Gold Nanoparticles for Photothermal Cancer Therapy

Identifying factors controlling cellular uptake of gold nanoparticles by machine learning

There is strong interest to improve the therapeutic potential of gold nanoparticles (GNPs) while ensuring their safe development. The utility of GNPs in medicine requires a molecular-level understanding of how GNPs interact with biological systems. Despite considerable research efforts devoted to monitoring the internalisation of GNPs, there is still insufficient understanding of the factors responsible for the variability in GNP uptake in different cell types. Data-driven models are useful for identifying the sources of this variability. Here, we trained multiple machine learning models on 2077 data points for 193 individual nanoparticles from 59 independent studies to predict cellular uptake level of GNPs and compared different algorithms for their efficacies of prediction. The five ensemble learners (Xgboost, random forest, bootstrap aggregation, gradient boosting, light gradient boosting machine) made the best predictions of GNP uptake, accounting for 80-90% of the variance in the test data. The models identified particle size, zeta potential, GNP concentration and exposure duration as the most important drivers of cellular uptake. We expect this proof-of-concept study will foster the more effective use of accumulated cellular uptake data for GNPs and minimise any methodological bias in individual studies that may lead to under- or over-estimation of cellular internalisation rates.

Phage-based delivery systems: engineering, applications, and challenges in nanomedicines

Bacteriophages (phages) represent a unique category of viruses with a remarkable ability to selectively infect host bacteria, characterized by their assembly from proteins and nucleic acids. Leveraging their exceptional biological properties and modifiable characteristics, phages emerge as innovative, safe, and efficient delivery vectors. The potential drawbacks associated with conventional nanocarriers in the realms of drug and gene delivery include a lack of cell-specific targeting, cytotoxicity, and diminished in vivo transfection efficiency. In contrast, engineered phages, when employed as cargo delivery vectors, hold the promise to surmount these limitations and attain enhanced delivery efficacy. This review comprehensively outlines current strategies for the engineering of phages, delineates the principal types of phages utilized as nanocarriers in drug and gene delivery, and explores the application of phage-based delivery systems in disease therapy. Additionally, an incisive analysis is provided, critically examining the challenges confronted by phage-based delivery systems within the domain of nanotechnology. The primary objective of this article is to furnish a theoretical reference that contributes to the reasoned design and development of potent phage-based delivery systems.

The Advancing Role of Nanocomposites in Cancer Diagnosis and Treatment

The relentless pursuit of effective cancer diagnosis and treatment strategies has led to the rapidly expanding field of nanotechnology, with a specific focus on nanocomposites. Nanocomposites, a combination of nanomaterials with diverse properties, have emerged as versatile tools in oncology, offering multifunctional platforms for targeted delivery, imaging, and therapeutic interventions. Nanocomposites exhibit great potential for early detection and accurate imaging in cancer diagnosis. Integrating various imaging modalities, such as magnetic resonance imaging (MRI), computed tomography (CT), and fluorescence imaging, into nanocomposites enables the development of contrast agents with enhanced sensitivity and specificity. Moreover, functionalizing nanocomposites with targeting ligands ensures selective accumulation in tumor tissues, facilitating precise imaging and diagnostic accuracy. On the therapeutic front, nanocomposites have revolutionized cancer treatment by overcoming traditional challenges associated with drug delivery. The controlled release of therapeutic agents from nanocomposite carriers enhances drug bioavailability, reduces systemic toxicity, and improves overall treatment efficacy. Additionally, the integration of stimuli-responsive components within nanocomposites enables site-specific drug release triggered by the unique microenvironment of the tumor. Despite the remarkable progress in the field, challenges such as biocompatibility, scalability, and long-term safety profiles remain. This article provides a comprehensive overview of recent developments, challenges, and prospects, emphasizing the transformative potential of nanocomposites in revolutionizing the landscape of cancer diagnostics and therapeutics. In Conclusion, integrating nanocomposites in cancer diagnosis and treatment heralds a new era for precision medicine.

Emerging Targets and Therapeutics in Immuno-Oncology: Insights from Landscape Analysis

In the ever-evolving landscape of cancer research, immuno-oncology stands as a beacon of hope, offering novel avenues for treatment. This study capitalizes on the vast repository of immuno-oncology-related scientific documents within the CAS Content Collection, totaling over 350,000, encompassing journals and patents. Through a pioneering approach melding natural language processing with the CAS indexing system, we unveil over 300 emerging concepts, depicted in a comprehensive "Trend Landscape Map". These concepts, spanning therapeutic targets, biomarkers, and types of cancers among others, are hierarchically organized into eight major categories. Delving deeper, our analysis furnishes detailed quantitative metrics showcasing growth trends over the past three years. Our findings not only provide valuable insights for guiding future research endeavors but also underscore the merit of tapping the vast and unparalleled breadth of existing scientific information to derive profound insights.

Gold/cobalt ferrite nanocomposite as a potential agent for photothermal therapy

The study encompasses an investigation of optical, photothermal and biocompatibility properties of a composite consisting of golden cores surrounded by superparamagnetic CoFe2O4 nanoparticles. Accompanied with the experiment, the computational modeling reveals that each adjusted magnetic nanoparticle redshifts the plasmon resonance frequency in gold and nonlinearly increases the extinction cross-section at ~800 nm. The concentration dependent photothermal study demonstrates a temperature increase of 8.2 K and the photothermal conversion efficiency of 51% for the 100 μg/mL aqueous solution of the composite nanoparticles, when subjected to a laser power of 0.5 W at 815 nm. During an in vitro photothermal therapy, a portion of the composite nanoparticles, initially seeded at this concentration, remained associated with the cells after washing. These retained nanoparticles effectively heated the cell culture medium, resulting in a 22% reduction in cell viability after 15 min of the treatment. The composite features a potential in multimodal magneto-plasmonic therapies.

