ICG-ALA complex for improved phototherapy of cancer

5-Aminolevulinic acid (ALA) based photodynamic therapy (PDT) is a clinically approved therapeutic method for cancer treatment. Indocyanine green (ICG) is on the other hand an FDA-approved fluorescent dye that has been widely used in medical imaging in the near-infrared (NIR), and lately recognized as an agent to induce photothermal therapy (PTT). However, the hydrophilicity of ALA and rapid degradation of ICG in aqueous or physiological media as well as their instability limit their clinical application. Besides, the combination of PDT and PTT is a promising alternative to a single therapy approach. Herein, electrostatic binding of ALA to ICG is proposed to bypass such handicaps and provide enhanced therapeutic outcomes with simultaneous PDT and PTT combination. ICG-ALA exhibited excellent biocompatibility up to 50 μg ICG/mL-10 mM ALA in the dark in both SKBR3 and MDA-MB-231 cell lines with higher cell uptake compared to free ALA or ICG. ICG-ALA treatment coupled with 640/808 nm 5 min co-irradiation caused significantly stronger phototoxicity in both cancer cell lines at very low concentrations, reaching near complete loss of viability at 2.5 μg ICG /mL-0.5 mM ALA equivalent concentration of the ICG-ALA. The temperature increase observed during irradiation of the cells and the elevated oxidative stress resulting in the release of caspase 3/7 agrees well with the onset of PTT and PDT. In addition, ICG-ALA demonstrates visualization of cancer cells in both NIR (ICG) and visible (PpIX) regions allowing imaging-guided phototherapy.

Biophysical stimuli for promoting bone repair and regeneration

Bone injuries and diseases are associated with profound changes in the biophysical properties of living bone tissues, particularly their electrical and mechanical properties. The biophysical properties of healthy bone are attributed to the complex network of interactions between its various cell types (i.e., osteocytes, osteoclast, immune cells and vascular endothelial cells) with the surrounding extracellular matrix (ECM) against the backdrop of a myriad of biomechanical and bioelectrical stimuli arising from daily physical activities. Understanding the pathophysiological changes in bone biophysical properties is critical to developing new therapeutic strategies and novel scaffold biomaterials for orthopedic surgery and tissue engineering, as well as provides a basis for the application of various biophysical stimuli as therapeutic agents to restore the physiological microenvironment of injured/diseased bone tissue, to facilitate its repair and regeneration. These include mechanical, electrical, magnetic, thermal and ultrasound stimuli, which will be critically examined in this review. A significant advantage of utilizing such biophysical stimuli to facilitate bone healing is that these may be applied non-invasively with minimal damage to surrounding tissues, unlike conventional orthopedic surgical procedures. Furthermore, the effects of such biophysical stimuli can be localized specifically at the bone defect site, unlike drugs or growth factors that tend to diffuse away after delivery, which may result in detrimental side effects at ectopic sites.

Advances in smart nanotechnology-supported photodynamic therapy for cancer

Cancer has emerged as a formidable challenge in the 21st century, impacting society, public health, and the economy. Conventional cancer treatments often exhibit limited efficacy and considerable side effects, particularly in managing the advanced stages of the disease. Photodynamic therapy (PDT), a contemporary non-invasive therapeutic approach, employs photosensitizers (PS) in conjunction with precise light wavelengths to selectively target diseased tissues, inducing the generation of reactive oxygen species and ultimately leading to cancer cell apoptosis. In contrast to conventional therapies, PDT presents a lower incidence of side effects and greater precision in targeting. The integration of intelligent nanotechnology into PDT has markedly improved its effectiveness, as evidenced by the remarkable synergistic antitumor effects observed with the utilization of multifunctional nanoplatforms in conjunction with PDT. This paper provides a concise overview of the principles underlying PS and PDT, while also delving into the utilization of nanomaterial-based PDT in the context of cancer treatment.

Indocyanine green-loaded N-doped carbon quantum dot nanoparticles for effective photodynamic therapy and cell imaging of melanoma cancer: in vitro, ex vivo and in vivo study

BACKGROUND

Indocyanine Green (ICG) as an agent for photodynamic therapy (PDT) of melanoma cancer has low quantum yield, short circulation half-life, poor photo-stability, and tendency to aggregation.

PURPOSE

N-doped carbon quantum dot (CQD) nanoparticle was applied to encapsulate ICG and overcome ICG obstacle in PDT with simultaneous cell imaging property.

METHODS

CQD was prepared using hydrothermal method. Cell culture study and In vivo assessments on C57BL/6 mice containing melanoma cancer cells was performed.

