EGFR-targeted micelles containing near-infrared dye for enhanced photothermal therapy in colorectal cancer

Recent progress in stimuli-responsive polymeric micelles for targeted delivery of functional nanoparticles

Stimuli-responsive polymeric micelles have emerged as a revolutionary approach for enhancing the in vivo stability, biocompatibility, and targeted delivery of functional nanoparticles (FNPs) in biomedicine. This article comprehensively reviews the preparation methods of these polymer micelles, detailing the innovative strategies employed to introduce stimulus responsiveness and surface modifications essential for precise targeting. We delve into the breakthroughs in utilizing these micelles to selectively deliver various FNPs including magnetic nanoparticles, upconversion nanoparticles, gold nanoparticles, and quantum dots, highlighting their transformative impact in the biomedical realm. Concluding, we present an insight into the current research landscape, addressing the challenges at hand, and envisioning the future trajectory in this burgeoning domain. Join us as we navigate the exciting confluence of polymer science and nanotechnology in reshaping biomedical solutions.

Advances in active targeting of ligand-directed polymeric nanomicelles via exploiting overexpressed cellular receptors for precise nanomedicine

Many of the utilized drugs which already exist in the pharmaceutical sector are hydrophobic in nature. These drugs are characterized by being poorly absorbed and difficult to formulate in aqueous environments with low bioavailability, which could result in consuming high and frequent doses in order to fulfil the required therapeutic effect. As a result, there is a decisive demand to find modern alternatives to overcome all these drawbacks. Self-assembling polymeric nanomicelles (PMs) with their unique structure appear to be a fascinating choice as a pharmaceutical carrier system for improving the solubility & bioavailability of many drugs. PMs as drug carriers have many advantages including suitable size, high stability, prolonged circulation time, elevated cargo capacity and controlled therapeutic release. Otherwise, the pathological features of some diseased cells, like cancer, allow PMs with particle size <200 nm to be passively uptaken via enhanced permeability and retention phenomenon (EPR). However, the passive targeting approach was proven to be insufficient in many cases. Consequently, the therapeutic efficiency of these PMs can be further reinforced by enhancing their cellular internalization via incorporating targeting ligands. These targeting ligands can enhance the assemblage of loaded cargos in the intended tissues via receptor-mediated endocytosis through exploiting receptors robustly expressed on the exterior of the intended tissue while minimizing their toxic effects. In this review, the up-to-date approaches of harnessing active targeting ligands to exploit certain overexpressed receptors will be summarized concerning the functionalization of the exterior of PMs for ameliorating their targeting potential in the scope of nanomedicine.

Investigating Effects of IR-780 in Animal Models of B16-F10 Melanoma: New Approach in Lung Metastasis

IR-780 is a fluorescent marker, photostable and non-toxic, and is widely used in tumor targeting; however, studies on the impact of IR-780 in animal models of B16-F10 melanoma are scarce in the literature. Therefore, this study aims to analyze behavior of this marker in melanoma cells using in vitro and in vivo analyses with fluorescence microscopy to conduct an analysis of cell culture, and an in vivo imaging system for an analysis of cell culture, tumor targeting on animals, and organ examination. In vitro analysis showed that B16-F10 cells at a concentration of 2 × 105 cells.plate-1 allowed a better visualization using 20 μM of IR-780. Furthermore, the location of IR-780 accumulation was confirmed by its fluorescence microscopy. Through in vivo studies, fluorescence was not observed in subcutaneous nodules, and it was found that animals that received intraperitoneal injection of B16-F10 cells presented ascites and did not absorb IR-780. Additionally, animals exhibiting lung metastasis showed fluorescence in ex vivo lung images. Therefore, use of the IR-780 marker for evaluating the progression of tumor growth did not demonstrate efficiency; however, it was effective in diagnosing pulmonary metastatic tumors. Although this marker presented limitations, results of evaluating pulmonary involvement through ex vivo fluorescence imaging were determined based on intensity of fluorescence.

Targeted EGFR Nanotherapy in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related mortality worldwide. Despite advances in treatment, the prognosis remains poor, highlighting the need for novel therapeutic strategies. The present review explores the potential of targeted epidermal growth factor receptor (EGFR) nanotherapy as an alternative treatment for NSCLC, showing that EGFR-targeted nanoparticles are efficiently taken up by NSCLC cells, leading to a significant reduction in tumor growth in mouse models. Consequently, we suggest that targeted EGFR nanotherapy could be an innovative treatment strategy for NSCLC; however, further studies are needed to optimize the nanoparticles and evaluate their safety and efficacy in clinical settings and human trials.