A recent insight of applications of gold nanoparticles in glioblastoma multiforme therapy

The application of gold nanoparticles (AuNPs) in cancer therapy, particularly targeted therapy of glioblastoma multiforme (GBM), is an up-and-coming field of research that has gained much interest in recent years. GBM is a life-threatening malignant tumour of the brain that currently has a 95 % death rate with an average of 15 months of survival. AuNPs have proven to have wide clinical implications and compelling therapeutic potential in many researches, specifically in GBM treatment. It was found that the reason why AuNPs were highly desired for GBM treatment was due to their unique properties that diversified the applications of AuNPs further to include imaging, diagnosis, and photothermal therapy. These properties include easy synthesis, biocompatibility, and surface functionalization. Various studies also underscored the ability of AuNPs to cross the blood-brain-barrier and selectively target tumour cells while displaying no major safety concerns which resulted in better therapy results. We attempt to bring together some of these studies in this review and provide a comprehensive overview of safety evaluations and current and potential applications of AuNPs in GBM therapy that may result in AuNP-mediated therapy to be the new gold standard for GBM treatment.

The nucleolus: Coordinating stress response and genomic stability

The perception that the nucleoli are merely the organelles where ribosome biogenesis occurs is challenged. Only around 30 % of nucleolar proteins are solely involved in producing ribosomes. Instead, the nucleolus plays a critical role in controlling protein trafficking during stress and, according to its dynamic nature, undergoes continuous protein exchange with nucleoplasm under various cellular stressors. Hence, the concept of nucleolar stress has evolved as cellular insults that disrupt the structure and function of the nucleolus. Considering the emerging role of this organelle in DNA repair and the fact that rDNAs are the most fragile genomic loci, therapies targeting the nucleoli are increasingly being developed. Besides, drugs that target ribosome synthesis and induce nucleolar stress can be used in cancer therapy. In contrast, agents that regulate nucleolar activity may be a potential treatment for neurodegeneration caused by abnormal protein accumulation in the nucleolus. Here, I explore the roles of nucleoli beyond their ribosomal functions, highlighting the factors triggering nucleolar stress and their impact on genomic stability.

Supported of gold nanoparticles on carboxymethyl lignin modified magnetic nanoparticles as an efficient catalyst for reduction of nitroarenes and treatment of human melanoma

This article represents the synthesis and characterizations of Au NPs immobilized and carboxymethyl lignin (CML) modified Fe3O4 nanoparticles (Fe3O4@CML/Au NPs) following a bio-inspired protocol without the participation of any toxic and harmful reductant or stabilizers. Following various physicochemical methodologies, such as FT-IR, FE-SEM, TEM, EDX, XRD, VSM, and ICP-OES, the textural characteristics and different structural aspects were evaluated. The Fe3O4@CML/Au NPs nanocomposite was subsequently explored towards the catalytic reduction of diverse aromatic nitro functions using green conditions. An excellent yield were achieved within very short reaction time. Nine recycling runs of the nanocatalyst were completed without a discernible loss of catalytic activity, thanks to its easy magnetic recovery. The DPPH assay was carried out to examine the antioxidant effectiveness. The Fe3O4@CML/Au NPs nanocomposite inhibited half of the DPPH in a 250 μg/mL solution. To measure the anti-human melanoma efficacy of Fe3O4@CML/Au NPs nanocomposite, MTT assay was applied on HT144, MUM2C, IPC-298 and SKMEL24 cell lines. Fe3O4@CML/Au NPs nanocomposite had high anti-human melanoma efficacy on above tumor cells. The best finding of anti-human melanoma properties of Fe3O4@CML/Au NPs nanocomposite was seen in the case of the SKMEL24 cell line. The IC50 of Fe3O4@CML/Au NPs nanocomposite was 137, 145, 185, and 125 μg/mL against HT144, MUM2C, IPC-298 and SKMEL24 cells, respectively. This research exhibited remarkable anti-human melanoma and antioxidant efficacies of Fe3O4@CML/Au NPs nanocomposite in the in vitro condition.

Review of NIR-responsive ''Smart'' carriers for photothermal chemotherapy

This review focuses on the versatile applications of near-infrared (NIR)-responsive smart carriers in biomedical applications, particularly drug delivery and photothermal chemotherapy. These carriers demonstrate multi-responsive theranostics capabilities, including pH-dependent drug release, targeted delivery of chemotherapeutics, heat-mediated drug release, and photothermal tumor damage. Biological samples are transparent to NIR light with a suitable wavelength, and therefore, NIR light is advantageous for deep-tissue penetration. It also generates sufficient heat in tissue samples, which is beneficial for on-demand NIR-responsive drug delivery in vivo systems. The development of biocompatible materials with sufficient NIR light absorption properties and drug-carrying functionality has shown tremendous growth in the last five years. Thus, this review offers insights into the current research development of NIR-responsive materials with therapeutic potential and prospects aimed at overcoming challenges to improve the therapeutic efficacy and safety in the dynamic field of NIR-responsive drug delivery.

Assessing the toxicity of one-step-synthesized PEG-coated gold nanoparticles: in vitro and in vivo studies

OBJECTIVE

To evaluate the in vitro and in vivo toxicities of polyethylene glycol-coated gold nanoparticles synthesized using a one-step process.

METHODS

Gold nanoparticles were prepared via a co-precipitation method using polyethylene glycol, and the synthesis product was characterized. For the in vitro evaluation, a flow cytometry analysis with Annexin V and iodide propidium staining was used to assess cytotoxicity in MG-63 cells labeled with 10, 50, and 100µg/mL of nanoparticle concentration. For the in vivo evaluation, nanoparticles were administered intraperitoneally at a dose of 10mg/kg dose in 10-week-old mice. Toxicity was assessed 24 hours and 7 days after administration via histopathological analysis of various tissues, as well as through renal, hepatic, and hematopoietic evaluations.

RESULTS

Synthesized nanoparticles exhibited different hydrodynamic sizes depending on the medium: 51.27±1.62nm in water and 268.12±28.45nm (0 hour) in culture medium. They demonstrated a maximum absorbance at 520nm and a zeta potential of -8.419mV. Cellular viability exceeded 90%, with less than 3% early apoptosis, 6% late apoptosis, and 1% necrosis across all labeling conditions, indicating minimal cytotoxicity differences. Histopathological analysis highlighted the accumulation of nanoparticles in the mesentery; however, no lesions or visible agglomeration was observed in the remaining tissues. Renal, hepatic, and hematopoietic analyses showed no significant differences at any time point.

CONCLUSION

Polyethylene glycol-coated gold nanoparticles exhibit extremely low toxicity and high biocompatibility, showing promise for future studies.