RESULTS

Results showed that CQD size slightly enhanced from 24.55 nm to 42.67 nm after ICG loading. Detection of reactive oxygen species (ROS) demonstrated that CQD improved ICG photo-stability and ROS generation capacity upon laser irradiation. Cell culture study illustrated that ICG@CQD could decrease survival rate of melanoma cancer cells of B16F10 cell line from 48% for pure ICG to 28% for ICG@CQD. Confocal microscopy images approved more cellular uptake and more qualified cell imaging ability of ICG@CQD. In vivo assessments displayed obvious inhibitory effect of tumor growth for ICG@CQD in comparison to free ICG on the C57BL/6 mice. In vivo fluorescence images confirmed that ICG@CQD accumulates remarkably more than free ICG in tumor region. Finally, ICG@CQD was proposed as an innovative nanocarrier for PDT and diagnosis.

Image-guided drug delivery in nanosystem-based cancer therapies

The past decades have shown significant advancements in the development of solid tumor treatment. For instance, implementation of nanosystems for drug delivery has led to a reduction in side effects and improved delivery to the tumor region. However, clinical translation has faced challenges, as tumor drug levels are still considered to be inadequate. Interdisciplinary research has resulted in the development of more advanced drug delivery systems. These are coined "smart" due to the ability to be followed and actively manipulated in order to have better control over local drug release. Therefore, image-guided drug delivery can be a powerful strategy to improve drug activity at the target site. Being able to visualize the inflow of the administered smart nanosystem within the tumor gives the potential to determine the right moment to apply the facilitator to initiate drug release. Here we provide an overview of available nanosystems, imaging moieties, and imaging techniques. We discuss preclinical application of these smart drug delivery systems, the strength of image-guided drug delivery, and the future of personalized treatment.

Nanomaterials-based photosensitizers and delivery systems for photodynamic cancer therapy

The increasing cancer morbidity and mortality requires the development of high-efficiency and low-toxicity anticancer approaches. In recent years, photodynamic therapy (PDT) has attracted much attention in cancer therapy due to its non-invasive features and low side effects. Photosensitizer (PS) is one of the key factors of PDT, and its successful delivery largely determines the outcome of PDT. Although a few PS molecules have been approved for clinical use, PDT is still limited by the low stability and poor tumor targeting capacity of PSs. Various nanomaterial systems have shown great potentials in improving PDT, such as metal nanoparticles, graphene-based nanomaterials, liposomes, ROS-sensitive nanocarriers and supramolecular nanomaterials. The small molecular PSs can be loaded in functional nanomaterials to enhance the PS stability and tumor targeted delivery, and some functionalized nanomaterials themselves can be directly used as PSs. Herein, we aim to provide a comprehensive understanding of PDT, and summarize the recent progress of nanomaterials-based PSs and delivery systems in anticancer PDT. In addition, the concerns of nanomaterials-based PDT including low tumor targeting capacity, limited light penetration, hypoxia and nonspecific protein corona formation are discussed. The possible solutions to these concerns are also discussed.

Photodynamic therapy: A next alternative treatment strategy for hepatocellular carcinoma?

Liver cancer is one of the most common cancers in the world. Of all types of liver cancer, hepatocellular carcinoma (HCC) is known to be the most frequent primary liver malignancy and has seriously compromised the health status of the general population. Locoregional thermal ablation techniques such as radiofrequency and microwave ablation, have attracted attention in clinical practice as an alternative strategy for HCC treatment. However, their aggressive thermal effect may cause undesirable complications such as hepatic decompensation, hemorrhage, bile duct injury, extrahepatic organ injuries, and skin burn. In recent years, photodynamic therapy (PDT), a gentle locoregional treatment, has attracted attention in ablation therapy for patients with superficial or luminal tumors as an alternative treatment strategy. However, some inherent defects and extrinsic factors of PDT have limited its use in clinical practice for deep-seated HCC. In this contribution, the aim is to summarize the current status and challenges of PDT in HCC treatment and provide potential strategies to overcome these deficiencies in further clinical translational practice.

