Two-Step Assembling of Near-Infrared "OFF-ON" Fluorescent Nanohybrids for Synchronous Tumor Imaging and MicroRNA Modulation-Based Therapy

Fluorescent Nanocarbons: From Synthesis and Structure to Cancer Imaging and Therapy

Nanocarbons are emerging at the forefront of nanoscience, with diverse carbon nanoforms emerging over the past two decades. Early cancer diagnosis and therapy, driven by advanced chemistry techniques, play a pivotal role in mitigating mortality rates associated with cancer. Nanocarbons, with an attractive combination of well-defined architectures, biocompatibility, and nanoscale dimension, offer an incredibly versatile platform for cancer imaging and therapy. This paper aims to review the underlying principles regarding the controllable synthesis, fluorescence origins, cellular toxicity, and surface functionalization routes of several classes of nanocarbons: carbon nanodots, nanodiamonds, carbon nanoonions, and carbon nanohorns. This review also highlights recent breakthroughs regarding the green synthesis of different nanocarbons from renewable sources. It also presents a comprehensive and unified overview of the latest cancer-related applications of nanocarbons and how they can be designed to interface with biological systems and work as cancer diagnostics and therapeutic tools. The commercial status for large-scale manufacturing of nanocarbons is also presented. Finally, it proposes future research opportunities aimed at engendering modifiable and high-performance nanocarbons for emerging applications across medical industries. This work is envisioned as a cornerstone to guide interdisciplinary teams in crafting fluorescent nanocarbons with tailored attributes that can revolutionize cancer diagnostics and therapy.

Application and development of nanomaterials in the diagnosis and treatment of esophageal cancer

Esophageal cancer is a malignant tumor with a high incidence worldwide. Currently, there are a lack of effective early diagnosis and treatment methods for esophageal cancer. However, delivery systems based on nanoparticles (NPs) have shown ideal efficacy in real-time imaging and chemotherapy, radiotherapy, gene therapy, and phototherapy for tumors, which has led to their recent widespread design as novel treatment strategies. Compared to traditional drugs, nanomedicine has unique advantages, including strong targeting ability, high bioavailability, and minimal side effects. This article provides an overview of the application of NPs in the diagnosis and treatment of esophageal cancer and provides a reference for future research.

Versatile nanodiamond-based tools for therapeutics and bioimaging

Nanodiamonds (NDs) are a remarkable class of carbon-based nanoparticles in nanomedicine which have recently become a hot topic of research due to their unique features including functionalization versatility, tunable opto-magnetic properties, chemical stability, minimal cytotoxicity, high affinity to biomolecules and biocompatibility. These attractive features make NDs versatile tools for a wide range of biologically relevant applications. In this feature article, we discuss the opto-magnetic properties of negatively charged nitrogen vacancy (NV^-) centres in NDs as fluorescence probes. We further discuss the frequently used chemical methods for surface chemistry modification of NDs which are relevant for biomedical applications. The in vitro and in vivo biocompatibility of modified NDs is also highlighted. Subsequently, we give an overview of recent state-of-the-art biomedical applications of NDs as versatile tools for bioimaging and detection, and as targeting nanocarriers for chemotherapy, photodynamic therapy, gene therapy, antimicrobial and antiviral therapy, and bone tissue engineering. Finally, we pinpoint the main challenges for NDs in biomedical applications which lie ahead and discuss perspectives on future directions in advancing the field for practical applications and clinical translations.

A multifunctional nanodiamond-based nanoplatform for the enhanced mild-temperature photothermal/chemo combination therapy of triple negative breast cancer via an autophagy regulation strategy

Owing to its aggressive biological behavior, the lack of specific targets, and the strong therapeutic resistance of triple negative breast cancer (TNBC), current therapeutic strategies are still limited. The combination of multiple treatments has been confirmed as a promising strategy for TNBC therapy. However, the efficacy of combination therapy can be restricted due to increasing therapeutic resistance to various treatments. Herein, we constructed a nanodiamond (ND)-based nanoplatform for augmented mild-temperature photothermal/chemo combination therapy against TNBC, weakening the therapeutic resistance via autophagy inhibition enabled by the NDs. A layer-by-layer self-assembly approach was utilized to construct the ND-based nanoplatform. First, the NDs were modified with protamine sulphate (PS). Meanwhile, the photosensitizer indocyanine green (ICG) and the HSP70 small molecule inhibitor apoptozole (APZ) could be synchronously incorporated to form positively charged PS@ND (ICG + APZ). Then negatively charged hyaluronic acid (HA) was assembled onto the outer face of PS@ND (ICG + APZ) to form the NPIAs. Finally, the positively charged small molecule anti-cancer drug doxorubicin (DOX) could be adsorbed onto the surface of the NPIAs through electrostatic interactions (NPIADs). The resulting NPIADs could be triggered by NIR laser irradiation to exhibit enhanced mild-temperature photothermal therapy (PTT) effects via suppressing the expression of HSP70, and PTT combined with chemotherapy could further enhance the anti-tumor efficacy. Subsequently, the sensitivity of MDA-MB-231 cells could be significantly improved through the weakening of the thermal/drug resistance via autophagy inhibition, leading to augmented combination therapy that is efficient both in vitro and in vivo. Furthermore, the NPIADs could be used as a theranostic nanoplatform for fluorescence (FL) and photoacoustic (PA) imaging. Taken together, this study demonstrated a multifunctional ND-based nanoplatform for FL/PA imaging-guided augmented mild-temperature photothermal/chemo combination therapy via an autophagy regulation strategy against TNBC.