Long-Term Accumulation, Biological Effects and Toxicity of BSA-Coated Gold Nanoparticles in the Mouse Liver, Spleen, and Kidneys

Introduction

Gold nanoparticles are promising candidates as vehicles for drug delivery systems and could be developed into effective anticancer treatments. However, concerns about their safety need to be identified, addressed, and satisfactorily answered. Although gold nanoparticles are considered biocompatible and nontoxic, most of the toxicology evidence originates from in vitro studies, which may not reflect the responses in complex living organisms.

Methods

We used an animal model to study the long-term effects of 20 nm spherical AuNPs coated with bovine serum albumin. Mice received a 1 mg/kg single intravenous dose of nanoparticles, and the biodistribution and accumulation, as well as the organ changes caused by the nanoparticles, were characterized in the liver, spleen, and kidneys during 120 days.

Results

The amount of nanoparticles in the organs remained high at 120 days compared with day 1, showing a 39% reduction in the liver, a 53% increase in the spleen, and a 150% increase in the kidneys. The biological effects of chronic nanoparticle exposure were associated with early inflammatory and fibrotic responses in the organs and were more pronounced in the kidneys, despite a negligible amount of nanoparticles found in renal tissues.

Conclusion

Our data suggest, that although AuNPs belong to the safest nanomaterial platforms nowadays, due to their slow tissue elimination leading to long-term accumulation in the biological systems, they may induce toxic responses in the vital organs, and so understanding of their long-term biological impact is important to consider their potential therapeutic applications.

Multifactorial drug carrier system bringing both chemical and physical therapeutics to the treatment of tumor heterogeneity

Tumor heterogeneity and drug resistance have been invincible features of cancer for its complete cure. Despite the advent of immunotherapy, the expansion and diversification of cancer cells evolved even in the absence or presence of drug treatment discourage additional therapeutic interventions. For the eradication of cancer cells, therefore, an 'all-at-once' strategy is required, which exploits both target-selective chemotherapy and non-selective physicotherapy. Multifactorial microcapsules comprising gold nanoparticles (AuNPs) and a self-assembly protein of α-synuclein (αS) were fabricated, in which hydrophobic and hydrophilic drugs could be separately encapsulated by employing lipid-based inverted micelles (IMs). Their combined physico-chemical therapeutic effects were examined since they also contained both membrane-disrupting IMs and heat-generating AuNPs upon irradiation as physicotherapeutic agents. For the optimal enclosure of IMs containing hydrophilic drugs, a porous inner skeleton made of poly(lactic-co-glycolic acid) was introduced, which would play the roles of not only compartmentalizing the internal space but also enhancing proteolytic disintegration of the microcapsules to discharge and stabilize IMs to the outside. In fact, hydrophobic paclitaxel and hydrophilic doxorubicin showed markedly enhanced drug efficacy when delivered in the IM-containing microcapsules exhibiting the 'quantal' release of both drugs into the cells whose integrity could be also affected by the IMs. In addition, the remnants of αS-AuNP microcapsules produced via proteolysis also caused cell death through photothermal effect. The multifactorial microcapsules are therefore considered as a promising anti-cancer drug carrier capable of performing combinatorial selective and non-selective chemical and physical therapies to overcome tumor heterogeneity and drug resistance.

Mechanism and potentialities of photothermal and photodynamic therapy of transition metal dichalcogenides (TMDCs) against cancer

The ultimate goal of nanoparticle-based phototherapy is to suppress tumor growth. Photothermal therapy (PTT) and photothermal photodynamic therapy (PDT) are two types of physicochemical therapy that use light radiation with multiple wavelength ranges in the near-infrared to treat cancer. When a laser is pointed at tissue, photons are taken in the intercellular and intracellular regions, converting photon energy to heat. It has attracted much interest and research in recent years. The advent of transition materials dichalcogenides (TMDCs) is a revolutionary step in PDT/PTT-based cancer therapy. The TMDCs is a multilayer 2D nano-composite. TMDCs contain three atomic layers in which two chalcogens squash in the transition metal. The chalcogen atoms are highly reactive, and the surface characteristics of TMDCs help them to target deep cancer cells. They absorb Near Infrared (NIR), which kills deep cancer cells. In this review, we have discussed the history and mechanism of PDT/PTT and the use of TMDCs and nanoparticle-based systems, which have been practiced for theranostics purposes. We have also discussed PDT/PTT combined with immunotherapy, in which the cancer cell apoptosis is done by activating the immune cells, such as CD8+.

211At on gold nanoparticles for targeted radionuclide therapy application

Targeted alpha therapy (TAT) is a methodology that is being developed as a promising cancer treatment using the α-particle decay of radionuclides. This technique involves the use of heavy radioactive elements being placed near the cancer target area to cause maximum damage to the cancer cells while minimizing the damage to healthy cells. Using gold nanoparticles (AuNPs) as carriers, a more effective therapy methodology may be realized. AuNPs can be good candidates for transporting these radionuclides to the vicinity of the cancer cells since they can be labeled not just with the radionuclides, but also a host of other proteins and ligands to target these cells and serve as additional treatment options. Research has shown that astatine and iodine are capable of adsorbing onto the surface of gold, creating a covalent bond that is quite stable for use in experiments. However, there are still many challenges that lie ahead in this area, whether they be theoretical, experimental, and even in real-life applications. This review will cover some of the major developments, as well as the current state of technology, and the problems that need to be tackled as this research topic moves along to maturity. The hope is that with more workers joining the field, we can make a positive impact on society, in addition to bringing improvement and more knowledge to science.

