Leveraging Engineering of Indocyanine Green-Encapsulated Polymeric Nanocomposites for Biomedical Applications

Enhanced stability and photothermal efficiency of Indocyanine Green J-aggregates by nanoformulation with Calix[4]arene for photothermal therapy of cancers

Photothermal therapy (PTT) is a method of growing attention, owing to its controllable process, high efficiency and minimal side effect. Indocyanine Green (ICG) is as Food and Drug Administration (FDA) approved agent that stands on the frontline of further developments of PTT toward clinics. However, the applicability of ICG-mediated PTT is limited by the rapid in vivo clearance and photo-degradation of ICG. To improve those parameters, nanosized ICG-loaded nanoparticles (ICG-J/CX) were fabricated in this study by co-assembly of anionic ICG J-aggregates (ICG-J) with cationic tetraguanidinium calix[4]arene (CX). This very simple approach produces ICG-J/CX with a well-defined nanometer range size and a close to neutral charge. The nanoparticles demonstrate high photothermal conversion efficiency (PCE) and dramatically improved photostability, as compared with ICG. The in vitro cellular uptake and cytotoxicity studies further demonstrated that the ICG-J/CX nanoparticles enhance uptake and photothermal efficiency in comparison with ICG or non-formulated ICG-J, overall demonstrating that ICG-J/CX mediated photothermal therapy have significant potential for attaining cancer treatment.

Medical Applications and Advancement of Near Infrared Photosensitive Indocyanine Green Molecules

Indocyanine green (ICG) is an important kind of near infrared (NIR) photosensitive molecules for PTT/PDT therapy as well as imaging. When exposed to NIR light, ICG can produce reactive oxygen species (ROS), which can kill cancer cells and pathogenic bacteria. Moreover, the absorbed light can also be converted into heat by ICG molecules to eliminate cancer cells. In addition, it performs exceptionally well in optical imaging-guided tumor therapy and antimicrobial therapy due to its deeper tissue penetration and low photobleaching properties in the near-infrared region compared to other dyes. In order to solve the problems of water and optical stability and multi-function problem of ICG molecules, composite nanomaterials based on ICG have been designed and widely used, especially in the fields of tumors and sterilization. So far, ICG molecules and their composite materials have become one of the most famous infrared sensitive materials. However, there have been no corresponding review articles focused on ICG molecules. In this review, the molecular structure and properties of ICG, composite material design, and near-infrared light- triggered anti-tumor, and antibacterial, and clinical applications are reviewed in detail, which of great significance for related research.

Photosensitizers-Loaded Nanocarriers for Enhancement of Photodynamic Therapy in Melanoma Treatment

Malignant melanoma poses a significant global health burden. It is the most aggressive and lethal form of skin cancer, attributed to various risk factors such as UV radiation exposure, genetic modifications, chemical carcinogens, immunosuppression, and fair complexion. Photodynamic therapy is a promising minimally invasive treatment that uses light to activate a photosensitizer, resulting in the formation of reactive oxygen species, which ultimately promote cell death. When selecting photosensitizers for melanoma photodynamic therapy, the presence of melanin should be considered. Melanin absorbs visible radiation similar to most photosensitizers and has antioxidant properties, which undermines the reactive species generated in photodynamic therapy processes. These characteristics have led to further research for new photosensitizing platforms to ensure better treatment results. The development of photosensitizers has advanced with the use of nanotechnology, which plays a crucial role in enhancing solubility, optical absorption, and tumour targeting. This paper reviews the current approaches (that use the synergistic effect of different photosensitizers, nanocarriers, chemotherapeutic agents) in the photodynamic therapy of melanoma.

Enhancing Photothermal Therapy Efficacy by In Situ Self-Assembly in Glioma

The residence time of some small molecular imaging and therapeutic agents in tumor tissue is short and the molecules can be easily dispersed, which decreases treatment efficacy. Therefore, methods that enhance oncotherapy performance are of significant importance. Here, we report an in situ self-assembly strategy aimed at enhancing the photothermal therapy of glioblastomas. The probe, ICG-PEP-c(RGD)fk, consisted of a glutathione-reactive self-assembling polypeptide as the skeleton, indocyanine green (ICG) as a theranostic agent, and cyclic Arg-Gly-Asp [c(RGD)fk] peptides as the targeting group. ICG-PEP-c(RGD)fk was synthesized and found to be assembled in the glutathione environment at 9.446 μM in vitro. Human glioblastoma cell line U87MG-luc with high integrin αvβ3 expression was applied to invivo experiments. ICG-PEP-c(RGD)fk provided clearer tumor imaging and had a tumor retention time of 6.12 times longer than that of ICG-c(RGD)fk. In therapeutic experiments, ICG-PEP-c(RGD)fk significantly suppressed glioblastoma growth and the tumor volume was 2.61 times smaller than in the ICG-c(RGD)fk group at the end of the observation period. Moreover, the median survival time of ICG-PEP-c(RGD)fk group was significantly improved by 2.78 times compared with that of the control group. In conclusion, glutathione-reactive self-assembling peptides are capable of increasing the tumor retention time and improving the photothermal therapeutic effect. The in situ self-assembly strategy is a potential and feasible method to enhance oncotherapy.

