tissue, resulting in the low-depth penetration of imaging. Contrast-enhanced imaging in the near-infrared window improves imaging penetration by taking advantage of reduced autofluorescence and scattering effects. Current contrast agents for fluorescence and photoacoustic imaging face several limitations from photostability and targeting specificity, highlighting the need for a novel imaging probe development. This review covers a broad range of near-infrared fluorescent and photoacoustic contrast agents, including organic dyes, polymers, and metallic nanostructures, focusing on their optical properties and applications in cellular and animal imaging. Similarly, we explore encapsulation and functionalization technologies toward building targeted, nanoscale imaging probes. Bioimaging applications such as angiography, tumor imaging, and the tracking of specific cell types are discussed. This review sheds light on recent advancements in fluorescent and photoacoustic nanoprobes in the near-infrared window. It serves as a valuable resource for researchers working in fields of biomedical imaging and nanotechnology, facilitating the development of innovative nanoprobes for improved diagnostic approaches in preclinical healthcare.

Biobased Agents for Single-Particle Detection with Optoacoustics

Optoacoustic (OA, photoacoustic) imaging synergistically combines rich optical contrast with the resolution of ultrasound within light-scattering biological tissues. Contrast agents have become essential to boost deep-tissue OA sensitivity and fully exploit the capabilities of state-of-the-art OA imaging systems, thus facilitating the clinical translation of this modality. Inorganic particles with sizes of several microns can also be individually localized and tracked, thus enabling new applications in drug delivery, microrobotics, or super-resolution imaging. However, significant concerns have been raised regarding the low bio-degradability and potential toxic effects of inorganic particles. Bio-based, biodegradable nano- and microcapsules consisting of an aqueous core with clinically-approved indocyanine green (ICG) and a cross-linked casein shell obtained in an inverse emulsion approach are introduced. The feasibility to provide contrast-enhanced in vivo OA imaging with nanocapsules as well as localizing and tracking individual larger microcapsules of 4-5 µm is demonstrated. All components of the developed capsules are safe for human use and the inverse emulsion approach is known to be compatible with a variety of shell materials and payloads. Hence, the enhanced OA imaging performance can be exploited in multiple biomedical studies and can open a route to clinical approval of agents detectable at a single-particle level.

A Spiky Silver-Iron Oxide Nanoparticle for Highly Efficient Targeted Photothermal Therapy and Multimodal Imaging of Thrombosis

Thrombosis and its complications are responsible for 30% of annual deaths. Limitations of methods for diagnosing and treating thrombosis highlight the need for improvements. Agents that provide simultaneous diagnostic and therapeutic activities (theranostics) are paramount for an accurate diagnosis and rapid treatment. In this study, silver-iron oxide nanoparticles (AgIONPs) are developed for highly efficient targeted photothermal therapy and imaging of thrombosis. Small iron oxide nanoparticles are employed as seeding agents for the generation of a new class of spiky silver nanoparticles with strong absorbance in the near-infrared range. The AgIONPs are biofunctionalized with binding ligands for targeting thrombi. Photoacoustic and fluorescence imaging demonstrate the highly specific binding of AgIONPs to the thrombus when functionalized with a single chain antibody targeting activated platelets. Photothermal thrombolysis in vivo shows an increase in the temperature of thrombi and a full restoration of blood flow for targeted group but not in the non-targeted group. Thrombolysis from targeted groups is significantly improved (p < 0.0001) in comparison to the standard thrombolytic used in the clinic. Assays show no apparent side effects of AgIONPs. Altogether, this work suggests that AgIONPs are potential theranostic agents for thrombosis.

Hollow Nanooxidase Enhanced Phototherapy Against Solid Tumors

Although phototherapy has attracted extensive attention in antitumor field in recent years, its therapeutic effect is usually unsatisfactory because of the complexity and variability of the tumor microenvironment (TME). Herein, we report novel CoSn(OH)₆@CoOOH hollow carriers with oxidase properties that can enhance phototherapy. Hollow CoSn(OH)₆@CoOOH nanocubes (NCs) with a particle size of ∼160 nm were synthesized via a two-step process of coprecipitation and etching. These NCs can react with O₂ to generate singlet oxygen without hydrogen peroxide and consume glutathione, and their hollow structure can be utilized to carry drug molecules. After loading indocyanine green (ICG) and 1,2-bis(2-(4,5-dihydro-1H-imidazol-2-yl)propan-2-yl) diazene dihydrochloride (AIPH), the resulting nanosystem (HCIA) exhibited enhanced phototherapy effects through the catalytic activity of oxidase, production of alkyl radicals, and consumption of glutathione. Cell and mouse experiments showed that HCIA combined with near-infrared laser irradiation significantly inhibited the growth of 4T1 tumors. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that PI3K-Akt and MAPK signaling pathways were highly relevant to this therapeutic system. Such hollow NCs with oxidase activity have considerable potential for the design of multifunctional drug delivery vehicles for tumor therapy.