Nanoparticles incorporated hydrogels for delivery of antimicrobial agents: developments and trends

The prevention and treatment of microbial infections is an imminent global public health concern due to the poor antimicrobial performance of the existing antimicrobial regime and rapidly emerging antibiotic resistance in pathogenic microbes. In order to overcome these problems and effectively control bacterial infections, various new treatment modalities have been identified. To attempt this, various micro- and macro-molecular antimicrobial agents that function by microbial membrane disruption have been developed with improved antimicrobial activity and lesser resistance. Antimicrobial nanoparticle-hydrogels systems comprising antimicrobial agents (antibiotics, biological extracts, and antimicrobial peptides) loaded nanoparticles or antimicrobial nanoparticles (metal or metal oxide) constitute an important class of biomaterials for the prevention and treatment of infections. Hydrogels that incorporate nanoparticles can offer an effective strategy for delivering antimicrobial agents (or nanoparticles) in a controlled, sustained, and targeted manner. In this review, we have described an overview of recent advancements in nanoparticle-hydrogel hybrid systems for antimicrobial agent delivery. Firstly, we have provided an overview of the nanoparticle hydrogel system and discussed various advantages of these systems in biomedical and pharmaceutical applications. Thereafter, different hybrid hydrogel systems encapsulating antibacterial metal/metal oxide nanoparticles, polymeric nanoparticles, antibiotics, biological extracts, and antimicrobial peptides for controlling infections have been reviewed in detail. Finally, the challenges and future prospects of nanoparticle-hydrogel systems have been discussed.

Quantifying particle concentration via AI-enhanced optical coherence tomography

Efficient and robust quantification of the number of nanoparticles in solution is not only essential but also insufficient in nanotechnology and biomedical research. This paper proposes to use optical coherence tomography (OCT) to quantify the number of gold nanorods, which exemplify the nanoparticles with high light scattering signals. Additionally, we have developed an AI-enhanced OCT image processing to improve the accuracy and robustness of the quantification result.

Oxidative stress and potential effects of metal nanoparticles: A review of biocompatibility and toxicity concerns

Metal nanoparticles (M-NPs) have garnered significant attention due to their unique properties, driving diverse applications across packaging, biomedicine, electronics, and environmental remediation. However, the potential health risks associated with M-NPs must not be disregarded. M-NPs' ability to accumulate in organs and traverse the blood-brain barrier poses potential health threats to animals, humans, and the environment. The interaction between M-NPs and various cellular components, including DNA, multiple proteins, and mitochondria, triggers the production of reactive oxygen species (ROS), influencing several cellular activities. These interactions have been linked to various effects, such as protein alterations, the buildup of M-NPs in the Golgi apparatus, heightened lysosomal hydrolases, mitochondrial dysfunction, apoptosis, cell membrane impairment, cytoplasmic disruption, and fluctuations in ATP levels. Despite the evident advantages M-NPs offer in diverse applications, gaps in understanding their biocompatibility and toxicity necessitate further research. This review provides an updated assessment of M-NPs' pros and cons across different applications, emphasizing associated hazards and potential toxicity. To ensure the responsible and safe use of M-NPs, comprehensive research is conducted to fully grasp the potential impact of these nanoparticles on both human health and the environment. By delving into their intricate interactions with biological systems, we can navigate the delicate balance between harnessing the benefits of M-NPs and minimizing potential risks. Further exploration will pave the way for informed decision-making, leading to the conscientious development of these nanomaterials and safeguarding the well-being of society and the environment.

Recent advances in photothermal nanomaterials-mediated detection of circulating tumor cells

Photothermal materials have shown great potential for cancer detection and treatment due to their excellent photothermal effects. Circulating tumor cells (CTCs) are tumor cells that are shed from the primary tumor into the blood and metastasize. In contrast to other tumor markers that are free in the blood, CTCs are a collective term for all types of tumor cells present in the peripheral blood, a source of tumor metastasis, and clear evidence of tumor presence. CTCs detection enables early detection, diagnosis and treatment of tumors, and plays an important role in cancer prevention and treatment. This review summarizes the application of various photothermal materials in CTC detection, including gold, carbon, molybdenum, phosphorus, etc. and describes the significance of CTC detection for early tumor diagnosis and tumor prognosis. Focus is also put on how various photothermal materials play their roles in CTCs detection, including CT, imaging and photoacoustic and therapeutic roles. The physicochemical properties, shapes, and photothermal properties of various photothermal materials are discussed to improve the detection sensitivity and efficiency and to reduce the damage to normal cells. These photothermal materials are capable of converting radiant light energy into thermal energy for highly-sensitive CTCs detection and improving their photothermal properties by various methods, and have achieved good results in various experiments. The use of photothermal materials for CTCs detection is becoming more and more widespread and can be of significant help in early cancer screening and later treatment.

A Biodegradable "One-For-All" Nanoparticle for Multimodality Imaging and Enhanced Photothermal Treatment of Breast Cancer

Silver sulfide nanoparticles (Ag2S-NP) hold promise for various optical-based biomedical applications, such as near-infrared fluorescence (NIRF) imaging, photoacoustics (PA), and photothermal therapy (PTT). However, their NIR absorbance is relatively low, and previous formulations are synthesized using toxic precursors under harsh conditions and are not effectively cleared due to their large size. Herein, sub-5 nm Ag2S-NP are synthesized and encapsulated in biodegradable, polymeric nanoparticles (AgPCPP). All syntheses are conducted using biocompatible, aqueous reagents under ambient conditions. The encapsulation of Ag2S-NP in polymeric nanospheres greatly increases their NIR absorbance, resulting in enhanced optical imaging and PTT effects. AgPCPP nanoparticles exhibit potent contrast properties suitable for PA and NIRF imaging, as well as for computed tomography (CT). Furthermore, AgPCPP nanoparticles readily improve the conspicuity of breast tumors in vivo. Under NIR laser irradiation, AgPCPP nanoparticles significantly reduce breast tumor growth, leading to prolonged survival compared to free Ag2S-NP. Over time, AgPCPP retention in tissues gradually decreases, without any signs of acute toxicity, providing strong evidence of their safety and biodegradability. Therefore, AgPCPP may serve as a "one-for-all" theranostic agent that degrades into small components for excretion after fulfilling diagnostic and therapeutic tasks, offering good prospects for clinical translation.