Fluoridated Apatite Coating on Human Dentin via Laser-Assisted Pseudo-Biomineralization with the Aid of a Light-Absorbing Molecule

A simple, area-specific coating technique for fluoridated apatite (FAp) on teeth would be useful in dental applications. Recently, we achieved area-specific FAp coating on a human dentin substrate within 30 min by a laser-assisted biomimetic (LAB) process; pulsed Nd:YAG laser irradiation in a fluoride-containing supersaturated calcium phosphate solution (FCP solution). The LAB-processed, FAp-coated dentin substrate exhibited antibacterial activity against a major oral bacterium, Streptococcus mutans. In the present study, we refined the LAB process with a combination of a dental diode laser and a clinically approved light-absorbing molecule, indocyanine green (ICG). A micron-thick FAp layer was successfully formed on the dentin surface within only 3 min by the refined LAB process, i.e., dental diode laser irradiation in the FCP solution following ICG treatment. The ICG layer precoated on the dentin substrate played a crucial role in inducing rapid pseudo-biomineralization (FAp layer formation) on the dentin surface by absorbing laser light at the solid-liquid interface. In the refined LAB process, the precoated ICG layer was eliminated and replaced with the newly formed FAp layer composed of vertically oriented pillar-like nanocrystals. Cross-sectional ultrastructural analysis revealed a smooth interface between the FAp layer and the dentin substrate. The refined LAB process has potential as a tool for the tooth surface functionalization and hence, is worth further process refinement and in vitro and in vivo studies.

Indocyanine green for targeted imaging of the gall bladder and fluorescence navigation

Researchers nowadays have devoted extra attention to the different biomedical applications of indocyanine green (ICG), a US Food and Drug Administration-approved fluorescent compound in the fields such as drug delivery, medical imaging and disease diagnosis. In addition, hepatic function evaluation could be conducted by using ICG before surgical procedures and angiographic assessment of blood. Therefore, ICG will be expected to be excellent imaging and targeting agent in various preclinical and clinical model systems. However, whether ICG possesses the potential for the gall bladder's intraoperative imaging guidance needs to be further explored in vivo animal experiments. Herein, near-infrared fluorophores ICG can display the specific uptake by the gall bladder cells and tissues. The dynamic process of biodistribution and the clearance of ICG in vivo in mice are clearly shown in real-time live-body imaging. Furthermore, ICG was rapidly excreted into the bile and lately biodistributed to the stomach after treatment in mice. Meanwhile, the signal-to-background ratio of the gall bladder demonstrated a tremendously higher level compared to other organs (stomach, heart, liver, lung, pancreas, spleen, intestine and duodenum). In conclusion, fluorescence navigation using ICG fluorescence imaging will provide good visualization and detection of the target lesions (gall bladder) in clinics such as diagnostic medical imaging and intraoperative navigation.

Nanoarchitectured two-dimensional layered double hydroxides-based nanocomposites for biomedical applications

Despite the exceptional physicochemical and morphological characteristics, the pristine layered double hydroxides (LDHs), or two-dimensional (2D) hydrotalcite clays, often suffer from various shortcomings in biomedicine, such as deprived thermal and chemical stabilities, acid-prone degradation, as well as lack of targeting ability, hampering their scale-up and subsequent clinical translation. Accordingly, diverse nanocomposites of LDHs have been fabricated by surface coating of organic species, impregnation of inorganic species, and generation of core-shell architectures, resulting in the complex state-of-the-art architectures. In this article, we initially emphasize various bothering limitations and the chemistry of these pristine LDHs, followed by discussions on the engineering strategies of different LDHs-based nanocomposites. Further, we give a detailed note on diverse LDH nanocomposites and their performance efficacy in various biomedical applications, such as drug delivery, bioimaging, biosensing, tissue engineering and cell patterning, deoxyribonucleic acid (DNA) extraction, as well as photoluminescence, highlighting the influence of various properties of installed supramolecular assemblies on their performance efficacy. In summary, we conclude with interesting perspectives concerning the lessons learned to date and the strategies to be followed to further advance their scale-up processing and applicability in medicine.

Biocompatible Supramolecular Mesoporous Silica Nanoparticles as the Next-Generation Drug Delivery System

Supramolecular mesoporous silica nanoparticles (MSNs) offer distinct properties as opposed to micron-sized silica particles in terms of their crystal structure, morphology–porosity, toxicity, biological effects, and others. MSN biocompatibility has touched the pharmaceutical realm to exploit its robust synthesis pathway for delivery of various therapeutic molecules including macromolecules and small-molecule drugs. This article provides a brief review of MSN history followed by special emphasis on the influencing factors affecting morphology–porosity characteristics. Its applications as the next-generation drug delivery system (NGDDS) particularly in a controlled release dosage form via an oral drug delivery system are also presented and shall be highlighted as oral delivery is the most convenient route of drug administration with the economical cost of development through to scale-up for clinical trials and market launch.

Nanoarchitectured prototypes of mesoporous silica nanoparticles for innovative biomedical applications

Despite exceptional morphological and physicochemical attributes, mesoporous silica nanoparticles (MSNs) are often employed as carriers or vectors. Moreover, these conventional MSNs often suffer from various limitations in biomedicine, such as reduced drug encapsulation efficacy, deprived compatibility, and poor degradability, resulting in poor therapeutic outcomes. To address these limitations, several modifications have been corroborated to fabricating hierarchically-engineered MSNs in terms of tuning the pore sizes, modifying the surfaces, and engineering of siliceous networks. Interestingly, the further advancements of engineered MSNs lead to the generation of highly complex and nature-mimicking structures, such as Janus-type, multi-podal, and flower-like architectures, as well as streamlined tadpole-like nanomotors. In this review, we present explicit discussions relevant to these advanced hierarchical architectures in different fields of biomedicine, including drug delivery, bioimaging, tissue engineering, and miscellaneous applications, such as photoluminescence, artificial enzymes, peptide enrichment, DNA detection, and biosensing, among others. Initially, we give a brief overview of diverse, innovative stimuli-responsive (pH, light, ultrasound, and thermos)- and targeted drug delivery strategies, along with discussions on recent advancements in cancer immune therapy and applicability of advanced MSNs in other ailments related to cardiac, vascular, and nervous systems, as well as diabetes. Then, we provide initiatives taken so far in clinical translation of various silica-based materials and their scope towards clinical translation. Finally, we summarize the review with interesting perspectives on lessons learned in exploring the biomedical applications of advanced MSNs and further requirements to be explored.