Biomedical Photoacoustic Imaging for Molecular Detection and Disease Diagnosis: "Always-On" and "Turn-On" Probes

Photoacoustic (PA) imaging is a nonionizing, noninvasive imaging technique that combines optical and ultrasonic imaging modalities to provide images with excellent contrast, spatial resolution, and penetration depth. Exogenous PA contrast agents are created to increase the sensitivity and specificity of PA imaging and to offer diagnostic information for illnesses. The existing PA contrast agents are categorized into two groups in this review: "always-on" and "turn-on," based on their ability to be triggered by target molecules. The present state of these probes, their merits and limitations, and their future development, is explored.

Silica nanoparticles: Biomedical applications and toxicity

Silica nanoparticles (SiNPs) are composed of silicon dioxide, the most abundant compound on Earth, and are used widely in many applications including the food industry, synthetic processes, medical diagnosis, and drug delivery due to their controllable particle size, large surface area, and great biocompatibility. Building on basic synthetic methods, convenient and economical strategies have been developed for the synthesis of SiNPs. Numerous studies have assessed the biomedical applications of SiNPs, including the surface and structural modification of SiNPs to target various cancers and diagnose diseases. However, studies on the in vitro and in vivo toxicity of SiNPs remain in the exploratory stage, and the toxicity mechanisms of SiNPs are poorly understood. This review covers recent studies on the biomedical applications of SiNPs, including their uses in drug delivery systems to diagnose and treat various diseases in the human body. SiNP toxicity is discussed in terms of the different systems of the human body and the individual organs in those systems. This comprehensive review includes both fundamental discoveries and exploratory progress in SiNP research that may lead to practical developments in the future.

Dual-Wavelength Photoacoustic Computed Tomography with Piezoelectric Ring-Array Transducer for Imaging of Indocyanine Green Liposomes Aggregation in Tumors

Recently, indocyanine green (ICG), as an FDA-approved dye, has been widely used for phototherapy. It is essential to obtain information on the migration and aggregation of ICG in deep tissues. However, existing fluorescence imaging platforms are not able to obtain the structural information of the tissues. Here, we prepared ICG liposomes (ICG-Lips) and built a dual-wavelength photoacoustic computed tomography (PACT) system with piezoelectric ring-array transducer to image the aggregation of ICG-Lips in tumors to guide phototherapy. Visible 780 nm light excited the photoacoustic (PA) effects of the ICG-Lips and near-infrared 1064 nm light provided the imaging of the surrounding tissues. The aggregation of ICG-Lips within the tumor and the surrounding tissues was visualized by PACT in real time. This work indicates that PACT with piezoelectric ring-array transducer has great potential in the real-time monitoring of in vivo drug distribution.

Exploiting the layer-by-layer nanoarchitectonics for the fabrication of polymer capsules: A toolbox to provide multifunctional properties to target complex pathologies

Polymer capsules fabricated via the layer-by-layer (LbL) approach have attracted a great deal of attention for biomedical applications thanks to their tunable architecture. Compared to alternative methods, in which the precise control over the final properties of the systems is usually limited, the intrinsic versatility of the LbL approach allows the functionalization of all the constituents of the polymeric capsules following relatively simple protocols. In fact, the final properties of the capsules can be adjusted from the inner cavity to the outer layer through the polymeric shell, resulting in therapeutic, diagnostic, or theranostic (i.e., combination of therapeutic and diagnostic) agents that can be adapted to the particular characteristics of the patient and face the challenges encountered in complex pathologies. The biomedical industry demands novel biomaterials capable of targeting several mechanisms and/or cellular pathways simultaneously while being tracked by minimally invasive techniques, thus highlighting the need to shift from monofunctional to multifunctional polymer capsules. In the present review, those strategies that permit the advanced functionalization of polymer capsules are accordingly introduced. Each of the constituents of the capsule (i.e., cavity, multilayer membrane and outer layer) is thoroughly analyzed and a final overview of the combination of all the strategies toward the fabrication of multifunctional capsules is presented. Special emphasis is given to the potential biomedical applications of these multifunctional capsules, including particular examples of the performed in vitro and in vivo validation studies. Finally, the challenges in the fabrication process and the future perspective for their safe translation into the clinic are summarized.

Liposomal Glucose Oxidase for Enhanced Photothermal Therapy and Photodynamic Therapy against Breast Tumors

Organic near-infrared fluorescent dye mediated photothermal therapy (PTT) and photodynamic therapy (PDT) suffer from heat shock response, since, heat shock proteins (HSPs) are overexpressed and can repair the proteins damaged by PTT and PDT. Starvation therapy by glucose oxide (GOx) can inhibit the heat shock response by limiting the energy supply. However, the delivery of sufficient and active GOx remains a challenge. To solve this problem, we utilize liposomes as drug carriers and prepare GOx loaded liposome (GOx@Lipo) with a high drug loading content (12.0%) and high enzymatic activity. The successful delivery of GOx shows excellent inhibition of HSPs and enhances PTT and PDT. Additionally, we apply the same liposome formulation to load near-infrared dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbo cyanine iodide (DiR) and prepare DiR contained liposomes (DiR@Lipo) for PTT and PDT. The liposomal formulation substantially enhances the PTT and PDT properties of DiR as well as the cellular uptake and tumor accumulation. Finally, the combination therapy shows excellent tumor inhibition on 4T1 tumor-bearing mice. Interestingly, we also find that the starvation therapy can efficiently inhibit tumor metastasis, which is probably due to the immunogenic effect. Our work presents a biocompatible and effective carrier for the combination of starvation therapy and phototherapy, emphasizing the importance of auxiliary starvation therapy against tumor metastasis and offering important guidance for clinical PTT and PDT.