Unlocking the potential of exosomes in cancer research: A paradigm shift in diagnosis, treatment, and prevention

Exosomes, which are tiny particles released by cells, have the ability to transport various molecules, including proteins, lipids, and genetic material containing non-coding RNAs (ncRNAs). They are associated with processes like cancer metastasis, immunity, and tissue repair. Clinical trials have shown exosomes to be effective in treating cancer, inflammation, and chronic diseases. Mesenchymal stem cells (MSCs) and dendritic cells (DCs) are common sources of exosome production. Exosomes have therapeutic potential due to their ability to deliver cargo, modulate the immune system, and promote tissue regeneration. Bioengineered exosomes could revolutionize disease treatment. However, more research is needed to understand exosomes in tumor growth and develop new therapies. This paper provides an overview of exosome research, focusing on cancer and exosome-based therapies including chemotherapy, radiotherapy, and vaccines. It explores exosomes as a drug delivery system for cancer therapy, highlighting their advantages. The article discusses using exosomes for various therapeutic agents, including drugs, antigens, and RNAs. It also examines challenges with engineered exosomes. Analyzing exosomes for clinical purposes faces limitations in sensitivity, specificity, and purification. On the other hand, Nanotechnology offers solutions to overcome these challenges and unlock exosome potential in healthcare. Overall, the article emphasizes the potential of exosomes for personalized and targeted cancer therapy, while acknowledging the need for further research.

Pulsed Electromagnetic Fields (PEMFs) Trigger Cell Death and Senescence in Cancer Cells

The currently available anti-cancer therapies, such as gamma-radiation and chemotherapeutic agents, induce cell death and cellular senescence not only in cancer cells but also in the adjacent normal tissue. New anti-tumor approaches focus on limiting the side effects on normal cells. In this frame, the potential anti-tumor properties of Pulsed Electromagnetic Fields (PEMFs) through the irradiation of breast cancer epithelial cells (MCF-7 and MDA-MB-231) and normal fibroblasts (FF95) were investigated. PEMFs had a frequency of 8 Hz, full-square wave type and magnetic flux density of 0.011 T and were applied twice daily for 5 days. The data collected showcase that PEMF application decreases the proliferation rate and viability of breast cancer cells while having the opposite effect on normal fibroblasts. Moreover, PEMF irradiation induces cell death and cellular senescence only in breast cancer cells without any effect in the non-cancerous cells. These findings suggest PEMF irradiation as a novel, non-invasive anti-cancer strategy that, when combined with senolytic drugs, may eliminate both cancer and the remaining senescent cells, while simultaneously avoiding the side effects of the current treatments.

Electron-Induced Damage by UV Photolysis of DNA Attached to Gold Nanoparticles

Photolysis of DNA attached to gold nanoparticles (AuNPs) with ultraviolet (UV) photons induces DNA damage. The release of nucleobases (Cyt, Gua, Ade, and Thy) from DNA was the major reaction (99%) with an approximately equal release of pyrimidines and purines. This reaction contributes to the formation of abasic sites in DNA. In addition, liquid chromatography-mass spectrometry/MS (LC-MS/MS) analysis revealed the formation of reduction products of pyrimidines (5,6-dihydrothymidine and 5,6-dihydro-2'-deoxyuridine) and eight 2',3'- and 2',5'-dideoxynucleosides. In contrast, there was no evidence of the formation of 5-hydroxymethyluracil and 8-oxo-7,8-dihydroguanine, which are common oxidation products of thymine and guanine, respectively. Using appropriate filters, the main photochemical reactions were found to involve photoelectrons ejected from AuNPs by UV photons. The contribution of "hot" conduction band electrons with energies below the photoemission threshold was minor. The mechanism for the release of free nucleobases by photoelectrons is proposed to take place by the initial formation of transient molecular anions of the nucleobases, followed by dissociative electron attachment at the C1'-N glycosidic bond connecting the nucleobase to the sugar-phosphate backbone. This mechanism is consistent with the reactivity of secondary electrons ejected by X-ray irradiation of AuNPs attached to DNA, as well as the reactions of various nucleic acid derivatives irradiated with monoenergetic very-low-energy electrons (∼2 eV). These studies should help us to understand the chemistry of nanoparticles that are exposed to UV light and that are used as scaffolds and catalysts in molecular biology, curative agents in photodynamic therapy, and components of sunscreens and cosmetics.

Gold Nanoparticles in Neurological Diseases: A Review of Neuroprotection

This review explores the diverse applications of gold nanoparticles (AuNPs) in neurological diseases, with a specific focus on Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. The introduction highlights the pivotal role of neuroinflammation in these disorders and introduces the unique properties of AuNPs. The review's core examines the mechanisms by which AuNPs exert neuroprotection and anti-neuro-inflammatory effects, elucidating various pathways through which they manifest these properties. The potential therapeutic applications of AuNPs in AD are discussed, shedding light on promising avenues for therapy. This review also explores the prospects of utilizing AuNPs in PD interventions, presenting a hopeful outlook for future treatments. Additionally, the review delves into the potential of AuNPs in providing neuroprotection after strokes, emphasizing their significance in mitigating cerebrovascular accidents' aftermath. Experimental findings from cellular and animal models are consolidated to provide a comprehensive overview of AuNPs' effectiveness, offering insights into their impact at both the cellular and in vivo levels. This review enhances our understanding of AuNPs' applications in neurological diseases and lays the groundwork for innovative therapeutic strategies in neurology.

The quest for nanoparticle-powered vaccines in cancer immunotherapy

Despite recent advancements in cancer treatment, this disease still poses a serious threat to public health. Vaccines play an important role in preventing illness by preparing the body's adaptive and innate immune responses to combat diseases. As our understanding of malignancies and their connection to the immune system improves, there has been a growing interest in priming the immune system to fight malignancies more effectively and comprehensively. One promising approach involves utilizing nanoparticle systems for antigen delivery, which has been shown to potentiate immune responses as vaccines and/or adjuvants. In this review, we comprehensively summarized the immunological mechanisms of cancer vaccines while focusing specifically on the recent applications of various types of nanoparticles in the field of cancer immunotherapy. By exploring these recent breakthroughs, we hope to identify significant challenges and obstacles in making nanoparticle-based vaccines and adjuvants feasible for clinical application. This review serves to assess recent breakthroughs in nanoparticle-based cancer vaccinations and shed light on their prospects and potential barriers. By doing so, we aim to inspire future immunotherapies for cancer that harness the potential of nanotechnology to deliver more effective and targeted treatments.

