Design and Application of Near-Infrared Nanomaterial-Liposome Hybrid Nanocarriers for Cancer Photothermal Therapy

Core-shell hybrid liposomes: Transforming imaging diagnostics and therapeutic strategies

For the last few years, researchers and industry have intensified efforts to develop a diverse array of diagnostic and therapeutic approaches to fight diseases such as cancer, diabetes, and viral infections. Among the emerging technologies, hybrid liposomes (HLs) stand out for their ability to address key limitations of conventional liposomes and deliver multifunctional solutions more effectively. While several novel nanosystems, including polymerlipid conjugates and inorganic nanoparticles (NPs), have shown great potential in the preclinical and clinical phases for the diagnosis and treatment of diseases, particularly cancer, HLs can integrate the best of both worlds, combining drug delivery properties with imaging capabilities. HLs, particularly those with core-shell structures, can surpass conventional liposomes by offering improved physicochemical properties, multifunctionality, and the capacity to overcome critical delivery challenges. The integration of natural and synthetic polymers has rapidly emerged as a preferred strategy in the development of HLs, providing significant advantages, such as enhanced stability, stimuli-responsive drug release, prolonged circulation, and improved therapeutic efficacy. Additionally, the customizable structure of HLs allows the incorporation of diverse materials, such as metals, ligands, and functional lipids, improving diagnosis and enhancing targeted delivery and cellular uptake far beyond what conventional liposomes offer. This review provides a critical and updated analysis of core-shell structure exhibiting HLs, with a focus on their preparation, characterization, and functional enhancements. We also examine in vitro/in vivo outcomes in imaging diagnosis and drug delivery while addressing the current barriers to clinical translation and future prospects for these versatile nanoplatforms.

Enhancing the photothermal properties of indocyanine green in melanoma spheroids via encapsulation in Span 80-containing lipid nanocapsules

Indocyanine green (ICG), a well-known photosensitiser, has shown potential in photothermal therapy (PTT) for cancer treatment, but its effectiveness is limited by poor skin penetration and rapid clearance. To address this, lipid nanocapsules (LNCs) were used as nanocarriers to enhance ICG's cellular uptake and photothermal (PT) performance in melanoma cells. Utilising our recently developed Span 80-modified LNCs (LNC100-S8) with high biocompatibility and enhanced cellular uptake in B16F10 melanoma cells, ICG was loaded into LNC100-S8 using the phase inversion temperature method. The results showed that ICG encapsulation at 4.5 mg/mL maintained small LNC sizes (95-105 nm). Moreover, the heating capacity of ICG in LNCs was approximately 1.5 times higher than free ICG, achieving temperature increases over 10 °C post-irradiation. In cell cancer monolayers, LNC100-S8 enhanced ICG uptake by 1.5 times compared to free ICG and reduced cell viability to 50 % following 808 nm laser irradiation. More promisingly, ICG-LNC100-S8 combined with laser irradiation significantly reduced three-dimensional B16F10 spheroids size up to 11 days post-treatment compared to free ICG. Overall, our findings validate LNC100-S8, as promising nanocarriers for enhancing ICG-based PTT, supporting their potential applications in vivo to treat melanoma and other skin cancers.

Biomimetic NIR-II aggregation-induced emission nanoparticles for targeted photothermal therapy of ovarian cancer

Photothermal therapy (PTT) is a cutting-edge technique that harnesses light energy and converts it into heat for precise tumor ablation. By employing photothermal agents to selectively generate heat and target cancer cells, PTT has emerged as a promising cancer treatment strategy. Notably, therapies conducted in the second near-infrared (NIR-II) window exhibit superior therapeutic outcomes, owing to deeper tissue penetration and reduced light scattering. In this study, we developed biomimetic NIR-II aggregation-induced emission (AIE) nanoparticles (2TB-NPs@TM) for high-efficiency NIR-II imaging and targeted phototherapy of ovarian cancer. The core nanoparticle aggregates (2TB-NPs) display strong NIR-II fluorescence and high photothermal conversion efficiency, while the outer tumor cell membrane coating facilitates active targeting and precise recognition of tumor tissues. This design imparts excellent biocompatibility and enhances drug delivery efficiency, leading to potent synergistic therapeutic effects. Our findings open new avenues for advancing targeted, high-performance phototherapy diagnostics in cancer treatment.