Viscosity Effects on the Excited-State Dynamics of Indocyanine Green for Phototheranostic

The excited-state dynamics of indocyanine green (ICG) fundamentally determine its photophysical properties for phototheranostic. However, its dynamics are predictable to be susceptible toward intracellular viscosity due to its almost freely rotating structure, making the precise phototheranostic very challenging. Therefore, correlating the viscosity with the dynamics of ICG is of great importance and urgency for precise phototheranostic prospects. This study presents systemic investigations on the viscosity-dependent dynamics of ICG for phototheranostic. Femtosecond transient absorption experiments elucidate a prolonged radiative transition (225 ps vs 152 ps) for ICG in a viscous environment, which benefits fluorescence. Viscosity remarkably extends the triplet excited-state lifetime of ICG but reduces its internal conversion (6.2 ps vs 2.2 ps). The extended triplet lifetime affords sufficient photosensitization time to enhance photodynamic therapy. A moderative internal conversion is unfavorable for heat production, resulting in inferior photothermal therapy. With this clear picture of excitation energy state dissipation in mind, we readily identified the safety laser power density for precise phototheranostic. This work provides an insightful understanding of viscosity-relevant excited-state dynamics toward phototheranostic, which is also beneficial for designing novel ICG derivatives with improved phototheranostic performance.

Kasmani R, Kasim H, Al-Ghaili AM, Saleh MA, Banoqitah EM, Alhawsawi AM, Baqer AA, Liu J, Xu S, Li Q, Noorazlan AM, Ahmed AAA, Flaifel MH, Paiman S, Nazrin N, Ali Al-Asbahi B, Wang J. The Effect of Precursor Concentration on the Particle Size, Crystal Size, and Optical Energy Gap of CexSn1-xO2 Nanofabrication

In the present work, a thermal treatment technique is applied for the synthesis of Ce_xSn_1-xO₂ nanoparticles. Using this method has developed understanding of how lower and higher precursor values affect the morphology, structure, and optical properties of Ce_xSn_1-xO₂ nanoparticles. Ce_xSn_1-xO₂ nanoparticle synthesis involves a reaction between cerium and tin sources, namely, cerium nitrate hexahydrate and tin (II) chloride dihydrate, respectively, and the capping agent, polyvinylpyrrolidone (PVP). The findings indicate that lower x values yield smaller particle size with a higher energy band gap, while higher x values yield a larger particle size with a smaller energy band gap. Thus, products with lower x values may be suitable for antibacterial activity applications as smaller particles can diffuse through the cell wall faster, while products with higher x values may be suitable for solar cell energy applications as more electrons can be generated at larger particle sizes. The synthesized samples were profiled via a number of methods, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). As revealed by the XRD pattern analysis, the Ce_xSn_1-xO₂ nanoparticles formed after calcination reflect the cubic fluorite structure and cassiterite-type tetragonal structure of Ce_xSn_1-xO₂ nanoparticles. Meanwhile, using FT-IR analysis, Ce-O and Sn-O were confirmed as the primary bonds of ready Ce_xSn_1-xO₂ nanoparticle samples, whilst TEM analysis highlighted that the average particle size was in the range 6-21 nm as the precursor concentration (Ce(NO₃)₃·6H₂O) increased from 0.00 to 1.00. Moreover, the diffuse UV-visible reflectance spectra used to determine the optical band gap based on the Kubelka-Munk equation showed that an increase in x value has caused a decrease in the energy band gap and vice versa.

Emerging indocyanine green-integrated nanocarriers for multimodal cancer therapy: a review

Nanotechnology is a branch of science dealing with the development of new types of nanomaterials by several methods. In the biomedical field, nanotechnology is widely used in the form of nanotherapeutics. Therefore, the current biomedical research pays much attention to nanotechnology for the development of efficient cancer treatment. Indocyanine green (ICG) is a near-infrared tricarbocyanine dye approved by the Food and Drug Administration (FDA) for human clinical use. ICG is a biologically safe photosensitizer and it can kill tumor cells by producing singlet oxygen species and photothermal heat upon NIR irradiation. ICG has some limitations such as easy aggregation, rapid aqueous degradation, and a short half-life. To address these limitations, ICG is further formulated with nanoparticles. Therefore, ICG is integrated with organic nanomaterials (polymers, micelles, liposomes, dendrimers and protein), inorganic nanomaterials (magnetic, gold, mesoporous, calcium, and LDH based), and hybrid nanomaterials. The combination of ICG with nanomaterials provides highly efficient therapeutic effects. Nowadays, ICG is used for various biomedical applications, especially in cancer therapeutics. In this review, we mainly focus on ICG-based combined cancer nanotherapeutics for advanced cancer treatment.

Advances in Indocyanine Green-Based Codelivery Nanoplatforms for Combinatorial Therapy

Indocyanine green (ICG), a near-infrared (NIR) agent with an excellent imaging performance, has captivated enormous interest from researchers owing to its excellent therapeutic and imaging abilities. Although various nanoplatforms-based drug delivery systems (DDS) with the ability to overcome the clinical limitations of ICG has been reported, ICG-medicated conventional cancer diagnosis and photorelated therapies still lack in exhibiting the therapeutic efficacy, resulting in incomplete or partly tumor elimination. In the view of addressing these concerns, various DDSs have been engineered for the efficient codelivery of combined therapeutic agents with ICG, aiming to achieve promising therapeutic results due to multifunctional imaging-guided synergistic antitumor effects. In this article, we will systematically review currently available nanoplatforms based on polymers, inorganic, proteins, and metal-organic frameworks (MOFs), among others, for codelivery of ICG along with other therapeutic agents, providing a foundation for future clinical development of ICG. In addition, codelivery systems for ICG and different mechanism-based therapeutic agents will be illustrated. In summary, we conclude the review with the challenges and perspectives of ICG-based versatile nanoplatforms in detail.