Nanomedicine-based multimodal therapies: Recent progress and perspectives in colon cancer

Colon cancer has attracted much attention due to its annually increasing incidence. Conventional chemotherapeutic drugs are unsatisfactory in clinical application because of their lack of targeting and severe toxic side effects. In the past decade, nanomedicines with multimodal therapeutic strategies have shown potential for colon cancer because of their enhanced permeability and retention, high accumulation at tumor sites, co-loading with different drugs, and comb-ination of various therapies. This review summarizes the advances in research on various nanomedicine-based therapeutic strategies including chemotherapy, radiotherapy, phototherapy (photothermal therapy and photodynamic therapy), chemodynamic therapy, gas therapy, and immunotherapy. Additionally, the therapeutic mechanisms, limitations, improvements, and future of the above therapies are discussed.

Dual-Functional Polymeric Micelles Co-Loaded with Antineoplastic Drugs and Tyrosine Kinase Inhibitor for Combination Therapy in Colorectal Cancer

The aim of this research was to evaluate the receptor tyrosine kinase inhibitor Sunitinib combined with SN-38 in polymeric micelles for antitumor efficacy in colorectal cancer. First, SN-38 and Sunitinib co-loaded micelles were developed and characterized. We studied cell viability and cellular uptake in HCT-116 cells. Then, subcutaneous HCT-116 xenograft tumors were used for ex vivo biodistribution, antitumor efficacy, and histochemical analysis studies. Results of cellular uptake and ex vivo biodistribution of SN-38/Sunitinib micelles showed the highest accumulation in tumors compared with other normal organs. In the antitumor effect studies, mice bearing HCT-116 tumors were smallest at day 28 after injection of SN-38/Sunitinib micelles, compared with other experiment groups (p < 0.01). As demonstrated by the results of inhibition on multi-receptors by Sunitinib, we confirmed that SN-38/Sunitinib co-loaded micelles to be a treatment modality that could inhibit VEGF and PDGF receptors and enhance the antitumor effect of SN-38 (p < 0.05). In summary, we consider that this micelle is a potential formulation for the combination of SN-38 and Sunitinib in the treatment of colorectal cancer.

EGFR-Based Targeted Therapy for Colorectal Cancer—Promises and Challenges

Colorectal carcinoma (CRC) is the most lethal and common form of cancer in the world. It was responsible for almost 881,000 cancer deaths in 2018. Approximately 25% of cases are diagnosed at advanced stages with metastasis—this poses challenges for effective surgical control and future tumor-related mortality. There are numerous diagnostic methods that can be used to reduce the risk of colorectal carcinoma. Among these, targeted nanotherapy aims to eliminate the tumor and any metastasis. Active targeting can increase the effectiveness and quantity of drugs delivered to the target site. Antibodies that target overexpressed receptors on cell surfaces and indicators are coupled with drug-loaded carriers. The major target receptors of chemotherapeutic drugs delivery include VEGFR, EGFR, FGFR, HER2, and TGF. On account of its major and diverse roles in cancer, it is important to target EGFR in particular for better tumor selection, as EGFR is overexpressed in 25 to 82% of colorectal carcinoma cases. The EGFR monoclonal immunoglobulins cetuximab/panitumumab can thus be used to treat colorectal cancer. This review examines carriers that contain cetuximab-conjugated therapeutic drugs as well as their efficacy in anticancer activities.

NIR-I Dye-Based Probe: A New Window for Bimodal Tumor Theranostics

Near-infrared (NIR, 650-1700 nm) bioimaging has emerged as a powerful strategy in tumor diagnosis. In particular, NIR-I fluorescence imaging (650-950 nm) has drawn more attention, benefiting from the high quantum yield and good biocompatibility. Since their biomedical applications are slightly limited by their relatively low penetration depth, NIR-I fluorescence imaging probes have been under extensive development in recent years. This review summarizes the particular application of the NIR-I fluorescent dye-contained bimodal probes, with emphasis on related nanoprobes. These probes have enabled us to overcome the drawbacks of individual imaging modalities as well as achieve synergistic imaging. Meanwhile, the application of these NIR-I fluorescence-based bimodal probes for cancer theranostics is highlighted.

Multifunctional Mitochondria-Targeting Nanosystems for Enhanced Anticancer Efficacy

Mitochondria, a kind of subcellular organelle, play crucial roles in cancer cells as an energy source and as a generator of reactive substrates, which concern the generation, proliferation, drug resistance, and other functions of cancer. Therefore, precise delivery of anticancer agents to mitochondria can be a novel strategy for enhanced cancer treatment. Mitochondria have a four-layer structure with a high negative potential, which thereby prevents many molecules from reaching the mitochondria. Luckily, the advances in nanosystems have provided enormous hope to overcome this challenge. These nanosystems include liposomes, nanoparticles, and nanomicelles. Here, we summarize the very latest developments in mitochondria-targeting nanomedicines in cancer treatment as well as focus on designing multifunctional mitochondria-targeting nanosystems based on the latest nanotechnology.