RGD Peptide Modified Erythrocyte Membrane/Porous Nanoparticles Loading Mir-137 for NIR-Stimulated Theranostics of Glioblastomas

Cell-derived drug carriers have increasingly gained the interest of the scientific community due to their ability to imitate various natural properties of their source cells. We developed theranostics nanoplatforms composed of mesoporous silica nanoparticles (MSNs), indocyanine green (ICG) molecules, microRNAs-137 (miR-137), red-blood-cell membranes (RM), and tumor-targeting cyclo Arg-Gly-Asp-d-Phe-Cys peptides (cRGD(fC)), which were abbreviated as MSNs/ICG/miR/RM/RGD particles. These particles possessed photothermal and gene therapy properties due to ICG and miR-137, respectively. The photothermal conversion efficiency was ~18.7%. Upon 808 nm light irradiation, the tumor inhibition rate reached 94.9% with dosage of 10 mg/kg. The developed nanoplatform possessed unique properties, such as exceptional biocompatibility, immune escaping, and specific recognition, which was also used for near-infrared fluorescence, photoacoustic (PA) bimodal imaging-guided tumor recognition.

Near-Infrared Light-Triggered Generation of Reactive Oxygen Species and Induction of Local Hyperthermia from Indocyanine Green Encapsulated Mesoporous Silica-Coated Graphene Oxide for Colorectal Cancer Therapy

Near-infrared (NIR) light-mediated photothermal therapy (PTT) and photodynamic therapy (PDT) have widely been used for cancer treatment applications. However, a number of limitations (e.g., low NIR absorption capacity of photothermal agents, insufficient loading efficiency of photosensitive molecules) have hindered the widespread use of NIR-mediated cancer therapy. Therefore, we developed a mesoporous silica-coated reduced graphene oxide (rGO) nanocomposite that could provide a high encapsulation rate of indocyanine green (ICG) and enhance PTT/PDT efficiency in vitro and in vivo. The ICG-encapsulated nanocomposite not only enhances the photothermal effect but also generates a large number of tumor toxic reactive oxygen species (ROS). By conjugation of polyethylene glycol (PEG) with folic acid (FA) as a tumor targeting moiety, we confirmed that ICG-encapsulated mesoporous silica (MS)-coated rGO nanocomposite (ICG@MS-rGO-FA) exhibited high colloidal stability and intracellular uptake in folate receptor-expressing CT-26 colorectal cancer cells. Upon NIR laser irradiation, this ICG@MS-rGO-FA nanocomposite induced the apoptosis of only CT-26 cells via enhanced PTT and PDT effects without any damage to normal cells. Furthermore, the ICG@MS-rGO-FA nanocomposite revealed satisfactory tumor targeting and biocompatibility in CT-26 tumor-bearing mice, thereby enhancing the therapeutic effects of PTT and PDT in vivo. Therefore, this tumor-targeted ICG@MS-rGO-FA nanocomposite shows a great potential for phototherapy applications.

Efficient Photoacoustic Imaging With Biomimetic Mesoporous Silica-Based Nanoparticles

Indocyanine green (ICG), a near-infrared (NIR) fluorescent dye approved by the Food and Drug Administration (FDA), has been extensively used as a photoacoustic (PA) probe for PA imaging. However, its practical application is limited by poor photostability in water, rapid body clearance, and non-specificity. Herein, we fabricated a novel biomimetic nanoprobe by coating ICG-loaded mesoporous silica nanoparticles with the cancer cell membrane (namely, CMI) for PA imaging. This probe exhibited good dispersion, large loading efficiency, good biocompatibility, and homologous targeting ability to Hela cells in vitro. Furthermore, the in vivo and ex vivo PA imaging on Hela tumor-bearing nude mice demonstrated that CMI could accumulate in tumor tissue and display a superior PA imaging efficacy compared with free ICG. All these results demonstrated that CMI might be a promising contrast agent for PA imaging of cervical carcinoma.

Phthalocyanine-based photoacoustic contrast agents for imaging and theranostics

Phthalocyanine, as an organic dye, has attracted much attention due to its high molar absorption coefficient in the near-infrared region (NIR). It is precisely because of this advantage that phthalocyanine is very beneficial to photoacoustic imaging (PAI). At present, many different strategies have been adopted to design phthalocyanine-based contrast agents with photoacoustic (PA) effect, including increasing water solubility, changing spectral properties, prolonging the circulation time, constructing activatable supramolecular nanoparticles, increasing targeting, etc. Based on this, this minireview highlighted the above ways to enhance the PA effect of phthalocyanine. What's more, the application of phthalocyanine-based PA contrast agents in biomedical imaging and image-guided phototherapy has been discussed. Finally, this minireview also provides the prospects and challenges of phthalocyanine-based PA contrast agents in order to provide some reference for the application of phthalocyanine-based PA contrast agents in biomedical imaging and guiding tumor treatment.