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.

Fenton-like reaction, glutathione reduction, and photothermal ablation-built-in hydrogels crosslinked by cupric sulfate for loco-regional cancer therapy

Fenton-like reaction-associated chemodynamic therapy (CDT) and hyperthermia-inducing photothermal therapy (PTT)-combined crosslinked hydrogel systems were developed for loco-regional cancer therapy. Cupric sulfate (Cu) has been employed to crosslink the catechol-functionalized hyaluronic acid (HC) polymer-based gel via metal-catechol coordination and covalent bonding of the catechol group (by pH adjustment). Cu can also be used as a hydroxyl radical-generating agent with endogenous H₂O₂ in cancer cells mediated by Fenton-like reaction and it can reduce intracellular glutathione (GSH) levels leading to the inhibition of reactive oxygen species (ROS) scavenging. These two strategies can amplify the ROS-initiated CDT efficiency for combating cancer. The Cu-incorporated crosslinked hydrogel structure with pH modulation was appropriate for injectable gel formation via a single syringe. The incorporation of indocyanine green (ICG) into the hydrogel network and near-infrared (NIR) laser irradiation provided a temperature elevation sufficient for induction of hyperthermia in cancer therapy. It is expected that the designed HC/Cu/ICG hydrogel can be used safely and efficiently for local CDT and PTT of breast cancer.

Targeting Fluorescence Imaging of RGD-Modified Indocyanine Green Micelles on Gastric Cancer

Early diagnosis and complete resection of the tumor is an important way to improve the quality of life of patients with gastric cancer. In recent years, near-infrared (NIR) materials show great potential in fluorescence-based imaging of the tumors. To realize a satisfying intraoperative fluorescence tumor imaging, there are two pre-requirements. One is to obtain a stable agent with a relatively longer circulation time. The second is to make it good biocompatible and specific targeting to the tumor. Here, we developed an RGD-modified Distearyl acylphosphatidyl ethanolamine-polyethylene glycol micelle (DSPE-PEG-RGD) to encapsulate indocyanine green (ICG) for targeting fluorescence imaging of gastric cancer, aimed at realizing tumor-targeted accumulation and NIR imaging. ¹H NMR spectroscopy confirmed its molecular structure. The characteristics and stability results indicated that the DSPE-PEG-RGD@ICG had a relatively uniform size of <200 nm and longer-term fluorescence stability. RGD peptides had a high affinity to integrin α_vβ₃ and the specific targeting effect on SGC7901 was assessed by confocal microscopy in vitro. Additionally, the results of cytotoxicity and blood compatibility in vitro were consistent with the acute toxicity test in vivo, which revealed good biocompatibility. The biodistribution and tumor targeting image of DSPE-PEG-RGD@ICG were observed by an imaging system in tumor-bearing mice. DSPE-PEG-RGD@ICG demonstrated an improved accumulation in tumors and longer circulation time when compared with free ICG or DSPE-PEG@ICG. In all, DSPE-PEG-RGD@ICG demonstrated ideal properties for tumor target imaging, thus, providing a promising way for the detection and accurate resection of gastric cancer.

6-Aminocaproic acid as a linker to improve near-infrared fluorescence imaging and photothermal cancer therapy of PEGylated indocyanine green

Clinical extensive application of indocyanine green (ICG) is limited by several drawbacks such as poor bioenvironmental stability, aggregate propensity, and rapid elimination from the body, etc. In this study, we construct a novel amphiphilic mPEG-ACA-ICG conjugate by modifying synthetic heptamethine cyanine derivative ICG-COOH with a hydrophobic linker 6-aminocaproic acid (ACA) and amino-terminal poly(ethylene glycol) (mPEG-NH₂). The as-prepared mPEG-ACA-ICG conjugate has the ability to self-assemble into micellar aggregates in an aqueous solution with a lower CMC value than mPEG-ICG conjugate without ACA linker. More importantly, compared with free ICG and mPEG-ICG conjugate, mPEG-ACA-ICG nanomicelles exhibited better stability and higher photothermal conversion efficiency upon near-infrared light irradiation due to the intramolecular introduction of a hydrophobic ACA segment. In our in vivo experiment, mPEG-ACA-ICG nanomicelles ensured the formidable effect on tumor photothermal therapy (PTT) and the maximum tumor inhibition rate reached 72.6 %. In addition, real-time determination ability for fluorescence image-guided surgery (FIGS) of mPEG-ACA-ICG nanomicelles was also confirmed on tumor xenograft mice model. Taken together, mPEG-ACA-ICG conjugate may hold great promise for non-invasive cancer theranostics.

Cell Membrane-Inspired Polymeric Vesicles for Combined Photothermal and Photodynamic Prostate Cancer Therapy