Gold Nanorod-Decorated Metallic MoS2 Nanosheets for Synergistic Photothermal and Photodynamic Antibacterial Therapy

Light-responsive nanocomposites have become increasingly attractive in the biomedical field for antibacterial applications. Visible-light-activated metallic molybdenum disulfide nanosheets (1T-MoS2 NSs) and plasmonic gold nanorods (AuNRs) with absorption at a wavelength of 808 nm were synthesized. AuNR nanocomposites decorated onto 1T-MoS2 NSs (MoS2@AuNRs) were successfully prepared by electrostatic adsorption for phototherapy applications. Based on the photothermal effect, the solution temperature of the MoS2@AuNR nanocomposites increased from 25 to 66.7 °C after 808 nm near-infrared (NIR) laser irradiation for 10 min. For the photodynamic effect, the MoS2@AuNR nanocomposites generated reactive oxygen species (ROS) under visible light irradiation. Photothermal therapy and photodynamic therapy of MoS2@AuNRs were confirmed against E. coli by agar plate counts. Most importantly, the combination of photothermal therapy and photodynamic therapy from the MoS2@AuNR nanocomposites revealed higher antibacterial activity than photothermal or photodynamic therapy alone. The light-activated MoS2@AuNR nanocomposites exhibited a remarkable synergistic effect of photothermal therapy and photodynamic therapy, which provides an alternative approach to fight bacterial infections.

Multifunctional Cyanine-Based Theranostic Probe for Cancer Imaging and Therapy

Cancer is one of the leading causes of death in the world. A cancer-targeted multifunctional probe labeled with the radionuclide has been developed to provide multi-modalities for NIR fluorescence and nuclear imaging (PET, SPECT), for photothermal therapy (PTT), and targeted radionuclide therapy of cancer. In this study, synthesis, characterization, in vitro, and in vivo biological evaluation of the cyanine-based probe (DOTA-NIR790) were demonstrated. The use of cyanine dyes for the selective accumulation of cancer cells were used to achieve the characteristics of tumor markers. Therefore, all kinds of organ tumors can be targeted for diagnosis and treatment. The DOTA-NIR790 labeled with lutetium-111 could detect original or metastatic tumors by using SPECT imaging and quantify tumor accumulation. The β-emission of ¹⁷⁷Lu-DOTA-NIR790 can be used for targeted radionuclide therapy of tumors. The DOTA-NIR790 enabled imaging by NIR fluorescence and by nuclear imaging (SPECT) to monitor in real-time the tumor accumulation and the situation of cancer therapy, and to guide the surgery or the photothermal therapy of the tumor. The radionuclide-labeled heptamethine cyanine based probe (DOTA-NIR790) offers multifunctional modalities for imaging and therapies of cancer.

Cetuximab-Ag2S quantum dots for fluorescence imaging and highly effective combination of ALA-based photodynamic/chemo-therapy of colorectal cancer cells

Colorectal cancer (CRC) has a poor prognosis and urgently needs better therapeutic approaches. 5-Aminolevulinic acid (ALA) induced protoporphyrin IX (PpIX) based photodynamic therapy (PDT) is already used in the clinic for several cancers but not yet well investigated for CRC. Currently, systemic administration of ALA offers a limited degree of tumour selectivity, except for intracranial tumours, limiting its wider use in the clinic. The combination of effective ALA-PDT and chemotherapy may provide a promising alternative approach for CRC treatment. Herein, theranostic Ag₂S quantum dots (AS-2MPA) optically trackable in near-infrared (NIR), conjugated with endothelial growth factor receptor (EGFR) targeting Cetuximab (Cet) and loaded with ALA for PDT monotherapy or ALA/5-fluorouracil (5FU) for the combination therapy are proposed for enhanced treatment of EGFR(+) CRC. AS-2MPA-Cet exhibited excellent targeting of the high EGFR expressing cells and showed a strong intracellular signal for NIR optical detection in a comparative study performed on SW480, HCT116, and HT29 cells, which exhibit high, medium and low EGFR expression, respectively. Targeting provided enhanced uptake of the ALA loaded nanoparticles by strong EGFR expressing cells and formation of higher levels of PpIX. Cells also differ in their efficiency to convert ALA to PpIX, and SW480 was the best, followed by HT29, while HCT116 was determined as unsuitable for ALA-PDT. The therapeutic efficacy was evaluated in 2D cell cultures and 3D spheroids of SW480 and HT29 cells using AS-2MPA with either electrostatically loaded, hydrazone or amide linked ALA to achieve different levels of pH or enzyme sensitive release. Most effective phototoxicity was observed in SW480 cells using AS-2MPA-ALA-electrostatic-Cet due to enhanced uptake of the particles, fast ALA release and effective ALA-to-PpIX conversion. Targeted delivery reduced the effective ALA concentration significantly which was further reduced with codelivery of 5FU. Delivery of ALA via covalent linkages was also effective for PDT, but required a longer incubation time for the release of ALA in therapeutic doses. Phototoxicity was correlated with high levels of reactive oxygen species (ROS) and apoptotic/necrotic cell death. Hence, both AS-2MPA-ALA-Cet based PDT and AS-2MPA-ALA-Cet-5FU based chemo/PDT combination therapy coupled with strong NIR tracking of the nanoparticles demonstrate an exceptional therapeutic effect on CRC cells and excellent potential for synergistic multistage tumour targeting therapy.