Mesoporous Silica Nanoparticle-Based Imaging Agents for Hepatocellular Carcinoma Detection

Hepatocellular carcinoma (HCC) is characterized by poor prognosis and high mortality. The treatment of HCC is closely related to the stage, and the early-stage of HCC patients usually accompanies a more long-term survival rate after clinical treatment. Hence, there are critical needs to develop effective imaging agents with superior diagnostic precision for HCC detection at an early stage. Recently, mesoporous silica nanoparticles (MSNs) based imaging agents have gained extensive attentions in HCC detection, which can serve as a multifunctional nanoplatform with controllable size and facile surface functionalization. This perspective summarizes recent advances in MSNs based imaging agents for HCC detection by the incorporation of several clinical imaging modalities. Multi-modal imaging system has been developed for higher spatial resolution and sensitivity. Even though some limitations and challenges need to be overcome, we envision the development of novel MSNs based imaging agents will offer great potential applications in clinical HCC detection.

Facile synthesis of lactoferrin conjugated ultra small large pore silica nanoparticles for the treatment of glioblastoma

The blood brain barrier (BBB) and blood tumour barrier (BTB) remain a major roadblock for delivering therapies to treat brain cancer. Amongst brain cancers, glioblastoma (GBM) is notoriously difficult to treat due to the challenge of delivering chemotherapeutic drugs across the BBB and into the tumour microenvironment. Consequently, GBM has high rates of tumour recurrence. Currently, limited numbers of chemotherapies are available that can cross the BBB to treat GBM. Nanomedicine is an attractive solution for treating GBM as it can augment drug penetration across the BBB and into the heterogeneous tumour site. However, very few nanomedicines exist that can easily overcome both the BBB and BTB owing to difficulty in synthesizing nanoparticles that meet the small size and surface functionality restrictions. In this study, we have developed for the first-time, a room temperature protocol to synthesise ultra-small size with large pore silica nanoparticles (USLP, size ∼30 nm, pore size >7 nm) with the ability to load high concentrations of chemotherapeutic drugs and conjugate a targeting moiety to their surface. The nanoparticles were conjugated with lactoferrin (>80 kDa), whose receptors are overexpressed by both the BBB and GBM, to achieve additional active targeting. Lactoferrin conjugated USLP (USLP-Lf) were loaded with doxorubicin - a chemotherapy agent that is known to be highly effective against GBM in vitro but cannot permeate the BBB. USLP-Lf were able to selectively permeate the BBB in vitro, and were effectively taken up by glioblastoma U87 cells. When compared to the uncoated USLP-NPs, the coating with lactoferrin significantly improved penetration of USLP into U87 tumour spheroids (after 12 hours at 100 μm distance, RFU value 19.58 vs. 49.16 respectively). Moreover, this USLP-Lf based delivery platform improved the efficacy of doxorubicin-mediated apoptosis of GBM cells in both 2D and 3D models. Collectively, our new nano-platform has the potential to overcome both the BBB and BTB to treat GBM more effectively.

iRGD Peptide-Mediated Liposomal Nanoparticles with Photoacoustic/Ultrasound Dual-Modality Imaging for Precision Theranostics Against Hepatocellular Carcinoma

Purpose

Prepare a multifunctional ultrasound molecular probe, cell-penetrating peptide-modified 10-hydroxycamptothecin-loaded phase-transformation lipid nanoparticles (iRGD-ICG-10-HCPT-PFP-NPs), and to combine iRGD-ICG-10-HCPT-PFP -NPs with low-intensity focused ultrasound (LIFU) for precision theranostics against hepatocellular carcinoma (HCC).

Materials and Methods

The morphology of nanoparticles (NPs) and iRGD-ICG-10-HCPT-PFP-NPs was detected. In vitro, we examined targeting ability by flow cytometry and confocal laser scanning microscopy (CLSM), assessed penetration ability into hepatoma cells, and assessed killing ability. In vivo, we examined the targeting ability of the NPs with a photoacoustic (PA) imager and fluorometer (FL), while LIFU irradiation was used to trigger the release of chemotherapeutic drugs, which had a therapeutic effect on tumors.

Results

The particle size of iRGD-ICG-10-HCPT-PFP-NPs was 298.4 ± 10.42 nm. In vitro, iRGD-ICG-10-HCPT-PFP-NPs bound more to SK-Hep1 cells than ICG-10-HCPT-PFP-NPs. iRGD-ICG-10-HCPT-PFP-NPs could achieve PA/ultrasound imaging. The percentage of antiproliferative and apoptotic cells in the iRGD-ICG-10-HCPT-PFP-NPs+LIFU group was significantly higher. In vivo, iRGD-ICG-10-HCPT-PFP-NPs can target tumor sites and achieve PA/ultrasound imaging. The tumor volume in the iRGD-ICG-10-HCPT-PFP-NPs+LIFU group was significantly smaller, and the antiproliferative and proapoptotic effects were higher.

Conclusion

We successfully prepared a novel molecular probe that has good targeting, can perform ultrasound/PA dual-modality imaging, and can penetrate deep into tumors to achieve better therapeutic tumor effects, providing a new idea and method for theranostics of HCC.

