LaB6 nanoparticles with carbon-doped silica coating for fluorescence imaging and near-IR photothermal therapy of cancer cells

The Fluorescent Effect of Withania Somnifera Chitosan Nanocomposite as an Effective Contrast Agent for Cancer Theragnostic: Experimental Study in Vitro

Nanomedicine and fluorescent optical imaging are effective in early cancer detection. The current study synthesized biocompatible nanocomposites from natural biomaterials towards inexpensive and safe cancer theragnostic. Two forms of nanocomposites were synthesized using the ionic gelation method: 1. Chitosan/ Withania Somnifera /tripolyphosphate nanocomposites, 2. Withania Somnifera/Chitosan nanocomposites. The nanocomposites were characterized by dynamic light scattering, zeta potential, and the transmission electron microscope. Fourier transform infrared spectroscopy analyzed the Withania Somnifera root water extract, Chitosan, and the synthesized nanocomposites. The cytotoxicity of the nanocomposites was investigated against the colon cancer cells (Caco2 cells) in the absence and the presence of laser (665 nm, 5 mW) irradiation. MTT assay evaluated the cytotoxicity, and Trypan blue assay assessed the cell viability. Cancerous cells were photographed under the inverted microscope in the presence and the absence of laser irradiation. Results were analyzed statistically using one-way variance (ANOVA) analysis with Bonferroni post-Hoc multiple two-group comparisons. The characterization results ensured the successful synthesis of Withania Somnifera/Chitosan nanocomposites. The results showed an increase in the cytotoxicity against colon carcinoma and a decrease in cell viability in the presence and absence of Near-infrared laser irradiation under the action of nanocomposites. The cytotoxicity of the synthesized nanocomposites increased by exposing the cells to the laser. The shining light of the nanocomposites appeared on the cells photographed under the inverted microscope. The synthesized natural nanocomposites promise systemic cytotoxicity will be efficient in molecular imaging in vivo applications.

Progress and perspective of microneedle system for anti-cancer drug delivery

Transdermal drug delivery exhibited encouraging prospects, especially through superficial drug administration routes. However, only a few limited lipophilic drug molecules could cross the skin barrier, those are with low molecular weight and rational Log P value. Microneedles (MNs) can overcome these limitations to deliver numerous drugs into the dermal layer by piercing the outermost skin layer of the body. In the case of superficial cancer treatments, topical drug administration faces severely low transfer efficiency, and systemic treatments are always associated with side effects and premature drug degradation. MN-based systems have achieved excellent technical capabilities and been tested for pre-clinical chemotherapy, photothermal therapy, photodynamic therapy, and immunotherapy. In this review, we will focus on the features, progress, and opportunities of MNs in the anticancer drug delivery system. Then, we will discuss the strategies and advantages in these works and summarize challenges, perspectives, and translational potential for future applications.

First-Principles Calculations of x-Dependent Ground Structures and Optical Properties of Ca x La1-x B6

High transparency in the visible region is desired to manufacture solar control films and glasses for various applications. To improve the visible light transparency of LaB₆ nanoparticles which exhibit strong absorption in the near-infrared region, the substitution of La with Ca is investigated using first-principles calculations. Among the numerous atomic replacement configurations in Ca _x La_1-x B₆, all 762 structures existing in the supercells that are up to 8 times the primitive cell are comprehensively evaluated, and the most stable ground structures in Ca _x La_1-x B₆ are deduced. The optical properties of the ground structures are derived by performing high-precision calculations using the HSE06 functional, which reveal that Ca _x La_1-x B₆ with 0 < x < 1/4 is preferred as a solar shielding material with improved visible transparency. This method is effective for the investigation of the effect of substitutional elements in composite compounds on their physical properties.