Cetuximab functionalization strategy for combining active targeting and antimigration capacities of a hybrid composite nanoplatform applied to deliver 5-fluorouracil: toward colorectal cancer treatment

Antibody-functionalized targeted nanocarriers to deliver chemotherapeutics have been widely explored. However, it remains highly desirable to understand and apply the antitumor potential of antibodies integrated in hybrid composite nanoplatforms. Herein, mesoporous silica nanoparticles, a supported lipid bilayer and cetuximab were integrated to fabricate a hybrid nanoplatform for effectively encapsulating and selectively delivering 5-fluorouracil (5-FU) against colorectal cancer (CRC) cells. The specially designed nanoplatform exhibited superior properties, such as satisfying size distribution, dispersity and stability, drug encapsulation, controlled release, and cellular uptake. Interestingly, the modification of cetuximab onto nanoplatforms without drug loading can significantly inhibit the migration and invasion of CRC cells through suppressing the epidermal growth factor receptor (EGFR)-associated signaling pathway. Furthermore, delivery of 5-FU by using this nanoplatform can remarkably induce cytotoxicity, cell cycle arrest, and cell apoptosis for CRC cells with high EGFR expression. Overall, this nanostructured platform can dramatically improve the tumor killing effects of encapsulated chemotherapeutics and present antimigration effects derived from the antibody modified on it. Moreover, in vivo biodistribution experiments demonstrated the superior tumor targeting ability of the targeted nanoparticles. Thus, this targeted nanoplatform has substantial potential in combinational therapy of antibodies and chemotherapy agents against colorectal cancer.

EGFR targeting for cancer therapy: Pharmacology and immunoconjugates with drugs and nanoparticles

The epidermal growth factor receptor (EGFR) belongs to the tyrosine kinase receptors family and is present in the epithelial cell membrane. Its endogenous activation occurs through the binding of different endogenous ligands, including the epidermal growth factor (EGF), leading to signaling cascades able to maintain normal cellular functions. Although involved in the development and maintenance of tissues in normal conditions, when EGFR is overexpressed, it stimulates the growth and progression of tumors, resulting in angiogenesis, invasion and metastasis, through some main cascades such as Ras/Raf/MAPK, PIK-3/AKT, PLC-PKC and STAT. Besides, considering the limitations of conventional chemotherapy that result in high toxicity and low tumor specificity, EGFR is currently considered an important target. As a result, several monoclonal antibodies are currently approved for use in cancer treatment, such as cetuximab (CTX), panitumumab, nimotuzumab, necitumumab and others are in clinical trials. Aiming to combine the chemotherapeutic agent toxicity and specific targeting to EGFR overexpressing tumor tissues, two main strategies will be discussed in this review: antibody-drug conjugates (ADCs) and antibody-nanoparticle conjugates (ANCs). Briefly, ADCs consist of antibodies covalently linked through a spacer to the cytotoxic drug. Upon administration, binding to EGFR and endocytosis, ADCs suffer chemical and enzymatic reactions leading to the release and accumulation of the drug. Instead, ANCs consist of nanotechnology-based formulations, such as lipid, polymeric and inorganic nanoparticles able to protect the drug against inactivation, allowing controlled release and also passive accumulation in tumor tissues by the enhanced permeability and retention effect (EPR). Furthermore, ANCs undergo active targeting through EGFR receptor-mediated endocytosis, leading to the formation of lysosomes and drug release into the cytosol. Herein, we will present and discuss some important aspects regarding EGFR structure, its role on internal signaling pathways and downregulation aspects. Then, considering that EGFR is a potential therapeutic target for cancer therapy, the monoclonal antibodies able to target this receptor will be presented and discussed. Finally, ADCs and ANCs state of the art will be reviewed and recent studies and clinical progresses will be highlighted. To the best of our knowledge, this is the first review paper to address specifically the EGFR target and its application on ADCs and ANCs.

Stimuli-Responsive Polymeric Nanocarriers for Drug Delivery, Imaging, and Theragnosis

In the past few decades, polymeric nanocarriers have been recognized as promising tools and have gained attention from researchers for their potential to efficiently deliver bioactive compounds, including drugs, proteins, genes, nucleic acids, etc., in pharmaceutical and biomedical applications. Remarkably, these polymeric nanocarriers could be further modified as stimuli-responsive systems based on the mechanism of triggered release, i.e., response to a specific stimulus, either endogenous (pH, enzymes, temperature, redox values, hypoxia, glucose levels) or exogenous (light, magnetism, ultrasound, electrical pulses) for the effective biodistribution and controlled release of drugs or genes at specific sites. Various nanoparticles (NPs) have been functionalized and used as templates for imaging systems in the form of metallic NPs, dendrimers, polymeric NPs, quantum dots, and liposomes. The use of polymeric nanocarriers for imaging and to deliver active compounds has attracted considerable interest in various cancer therapy fields. So-called smart nanopolymer systems are built to respond to certain stimuli such as temperature, pH, light intensity and wavelength, and electrical, magnetic and ultrasonic fields. Many imaging techniques have been explored including optical imaging, magnetic resonance imaging (MRI), nuclear imaging, ultrasound, photoacoustic imaging (PAI), single photon emission computed tomography (SPECT), and positron emission tomography (PET). This review reports on the most recent developments in imaging methods by analyzing examples of smart nanopolymers that can be imaged using one or more imaging techniques. Unique features, including nontoxicity, water solubility, biocompatibility, and the presence of multiple functional groups, designate polymeric nanocues as attractive nanomedicine candidates. In this context, we summarize various classes of multifunctional, polymeric, nano-sized formulations such as liposomes, micelles, nanogels, and dendrimers.