Indocyanine green-mediated photothermal release of lidocaine from genipin-crosslinked gelatin hydrogel in nerve block

Local anesthetic (LA)-induced peripheral nerve block (PNB) is an important part of multimodal analgesia to reduce postoperative pain, accelerate postoperative recovery, and improve clinical prognosis. The duration of LA depends on anesthetics, and the repeated nerve positioning, puncture injection or indwelling catheter is often required to prolong the effect of PNB. In this study, the genipin, was used to crosslink gelatin-based hydrogel, and then co-loaded with indocyanine green (ICG) and lidocaine as an LA-controlled release system (ICG@Lido/Gel and ICG@Lido/gGel). The viscosity of the genipin-crosslinked gelatin hydrogel (gGel) could be controlled by the genipin/gelatin ratio to achieve the slow release of lidocaine. The ICG@Lido/Gel and ICG@Lido/gGel were biocompatible, and could reduce the instant concentration of lidocaine to minimize its direct cytotoxicity. The ICG@Lido/Gel and ICG@Lido/gGel could increase the PNB period to 70.8 min and 77.8 min, respectively. After NIR exposure, the PNB was introduced again and sustained to 20.8 min for ICG@Lido/Gel and 31.7 min for ICG@Lido/gGel. Therefore, the ICG@Lido/gGel could significantly prolong the PNB duration via increasing the residence time of lidocaine at the injection site, slowing the lidocaine release, and triggering the lidocaine release by NIR exposure. The ICG@Lido/gGel may expresses potential as a photothermal-triggered release system for PNB.

Traditional Chinese Medicine-Based Nanoformulations for Enhanced Photothermal Therapy of Cancer

Photothermal therapy (PTT) has shown promise in the ablation of small, unresectable tumors by boosting the tumor's temperature above 50 °C. However, the high local temperature-induced cancer cell necrosis could create severe local inflammation, which may deteriorate normal tissues and increase tumor spreading. Although mild photothermal therapy (MPTT) at 42-45 °C could avoid the undesired side effect to some extent with minimal nonspecific heat diffusion, the self-protective behavior of tumors during MPTT results in an unsatisfactory therapeutic effect. Inspired by the widespread applications of traditional Chinese medicine (TCM) in various ailments, we also extensively explored the use of TCM in PTT and MPTT. In this Review, we summarize the application and function of TCM in PTT and MPTT, including the following: (1) TCM improves the performance of PTT and MPTT by elevating the photothermal conversion ability of photothermal agents (PTAs) and overcoming the self-protective effect of tumors, (2) PTT enhances TCM-based chemotherapy by improving the sensitivity and cellular uptake of TCM in tumors, and (3) natural TCM and metal-chelated TCM-based nanoparticles could directly act as PTAs for carrier-free combination therapy. We expect this Review will further illuminate TCM's utility and applicability in cancer treatment and create new combination strategies for theragnostic use.

Preclinical advance in nanoliposome-mediated photothermal therapy in liver cancer

Liver cancer is a highly lethal malignant tumor with a high incidence worldwide. Therefore, its treatment has long been a focus of medical research. Although traditional treatment methods such as surgery, radiotherapy, and chemotherapy have increased the survival rate of patients, their efficacy remains unsatisfactory owing to the nonspecific distribution of drugs, high toxicity, and drug resistance of tumor tissues. In recent years, the application of nanotechnology in the medical field has opened a new avenue for the treatment of liver cancer. Among these treatment methods, photothermal therapy (PTT) based on nanoliposomes has attracted wide attention owing to its unique targeting and high efficiency. This article reviews the latest preclinical research progress of nanoliposome-based PTT for liver cancer and its metastasis, discusses the preclinical challenges in this field, and proposes directions for improvement, with the aim of improving the effectiveness of liver cancer treatment.