Current Advancements in Transdermal Biosensing and Targeted Drug Delivery

In this manuscript, recent advancements in the area of minimally-invasive transdermal biosensing and drug delivery are reviewed. The administration of therapeutic entities through the skin is complicated by the stratum corneum layer, which serves as a barrier to entry and retards bioavailability. A variety of strategies have been adopted for the enhancement of transdermal permeation for drug delivery and biosensing of various substances. Physical techniques such as iontophoresis, reverse iontophoresis, electroporation, and microneedles offer (a) electrical amplification for transdermal sensing of biomolecules and (b) transport of amphiphilic drug molecules to the targeted site in a minimally invasive manner. Iontophoretic delivery involves the application of low currents to the skin as well as the migration of polarized and neutral molecules across it. Transdermal biosensing via microneedles has emerged as a novel approach to replace hypodermic needles. In addition, microneedles have facilitated minimally invasive detection of analytes in body fluids. This review considers recent innovations in the structure and performance of transdermal systems.

Glucose oxidase and polydopamine functionalized iron oxide nanoparticles: combination of the photothermal effect and reactive oxygen species generation for dual-modality selective cancer therapy

Cancer cells possess some inherent characteristics, such as glucose-dependence and intolerance to heat and exogenous reactive oxygen species (ROS). In this study, a strategy has been developed to target these vulnerable weaknesses of cancer cells using glucose oxidase (GOx) and polydopamine (PDA) functionalized iron oxide nanoparticles (Fe₃O₄@PDA/GOx NPs). PDA is first deposited on the surfaces of iron oxide NPs through self-polymerization, and then GOx is covalently linked with PDA upon mixing the enzyme and Fe₃O₄@PDA under alkaline conditions. In this system, the PDA layer along with iron oxide NPs serves as a photothermal transfer material converting near infrared (NIR) radiation into heat. The covalently linked GOx can competitively consume glucose and spontaneously generate ROS H₂O₂ that can be further converted by the iron oxide NPs into more toxic ˙OH, inducing apoptosis of cancer cells. The selective toxicity of Fe₃O₄@PDA/GOx NPs on cancer cells is demonstrated both in vitro and in vivo. In particular, a single injection rather than multiple doses results in significant suppression of tumors, and does not induce apparent histological lesions in the 4T1 tumor-bearing Balb/c mice. The versatility of the functionalization strategy reported in this study will contribute to developing efficient therapies for selective cancer treatment.

Toward Highly Efficient Cancer Imaging and Therapy Using the Environment-Friendly Chitosan Nanoparticles and NIR Laser

Chitosan-tripolyphosphate nanoparticles (C-TPP NPs) were synthesized to investigate their cytotoxicity against colon cancer cells (Caco2 cells) in the absence and the presence of a near-infrared (NIR) laser to evaluate their influence in cancer detection using the NIR laser and to evaluate the NIR laser on cancer treatment. The synthesized NPs were characterized by Fourier transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS), zeta potential (ZP), and transmission electronic microscope (TEM). The cytotoxicity was analyzed by the MTT test and the cell viability was assessed using the Trypan blue method. C-TPP NPs showed increased cytotoxicity and decreased cell viability against Caco2 cells. Upon laser exposure only, the cell viability decreased. The C-TPP NPs appeared to have a shining light on the cancerous cells which were photographed under the inverted microscope.

Tuning the Surface Plasmon Resonance of Lanthanum Hexaboride to Absorb Solar Heat: A Review

While traditional noble metal (Ag, Au, and Cu) nanoparticles are well known for their plasmonic properties, they typically only absorb in the ultraviolet and visible regions. The study of metal hexaborides, lanthanum hexaboride (LaB₆) in particular, expands the available absorbance range of these metals well into the near-infrared. As a result, LaB₆ has become a material of interest for its energy and heat absorption properties, most notably to those trying to absorb solar heat. Given the growing popularity of LaB₆, this review focuses on the advances made in the past decade with respect to controlling the plasmonic properties of LaB₆ nanoparticles. This review discusses the fundamental structure of LaB₆ and explains how decreasing the nanoparticle size changes the atomic vibrations on the surface and thus the plasmonic absorbance band. We explain how doping LaB₆ nanoparticles with lanthanide metals (Y, Sm, and Eu) red-shifts the absorbance band and describe research focusing on the correlation between size dependent and morphological effects on the surface plasmon resonance. This work also describes successes that have been made in dispersing LaB₆ nanoparticles for various optical applications, highlighting the most difficult challenges encountered in this field of study.