Reactive oxygen species and enzyme dual-responsive biocompatible drug delivery system for targeted tumor therapy

Spurred by newly developed drug delivery systems (DDSs), side effects of cancer chemotherapy could be reduced by using multifunctional nanoplatforms. However, the facile synthesis of effective DDSs remains a challenge. Here, a six-arginine-tailed anti-epidermal growth factor receptor (EGFR) affibody was employed to easily synthesize the highly reactive oxygen species (hROS)- and trypsin-responsive 11-mercaptoundecanoic acid-modified gold nanoclusters (MUA-Au NCs) for tumor-targeted drug delivery. The polyarginine moiety of affibody sealed methotrexate (MTX)-loaded MUA-Au NCs through charge effect, as well as leaving the rest targeting fragment of the affibody to specifically bind tumor overexpressed EGFR. As the shell of MUA-Au NCs-MTX-Affibody (MAMA), polyarginine chains of affibody could be digested by trypsin, helping to release MTX from MAMA. The released MTX accelerated destroying MUA-Au NCs through inducing the generation of hROS. Specifically targeting EGFR-overexpressed tumors, quickly delivering a sufficient amount of drug to the tumor, subsequently increasing the local MTX and hROS levels, and safely eliminating the biocompatible structure from kidney, endowed MAMA greater treatment effectiveness and lower side effect than chemotherapy, especially in pancreatic cancer due to its high trypsin level. This simply fabricated DDS may find applications in high effective cancer therapy, especially for tumors with high trypsin activity.

Multifunctional nanomedicines for targeting epidermal growth factor receptor in colorectal cancer

Systemic administration of chemotherapeutics by nanocarriers (NCs) functionalized with targeting agents provides a localized accumulation of drugs in the target tissues and cells. Advanced nanoscaled medicaments can enter into the tumor microenvironment (TME) and overcome the uniquely dysregulated biological settings of TME, including highly pressurized tumor interstitial fluid in an acidic milieu. Such multimodal nanomedicines seem to be one of the most effective treatment modalities against solid tumors such as colorectal cancer (CRC). To progress and invade, cancer cells overexpress various oncogenes and molecular markers such as epidermal growth factor receptors (EGFRs), which can be exploited for targeted delivery of nanoscaled drug delivery systems (DDSs). In fact, to develop effective personalized multimodal nanomedicines, the type of solid tumor and status of the disease in each patient should be taken into consideration. While the development of such multimodal-targeted nanomedicines is largely dependent on the expression level of oncomarkers, the type of NCs and homing/imaging agents play key roles in terms of their efficient applications. In this review, we provide deep insights into the development of EGFR-targeting nanomedicines and discuss various types of nanoscale DDSs (e.g., organic and inorganic nanoparticles) for targeting of the EGFR-positive solid tumors such as CRC.

Liposomes in Active, Passive and Acoustically-Triggered Drug Delivery

Cancer has become one of the most deadly noncommunicable diseases globally. Several modalities used to treat cancer patients exist today yet many have failed to prove high efficacy with low side effects. The most common example of such modalities is the use of chemotherapeutic drugs to treat cancerous cells and deter their uncontrolled proliferation. In addition to the destruction of cancerous tissues, chemotherapy destroys healthy tissues as it lacks the specificity to annihilate cancerous cells only and preferentially, which result in adverse side effects including nausea, hair fall and myocardial infarction. To prevent the side effects of non-selective chemotherapy, cancer therapy research has been focused on the implementation of nanocarrier systems that act as vehicles to encapsulate drugs and selectively transport their agent to the tumor site. In this paper, we shed light on liposomes along with three anticancer drug delivery approaches: passive, active and ultrasound-triggered drug delivery.

Recent advances in targeted therapy of colorectal cancer: impacts of monoclonal antibodies nanoconjugates

Despite rapid advances in diagnostic and treatment approaches, the overall survival rate of cancer has not been improved. Colorectal cancer (CRC) is recognized as the third leading cause of neoplasm-related deaths worldwide, in large part due to its considerable metastasis and drug resistance. For developing new anticancer strategies, rapid progression of multimodal nanomedicines and nanoconjugates has provided promising treatment modalities for effective therapy of cancer. The limitations of cancer chemotherapy might be overcome through the use of such nanosized therapeutics, including nanoconjugates of monoclonal antibodies (mAbs) along with drugs and organic/inorganic nanoparticles. CRC cells express various molecular markers against which mAbs can be designed and used as targeting/therapeutic agents. This editorial highlights the importance of such targeted nanosystems against CRC.