Carbon-based Nanomaterials in Photothermal Therapy Guided by Photoacoustic Imaging: State of Knowledge and Recent Advances

Carbon-based nanomaterials (CBNM) have been widely used in various fields due to their excellent physicochemical properties. In particular, in the area of tumor diagnosis and treatment, researchers have frequently reported them for their potential fluorescence, photoacoustic (PA), and ultrasound imaging performance, as well as their photothermal, photodynamic, sonodynamic, and other therapeutic properties. As the functions of CBNM are increasingly developed, their excellent imaging properties and superior tumor treatment effects make them extremely promising theranostic agents. This review aims to integrate the considered and researched information in a specific field of this research topic and systematically present, summarize, and comment on the efforts made by authoritative scholars. In this review, we summarized the work exploring carbon-based materials in the field of tumor imaging and therapy, focusing on PA imaging-guided photothermal therapy (PTT) and discussing their imaging and therapeutic mechanisms and developments. Finally, the current challenges and potential opportunities of carbon-based materials for PA imaging-guided PTT are presented, and issues that researchers should be aware of when studying CBNM are provided.

Recent advancements and clinical aspects of engineered iron oxide nanoplatforms for magnetic hyperthermia-induced cancer therapy

The pervasiveness of cancer is a global health concern posing a major threat in terms of mortality and incidence rates. Magnetic hyperthermia (MHT) employing biocompatible magnetic nanoparticles (MNPs) ensuring selective attachment to target sites, better colloidal stability and conserving nearby healthy tissues has garnered widespread acceptance as a promising clinical treatment for cancer cell death. In this direction, multifunctional iron oxide nanoparticles (IONPs) are of significant interest for improved cancer care due to finite size effect associated with inherent magnetic properties. This review offers a comprehensive perception of IONPs-mediated MHT from fundamentals to clinical translation, by elucidating the underlying mechanism of heat generation and the related influential factors. Biological mechanisms underlying MHT-mediated cancer cell death such as reactive oxygen species generation and lysosomal membrane permeabilization have been discussed in this review. Recent advances in biological interactions (in vitro and in vivo) of IONPs and their translation to clinical MHT applications are briefed. New frontiers and prospects of promising combination cancer therapies such as MHT with photothermal therapy, cancer starvation therapy and sonodynamic therapy are presented in detail. Finally, this review concludes by addressing current crucial challenges and proposing possible solutions to achieve clinical success.

Transforming Medicine with Nanobiotechnology: Nanocarriers and Their Biomedical Applications

Nanobiotechnology, at the intersection of nanotechnology and biology, represents a burgeoning field poised to revolutionize medicine through the use of advanced nanocarriers. These nanocarriers, endowed with distinctive physiobiological attributes, are instrumental in diverse therapeutic domains including drug delivery for microbial infections, cancer treatment, tissue engineering, immunotherapy, and gene therapy. Despite the transformative potential, several challenges hinder their efficacy, such as limited drug capacity, suboptimal targeting, and poor solubility. This review delves into the latest advancements in nanocarrier technologies, examining their properties, associated limitations, and the innovative solutions developed to address these issues. It highlights promising nanocarrier systems like nanocomposites, micelles, hydrogels, microneedles, and artificial cells that employ advanced conjugation techniques, sustained and stimulus-responsive release mechanisms, and enhanced solubility. By exploring these novel structures and their contributions to overcoming existing barriers, the article emphasizes the vital role of interdisciplinary research in advancing nanobiotechnology. This field offers unparalleled opportunities for precise and effective therapeutic delivery, underscoring its potential to reshape healthcare through personalized, targeted treatments and improved drug performance.

Three-Dimensional Imaging of Bioinspired Lipidic Mesophases Using Multicolored Light-Emitting Carbon Nanodots

Recent progress in the design of carbon nanostructures exhibiting strong multiphoton-excited emission opens new pathways to explore the self-organization of lipids found in living organisms. Phospholipid-based lyotropic myelin figures (MFs) are promising materials as simplified models of biomembranes due to their structural resemblance to a multilamellar sheath insulating the axon. This study demonstrates the possibility of selective labeling of MFs by strongly emitting multicolor phloroglucinol-derived carbon nanodots (PG CNDs). Such dopants are efficiently excited by visible and near-infrared light; therefore, one- and two-photon fluorescence microscopies are incorporated to gain 3D insights into the MFs. Combining nondestructive fluorescence microscopy and spectroscopy techniques along with polarized light microscopy gives details on the stability and morphology of lipidic mesophases. Our findings suggest that PG CNDs can be a viable and simple alternative to conventional fluorescent lipid stains to image biologically relevant phospholipid-based structures.