Engineering mesoporous silica nanoparticles towards oral delivery of vancomycin

Vancomycin (Van) is a key antibiotic of choice for the treatment of systemic methicillin resistant Staphylococcus aureus (MRSA) infections. However, due to its poor membrane permeability, it is administered parenterally, adding to the cost and effort of treatment. The poor oral bioavailability of Van is mainly due to its physico-chemical properties that limit its paracellular and transcellular transport across gastrointestinal (GI) epithelium. Herein we report the development of silica nanoparticles (SNPs)-based formulations that are able to enhance the epithelial permeability of Van. We synthesized SNPs of different pore sizes (2 nm and 9 nm) and modified their surface charge and polarity by attaching different functional groups (-NH₂, -PO₃, and -CH₃). Van was loaded within these SNPs at a loading capacity in the range of ca. 18-29 wt%. The Van-loaded SNPs exhibited a controlled release behaviour when compared to un-encapsulated Van which showed rapid release due to its hydrophilic nature. Among Van-loaded SNPs, SNPs with large pores showed a prolonged release compared to SNPs with small pores while SNPs functionalised with -CH₃ groups exhibited a slowest release among the functionalised SNPs. Importantly, Van-loaded SNPs, especially the large pore SNPs with negative charge, enhanced the permeability of Van across an epithelial cell monolayer (Caco-2 cell model) by up to 6-fold, with P_app values up to 1.716 × 10^-5 cm s^-1 (vs. 0.304 × 10^-5 cm s^-1 for un-encapsulated Van) after 3 h. The enhancement was dependent on both the type of SNPs and their surface functionalisation. The permeation enhancing effect of SNPs was due to its ability to transiently open the tight junctions measured by decrease in transepithelial resistance (TEER) which was reversible after 3 h. All in all, our data highlights the potential of SNPs (especially SNPs with large pores) for oral delivery of Van or other antimicrobial peptides.

Photophysical Properties of Indocyanine Green in the Shortwave Infrared Region

With the growing development of new contrast agents for optical imaging using near-infrared and shortwave infrared (SWIR) wavelengths, it is essential to have consistent bench-marks for emitters in these regions. Indocyanine green (ICG), a ubiquitous and FDA-approved organic dye and optical imaging agent, is commonly employed as a standard for photophysical properties and biological performance for imaging experiments at these wavelengths. Yet, its reported photophysical properties across organic and aqueous solvents vary greatly in the literature, which hinders its ability to be used as a consistent benchmark. Herein, we measure photophysical properties in organic and aqueous solvents using InGaAs detection (~950-1,700 nm), providing particular relevance for SWIR imaging.

Nanocarrier-based Drug Delivery System for Cancer Therapeutics: A Review of the Last Decade

In recent years, due to the shortcomings of conventional chemotherapy, such as poor bioavailability, low treatment index, and unclear side effects, the focus of cancer research has shifted to new nanocarriers of chemotherapeutic drugs. By using biodegradable materials, nanocarriers generally have the advantages of good biocompatibility, low side effects, targeting, controlled release profile, and improved efficacy. More to the point, nanocarrier based anti-cancer drug delivery systems clearly show the potential to overcome the problems associated with conventional chemotherapy. In order to promote the in-depth research and development in this field, we herein summarized and analyzed various nanocarrier based drug delivery systems for cancer therapy, including the concepts, types, characteristics, and preparation methods. The active and passive targeting mechanisms of cancer therapy were also included, along with a brief introduction of the research progress of nanocarriers used for anti-cancer drug delivery in the past decade.

Mesoporous Silica Particles as Drug Delivery Systems-The State of the Art in Loading Methods and the Recent Progress in Analytical Techniques for Monitoring These Processes

Conventional administration of drugs is limited by poor water solubility, low permeability, and mediocre targeting. Safe and effective delivery of drugs and therapeutic agents remains a challenge, especially for complex therapies, such as cancer treatment, pain management, heart failure medication, among several others. Thus, delivery systems designed to improve the pharmacokinetics of loaded molecules, and allowing controlled release and target specific delivery, have received considerable attention in recent years. The last two decades have seen a growing interest among scientists and the pharmaceutical industry in mesoporous silica nanoparticles (MSNs) as drug delivery systems (DDS). This interest is due to the unique physicochemical properties, including high loading capacity, excellent biocompatibility, and easy functionalization. In this review, we discuss the current state of the art related to the preparation of drug-loaded MSNs and their analysis, focusing on the newest advancements, and highlighting the advantages and disadvantages of different methods. Finally, we provide a concise outlook for the remaining challenges in the field.

Development of mesoporous silica-based nanoprobes for optical bioimaging applications

A mesoporous silica nanoparticle (MSN)-based nanoplatform has attracted growing attention in the biomedical field due to the unique characteristics of MSNs including a high surface area, tunable pore sizes, colloidal stability, ease of functionalization, and desirable biocompatibility. Typically, MSNs are designed as nanocarriers for the incorporation of a variety of contrast agents for bioimaging, which can address the intrinsic drawbacks of contrast agents, including poor solubility in water, rapid photobleaching, and low stability. This review summarizes the recent advances in the field of MSN-based nanoprobes for fluorescence imaging and photoacoustic (PA) imaging applications. The approaches for the incorporation of contrast agents into MSN-based nanoplatforms including encapsulating contrast agents within MSNs, covalently conjugating contrast agents on the surface or pores of MSNs, physically absorbing contrast agents in the pores of MSNs, and doping contrast agents in the framework of MSNs are introduced. MSN-based nanoprobes for fluorescence imaging and PA imaging are discussed. The enhanced fluorescence imaging and PA imaging performances of MSN-based nanoprobes relative to the bare contrast agents are introduced and the underlying mechanisms are discussed in detail. Finally, current challenges and perspectives of MSN-based nanoprobes in the bioimaging field are discussed.