Doxorubicin and Anti-PD-L1 Antibody Conjugated Gold Nanoparticles for Colorectal Cancer Photochemotherapy

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. The prognosis and overall survival of CRC are known to be significantly correlated with the overexpression of PD-L1. Since combination therapies can significantly improve therapeutic efficacy, we constructed doxorubicin (DOX) conjugated and anti-PD-L1 targeting gold nanoparticles (PD-L1-AuNP-DOX) for the targeted chemo-photothermal therapy of CRC. DOX and anti-PD-L1 antibody were conjugated to the α-terminal end group of lipoic acid polyethylene glycol N-hydroxysuccinimide (LA-PEG-NHS) using an amide linkage, and PD-L1-AuNP-DOX was constructed by linking LA-PEG-DOX, LA-PEG-PD-L1, and a short PEG chain on the surface of AuNP using thiol-Au covalent bonds. Physicochemical characterizations and biological studies of PD-L1-AuNP-DOX were performed in the presence of near-infrared (NIR) irradiation (biologic studies were conducted using cellular uptake, apoptosis, and cell cycle assays in CT-26 cells). PD-L1-AuNP-DOX (40.0 ± 3.1 nm) was successfully constructed and facilitated the efficient intracellular uptake of DOX as evidenced by pronounced apoptotic effects (66.0%) in CT-26 cells. PD-L1-AuNP-DOX treatment plus NIR irradiation significantly and synergistically suppressed the in vitro proliferation of CT-26 cells by increasing apoptosis and cell cycle arrest. The study demonstrates that PD-L1-AuNP-DOX in combination with synergistic targeted chemo-photothermal therapy has a considerable potential for the treatment of localized CRC.

A Review on the Scope of Photothermal Therapy-Based Nanomedicines in Preclinical Models of Colorectal Cancer

Oncologic thermal ablation involves the use of hyperthermic temperatures to damage and treat solid cancers. Thermal ablation is being investigated as a method of treatment in colorectal cancers and has the potential to complement conventional anticancer treatments in managing local recurrence and metastatic disease. Photothermal therapy utilizes photosensitive agents to generate local heat and induce thermal ablation. There is growing interest in developing nanotechnology platforms to deliver such photosensitive agents. An advantage of nanomedicines is their multifunctionality, with the capability to deliver combinations of chemotherapeutics and cancer-imaging agents. To date, there have been no clinical studies evaluating photothermal therapy-based nanomedicines in colorectal cancers. This review presents the current scope of preclinical studies, investigating nanomedicines that have been developed for delivering multimodal photothermal therapy to colorectal cancers, with an emphasis on potential clinical applications.

Cetuximab-modified CuS nanoparticles integrating near-infrared-II-responsive photothermal therapy and anti-vessel treatment

BACKGROUND

Photothermal therapy (PTT) has received extensive attention owing to its non-invasive nature and highly therapeutic outcomes. PTT agents and near-infrared (NIR) laser are essential elements in PTT. However, most PTT agents are composed of heavy metals, characterized by serious cytotoxicity and side effects, and NIR irradiation often damages normal tissue owing to the high dose, thus limiting the clinical application of PTT.

PURPOSE

In this regard, exploring new perspectives enabling more PTT agents to be enriched into the tumor and NIR laser irradiation decay in PTT is vital.

METHODS

In this study, cetuximab (Ab), an anti-angiogenic antibody which targets the EGFR, was modified on CuS NPs (CuS-Ab NPs) to improve the aggregation of CuS NPs in the tumor.

RESULTS

The cellular uptake data and the biodistribution results showed comparable accumulation of CuS-Ab NPs in tumor, thus decreasing the cytotoxicity and side effects in normal tissues. More importantly, the modification of Ab in CuS-Ab NPs impressively inhibited the formation and progression of tumor vessels, as demonstrated by immunohistochemistry staining. The introduction of anti-vessel treatment requires CuS-Ab NPs to provide weak PTT, which means that a small amount of laser energy is required, inevitably causing negligible damage to normal tissue.

CONCLUSION

Therefore, our tailor-made CuS-Ab NPs have promising potential in clinical applications.