Recent advances in different modal imaging-guided photothermal therapy

Photothermal therapy (PTT) has recently attracted considerable attention owing to its controllable treatment process, high tumour eradication efficiency and minimal side effects on non-cancer cells. PTT can melt cancerous cells by localising tissue hyperthermia induced by internalised therapeutic agents with a high photothermal conversion efficiency under external laser irradiation. Numerous in vitro and in vivo studies have shown the significant potential of PTT to treat tumours in future practical applications. Unfortunately, the lack of visualisation towards agent delivery and internalisation, as well as imaging-guided comprehensive evaluation of therapeutic outcome, limits its further application. Developments in combined photothermal therapeutic nanoplatforms guided by different imaging modalities have compensated for the major drawback of PTT alone, proving PTT to be a promising technique in biomedical applications. In this review, we introduce recent developments in different imaging modalities including single-modal, dual-modal, triple-modal and even multi-modal imaging-guided PTT, together with imaging-guided multi-functional theranostic nanoplatforms.

Optical properties of group-3 metal hexaboride nanoparticles by first-principles calculations

LaB6 nanoparticles are widely used as solar control materials for strong near-infrared absorption and high visible transparency. In order to elucidate the origin of this unique optical property, first-principles calculations have been made for the energy-band structure and dielectric functions of R(III)B6 (R(III) = Sc, Y, La, Ac). On account of the precise assessment of the energy eigenvalues of vacant states in conduction band by employing the screened exchange method, as well as to the incorporation of the Drude term, dielectric functions and various physical properties of LaB6 have been reproduced in excellent agreement with experimental values. Systematic examinations of dielectric functions and electronic structures of the trivalent metal hexaborides have clarified the origin of the visible transparency and the near-infrared plasmon absorption of R(III)B6 nanoparticles.

Near-Infrared Light-Activatable Microneedle System for Treating Superficial Tumors by Combination of Chemotherapy and Photothermal Therapy

Because of the aggressive and recurrent nature of cancers, repeated and multimodal treatments are often necessary. Traditional cancer therapies have a risk of serious toxicity and side effects. Hence, it is crucial to develop an alternative treatment modality that is minimally invasive, effectively treats cancers with low toxicity, and can be repeated as required. We developed a light-activatable microneedle (MN) system that can repeatedly and simultaneously provide photothermal therapy and chemotherapy to superficial tumors and exert synergistic anticancer effects. This system consists of embeddable polycaprolactone MNs containing a photosensitive nanomaterial (lanthanum hexaboride) and an anticancer drug (doxorubicin; DOX), and a dissolvable poly(vinyl alcohol)/polyvinylpyrrolidone supporting array patch. Because of this supporting array, the MNs can be completely inserted into the skin and embedded within the target tissue for locoregional cancer treatment. When exposed to near-infrared light, the embedded MN array uniformly heats the target tissue to induce a large thermal ablation area and then melts at 50 °C to release DOX in a broad area, thus destroying tumors. This light-activated heating and releasing behavior can be precisely controlled and switched on and off on demand for several cycles. We demonstrated that the MN-mediated synergistic therapy completely eradicated 4T1 tumors within 1 week after a single application of the MN and three cycles of laser treatment. No tumor recurrence and no significant body weight loss of mice were observed. Thus, the developed light-activatable MN with a unique embeddable feature offers an effective, user-friendly, and low-toxicity option for patients requiring long-term and multiple cancer treatments.

Effects of induced optical tunable and ferromagnetic behaviors of Ba doped nanocrystalline LaB6

Multiple nanocrystalline rare-earth hexaborides La_1−xBa_xB₆ have been synthesized via a single step solid-state reaction.