Photothermal therapy (PTT) and photodynamic therapy (PDT) have emerged as highly prospective therapeutic modalities in cancer therapy. Notwithstanding, a critical challenge still remains in the exploration of an effective strategy to maximize the synergistic efficacy of PTT and PDT due to low photoconversion efficiency. Herein, inspired by the phospholipid bimolecular structure of the cell membrane, bionic cell membrane polymeric vesicles with photothermal/photodynamic synergy for prostate cancer therapy at one wavelength's excitation are constructed in one step by the coordination of hexadecyl trimethyl ammonium bromide (CTAB) from the surface of hydrophobic gold nanorods (AuNRs) with indocyanine green (ICG) and polycaprolactone (PCL), achieving their self-assembly in aqueous solutions. Importantly, the aggregation of the assembly improves the stability of the vesicles, realizing the synergistic effect of PTT and PDT for prostate cancer therapy. After being assembled within polymeric vesicles, bifunctional photosensitizer ICG can generate reactive oxygen species (ROS) and photothermal effect under light treatment. Their ROS not only induce PDT efficacy but also destroy the integrity of the lysosomal membrane, promoting the translocation of ICG and another photosensitizer called gold nanorods (AuNRs) into the cytosol. Moreover, their photothermal effects produced by both photosensitizers are able to engender greater damage to the tumor cells because of the close distance with organelles. This structure manifests good cellular uptake, highly effective tumor accumulation, high photothermal conversion efficiency, and excellent properties of enhanced photobleaching resistance, which are beneficial to ICG-based fluorescence tumor imaging. Using the same near-infrared (NIR) wavelength for excitation, the AuNR/ICG vesicles can reduce the side effect rate of photodamage on the skin. In addition, by generating reactive oxygen species (ROS) and double photothermal effect, the vesicles under NIR excitation can promote the apoptosis of PC3 tumor cells. Taken together, the spontaneous self-assembled AuNR/ICG vesicles exhibit huge potential in advanced-stage prostate cancer therapy, especially for the prostate-specific membrane antigen (PSMA)-negative castration-resistant subtype.

Indocyanine Green Nanoparticles: Are They Compelling for Cancer Treatment?

Indocyanine green (ICG) is a Food and Drug Administration–approved near-infrared fluorescent dye, employed as an imaging agent for different clinical applications due to its attractive physicochemical properties, high sensitivity, and safety. However, free ICG suffers from some drawbacks, such as relatively short circulation half-life, concentration-dependent aggregation, and rapid clearance from the body, which would confine its feasible application in oncology. Here, we aim to discuss encapsulation of ICG within a nanoparticle formulation as a strategy to overcome some of its current limitations and to enlarge its possible applications in cancer diagnosis and treatment. Our purpose is to provide a short but exhaustive overview of clinical outcomes that these nanocomposites would provide, discussing opportunities, limitations, and possible impacts with regard to the main clinical needs in oncology.

Hydrogen-Peroxide-Responsive Protein Biomimetic Nanoparticles for Photothermal-Photodynamic Combination Therapy of Melanoma

BACKGROUND AND OBJECTIVES

Recently, there has been a rapid increase in the incidences of melanoma, which represents a serious threat to human health. Generally, tumor-microenvironment-responsive nanoparticle-based photothermal-photodynamic combination therapy (PTT-PDT) is characterized by intratumoral response and tumor targeting. In this study, we designed and synthesized hydrogen-peroxide-responsive protein biomimetic nanoparticles (MnO₂ -ICG@BSA) for the treatment of melanoma.

STUDY DESIGN/MATERIALS AND METHODS

Briefly, MnO₂ -ICG@BSA was prepared using a mild protein synthesis method by loading indocyanine green (ICG) into a bovine serum albumin-manganese dioxide complex (MnO₂ @BSA); next, its characteristics were determined. In addition, in vitro biocompatibility and antitumor efficacy were assessed using the classic cell counting kit-8 assay. Moreover, in vivo high-frequency ultrasound and thermal imaging were used to evaluate the oxygen-production capacity and photothermal conversion effect of MnO₂ -ICG@BSA at the tumor site, and Singlet Oxygen Sensor Green (SOSG) was used to measure singlet oxygen levels in the tumor. The antitumor efficacy was assessed based on relative tumor size, bodyweight, survival curves, and hematoxylin and eosin staining.

RESULTS

The results showed that MnO₂ -ICG@BSA has a high photothermal conversion efficiency, a strong singlet oxygen-generation ability, and high photothermal stability. In addition, in vitro PTT-PDT experiments showed that MnO₂ -ICG@BSA has a significant inhibitory effect on the proliferation of B16F10 melanoma cells. Meanwhile, in vivo experiments showed that MnO₂ -ICG@BSA has a significant inhibitory effect on melanoma in mice. Preliminary toxicity studies indicated that MnO₂ -ICG@BSA exhibits low toxicity.

CONCLUSION

From the results, we can conclude that MnO₂ -ICG@BSA could be used in PTT-PDT to treat melanoma, making it a good candidate material for PTT-PDT. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Cross-linked nanoparticles of silk fibroin with proanthocyanidins as a promising vehicle of indocyanine green for photo-thermal therapy of glioma

Instability of silk fibroin nanoparticles (SFNPs) in physiologic condition hinders its application as drug delivery vehicle. Herein, indocyanine green (ICG) loaded silk fibroin nanoparticles (ICG-SFNPs) was firstly prepared and then crosslinked by proanthocyanidins to obtain the stable ICG-CSFNPs for killing the residual tumour niche under near infra-red irradiation (NIR) after surgery. The particle size and zeta potentials of ICG-CSFNPs was 120.1 nm and -40.4 mV, respectively. Moreover, ICG-CSFNPs exhibited good stability of particle size in the physiological medium. Meanwhile, the stable photothermal properties of ICG-CSFNPs were not compromised even after several cycles of NIR. Few of the ICG-CSFNPs were phagocytized by RAW264.7 macrophage in vitro, while they were easily internalized by C6 glioma cells, resulting in their significant toxicity on tumour cells after NIR. The pharmacokinetic study showed that ICG-CSFNPs had a longer blood circulation time than ICG-SFNPs, making them more distribution in glioma after intravenous administration in vivo. Meanwhile, the pharmacological study showed the more effective inhibition of tumour growth was exhibited by ICG-CSFNPs in C6 glioma-bearing mice after NIR. Overall, the cross-linked nanoparticles of silk fibroin may be a promising vehicle of ICG for photothermal therapy of glioma after surgical resection.