Dual-triggered drug-release vehicles for synergistic cancer therapy

Cancer is a complex and tenacious disease. Drug-delivery systems in combination with multimodal therapy strategies are very promising candidates for cancer theranostic applications. In this study, a new drug-delivery vehicle that combine human serum albumin (HSA)- and poly(sodium 4-styrenesulfonate) (PSS)-coated gold nanorod nanoparticles(GNR/PSS/HSA NPs) was developed for synergistic cancer therapy. Doxorubicin (DOX) was loaded onto GNR/PSS/HSA NPs, by electrostatic and hydrophobic forces, to create multimodal DOX@GNR/PSS/HSA NPs. DOX@GNR/PSS/HSA NPs were found to be highly biocompatible and stable in physiological solutions. Furthermore, GNR/PSS/HSA NPs with or without DOX were designed to exhibit strong absorbance in the near-infrared region and high photothermal conversion efficiency. Therefore, bimodal DOX release from DOX@GNR/PSS/HSA NPs could be triggered by an acidic pH and by near-infrared irradiation after NPs preferentially accumulated at tumor sites, leading to a significant chemotherapeutic effect. Moreover, DOX@GNR/PSS/HSA NPs were designed to be applied during chemo- and photo-thermal combination therapy and exhibited a synergistic anticancer effect that was superior to the effect of monotherapy, from both in vitro and in vivo results. These results suggest that DOX@GNR/PSS/HSA NPs are a strong candidate for a nanoplatform for future antitumor therapeutic strategies.

Lanthanide-doped upconversion nanoparticles complexed with nano-oxide graphene used for upconversion fluorescence imaging and photothermal therapy

In recent years, multifunctional nanoparticles have attracted much research interest in various biomedical applications such as biosensors, diagnosis, and drug delivery systems. In this study, we report an NIR imaging diagnosis and therapy nanoplatform which is developed by complexing upconversion nanoparticles (UCNP@OA) NaLuF4:Er3+,Yb3+ with nanographene oxide (NGO). The obtained nanocomposites UCNP@NGO showed excellent stability and low cell toxicity, which not only acted as upconversion luminescence (UCL) probes for tumor imaging, but also served as therapy agents by converting laser energy into thermal energy for photothermal therapy (PTT) with high photothermal conversion efficiency. This work highlights the potential of UCNP@NGO nanocomposites as an integrated theranostic nanoplatform for the UCL image combinatorial PTT of cancer, providing a promising candidate for clinical antitumor treatments.

Recent progress in the development of near-infrared organic photothermal and photodynamic nanotherapeutics

Phototherapies including photothermal therapy (PTT) and photodynamic therapy (PDT) have gained considerable attention due to their high tumor ablation efficiency, excellent spatial resolution and minimal side effects on normal tissue. In contrast to inorganic nanoparticles, near-infrared (NIR) absorbing organic nanoparticles bypass the issue of metal-ion induced toxicity and thus are generally considered to be more biocompatible. Moreover, with the guidance of different kinds of imaging methods, the efficacy of cancer phototherapy based on organic nanoparticles has shown to be optimizable. In this review, we summarize the synthesis and application of NIR-absorbing organic nanoparticles as phototherapeutic nanoagents for cancer phototherapy. The chemistry, optical properties and therapeutic efficacies of organic nanoparticles are firstly described. Their phototherapy applications are then surveyed in terms of therapeutic modalities, which include PTT, PDT and PTT/PDT combined therapy. Finally, the present challenges and potential of imaging guided PTT/PDT are discussed.

Sorafenib and indocyanine green co-loaded in photothermally sensitive liposomes for diagnosis and treatment of advanced hepatocellular carcinoma

Sorafenib (SF), as an irreplaceable first-line drug to help advanced hepatocellular carcinoma (HCC) patients to prolong their lives, has already been used in clinical practice for several years. However, this treatment causes several side effects, and few alternatives to SF treatment exist. Herein, we designed NIR fluorescence imaging-guided photothermally sensitive nanoliposomes based on co-encapsulation of SF and the clinical photothermal and photodynamic therapy agent Indocyanine Green (ICG) to solve the problems of SF-based treatment in advanced HCC. As expected, in vitro and in vivo drug release studies on SF-ICG liposomes (SILs) demonstrated SF release from SILs compared with free SF at the same concentration. In addition, in vivo NIR fluorescence imaging and anti-tumor treatment using SILs have been demonstrated by using Hep3B tumor-bearing xenograft nude mice. All detailed experimental evidence suggested that biocompatibility, biotoxicity, and anti-tumor effects were improved by using SILs instead of free SF. In conclusion, our designed SILs could present a novel and suitable SF-based treatment strategy for advanced HCC therapy in the future.

pH-Responsive Nanophotosensitizer for an Enhanced Photodynamic Therapy of Colorectal Cancer Overexpressing EGFR

Photodynamic therapy (PDT) has been shown to kill cancer cells and improve survival and quality of life in cancer patients, and numerous new approaches have been considered for maximizing the efficacy of PDT. In this study, a new multifunctional nanophotosensitizer Ce6/GE11-^(pH)micelle was developed to target epidermal growth factor receptor (EGFR) overexpressing colorectal cancer (CRC) cells. This nanophotosensitizer was synthesized using a micelle comprising pH-responsive copolymers (PEGMA-PDPA), biodegradable copolymers (mPEG-PCL), and maleimide-modified biodegradable copolymers (Mal-PEG-PCL) to entrap the potential hydrophobic photosensitizer chlorin e6 (Ce6) and to present EGFR-targeting peptides (GE11) on its surface. In the presence of Ce6/GE11-^(pH)micelles, Ce6 uptake by EGFR-overexpressing CRC cells significantly increased due to GE11 specificity. Moreover, Ce6 was released from Ce6/GE11-^(pH)micelles in tumor environments, leading to improved elimination of cancer cells in PDT. These results indicate enhanced efficacy of PDT using Ce6/GE11-^(pH)micelle, which is a powerful nanophotosensitizer with high potential for application to future PDT for CRC.