Nano-Proteolysis Targeting Chimeras (Nano-PROTACs) in Cancer Therapy

Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules that have the capability to induce specific protein degradation. While playing a revolutionary role in effectively degrading the protein of interest (POI), PROTACs encounter certain limitations that impede their clinical translation. These limitations encompass off-target effects, inadequate cell membrane permeability, and the hook effect. The advent of nanotechnology presents a promising avenue to surmount the challenges associated with conventional PROTACs. The utilization of nano-proteolysis targeting chimeras (nano-PROTACs) holds the potential to enhance specific tissue accumulation, augment membrane permeability, and enable controlled release. Consequently, this approach has the capacity to significantly enhance the controllable degradation of target proteins. Additionally, they enable a synergistic effect by combining with other therapeutic strategies. This review comprehensively summarizes the structural basis, advantages, and limitations of PROTACs. Furthermore, it highlights the latest advancements in nanosystems engineered for delivering PROTACs, as well as the development of nano-sized PROTACs employing nanocarriers as linkers. Moreover, it delves into the underlying principles of nanotechnology tailored specifically for PROTACs, alongside the current prospects of clinical research. In conclusion, the integration of nanotechnology into PROTACs harbors vast potential in enhancing the anti-tumor treatment response and expediting clinical translation.

Advances in liposomes loaded with photoresponse materials for cancer therapy

Cancer treatment is presently a significant challenge in the medical domain, wherein the primary modalities of intervention include chemotherapy, radiation therapy and surgery. However, these therapeutic modalities carry side effects. Photothermal therapy (PTT) and photodynamic therapy (PDT) have emerged as promising modalities for the treatment of tumors in recent years. Phototherapy is a therapeutic approach that involves the exposure of materials to specific wavelengths of light, which can subsequently be converted into either heat or Reactive Oxygen Species (ROS) to effectively eradicate cancer cells. Due to the hydrophobicity and lack of targeting of many photoresponsive materials, the use of nano-carriers for their transportation has been extensively explored. Among these nanocarriers, liposomes have been identified as an effective drug delivery system due to their controllability and availability in the biomedical field. By binding photoresponsive materials to liposomes, it is possible to reduce the cytotoxicity of the material and regulate drug release and accumulation at the tumor site. This article provides a comprehensive review of the progress made in cancer therapy using photoresponsive materials loaded onto liposomes. Additionally, the article discusses the potential synergistic treatment through the combination of phototherapy with chemo/immuno/gene therapy using liposomes.

Plasmonic porous micro- and nano-materials based on Au/Ag nanostructures developed for photothermal cancer therapy: challenges in clinicalization

Photothermal therapy (PTT) has developed in recent decades as a relatively safe method for the treatment of cancers. Recently, various species of gold and silver (Au and Ag) nanostructures have been developed and investigated to achieve PTT due to their highly localized surface plasmon resonance (LSPR) effect. Concisely, the collective oscillation of electrons on the surface of Au and Ag nanostructures upon exposure to a specific wavelength (depending on their size and shape) and further plasmonic resonance leads to the heating of the surface of these particles. Hence, porous species can be equipped with tiny plasmonic ingredients that add plasmonic properties to therapeutic cargoes. In this case, a precise review of the recent achievements is very important to figure out to what extent plasmonic photothermal therapy (PPTT) by Au/Ag-based plasmonic porous nanomedicines successfully treated cancers with satisfactory biosafety. Herein, we classify the various species of LSPR-active micro- and nano-materials. Moreover, the routes for the preparation of Ag/Au-plasmonic porous cargoes and related bench assessments are carefully reviewed. Finally, as the main aim of this study, principal requirements for the clinicalization of Ag/Au-plasmonic porous cargoes and their further challenges are discussed, which are critical for specialists in this field.