Overcoming therapeutic failure in osteosarcoma via Apatinib-encapsulated hydrophobic poly(ester amide) nanoparticles

Anti-angiogenic tyrosine kinase inhibitors (TKIs) have been proved to be effective in prolonging progression-free survival in advanced osteosarcoma. However, osteosarcoma stem-like cells persist for a long time and ultimately cause disease recurrence and therapy resistance. Here, we reveal that inefficient accumulation of Apatinib, an anti-angiogenic TKI, induces the expression of ribosome-associated genes in osteosarcoma, and confers apoptosis resistance. An engineered nanoscale delivery system based on hydrophobic poly(ester amide) has been established to effectively deliver Apatinib to improve the treatment. Notably, the considerable uptake by osteosarcoma cells enables this nanodrug to distribute increasingly inside the tumor. Furthermore, the delivered nano-Apatinib can suppress osteosarcoma stemness and enhance osteosarcoma stem-like cell apoptosis, and overcomes the crucial bottleneck of the unfavorable stem-like cell residue for TKI therapy. Importantly, nano-Apatinib significantly inhibits the osteosarcoma stem-like cell-derived tumor growth in contrast with free Apatinib, with minimal side effects. These results suggest that this Apatinib-loaded nano delivery system may serve as a promising strategy to solve the issue of TKI therapeutic resistance existing in advanced osteosarcoma.

A size-tunable nanoplatform: enhanced MMP2-activated chemo-photodynamic immunotherapy based on biodegradable mesoporous silica nanoparticles

Although immunotherapy is emerging as a revolutionary strategy for cancer therapy, its clinical effect is severely impaired by adaptive immune evasion and inefficient activation of antitumor immune response. Photodynamic therapy and chemotherapy have been shown to efficiently enhance the therapeutic effect of PD-L1 immunotherapy via different mechanisms. However, the lack of a precise drug delivery system seriously impedes the clinical application of combination therapy. To address these restrictions, a matrix metalloproteinases-2 (MMP2)-activated shrinkable nanosystem was developed to potentiate the antitumor efficacy of anti-PD-L1 antibody (aPDL1) delivered along with a chemo-photodynamic therapy. The nanosystem maintains its structure to accelerate tumor accumulation and shrinks down to a smaller size to facilitate tumor penetration and cellular uptake upon arriving in the tumor microenvironment. The exposure of aPDL1 on the surface of the biodegradable mesoporous silica cores (bMSNs) blocks the PD-1/PD-L1 interaction between tumor cells and T cells. Meanwhile, photosensitizer chlorin e6 (Ce6) and paclitaxel (PTX) loaded bMSNs effectively enter tumor cells and induce chemo-photodynamic therapy. The nanosystem elicits a chemo-photodynamic-induced immune response and improves the therapeutic effect of PD-L1 blockade mediated by aPDL1. Furthermore, the nanosystem displays a sustained prohibitive effect on tumor metastasis to distant sites. Our work presents a promising strategy for enhancing the efficacy of cancer immunotherapy.

Microfluidic assembly of pomegranate-like hierarchical microspheres for efflux regulation in oral drug delivery

Herein, a multi-functional nano-in-micro hierarchical microsphere system is demonstrated for controlling the intestinal efflux pumps that affect the oral bioavailability of many therapeutic drugs. The hierarchical particles were generated by a co-flow microfluidic device and consisted of porous silica nanoparticles packed in Eudragit® polymeric matrix. Meropenem (MER), a last-resort antibacterial drug, was loaded into porous silica (MCM-48) with a loading capacity of 34.3 wt%. In this unique materials combination, MCM-48 enables ultrahigh loading of a hydrophilic MER, while the Eudragit® polymers not only protect MER from gastric pH but also act as an antagonist for p-glycoprotein protein efflux pumps to reduce the efflux of MER back into the gastrointestinal lumen. We investigated the in-vitro temporal MER release and bidirectional (absorptive and secretory) drug permeation model across the Caco-2 monolayer. The bioavailability of MER was significantly improved by all of the prepared formulations (i.e. increased absorptive transport and reduced secretory transport). The Eudragit® RSPO formulated MER-MCM showed the best performance with an efflux ratio (i.e. secretory transport/absorptive transport) of 0.35, which is 7.4 folds less than pure MER (2.62). Lastly, the prepared formulations were able to retain the antibacterial activity of MER against Staphylococcus aureus and Pseudomonas aeruginosa. STATEMENT OF SIGNIFICANCE: Meropenem (MER) is a last resort antibiotic used for the treatment of drug-resistant and acute infections and only available as intravenous injectable dosage due to its poor chemical and thermal stability, and ultra-poor oral bioavailability because of the efflux action of P-glycoprotein (P-gp) pumps. Multifunctional colloidal micro/nanoparticles can help to solve these issues. Herein, we designed pomegranate-like hierarchical microspheres comprised of porous silica nanoparticles and enteric Eudragit® polymers (Eudragit®S100, Eudragit®RSPO, and Eudragit®RS100) using a co-flow microfluidic device. Our formulations allow for ultrahigh loading of hydrophilic MER, protects MER from gastric pH, and also block P-gp efflux pumps for enhanced MER permeation/retention with Eudragit®RSPO - showing 13.9-folds higher permeation and 7.4-folds reduction in efflux ratio in a bi-directional Caco-2 monolayer culture system.