Subcellular Performance of Nanoparticles in Cancer Therapy

With the advent of nanotechnology, various modes of traditional treatment strategies have been transformed extensively owing to the advantageous morphological, physiochemical, and functional attributes of nano-sized materials, which are of particular interest in diverse biomedical applications, such as diagnostics, sensing, imaging, and drug delivery. Despite their success in delivering therapeutic agents, several traditional nanocarriers often end up with deprived selectivity and undesired therapeutic outcome, which significantly limit their clinical applicability. Further advancements in terms of improved selectivity to exhibit desired therapeutic outcome toward ablating cancer cells have been predominantly made focusing on the precise entry of nanoparticles into tumor cells via targeting ligands, and subsequent delivery of therapeutic cargo in response to specific biological or external stimuli. However, there is enough room intracellularly, where diverse small-sized nanomaterials can accumulate and significantly exert potentially specific mechanisms of antitumor effects toward activation of precise cancer cell death pathways that can be explored. In this review, we aim to summarize the intracellular pathways of nanoparticles, highlighting the principles and state of their destructive effects in the subcellular structures as well as the current limitations of conventional therapeutic approaches. Next, we give an overview of subcellular performances and the fate of internalized nanoparticles under various organelle circumstances, particularly endosome or lysosome, mitochondria, nucleus, endoplasmic reticulum, and Golgi apparatus, by comprehensively emphasizing the unique mechanisms with a series of interesting reports. Moreover, intracellular transformation of the internalized nanoparticles, prominent outcome and potential affluence of these interdependent subcellular components in cancer therapy are emphasized. Finally, we conclude with perspectives with a focus on the contemporary challenges in their clinical applicability.

Novel fluorescein polymer-based nanoparticles: facile and controllable one-pot synthesis, assembly, and immobilization of biomolecules for application in a highly sensitive biosensor

A key aspect of biochip and biosensor preparation is optimization of the optical or electrochemical techniques that combine high sensitivity and specificity. Among them, optical techniques such as the use of fluorescent polymeric nanoparticles have resulted in dramatic progress in the field of diagnostics due to their range of advantages. We herein report a facile approach for the development of novel fluorescein polymeric nanoparticles (FPNPs) with immobilization of specific biomolecules for application in a highly sensitive optical biosensor. A series of three amphiphilic fluorescein polymers (poly(FMA-r-NAS-r-MA)), comprising hydrophobic fluorescein O-methacrylate (FMA), hydrophilic N-acryloxysuccinimide (NAS), and methacrylic acid (MA) monomers were synthesized through radical polymerization. In an aqueous environment, these fluorescein polymers self-assembled into spherical shaped nanoparticles with a well-defined particle size, narrow particle size distribution, and enhanced fluorescence properties. The bio-immobilization properties of the FPNPs were also tunable by control of the activated N-hydroxysuccinimide ester group in the polymer series. Furthermore, the fluorescence sensitivity of bovine serum albumin detection by the FPNPs indicates that the limit of detection and sensitivity were improved compared to conventional fluorescence dye-labelled proteins. These novel FPNPs therefore represent a suitable technology for disease diagnosis and biomarker detection to ultimately improve the sensitivity of existing analytical methodologies in a facile and cost-effective manner.

We report a facile approach for the development of novel fluorescein polymeric nanoparticles (FPNPs) with immobilization of specific biomolecules for application in a highly sensitive optical biosensor.

Recent Advances in Polymeric Nanocomposites of Metal-Organic Frameworks (MOFs)

Recently, metal-organic frameworks (MOFs) have garnered enormous attention from researchers owing to their superior physicochemical properties, which are of particular interest in various fields such as catalysis and the diverse areas of biomedicine. Despite their position in the utilization for various applications compared to other innovative nanocarriers such as dendrimers and mesoporous silica nanoparticles (MSNs), in terms of advantageous physicochemical attributes, as well as attractive textural properties, ease of characterization, and abundant surface chemistry for functionalization and other benefits, MOFs yet suffer from several issues such as poor degradability, which might lead to accumulation-induced biocompatibility risk. In addition, some of the MOFs suffer from a shortcoming of poor colloidal stability in the aqueous solution, hindering their applicability in diverse biomedical fields. To address these limitations, several advancements have been made to fabricate polymeric nanocomposites of MOFs for their utility in various biomedical fields. In this review, we aim to provide a brief emphasis on various organic polymers used for coating over MOFs to improve their physicochemical attributes considering a series of recently reported intriguing studies. Finally, we summarize with perspectives.

Fluorescence Imaging as a Tool in Preclinical Evaluation of Polymer-Based Nano-DDS Systems Intended for Cancer Treatment

Targeted drug delivery using nano-sized carrier systems with targeting functions to malignant and inflammatory tissue and tailored controlled drug release inside targeted tissues or cells has been and is still intensively studied. A detailed understanding of the correlation between the pharmacokinetic properties and structure of the nano-sized carrier is crucial for the successful transition of targeted drug delivery nanomedicines into clinical practice. In preclinical research in particular, fluorescence imaging has become one of the most commonly used powerful imaging tools. Increasing numbers of suitable fluorescent dyes that are excitable in the visible to near-infrared (NIR) wavelengths of the spectrum and the non-invasive nature of the method have significantly expanded the applicability of fluorescence imaging. This chapter summarizes non-invasive fluorescence-based imaging methods and discusses their potential advantages and limitations in the field of drug delivery, especially in anticancer therapy. This chapter focuses on fluorescent imaging from the cellular level up to the highly sophisticated three-dimensional imaging modality at a systemic level. Moreover, we describe the possibility for simultaneous treatment and imaging using fluorescence theranostics and the combination of different imaging techniques, e.g., fluorescence imaging with computed tomography.