Light Absorption Analysis and Optimization of Ag@TiO2 Core-Shell Nanospheroid and Nanorod

For photothermal therapy of cancer, it is necessary to find Ag @TiO2 core-shell nanoparticles that can freely tune the resonance wavelength within the near-infrared biological window. In this paper, the finite element method and the size-dependent refractive index of metal nanoparticles were used to theoretically investigate the effects of the core material, core length, core aspect ratio, shell thickness, refractive index of the surrounding medium, and the particle orientation on the light absorption properties of Ag@TiO2 core-shell nanospheroid and nanorod. The calculations show that the position and intensity of the light absorption resonance peaks can be freely tuned within the first and second biological windows by changing the above-mentioned parameters. Two laser wavelengths commonly used in photothermal therapy, 808 nm (first biological window) and 1064 nm (second biological window), were selected to optimize the core length and aspect ratio of Ag@TiO2 core-shell nanospheroid and nanorod. It was found that the optimized Ag@TiO2 core-shell nanospheroid has a stronger light absorption capacity at the laser wavelengths of 808 nm and 1064 nm. The optimized Ag@TiO2 core-shell nanoparticles can be used as ideal therapeutic agents in photothermal therapy.

Gold nanobipyramids-based laser-activated sealants for effective skin sealing and repair

Anisotropic gold nanostructures have gained increased attention for biomedical applications because of their remarkable optical properties. An emerging type of gold nanostructure-gold nanobipyramids (AuNBP)-has been shown to exhibit superior absorption properties compared to conventionally used gold nanoparticles, which makes them attractive for photothermal applications. We generated a high-shape-purity dispersion of AuNBP using a seed-mediated method and embedded them as photothermal conversion agents in a silk fibroin matrix to investigate their efficacy in photothermal sealing of incisional wounds in immunocompetent mice. These AuNBP-doped laser-activated sealants, or AuNBP-LASE were able to absorb near-infrared laser energy and convert it to heat, thereby inducing transient hyperthermia in the wound and the surrounding tissue. This photothermal conversion facilitated rapid sealing of the skin tissue by the AuNBP-LASE, which resulted in faster functional recovery of skin barrier function compared to nylon sutures at the early stages of repair. Further, the biomechanical properties of the healing skin closed with AuNBP-LASE those of intact skin more rapidly compared to incisions approximated with sutures. Histology studies indicated higher penetration of the LASE within the volume of the incision in skin tissue, lower scab formation, and a similar epidermal gap compared to conventional suturing. These results demonstrate that AuNBP-LASEs can be effective as wound approximation devices for photothermal sealing.

Multifunctional chitosan-bimetallic nanocarrier deliver 5-fluorouracil for enhanced treatment of pancreatic and triple-negative breast cancer

This work aimed to prepare multifunctional aptamer-conjugated, photothermally responsive 5-fluorouracil (5fu)-loaded chitosan-bimetallic (Au/Pd) nanoparticles (APT-CS-5fu-Au/Pd NPs) for improved cytotoxicity in two cancer cell lines (PANC-1 and MDA-MD 231). The CS-5fu-Au/Pd NPs were polydispersed with a size of 34.43 ± 1.59 nm. FTIR analysis indicated the presence of CS, 5fu in CS-5fu-Au/Pd NPs. The 2 theta degrees in CS-5fu-Au/Pd NPs accounted for CS and Au/Pd. Additionally, AGE revealed the conjugation of APT in CS-5fu-Au/Pd NPs. The APT-CS-5fu-Au/Pd NPs (180 μg/mL) with NIR treatment increased the temperature to >50 °C. The optimized 5fu input was 0.075 % in CS-5fu-Au/Pd NPs, exhibiting a hydrodynamic size of 112.96 ± 17.23 nm, DEE of 64.2 ± 3.77 %, and DLE of 11.1 ± 0.65 %. A higher level of 5fu release (69.8 ± 2.78 %) was observed under pH 5.4 at 74 h. In conclusion, NIR-APT-CS-5fu-Au/Pd NPs did not cause toxicity to RBC and Egg CAM, but increased cytotoxicity in MDA-MB 231 and PANC-1 cells by triggering oxidative stress-mediated cell death.

Intratumor injected gold molecular clusters for NIR-II imaging and cancer therapy

Surgical resections of solid tumors guided by visual inspection of tumor margins have been performed for over a century to treat cancer. Near-infrared (NIR) fluorescence labeling/imaging of tumor in the NIR-I (800 to 900 nm) range with systemically administrated fluorophore/tumor-targeting antibody conjugates have been introduced to improve tumor margin delineation, tumor removal accuracy, and patient survival. Here, we show Au25 molecular clusters functionalized with phosphorylcholine ligands (AuPC, ~2 nm in size) as a preclinical intratumorally injectable agent for NIR-II/SWIR (1,000 to 3,000 nm) fluorescence imaging-guided tumor resection. The AuPC clusters were found to be uniformly distributed in the 4T1 murine breast cancer tumor upon intratumor (i.t.) injection. The phosphocholine coating afforded highly stealth clusters, allowing a high percentage of AuPC to fill the tumor interstitial fluid space homogeneously. Intra-operative surgical navigation guided by imaging of the NIR-II fluorescence of AuPC allowed for complete and non-excessive tumor resection. The AuPC in tumors were also employed as a photothermal therapy (PTT) agent to uniformly heat up and eradicate tumors. Further, we performed in vivo NIR-IIb (1,500 to 1,700 nm) molecular imaging of the treated tumor using a quantum dot-Annexin V (QD-P3-Anx V) conjugate, revealing cancer cell apoptosis following PTT. The therapeutic functionalities of AuPC clusters combined with rapid renal excretion, high biocompatibility, and safety make them promising for clinical translation.

Recent nanotheranostic approaches in cancer research

Humanity is suffering from cancer which has become a root cause of untimely deaths of individuals around the globe in the recent past. Nanotheranostics integrates therapeutics and diagnostics to monitor treatment response and enhance drug efficacy and safety. We hereby propose to discuss all recent cancer imaging and diagnostic tools, the mechanism of targeting tumor cells, and current nanotheranostic platforms available for cancer. This review discusses various nanotheranostic agents and novel molecular imaging tools like MRI, CT, PET, SPEC, and PAT used for cancer diagnostics. Emphasis is given to gold nanoparticles, silica, liposomes, dendrimers, and metal-based agents. We also highlight the mechanism of targeting the tumor cells, and the limitations of different nanotheranostic agents in the field of research for cancer treatment. Due to the complexity in this area, multifunctional and hybrid nanoparticles functionalized with targeted moieties or anti-cancer drugs show the best feature for theranostics that enables them to work on carrying and delivering active materials to the desired area of the requirement for early detection and diagnosis. Non-invasive imaging techniques have a specificity of receptor binding and internalization processes of the nanosystems within the cancer cells. Nanotheranostics may provide the appropriate medicine at the appropriate dose to the appropriate patient at the appropriate time.