Nanoparticles for imaging-guided photothermal therapy of colorectal cancer

Colorectal cancer (CRC) is one of the most common malignancies with a high mortality rate worldwide. While surgery, chemotherapy, and radiotherapy have shown some effectiveness in improving survival rates, they come with drawbacks such as side effects and harm to healthy tissues. The theranostic approach, which integrates the processes of cancer diagnosis and treatment, can minimize biological side effects. Photothermal therapy (PTT) is an emerging treatment method that usages light-sensitive agents to generate heat at the tumor site and induce thermal erosion. The development of nanotechnology for CRC treatment using imaging-guided PTT has garnered significant. Nanoparticles with suitable physical and chemical properties can enhance the efficiency of cancer diagnosis and PTT. This approach enables the monitoring of cancer treatment progress and safeguards healthy tissues. In this article, we concisely introduce the application of metal nanoparticles, polymeric nanoparticles, and carbon nanoparticles in imaging-guided PTT of colorectal cancer.

Recent Advances of Tumor Microenvironment-Responsive Nanomedicines-Energized Combined Phototherapy of Cancers

Photodynamic therapy (PDT) has emerged as a powerful tumor treatment tool due to its advantages including minimal invasiveness, high selectivity and thus dampened side effects. On the other side, the efficacy of PDT is severely frustrated by the limited oxygen level in tumors, thus promoting its combination with other therapies, particularly photothermal therapy (PTT) for bolstered tumor treatment outcomes. Meanwhile, nanomedicines that could respond to various stimuli in the tumor microenvironment (TME) provide tremendous benefits for combined phototherapy with efficient hypoxia relief, tailorable drug release and activation, improved cellular uptake and intratumoral penetration of nanocarriers, etc. In this review, we will introduce the merits of combining PTT with PDT, summarize the recent important progress of combined phototherapies and their combinations with the dominant tumor treatment regimen, chemotherapy based on smart nanomedicines sensitive to various TME stimuli with a focus on their sophisticated designs, and discuss the challenges and future developments of nanomedicine-mediated combined phototherapies.

Cubosomes-assisted transdermal delivery of doxorubicin and indocyanine green for chemo-photothermal combination therapy of melanoma

Melanoma is a highly aggressive form of skin cancer with limited therapeutic options. Chemo-photothermal combination therapy has demonstrated potential for effectively treating melanoma, and transdermal administration is considered the optimal route for treating skin diseases due to its ability to bypass first-pass metabolism and enhance drug concentration. However, the stratum corneum presents a formidable challenge as a significant barrier to drug penetration in transdermal drug delivery. Lipid-nanocarriers, particularly cubosomes, have been demonstrated to possess significant potential in augmenting drug permeation across the stratum corneum. Herein, cubosomes co-loaded with doxorubicin (DOX, a chemotherapeutic drug) and indocyanine green (ICG, a photothermal agent) (DOX-ICG-cubo) transdermal drug delivery system was developed to enhance the therapeutic efficiency of melanoma by improving drug permeation. The DOX-ICG-cubo showed high encapsulation efficiency of both DOX and ICG, and exhibited good stability under physiological conditions. In addition, the unique cubic structure of the DOX-ICG-cubo was confirmed through transmission electron microscopy (TEM) images, polarizing microscopy, and small angle X-ray scattering (SAXS). The DOX-ICG-cubo presented high photothermal conversion efficiency, as well as pH and thermo-responsive DOX release. Notably, the DOX-ICG-cubo exhibited enhanced drug permeation efficiency, good biocompatibility, and improved in vivo anti-melanoma efficacy through the synergistic effects of chemo-photothermal therapy. In conclusion, DOX-ICG-cubo presented a promising strategy for melanoma treatment.

An X-ray activatable gold nanorod encapsulated liposome delivery system for mitochondria-targeted photodynamic therapy (PDT)

In this work, we developed a mitochondria-targeted nanomaterial for neoadjuvant X-ray-triggered photodynamic therapy of rectal cancer. Herein, we designed a biodegradable liposome incorporating a photosensitizer, verteporfin, to generate X-ray-induced reactive oxygen species, gold nanorods as radiation enhancers, and triphenylphosphonium as the mitochondrial targeting moiety. The average size of the nanocarrier was about 150 nm. Due to the synergetic effect between X-ray and a combination of verteporfin and gold nanorods, as well as precise site-targeted TPP-modified liposomal nanocarriers, our nanoconjugates generated sufficient cytotoxic singlet oxygen within the mitochondria under X-ray irradiation, triggering the loss of membrane potential and mitochondria-related apoptosis of cancer cells.