Polydopamine-Coated Laponite Nanoplatforms for Photoacoustic Imaging-Guided Chemo-Phototherapy of Breast Cancer

Theranostic nanoplatforms combining photosensitizers and anticancer drugs have aroused wide interest due to the real-time photoacoustic (PA) imaging capability and improved therapeutic efficacy by the synergistic effect of chemotherapy and phototherapy. In this study, polydopamine (PDA) coated laponite (LAP) nanoplatforms were synthesized to efficiently load indocyanine green (ICG) and doxorubicin (DOX), and modified with polyethylene glycol-arginine-glycine-aspartic acid (PEG-RGD) for PA imaging-guided chemo-phototherapy of cancer cells overexpressing α_vβ₃ integrin. The formed ICG/LAP-PDA-PEG-RGD/DOX nanoplatforms showed significantly higher photothermal conversion efficiency than ICG solution and excellent PA imaging capability, and could release DOX in a pH-sensitive and NIR laser-triggered way, which is highly desirable feature in precision chemotherapy. In addition, the ICG/LAP-PDA-PEG-RGD/DOX nanoplatforms could be uptake by cancer cells overexpressing α_vβ₃ integrin with high specificity, and thus serve as a targeted contrast agent for in vivo PA imaging of cancer. In vivo experiments with 4T1 tumor-bearing mouse model demonstrated that ICG/LAP-PDA-PEG-RGD/DOX nanoplatforms exhibited much stronger therapeutic effect and higher survival rate than monotherapy due to the synergetic chemo-phototherapy under NIR laser irradiation. Therefore, the reported ICG/LAP-PDA-PEG-RGD/DOX represents a promising theranostic nanoplatform for high effectiveness PA imaging-guided chemo-phototherapy of cancer cells overexpressing α_vβ₃ integrin.

In Vivo Regenerable Cerium Oxide Nanozyme-Loaded pH/H2O2-Responsive Nanovesicle for Tumor-Targeted Photothermal and Photodynamic Therapies

Photodynamic therapy (PDT) and photothermal therapies (PTTs) are both promising strategies for effective tumor therapy. However, the absence of O2 at tumor sites hinders the sustained response of photosensitizers. Here, we develop a recycled cerium oxide (CeO2) catalase nanozyme-loaded hyaluronic acid nanovesicle to address the hypoxic tumor microenvironments and targeted delivery of the photosensitizers [indocyanine green (ICG)] to tumors. A polysaccharide complex effectively modifies the surface of a polyethylenimine phenylboronic acid nanostructure to achieve the CeO2 nanozyme-loading nanovesicles that exhibit both tumor-targeted enhancement and an improved hypoxic microenvironment. Also, the hydrogen peroxide responsiveness and acid-sensitive cleavage of phenylboronic acid specifically disintegrate the ICG/nanozyme coloaded nanovesicles in the tumor microenvironment. The in vitro synergistic tests and tumor suppression rate tests indicated that the cerium oxide nanozyme significantly improves the outcomes of PDT via cerium-element valence state recycling and hypoxia improvement, thus enhancing the tumor suppression efficiency. This pH/H2O2-responsive nanozyme/ICG codelivery system provides a good carrier model for improving the tumor microenvironment and increasing the efficiency of tumor-targeted PTT and PDT therapies.

Ligand-Targeted Delivery of Photosensitizers for Cancer Treatment

Photodynamic therapy (PDT) is a promising cancer treatment which involves a photosensitizer (PS), light at a specific wavelength for PS activation and oxygen, which combine to elicit cell death. While the illumination required to activate a PS imparts a certain amount of selectivity to PDT treatments, poor tumor accumulation and cell internalization are still inherent properties of most intravenously administered PSs. As a result, common consequences of PDT include skin photosensitivity. To overcome the mentioned issues, PSs may be tailored to specifically target overexpressed biomarkers of tumors. This active targeting can be achieved by direct conjugation of the PS to a ligand with enhanced affinity for a target overexpressed on cancer cells and/or other cells of the tumor microenvironment. Alternatively, PSs may be incorporated into ligand-targeted nanocarriers, which may also encompass multi-functionalities, including diagnosis and therapy. In this review, we highlight the major advances in active targeting of PSs, either by means of ligand-derived bioconjugates or by exploiting ligand-targeting nanocarriers.

Hyaluronic acid wreathed, trio-stimuli receptive and on-demand triggerable nanoconstruct for anchored combinatorial cancer therapy

Hyaluronic acid (HA) assisted effective internalization into CD44 receptor-overexpressing cancer cells, which could offer an excellent cytotoxic profile and tumor alterations. In this study, duo-photothermal agents (copper sulfide (CuS) and graphene oxide (GO)), chemotherapeutic drug (doxorubicin (DOX)), and targeting moiety (HA) were incorporated into a complexed nanoconstruct for trio-responsive chemo-phototherapy. The nanosystem (CuS(DOX)-GO-HA) was demonstrating its responsive drug release and escalated photothermal behavior. The hyperthermia and photodynamic effect were observed along with efficient ROS generation in the presence of dual photosensitizers. The in vivo biodistribution and photothermal profile reflected a high accumulation and retention of the nanoconstruct in the tumor. Importantly, nanoconstructs effectively inhibit tumor growth based on tumor volume analysis and the altered expression of apoptosis, cell proliferation, and angiogenesis markers. Collectively, these findings suggest that this nanoconstruct has excellent antitumor effects in CD44 overexpressed cells showing the potential for clinical translation in the future.