Sprayable tissue adhesive microparticle-magnetic nanoparticle composites for local cancer hyperthermia

Incomplete removal of early-stage gastrointestinal cancers by endoscopic treatments often leads to recurrence induced by residual cancer cells. To completely remove or kill cancer tissues and cells and prevent recurrence, chemotherapy, radiotherapy, and hyperthermia using biomaterials with drugs or nanomaterials are usually administered following endoscopic treatments. However, there are few biomaterials that can be applied using endoscopic devices to locally kill cancer tissues and cells. We previously reported that decyl group-modified Alaska pollock gelatin-based microparticles (denoted C10MPs) can adhere to gastrointestinal tissues under wet conditions through the formation of a colloidal gel driven by hydrophobic interactions. In this study, we combined C10MPs with superparamagnetic iron oxide nanoparticles (SPIONs) to develop a sprayable heat-generating nanomaterial (denoted SP/C10MP) for local hyperthermia of gastrointestinal cancers. The rheological property, tissue adhesion strength, burst strength, and underwater stability of SP/C10MP were improved through decyl group modification and SPION addition. Moreover, SP/C10MP that adhered to gastrointestinal tissues formed a colloidal gel, which locally generated heat in response to an alternating magnetic field. SP/C10MP successfully killed cancer tissues and cells in colon cancer-bearing mouse models in vitro and in vivo. Therefore, SP/C10MP has the potential to locally kill residual cancer tissues and cells after endoscopic treatments.

Laser-induced vapor nanobubbles for B16-F10 melanoma cell killing and intracellular delivery of chemotherapeutics

The most lethal form of skin cancer is cutaneous melanoma, a tumor that develops in the melanocytes, which are found in the epidermis. The treatment strategy of melanoma is dependent on the stage of the disease and often requires combined local and systemic treatment. Over the years, systemic treatment of melanoma has been revolutionized and shifted toward immunotherapeutic approaches. Phototherapies like photothermal therapy (PTT) have gained considerable attention in the field, mainly because of their straightforward applicability in melanoma skin cancer, combined with the fact that these strategies are able to induce immunogenic cell death (ICD), linked with a specific antitumor immune response. However, PTT comes with the risk of uncontrolled heating of the surrounding healthy tissue due to heat dissipation. Here, we used pulsed laser irradiation of endogenous melanin-containing melanosomes to induce cell killing of B16-F10 murine melanoma cells in a non-thermal manner. Pulsed laser irradiation of the B16-F10 cells resulted in the formation of water vapor nanobubbles (VNBs) around endogenous melanin-containing melanosomes, causing mechanical cell damage. We demonstrated that laser-induced VNBs are able to kill B16-F10 cells with high spatial resolution. When looking more deeply into the cell death mechanism, we found that a large part of the B16-F10 cells succumbed rapidly after pulsed laser irradiation, reaching maximum cell death already after 4 h. Practically all necrotic cells demonstrated exposure of phosphatidylserine on the plasma membrane and caspase-3/7 activity, indicative of regulated cell death. Furthermore, calreticulin, adenosine triphosphate (ATP) and high-mobility group box 1 (HMGB1), three key damage-associated molecular patterns (DAMPs) in ICD, were found to be exposed from B16-F10 cells upon pulsed laser irradiation to an extent that exceeded or was comparable to the bona fide ICD-inducer, doxorubicin. Finally, we could demonstrate that VNB formation from melanosomes induced plasma membrane permeabilization. This allowed for enhanced intracellular delivery of bleomycin, an ICD-inducing chemotherapeutic, which further boosted cell death with the potential to improve the systemic antitumor immune response.

Tumor-tropic Trojan horses: Using mesenchymal stem cells as cellular nanotheranostics

Various classes of nanotheranostics have been developed for enhanced tumor imaging and therapy. However, key limitations for a successful use of nanotheranostics include their targeting specificity with limited off-site tissue accumulation as well as their distribution and prolonged retention throughout the entire tumor. Due to their inherent tumor-tropic properties, the use of mesenchymal stem cells (MSCs) as a "Trojan horse" has recently been proposed to deliver nanotheranostics more effectively. This review discusses the current status of "cellular nanotheranostics" for combined (multimodal) imaging and therapy in preclinical cancer models. Emphasis is placed on the limited knowledge of the signaling pathways and molecular mechanisms of MSC tumor-tropism, and how such information may be exploited to engineer MSCs in order to further improve tumor homing and nanotheranostic delivery using image-guided procedures.

Utilizing peptide-anchored DNA templates for novel programmable nanoparticle assemblies in biological macromolecules: A review

Biological macromolecules such as proteins and DNA are known to self-assemble into various structural moieties with distinct functions. While nucleic acids are the structural building blocks, peptides exemplify diversity as tailorable biochemical units. Thus, combining the scaffold properties of the biomacromolecule DNA and the functionality of peptides could evolve into a powerful method to obtain tailorable nano assemblies. In this review, we discuss the assembly of non-DNA-coated colloidal NPs on DNA/peptide templates using functional anchors. We begin with strategies for directly attaching metallic NPs to DNA templates to ascertain the functional role of DNA as a scaffold. Followed by methods to assemble peptides onto DNA templates to emphasize the functional versatility of biologically abundant DNA-binding peptides. Next, we focus on studies corroborating peptide self-assembling into macromolecular templates onto which NPs can attach to emphasize the properties of NP-binding peptides. Finally, we discuss the assembly of NPs on a DNA template with a focus on the bifunctional DNA-binding peptides with NP-binding affinity (peptide anchors). This review aims to highlight the immense potential of combining the functional power of DNA scaffolds and tailorable functionalities of peptides for NP assembly and the need to utilize them effectively to obtain tailorable hierarchical NP assemblies.