Targeting integrins for cancer management using nanotherapeutic approaches: Recent advances and challenges

Integrins are the main cell surface receptors and execute multifaceted functions such as the bidirectional transmission of signals (i.e., inside-out and outside-in) and provide communication between cells and their microenvironments. Integrins are the key regulators of critical biological functions and contribute significantly to the promotion of cancer at almost every stage of disease progression from initial tumor formation to metastasis. Integrin expressions are frequently altered in different cancers, and consequently, several therapeutic strategies targeting integrins have been developed. Furthermore, nanotechnology-based approaches have been devised to overcome the intrinsic limitations of conventional therapies for cancer management, and have been shown to more precise, safer, and highly effective therapeutic tools. Although nanotechnology-based approaches have achieved substantial success for the management of cancer, certain obstacles remain such as inadequate knowledge of nano-bio interactions and the challenges associated with the three stages of clinical trials. This review highlights the different roles of integrins and of integrin-dependent signaling in various cancers and describes the applications of nanotherapeutics targeting integrins. In addition, we discuss RGD-based approaches and challenges posed to cancer management.

Acid specific dark quencher QC1 pHLIP for multi-spectral optoacoustic diagnoses of breast cancer

Breast cancer is the most common type of malignant growth in women. Early detection of breast cancer, as well as the identification of possible metastatic spread poses a significant challenge because of the structural and genetic heterogeneity that occurs during the progression of the disease. Currently, mammographies, biopsies and MRI scans are the standard of care techniques used for breast cancer diagnosis, all of which have their individual shortfalls, especially when it comes to discriminating tumors and benign growths. With this in mind, we have developed a non-invasive optoacoustic imaging strategy that targets the acidic environment of breast cancer. A pH low insertion peptide (pHLIP) was conjugated to the dark quencher QC1, yielding a non-fluorescent sonophore with high extinction coefficient in the near infrared that increases signal as a function of increasing amounts of membrane insertion. In an orthotopic murine breast cancer model, pHLIP-targeted optoacoustic imaging allowed us to differentiate between healthy and breast cancer tissues with high signal/noise ratios. In vivo, the sonophore QC1-pHLIP could detect malignancies at higher contrast than its fluorescent analog ICG-pHLIP, which was developed for fluorescence-guided surgical applications. PHLIP-type optoacoustic imaging agents in clinical settings are attractive due to their ability to target breast cancer and a wide variety of other malignant growths for diagnostic purposes. Intuitively, these agents could also be used for visualization during surgery.

Engineered pH-responsive hydrazone-carboxylate complexes-encapsulated 2D matrices for cathepsin-mediated apoptosis in cancer

Spurred by the current advancements in engineering various intelligent nanoparticle-based drug delivery systems, conjugation of drugs with the stimuli-responsive molecular switches has become one of the most efficient approaches to deliver a drug cargo in spatiotemporal controlled fashions. In this study, we fabricated an innovative pH-triggered hydrazone-carboxylate complex of doxorubicin (Dox), which was subsequently encapsulated in the layered double hydroxide (LDH) nanoparticles for effective cancer therapeutics. These two-dimensional (2D) biodegradable matrices efficiently delivered Dox by pH-triggered release in the acidic lysosomal environment and their subsequent escape to cytosol. Moreover, the delivered Dox molecules and high positively-charged surfaces of LDHs facilitated the cancer cell ablation via enhancing the cathepsins-mediated cell apoptosis assisted by free radical species generation. The critical advancements in the nanoparticle-based designs and substantial ablation of tumor cells through a free radical attack indicate that the designed pH-triggered drug composites can be used for efficient cancer therapeutics. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1184-1194, 2019.

Bacterial magnetosomes-based nanocarriers for co-delivery of cancer therapeutics in vitro

In recent times, co-delivery of therapeutics has emerged as a promising strategy for treating dreadful diseases such as cancer.

MATERIALS AND METHODS

In this study, we developed a novel nanocarrier based on bacterial magnetosomes (BMs) that co-loaded with siRNA and doxorubicin (DOX) using polyethyleneimine (PEI) as a cross-linker (BMs/DP/siRNA). The delivery efficiency of siRNA as well as the pH-responsive release of DOX, and synergistic efficacy of these therapeutics in vitro were systematically investigated.

RESULTS

The structure of DOX-PEI (DP) conjugates that synthesized via hydrazone bond formation was confirmed by 1H nuclear magnetic resonance (NMR). The in vitro release experiments showed that the DP conjugate (DOX-loading efficiency - 5.77%±0.08%) exhibited the long-term release behavior. Furthermore, the optimal BMs/DP/siRNA particle size of 107.2 nm and the zeta potential value of 31.1±1.0 mV facilitated enhanced cellular internalization efficiency. Moreover, the agarose gel electrophoresis showed that the co-delivery system could protect siRNA from degradation in serum and RNase A. In addition, the cytotoxicity assay showed that BMs/DP/siRNA could achieve an excellent synergistic effect compared to that of siRNA delivery alone. The acridine orange (AO)/ethidium bromide (EB) double staining assay also showed that BMs/DP/siRNA complex could induce cells in a stage of late apoptosis and nanocomplex located in the proximity of the nucleus.

CONCLUSION

The combination of gene and chemotherapeutic drug using BMs is highly efficient, and the BMs/DP/siRNA would be a promising therapeutic strategy for the future therapeutics.