Hybrid Hierarchical Heterostructures of Nanoceramic Phosphors as Imaging Agents for Multiplexing and Living Cancer Cells Translocation

Existing fluorescent labels used in life sciences are based on organic compounds with limited lifetime or on quantum dots which are either expensive or toxic and have low kinetic stability in biological environments. To address these challenges, luminescent nanomaterials have been conceived as hierarchical, core–shell structures with spherical morphology and highly controlled dimensions. These tailor-made nanophosphors incorporate Ln:YVO₄ nanoparticles (Ln = Eu(III) and Er(III)) as 50 nm cores and display intense and narrow emission maxima centered at ∼565 nm. These cores can be encapsulated in silica shells with highly controlled dimensions as well as functionalized with chitosan or PEG5000 to reduce nonspecific interactions with biomolecules in living cells. Confocal fluorescence microscopy in living prostate cancer cells confirmed the potential of these platforms to overcome the disadvantages of commercial fluorophores and their feasibility as labels for multiplexing, biosensing, and imaging in life science assays.

A carboxymethyl lentinan layer by layer self-assembly system as a promising drug chemotherapeutic platform

Surface functionalization of mesoporous silica nanoparticles (MSNs) has been proposed as an efficient strategy for enhancing the biocompatibility and efficiency of an MSN-based carrier platform. Herein, natural polyelectrolyte multilayers composed of poly-l-ornithine (PLO) and carboxymethyl lentinan (LC) were coated on the surface of MSNs through a layer-by-layer (LbL) self-assembly technique, and were characterized by ζ-potential, FTIR, ¹³C NMR, SEM, TEM, XRD, and TG. The prepared carrier presented alternating positive and negative potentials when coated with the polyelectrolytes, and the surface of MSN-PLO/LC was rougher compared to the naked MSNs. The biocompatibility tests, including cytocompatibility, hemocompatibility, and histocompatibility, showed that MSNs biocompatibility could be improved by modifying LC. A high loading and sustained release drug delivery system was constructed after loading doxorubicin (DOX) into the prepared MSN-PLO/LC, which exhibited significant anti-proliferative efficiency in human cervical cancer cell lines (Hela). Therefore, the PLO/LC LbL NPs (layer-by-layer self-assembled nanoparticles coated with PLO/LC layers) based on MSNs, which is easily prepared by electrostatic interactions, can be considered a promising drug chemotherapeutic platform and delivery technique for future human cervical cancer therapy.

Photoacoustic Imaging of Myocardial Infarction Region Using Non-Invasive Fibrin-Targeted Nanoparticles in a Rat Myocardial Ischemia-Reperfusion Model

BACKGROUND AND PURPOSE

Myocardial infarction (MI) is a serious threat to public health. The early identification of MI is important to promote appropriate treatment strategies for patients. Recently, strategies targeting extracellular matrix (ECM) components have gained attention. Fibrin is an ECM protein involved after MI. In this work, we constructed fibrin-targeted nanoparticles (NPs) by co-assembling a fibrin-targeted peptide (CREKA) and indocyanine green (ICG) and used them to enhance photoacoustic (PA) imaging for noninvasive detection of the infarct region to help diagnose MI.

METHODS

ICG NPs modified with CREKA were prepared (CREKA-ICG-LIP NPs). Then, the fundamental characteristics, stability, safety, and targeting ability of the NPs were detected. Finally, in an ischemia-reperfusion (IR) injury model, the performance of the NPs in detecting the infarct region in the model on PA imaging was evaluated.

RESULTS

CREKA-ICG-LIP NPs were successfully constructed and showed excellent basic characteristics, a high safety level, and an excellent targeting ability. After intravenous injection, the CREKA-ICG-LIP NPs accumulated in the injured region in the IR model. Then, the PA signal in the infarct region could be detected by the ultrasound transducer of the Vevo LAZR Photoacoustic Imaging System.

CONCLUSION

This work provides new insights for non-invasive, real-time imaging techniques to detect the region of myocardial injury and help diagnose MI based on a PA imaging system with high sensitivity in optical imaging and deep penetration in ultrasound imaging.

Preparation and preliminary evaluation of hepatitis B core antigen virus like nanoparticles loaded with indocyanine green

Background

In recent years, nanotechnology has attracted a plethora of attention due of its ability to effectively diagnose and treat various tumors. Virus-like particles (VLPs) have good biocompatibility, are safe and non-toxic, and have an internal hollow space, and as such they are often used as nano drug carriers. In recent years, it has become one of the hot spots in the field of biopharmaceutical engineering.