A new theranostic pH-responsive niosome formulation for Doxorubicin delivery and bio-imaging against breast cancer

As one of the newest generations of nanoplatforms, smart nanotheranostics have attracted signifivant attentions for medical applications, especially in oncology and cancer treatment. Indeed, their capability to provide treatment and diagnosis simultaneously leads to reduce time and side effects along with improving the performance. This study aims to introduce a novel smart nano-platform composed of doxorubicin-loaded pH-responsive stealth niosomes containing CdSe/ZnS Quantum dots as an imaging agent. Drug loaded nano-platform was fabricated via thin-film hydration method and then evaluated using different physicochemical tests. The entrapment efficiency and release profile of doxorubicin were assessed at three different pH (4, 6.5, and 7.4). Biological features and imaging ability of the nanoparticles were also evaluated by MTT assay, apoptosis assay, and fluorescence microscopy. Results showed that the fabricated nanoparticles were round-shaped, with a mean size of about 100±10 nm, -2 mV surface charge, and about 87% entrapment efficiency. The drug release profile presented a pH-responsive behavior (80, 60, and 40% drug release in pH 4, 6.5, and 7.4, respectively). The bio-activity assessments showed nearly 55% cytotoxicity effects via inducing cell apoptosis. Besides, the uptake of samples by the cells was confirmed through fluorescence imaging. Based on the results, this new nanoformulation could be considered as a candidate for future cancer theranostic applications.

Liposome-based diagnostic and therapeutic applications for pancreatic cancer

Pancreatic cancer is one of the harshest and most challenging cancers to treat, often labeled as incurable. Chemotherapy continues to be the most popular treatment yet yields a very poor prognosis. The main barriers such as inefficient drug penetration and drug resistance, have led to the development of drug carrier systems. The benefits, ease of fabrication and modification of liposomes render them as ideal future drug delivery systems. This review delves into the versatility of liposomes to achieve various mechanisms of treatment for pancreatic cancer. Not only are there benefits of loading chemotherapy drugs and targeting agents onto liposomes, as well as mRNA combined therapy, but liposomes have also been exploited for immunotherapy and can be programmed to respond to photothermal therapy. Multifunctional liposomal formulations have demonstrated significant pre-clinical success. Functionalising drug-encapsulated liposomes has resulted in triggered drug release, specific targeting, and remodeling of the tumor environment. Suppressing tumor progression has been achieved, due to their ability to more efficiently and precisely deliver chemotherapy. Currently, no multifunctional surface-modified liposomes are clinically approved for pancreatic cancer thus we aim to shed light on the trials and tribulations and progress so far, with the hope for liposomal therapy in the future and improved patient outcomes. STATEMENT OF SIGNIFICANCE: Considering that conventional treatments for pancreatic cancer are highly associated with sub-optimal performance and systemic toxicity, the development of novel therapeutic strategies holds outmost relevance for pancreatic cancer management. Liposomes are being increasingly considered as promising nanocarriers for providing not only an early diagnosis but also effective, highly specific, and safer treatment, improving overall patient outcome. This manuscript is the first in the last 10 years that revises the advances in the application of liposome-based formulations in bioimaging, chemotherapy, phototherapy, immunotherapy, combination therapies, and emergent therapies for pancreatic cancer management. Prospective insights are provided regarding several advantages resulting from the use of liposome technology in precision strategies, fostering new ideas for next-generation diagnosis and targeted therapies of pancreatic cancer.

A Review on the Use of Gold Nanoparticles in Cancer Treatment

According to a 2020 WHO study, cancer is responsible for one in every six fatalities. One in four patients die due to side effects and intolerance to chemotherapy, making it a leading cause of patient death. Compared to traditional tumor therapy, emerging treatment methods, including immunotherapy, gene therapy, photothermal therapy, and photodynamic therapy, have proven to be more effective. The aim of this review is to highlight the role of gold nanoparticles in advanced cancer treatment. A systematic and extensive literature review was conducted using the Web of Science, PubMed, EMBASE, Google Scholar, NCBI, and various websites. Highly relevant literature from 141 references was chosen for inclusion in this review. Recently, the synergistic benefits of nano therapy and cancer immunotherapy have been shown, which could allow earlier diagnosis, more focused cancer treatment, and improved disease control. Compared to other nanoparticles, the physical and optical characteristics of gold nanoparticles appear to have significantly greater effects on the target. It has a crucial role in acting as a drug carrier, biomarker, anti-angiogenesis agent, diagnostic agent, radiosensitizer, cancer immunotherapy, photodynamic therapy, and photothermal therapy. Gold nanoparticle-based cancer treatments can greatly reduce current drug and chemotherapy dosages.