Remotely triggered release of small molecules from LaB6@SiO2-loaded polycaprolactone microneedles

We established near-infrared (NIR)-light-triggered transdermal delivery systems by encapsulating NIR absorbers, silica-coated lanthanum hexaboride (LaB6@SiO2) nanostructures and the cargo molecule to be released in biodegradable polycaprolactone (PCL) microneedles. Acting as a local heat source when exposed to an NIR laser, these nanostructures cause a phase transition of the microneedles, thereby increasing the mobility of the polymer chains and triggering drug release from the microneedles. On IR thermal images, the light-triggered melting behavior of the LaB6@SiO2-loaded microneedles was observed. By adjusting the irradiation time and the laser on/off cycles, the amount of molecules released was controlled accurately. Drug release was switched on and off for at least three cycles, and a consistent dose was delivered in each cycle with high reproducibility. The designed microneedles were remotely triggered by laser irradiation for the controlled release of a chemotherapeutic drug, doxorubicin hydrochloride, in vivo. This system would enable dosages to be adjusted accurately to achieve a desired effect, feature a low off-state drug leakage to minimize basal effects and can increase the flexibility of pharmacotherapy performed to treat various medical conditions.

Comparison of gold nanoparticle mediated photoporation: vapor nanobubbles outperform direct heating for delivering macromolecules in live cells

There is a great interest in delivering macromolecular agents into living cells for therapeutic purposes, such as siRNA for gene silencing. Although substantial effort has gone into designing nonviral nanocarriers for delivering macromolecules into cells, translocation of the therapeutic molecules from the endosomes after endocytosis into the cytoplasm remains a major bottleneck. Laser-induced photoporation, especially in combination with gold nanoparticles, is an alternative physical method that is receiving increasing attention for delivering macromolecules in cells. By allowing gold nanoparticles to bind to the cell membrane, nanosized membrane pores can be created upon pulsed laser illumination. Depending on the laser energy, pores are created through either direct heating of the AuNPs or by vapor nanobubbles (VNBs) that can emerge around the AuNPs. Macromolecules in the surrounding cell medium can then diffuse through the pores directly into the cytoplasm. Here we present a systematic evaluation of both photoporation mechanisms in terms of cytotoxicity, cell loading, and siRNA transfection efficiency. We find that the delivery of macromolecules under conditions of VNBs is much more efficient than direct photothermal disturbance of the plasma membrane without any noticeable cytotoxic effect. Interestingly, by tuning the laser energy, the pore size could be changed, allowing control of the amount and size of molecules that are delivered in the cytoplasm. As only a single nanosecond laser pulse is required, we conclude that VNBs are an interesting photoporation mechanism that may prove very useful for efficient high-throughput macromolecular delivery in live cells.

Near-infrared fluorescent probes in cancer imaging and therapy: an emerging field

Near-infrared fluorescence (NIRF) imaging is an attractive modality for early cancer detection with high sensitivity and multi-detection capability. Due to convenient modification by conjugating with moieties of interests, NIRF probes are ideal candidates for cancer targeted imaging. Additionally, the combinatory application of NIRF imaging and other imaging modalities that can delineate anatomical structures extends fluorometric determination of biomedical information. Moreover, nanoparticles loaded with NIRF dyes and anticancer agents contribute to the synergistic management of cancer, which integrates the advantage of imaging and therapeutic functions to achieve the ultimate goal of simultaneous diagnosis and treatment. Appropriate probe design with targeting moieties can retain the original properties of NIRF and pharmacokinetics. In recent years, great efforts have been made to develop new NIRF probes with better photostability and strong fluorescence emission, leading to the discovery of numerous novel NIRF probes with fine photophysical properties. Some of these probes exhibit tumoricidal activities upon light radiation, which holds great promise in photothermal therapy, photodynamic therapy, and photoimmunotherapy. This review aims to provide a timely and concise update on emerging NIRF dyes and multifunctional agents. Their potential uses as agents for cancer specific imaging, lymph node mapping, and therapeutics are included. Recent advances of NIRF dyes in clinical use are also summarized.