Methods

In this study, the tumor-targeting peptide RGD (Arg-Gly-Asp) was genetically inserted into the major immunodominant region (MIR) of the hepatitis B virus core protein (HBc). A series of characterization, including stability and optical properties, were evaluated. A visual diagnosis and analysis of the efficacy against tumor cells were conducted at the cell level and using a live animal model.

Results

This study demonstrated that the recombinant HBc-based VLPs could participate in self-assembly of monodispersed nanoparticles with well-defined morphology, and the near-infrared dye indocyanine green (ICG) could be packaged into the VLPs without any chemical modification. Moreover, the HBc-based VLPs could specifically target cancer cells via the interaction with overexpressed integrin αvβ3. The treatment with ICG-loaded HBc-based VLPs showed significant inhibition of 4T1 breast cancer cell growth (84.87% tumor growth inhibition). The in vivo imaging experiments demonstrated that the ICG-loaded HBc-based VLPs generated excellent fluorescence in tumor sites in 4T1 breast cancer bearing mice. This provided crucial information on tumor mass location, boundaries, and shape. Moreover, compared to free ICG, the nanosystem showed significantly longer blood circulation time and superior accuracy in targeting the tumor.

Conclusions

The ICG-loaded HBc-based VLPs prepared in this study were of good stability and biocompatibility. It showed strong tumor targeting specificity and tumor visualization. Thus, it is expected to provide a new experimental basis and theoretical support for the integration of VLPs in the clinical diagnosis and treatment of breast cancer.

Mesoporous silica nanoparticles: facile surface functionalization and versatile biomedical applications in oncology

Mesoporous silica nanoparticles (MSNs) have received increasing interest due to their tunable particle size, large surface area, stable framework, and easy surface modification. They are increasingly being used in varying applications as delivery vehicles including bio-imaging, drug delivery, biosensors and tissue engineering etc. Precise structure control and the ability to modify surface properties of MSNs are important for their applications. This review summarises the different synthetic methods for the preparation of well-ordered MSNs with tunable pore volume as well as the approaches of drugs loading, especially highlighting the facile surface functionalization for various purposes and versatile biomedical applications in oncology. Finally, the challenges of clinical transformation of MSNs-based nanomedicines are further discussed.

Manganese(II) Texaphyrin: A Paramagnetic Photoacoustic Contrast Agent Activated by Near-IR Light

The NIR absorptivity of the metallotexaphyrin derivatives MMn, MGd, and MLu for photoacoustic (PA)-based imaging is explored in this study. All three complexes demonstrated excellent photostabilities; however, MMn provided the greatest PA signal intensities in both doubly distilled water and RAW 264.7 cells. In vivo experiments using a prostate tumor mouse model were performed. MMn displayed no adverse toxicity to major organs as inferred from hematoxylin and eosin (H&E) staining and cell blood count testing. MMn also allowed for PA-based imaging of tumors with excellent in vivo stability to provide 3D tumor diagnostic information. Based on the present findings and previous magnetic resonance imaging (MRI) studies, we believe MMn may have a role to play either as a stand-alone PA contrast agent or as a single molecule dual modal (PA and MR) imaging agent for tumor diagnosis.

Imaging-based vascular-related biomarkers for early detection of acetaminophen-induced liver injury

Acetaminophen (APAP) is the foremost cause of drug-induced liver injury in the Western world. Most studies of APAP hepatotoxicity have focused on the hepatocellular injury, but current hepatocyte-related biomarkers have delayed presentation time and a lack of sensitivity. APAP overdose can induce hepatic microvascular congestion, which importantly precedes the injury of hepatocytes. However, the underlying molecular mechanisms remain unclear. It is imperative to discover and validate sensitive and specific translational biomarkers of APAP-induced liver injury. Methods: In this study, we assessed APAP toxicity in sinusoidal endothelial cells and hepatocytes in mice treated with overdose APAP at different time points. The underlying mechanisms of APAP overdose induced sinusoidal endothelial cell injury were investigated by RT2 Profiler PCR arrays. The impact of APAP overdose on endothelial cell function was assessed by pseudovessel formation of endothelial cells in 2D Matrigel and in vivo hepatic vascular integrity using multiphoton microscopy. Finally, the effects of APAP overdose on oxygen levels in the liver and hepatic microcirculation were evaluated by contrast enhanced ultrasonography. Potential imaging-based vascular-related markers for early detection of APAP induced liver injury were assessed. Results: Our study confirmed that hepatic endothelial cells are an early and direct target for APAP hepatotoxicity. ICAM1-related cellular adhesion pathways played a prominent role in APAP-induced endothelial cell injury, which was further validated in primary human sinusoidal endothelial cells and human livers after APAP overdose. APAP overdose impacted pseudovessel formation of endothelial cells and in vivo hepatic vascular integrity. Use of ultrasound to detect APAP-induced liver injury demonstrated that mean transit time, an imaging-based vascular-related biomarker, was more sensitive and precise for early detection of APAP hepatotoxicity and monitoring the treatment response in comparison with a conventional blood-based biomarker. Conclusion: Imaging-based vascular-related biomarkers can identify early and mild liver injury induced by APAP overdose. With further development, such biomarkers may improve the assessment of liver injury and the efficacy of clinical decision-making, which can be extended to other microvascular dysfunction of deep organs.