Antitumor Applications of Photothermal Agents and Photothermal Synergistic Therapies

As a new tumor treatment strategy, photothermal therapy (PTT) has the advantages of accuracy, ease of administration, a high efficiency and low side effects. Photothermal transduction agents (PTAs) are the key factor which play an important role in PTT. The mechanism of PTT is discussed in detail. The photothermal conversion efficiency (PCE) can be improved by increasing the light absorption and reducing the light scattering of photothermal conversion agents. Additionally, non-radiative relaxation path attenuation can also promote energy conversion to obtain a higher value in terms of PCE. The structure and photothermal characteristics of various kinds of PTAs (metal materials, carbon-based nanomaterials, two-dimensional nanomaterials, and organic materials) were compared and analyzed. This paper reviews the antitumor applications of photothermal synergistic therapies, including PTT combined with immunotherapy, chemotherapy, and photodynamic therapy. This review proposes that these PTAs promote the development of photothermal synergistic therapies and have a great potential in the application of tumor treatment.

Cyclodextrin-Based Nanoplatforms for Tumor Phototherapy: An Update

Tumor phototherapies are light-mediated tumor treatment modalities, which usually refer to tumor photothermal therapy (PTT) and photodynamic therapy (PDT). Due to the outstanding spatial-temporal control over treatment through light irradiation, tumor phototherapies display extremely low side effects during treatment and are believed to be a tumor treatment method with a clinical translation potential. However, current tumor phototherapy nanoplatforms face obstacles, including light irradiation-induced skin burning, tumor hypoxia microenvironments, limited light penetration depth, et al. Therefore, one important research direction is developing a tumor phototherapy nanoplatform with multifunctionality and enhanced pharmacological effects to overcome the complexity of tumor treatment. On the other hand, cyclodextrins (CDs) are starch-originated circular oligosaccharides with negligible toxicity and have been used to form supermolecular nanostructures through a host-guest interaction between the inner cavity of CDs and functional biomolecules. In the past few years, numerous studies have focused on CD-based multifunctional tumor phototherapy nanoplatforms with an enhanced photoeffect, responsive morphological transformation, and elevated drug bioavailability. This review focuses on the preparation methods of CD-based tumor phototherapy nanoplatforms and their unique physiochemical properties for improving anti-tumor pharmacological efficacy.

Liposome-Tethered Gold Nanoparticles Triggered by Pulsed NIR Light for Rapid Liposome Contents Release and Endosome Escape

Remote triggering of contents release with micron spatial and sub-second temporal resolution has been a long-time goal of medical and technical applications of liposomes. Liposomes can sequester a variety of bioactive water-soluble ions, ligands and enzymes, and oligonucleotides. The bilayer that separates the liposome interior from the exterior solution provides a physical barrier to contents release and degradation. Tethering plasmon-resonant, hollow gold nanoshells to the liposomes, or growing gold nanoparticles directly on the liposome exterior, allows liposome contents to be released by nanosecond or shorter pulses of near-infrared light (NIR). Gold nanoshells or nanoparticles strongly adsorb NIR light; cells, tissues, and physiological media are transparent to NIR, allowing penetration depths of millimeters to centimeters. Nano to picosecond pulses of NIR light rapidly heat the gold nanoshells, inducing the formation of vapor nanobubbles, similar to cavitation bubbles. The collapse of the nanobubbles generates mechanical forces that rupture bilayer membranes to rapidly release liposome contents at the preferred location and time. Here, we review the syntheses, characterization, and applications of liposomes coupled to plasmon-resonant gold nanostructures for delivering a variety of biologically important contents in vitro and in vivo with sub-micron spatial control and sub-second temporal control.