Biodegradable Natural Product-Based Nanoparticles for Near-Infrared Fluorescence Imaging-Guided Sonodynamic Therapy

Natural products show high potential for clinical translation because of their specific biological activities and molecular structure diversities. Sonosensitizers that originate from natural products play a crucial role as anti-inflammatory and anticancer agents. Herein, hypocrellin-derivative nanoparticles (APHB NPs) were constructed for synchronous near-infrared fluorescence (NIR FL) imaging and sonodynamic therapy (SDT) for deep-seated tumors in vivo. The prepared APHB NPs exhibit excellent water solubility, FL in the NIR region, and effective reactive oxygen species generation under ultrasound stimulation. Furthermore, the APHB NPs show excellent biocompatibility, suitable biodegradation rate, and enhanced tumor accumulation. Therefore, the APHB NPs exhibit promising clinical potential as novel safe and precise NIR FL imaging and SDT agents for deep-seated tumor therapy.

A photo-inducible protein-inorganic nanoparticle assembly for active targeted tumour theranostics

The assembly of protein-inorganic nanoparticles is an important yet challenging approach that is utilized to develop functional materials in numerous areas, such as bio-catalysis, drug delivery, and biosensing. In this study, we report on a facile, photo-inducible self-assembly method to generate protein-inorganic hybrid nanoplatforms. More specifically, photo-treated disulfide bond rich proteins of lysozyme (LYS) were able to be used as host materials in order to encapsulate nanoparticles (i.e., as-synthesized hydrophobic NIR quantum dots (QDs)) and anti-cancer small molecule drugs (i.e., paclitaxel (PTX)), constructing functional theranostic protein-inorganic hybrid nanoparticles. The modification of the functional polymer of cRGD-PEG contributes to the active tumour targeting characteristic of this protein-inorganic nanocarrier. This novel PTX loaded protein-inorganic hybrid nanoplatform showed high tumour homing accumulation as well as effective tumour inhibition. We believe that this general approach represents a new direction for the development of a photo-induced assembly of protein-inorganic nanoparticles towards versatile applications in both materials science and biomedical fields.

Design of dual drug-loaded dendrimer/carbon dot nanohybrids for fluorescence imaging and enhanced chemotherapy of cancer cells

Design of powerful nanosystems to overcome multidrug resistance (MDR) for effective chemotherapy of cancer currently remains a great challenge. Herein, we report the development of a poly(amidoamine) (PAMAM) dendrimer/carbon dot nanohybrid for dual drug loading to overcome MDR and simultaneously monitor cancer cells via fluorescence imaging. First, blue-emitting carbon dots (CDs) were synthesized using sodium citrate as a carbon source via the hydrothermal method and used as a carrier to load the anticancer drug doxorubicin (DOX) through non-covalent interactions, thus forming CDs/DOX complexes. In parallel, PAMAM dendrimers of generation 5 (G5) were covalently modified by the targeting ligand cyclic arginine-glycine-aspartic (RGD) peptide and the drug efflux inhibitor d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS). Then, through electrostatic interaction, functional dendrimers (G5-RGD-TPGS) were complexed with CDs/DOX complexes to form a dual drug-loaded nanohybrid system. The dual drug-loaded dendrimer/CD nanohybrids were well characterized. We showed that the nanohybrids possessed good colloidal stability and enabled significant inhibition of cancer cells due to the presence of TPGS, which can inhibit P-glycoprotein (P-gp) by decreasing ATP levels and increasing ROS levels; simultaneously, fluorescence imaging of cancer cells could be achieved in vitro due to the luminescence of CDs. In addition, the attached RGD ligands rendered the nanohybrid with targeting specificity to cancer cells expressing αvβ3 integrin receptors. The developed dual drug-loaded dendrimer/CD nanohybrid may be used as a promising theranostic platform to overcome MDR for enhanced chemotherapy as well as for fluorescence imaging of cancer cells.

Recent advances in nanomaterial-based synergistic combination cancer immunotherapy

This review aims to summarize various synergistic combination cancer immunotherapy strategies based on nanomaterials.