VE-Albumin Core-Shell Nanoparticles for Paclitaxel Delivery to Treat MDR Breast Cancer

Multi-drug resistance (MDR) presents a serious problem in cancer chemotherapy. In this study, Vitamin E (VE)-Albumin core-shell nanoparticles were developed for paclitaxel (PTX) delivery to improve the chemotherapy efficacy in an MDR breast cancer model. The PTX-loaded VE-Albumin core-shell nanoparticles (PTX-VE NPs) had small particle sizes (about 100 nm), high drug entrapment efficiency (95.7%) and loading capacity (12.5%), and showed sustained release profiles, in vitro. Docking studies indicated that the hydrophobic interaction and hydrogen bonds play a significant role in the formation of the PTX-VE NPs. The results of confocal laser scanning microscopy analysis demonstrated that the cell uptake of PTX was significantly increased by the PTX-VE NPs, compared with the NPs without VE (PTX NPs). The PTX-VE NPs also exhibited stronger cytotoxicity, compared with PTX NPs with an increased accumulation of PTX in the MCF-7/ADR cells. Importantly, the PTX-VE NPs showed a higher anti-cancer efficacy in MCF-7/ADR tumor xenograft model than the PTX NPs and the PTX solutions. Overall, the VE-Albumin core-shell nanoparticles could be a promising nanocarrier for PTX delivery to improve the chemotherapeutic efficacy of MDR cancer.

Characterization and Preliminary Biological Evaluation of 3D-Printed Porous Scaffolds for Engineering Bone Tissues

Some basic requirements of bone tissue engineering include cells derived from bone tissues, three-dimensional (3D) scaffold materials, and osteogenic factors. In this framework, the critical architecture of the scaffolds plays a crucial role to support and assist the adhesion of the cells, and the subsequent tissue repairs. However, numerous traditional methods suffer from certain drawbacks, such as multi-step preparation, poor reproducibility, high complexity, difficulty in controlling the porous architectures, the shape of the scaffolds, and the existence of solvent residue, which limits their applicability. In this work, we fabricated innovative poly(lactic-co-glycolic acid) (PLGA) porous scaffolds, using 3D-printing technology, to overcome the shortcomings of traditional approaches. In addition, the printing parameters were critically optimized for obtaining scaffolds with normal morphology, appropriate porous architectures, and sufficient mechanical properties, for the accommodation of the bone cells. Various evaluation studies, including the exploration of mechanical properties (compressive strength and yield stress) for different thicknesses, and change of structure (printing angle) and porosity, were performed. Particularly, the degradation rate of the 3D scaffolds, printed in the optimized conditions, in the presence of hydrolytic, as well as enzymatic conditions were investigated. Their assessments were evaluated using the thermal gravimetric analyzer (TGA), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). These porous scaffolds, with their biocompatibility, biodegradation ability, and mechanical properties, have enabled the embryonic osteoblast precursor cells (MC3T3-E1), to adhere and proliferate in the porous architectures, with increasing time. The generation of highly porous 3D scaffolds, based on 3D printing technology, and their critical evaluation, through various investigations, may undoubtedly provide a reference for further investigations and guide critical optimization of scaffold fabrication, for tissue regeneration.

Mesoporous Silica Nanoparticles: A Comprehensive Review on Synthesis and Recent Advances

Recent advancements in drug delivery technologies utilizing a variety of carriers have resulted in a path-breaking revolution in the approach towards diagnosis and therapy alike in the current times. Need for materials with high thermal, chemical and mechanical properties have led to the development of mesoporous silica nanoparticles (MSNs). These ordered porous materials have garnered immense attention as drug carriers owing to their distinctive features over the others. They can be synthesized using a relatively simple process, thus making it cost effective. Moreover, by controlling the parameters during the synthesis; the morphology, pore size and volume and particle size can be transformed accordingly. Over the last few years, a rapid increase in research on MSNs as drug carriers for the treatment of various diseases has been observed indicating its potential benefits in drug delivery. Their widespread application for the loading of small molecules as well as macromolecules such as proteins, siRNA and so forth, has made it a versatile carrier. In the recent times, researchers have sorted to several modifications in the framework of MSNs to explore its potential in drug resistant chemotherapy, antimicrobial therapy. In this review, we have discussed the synthesis of these multitalented nanoparticles and the factors influencing the size and morphology of this wonder carrier. The second part of this review emphasizes on the applications and the advances made in the MSNs to broaden the spectrum of its use especially in the field of biomedicine. We have also touched upon the lacunae in the thorough understanding of its interaction with a biological system which poses a major hurdle in the passage of this carrier to the clinical level. In the final part of this review, we have discussed some of the major patents filed in the field of MSNs for therapeutic purpose.

Nanostructured Lipid Carriers as Promising Delivery Systems for Plant Extracts: The Case of Silymarin

Background: Silymarin is the extract from seeds of Silybum marianum L. Gaertn. and it has been used for decades as hepatoprotectant. Recently, it has been proposed to be beneficial in type 2 diabetes patients. However, silymarin is a poorly water soluble drug with limited oral bioavailability. In this study, nanostructured lipid carriers were proposed to enhance its solubility and intestinal absorption. Methods: Nanostructured lipid carriers were made of Stearic acid:Capryol 90 as lipid mixtures and Brij S20 as surfactant. Formulations were physically and chemically characterized. Stability and in vitro release studies were also assessed. In vitro permeability and Caco-2 cellular uptake mechanism were investigated. Results: Obtained results were based on size, homogeneity, ζ-potential and EE%. Nanostructured lipid carriers could be orally administered. No degradation phenomena were observed in simulated gastrointestinal fluids. Storage stability of suspensions and lyophilized products was also tested. Glucose was selected as best cryoprotectant agent. About 60% of silymarin was released in 24 h in phosphate buffered saline. In vitro parallel artificial membrane permeability assay experiments revealed that the nanocarrier enhanced the permeation of Silymarin. Caco-2 study performed with fluorescent nanoparticles revealed the ability of carrier to enhance the permeation of a lipophilic probe. Cellular uptake studies indicated that active process is involved in the internalization of the formulation. Conclusions: The optimized nanostructured lipid carriers showed excellent chemical and physical stability and enhanced the absorption of silymarin.