Multicomponent-assembled nanodiamond hybrids for targeted and imaging guided triple-negative breast cancer therapy via a ternary collaborative strategy

Uniting combinational strategies has been confirmed to be a robust choice for high-performance cancer treatment due to their abilities to overcome tumor heterogeneity and complexity. However, the development of a simple, effective, and multifunctional theranostics nanoplatform still remains a challenge. In this study, we integrated multicomponent hyaluronic acid (HA), protamine (PS), nanodiamonds (NDs), curcumin (Cur), and IR780 into a single nanoplatform (denoted as HPNDIC) based on the combination of hydrophobic and electrostatic noncovalent interactions for dual-modal fluorescence/photoacoustic imaging guided ternary collaborative Cur/photothermal/photodynamic combination therapy of triple-negative breast cancer (TNBC). A two-step coordination assembly strategy was utilized to realize this purpose. In the first step, PS was utilized to modify the NDs clusters to form positively charged PS@NDs (PND) and the simultaneous encapsulation of the natural small-molecule drug Cur and the photosensitive small-molecule IR780 (PNDIC). Second, HA was adsorbed onto the outer surface of the PNDIC through charge complexation for endowing a tumor-targeting ability (HPNDIC). The resulting HPNDIC had a uniform size, high drug-loading ability, and excellent colloidal stability. It was found that under the near-infrared irradiation condition, IR780 could be triggered to exhibit both PTT/PDT dual-pattern therapy effects, leading to an enhanced therapy efficiency of Cur both in vitro and in vivo with good biocompatibility. Due to the intrinsic imaging property of IR780, the biodistribution and accumulation behavior of HPNDIC in vivo could be monitored by dual-modal fluorescence/photoacoustic imaging. Taken together, our current work demonstrated the assembly of a NDs-based multicomponent theranostic platform for dual-modal fluorescence/photoacoustic imaging guided triple-collaborative Cur/photothermal/photodynamic against TNBC.

Nanodiamonds for In Vivo Applications

Due to their unique optical properties, diamonds are the most valued gemstones. However, beyond the sparkle, diamonds have a number of unique properties. Their extreme hardness gives them outstanding performance as abrasives and cutting tools. Similar to many materials, their nanometer-sized form has yet other unique properties. Nanodiamonds are very inert but still can be functionalized on the surface. Additionally, they can be made in very small sizes and a narrow size distribution. Nanodiamonds can also host very stable fluorescent defects. Since they are protected in the crystal lattice, they never bleach. These defects can also be utilized for nanoscale sensing since they change their optical properties, for example, based on temperature or magnetic fields in their surroundings. In this Review, in vivo applications are focused upon. To this end, how different diamond materials are made and how this affects their properties are discussed first. Next, in vivo biocompatibility studies are reviewed. Finally, the reader is introduced to in vivo applications of diamonds. These include drug delivery, aiding radiology, labeling, and use in cosmetics. The field is critically reviewed and a perspective on future developments is provided.

Color-tunable AIE-active conjugated polymer nanoparticles as drug carriers for self-indicating cancer therapy via intramolecular FRET mechanism

In this paper, two novel AIE-active conjugated polymers were synthesized by Pd-catalyzed Suzuki coupling polymerization reaction.

Tumor acidity-activatable TAT targeted nanomedicine for enlarged fluorescence/magnetic resonance imaging-guided photodynamic therapy

Nanoparticles simultaneously integrated the photosensitizers and diagnostic agents represent an emerging approach for imaging-guided photodynamic therapy (PDT). However, the diagnostic sensitivity and therapeutic efficacy of nanoparticles as well as the heterogeneity of tumors pose tremendous challenges for clinical imaging-guided PDT treatment. Herein, a polymeric nanoparticle with tumor acidity (pH_e)-activatable TAT targeting ligand that encapsulates the photosensitizer chlorin e6 (Ce6) and chelates contrast agent Gd³⁺ is successfully developed for fluorescence/magnetic resonance (MR) dual-model imaging-guided precision PDT. We show clear evidence that the resulting nanoparticle ^DATAT-NP [its TAT lysine residues' amines was modified by 2,3-dimethylmaleic anhydride (DA)] efficiently avoids the rapid clearance by reticuloendothelial system (RES) by masking of the TAT peptide, resulting in the significantly prolonged circulation time in the blood. Once accumulating in the tumor tissues, ^DATAT-NP is reactivated by tumor acidity to promote cellular uptake, resulting in enlarged fluorescence/MR imaging signal intensity and elevated in vivo PDT therapeutic effect. This concept provides new avenues to design tumor acidity-activatable targeted nanoparticles for imaging-guided cancer therapy.