Multistage Targeting Strategy Using Magnetic Composite Nanoparticles for Synergism of Photothermal Therapy and Chemotherapy

Mitochondrial-targeting therapy is an emerging strategy for enhanced cancer treatment. In the present study, a multistage targeting strategy using doxorubicin-loaded magnetic composite nanoparticles is developed for enhanced efficacy of photothermal and chemical therapy. The nanoparticles with a core-shell-SS-shell architecture are composed of a core of Fe₃ O₄ colloidal nanocrystal clusters, an inner shell of polydopamine (PDA) functionalized with triphenylphosphonium (TPP), and an outer shell of methoxy poly(ethylene glycol) linked to the PDA by disulfide bonds. The magnetic core can increase the accumulation of nanoparticles at the tumor site for the first stage of tumor tissue targeting. After the nanoparticles enter the tumor cells, the second stage of mitochondrial targeting is realized as the mPEG shell is detached from the nanoparticles by redox responsiveness to expose the TPP. Using near-infrared light irradiation at the tumor site, a photothermal effect is generated from the PDA photosensitizer, leading to a dramatic decrease in mitochondrial membrane potential. Simultaneously, the loaded doxorubicin can rapidly enter the mitochondria and subsequently damage the mitochondrial DNA, resulting in cell apoptosis. Thus, the synergism of photothermal therapy and chemotherapy targeting the mitochondria significantly enhances the cancer treatment.

Application Potential of Polymeric Nanoconstructs for Colon-Specific Drug Delivery

Numerous applications of colon-specific drug delivery have been found in a wide array of diseases like irritable bowel syndrome (IBS), inflammatory bowel diseases (ulcerative colitis and Crohn's disease), colorectal cancer, and diverticulitis. Drug delivery to the colon has different anatomic and pathophysiological barriers. In recent advancements, these barriers were overcome by using biodegradable polymeric nanoconstructs, which are exhibiting minimal systemic adverse effects. Various polymeric nanoconstructs (PNCs) such as nanoparticles, micelles, and dendrimers have been exploited for effective targeting to pathological sites of colon. PNCs on oral administration not only protect the bioactive from physicochemical degradation but also prevent premature leakage in the upper parts of gastrointestinal tract. The chapter summarizes various PNCs-based approaches for colon-specific drug delivery.

Recent advances in cell-mediated nanomaterial delivery systems for photothermal therapy

Cell-mediated “Trojan Horse” delivery vehicles overcome the drug delivery barriers to transport nano-agents enhancing the efficiency of photothermal therapy.

Recent Advances in Nanoparticle-Based Cancer Drug and Gene Delivery

Effective and safe delivery of anticancer agents is among the major challenges in cancer therapy. The majority of anticancer agents are toxic to normal cells, have poor bioavailability, and lack in vivo stability. Recent advancements in nanotechnology provide safe and efficient drug delivery systems for successful delivery of anticancer agents via nanoparticles. The physicochemical and functional properties of the nanoparticle vary for each of these anticancer agents, including chemotherapeutics, nucleic acid-based therapeutics, small molecule inhibitors, and photodynamic agents. The characteristics of the anticancer agents influence the design and development of nanoparticle carriers. This review focuses on strategies of nanoparticle-based drug delivery for various anticancer agents. Recent advancements in the field are also highlighted, with suitable examples from our own research efforts and from the literature.

Nanotechnologies in Pancreatic Cancer Therapy

Pancreatic cancer has been classified as a cancer of unmet need. After diagnosis the patient prognosis is dismal with few surviving over 5 years. Treatment regimes are highly patient variable and often the patients are too sick to undergo surgical resection or chemotherapy. These chemotherapies are not effective often because patients are diagnosed at late stages and tumour metastasis has occurred. Nanotechnology can be used in order to formulate potent anticancer agents to improve their physicochemical properties such as poor aqueous solubility or prolong circulation times after administration resulting in improved efficacy. Studies have reported the use of nanotechnologies to improve the efficacy of gemcitabine (the current first line treatment) as well as investigating the potential of using other drug molecules which have previously shown promise but were unable to be utilised due to the inability to administer through appropriate routes-often related to solubility. Of the nanotechnologies reported, many can offer site specific targeting to the site of action as well as a plethora of other multifunctional properties such as image guidance and controlled release. This review focuses on the use of the major nanotechnologies both under pre-clinical development and those which have recently been approved for use in pancreatic cancer therapy.