Carbohydrate polymers-based surface modified nano delivery systems for enhanced target delivery to colon cancer - A review

Carbohydrate polymers-based surface-modified nano-delivery systems have gained significant attention in recent years for enhancing targeted delivery to colon cancer. These systems leverage carbohydrate polymers' unique properties, such as biocompatibility, biodegradability, and controlled release. These properties make them suitable candidates for drug delivery applications. Nano-delivery systems loaded with bioactive compounds are well-studied for targeted colorectal cancer delivery. However, those drugs' target reach is still limited in various nano-delivery systems. To overcome this limitation, surface modification of nanoparticles with carbohydrate polymers like chitosan, pectin, alginate, and guar gum showed enhanced target-reaching capacity along with enhanced anticancer efficacy. Recently, a chitosan-decorated PLGA nanoparticle was constructed with tannic acid and vitamin E and showed long-term release of specific targets along with higher anticancer efficacy. Similarly, Chitosan-conjugated glucuronic acid-coated silica nanoparticles loaded with capecitabine were studied against colon cancer and found to be the pH-responsive controlled release of capecitabine with higher anticancer efficacy. Surface-modified carbohydrate polymers have promising potential for improving colon cancer target delivery. By leveraging the unique properties of these polymers, such as surface modification, pH responsiveness, mucoadhesion, controlled drug release, and combination therapy, researchers are working toward developing more effective and targeted treatment strategies for colon cancer.

A new vision of photothermal therapy assisted with gold nanorods for the treatment of mammary cancers in adult female rats

Over the past decade, the therapeutic landscape has markedly changed for patients with breast cancers (BCs), yet few studies have evaluated the power of the photothermal therapy (PTT) technique. The present study aimed to assess the potency of 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary cancer treatment with this technique. In total, forty-two adult virgin female Wistar rats were categorized into seven groups, negative control, polyvinylpyrrolidone-capped gold nanorods (PVP-AuNRs) positive control (400 μL per rat ∼ 78 ppm), NIR laser irradiation 808 nm positive control with an intensity of (808 nm NIR CW diode laser, 200 mW cm-2 for 5 min), DMBA-treatment, DMBA-induced mammary cancer group treated with polyvinylpyrrolidone-capped gold nanorods, DMBA-induced mammary cancer group treated with NIR laser irradiation, and DMBA-induced mammary cancer group treated with polyvinylpyrrolidone-capped gold nanorods and NIR laser irradiation. Treatment with polyvinylpyrrolidone-capped gold nanorods and/or NIR laser irradiation was performed after three weeks of DMBA-induced mammary cancer. The mammary tumor lesions in the rat model induced with DMBA are highly invasive. Synthesis and characterization of gold nanorods (AuNRs) with an aspect ratio ranging from 2.8 to 3 were employed to validate the nanostructure and polyvinylpyrrolidone capping and their stability in absorbing near-infrared light. As a result, the therapy strategy, DMBA + PVP-AuNRs + NIR, effectively treated the tumor and halted its growth. The mammary glands were dissected and subjected to biochemical analysis for serum and tissue. Our treatment technique improved the histological aspects of mammary cancer in various forms of mammary cancer detected. Immuno-histochemical localization and TEM images supported these results reflecting the efficacy of this technique. Finally, our findings uncover for the first time the revolutionary effect of the PTT strategy using PVP-capped AuNRs in selectively destroying mammary cancer cells in rats.

Optimizing the average distance between a blue light photosensitizer and a harmonic nanoparticle for effective infrared photodynamic therapy

Photodynamic therapy can be significantly improved by techniques utilizing light windows of higher tissue penetration depths with optimally matched photoactive agents to provide deep interstitial treatment. Classical blue light photosensitizers were photodynamically activated using infrared light via coupled harmonic nanoparticles with optimized intermediary distances using spacers. Upon 800 nm pulsed laser irradiation perovskite nanoparticles with optimized coupling to either curcumin or protoporphyrin IX reduced the viability of MCF7 breast cancer cells by 73 percent and 64 percent, respectively, while exhibiting negligible dark toxicity. The findings pave the way for clinical adaptation of ease-of-synthesis photodynamically active preparations operable under deep tissue penetrating infrared lights using commonly available otherwise infrared inactive classical blue light photosensitizers.

Plasmonic Magnesium Nanoparticles Are Efficient Nanoheaters

Understanding and guiding light at the nanoscale can significantly impact society, for instance, by facilitating the development of efficient, sustainable, and/or cost-effective technologies. One emergent branch of nanotechnology exploits the conversion of light into heat, where heat is subsequently harnessed for various applications including therapeutics, heat-driven chemistries, and solar heating. Gold nanoparticles are overwhelmingly the most common material for plasmon-assisted photothermal applications; yet magnesium nanoparticles present a compelling alternative due to their low cost and superior biocompatibility. Herein, we measured the heat generated and quantified the photothermal efficiency of the gold and magnesium nanoparticle suspensions. Photothermal transduction experiments and optical and thermal simulations of different sizes and shapes of gold and magnesium nanoparticles showed that magnesium is more efficient at converting light into heat compared to gold at near-infrared wavelengths, thus demonstrating that magnesium nanoparticles are a promising new class of inexpensive, biodegradable photothermal platforms.

Theoretical and experimental study on the photothermal effect of palladium nanoparticles based on a finite element model

Palladium nanoparticles (Pd NPs) show significant promise as agents for the photothermal treatment of tumors due to their high photothermal conversion efficiency and thermal stability. theoretical calculations were conducted to investigate the electric field and solid heat conduction of Pd NPs with various sizes and particle distances, aiming to achieve the maximum photothermal conversion efficiency during laser irradiation. Subsequently, Pd NPs with optimal size and structure were synthesized. In vitro and in vivo experiments were conducted to evaluate photothermal conversion. The theoretical results indicated that a peak temperature of 90.12 °C is achieved when the side length is 30 nm with a distance of 2 nm. In vitro experiments demonstrated that the photothermal conversion efficiency of Pd NPs can reach up to 61.9%. in vivo experiments revealed that injecting Pd NPs into blood vessels can effectively reduce the number of laser pulses by 22.22%, thereby inducing obvious vasoconstriction.

Heat Transfer in Gold Interfaces Capped with Thiolated Polyethylene Glycol: A Molecular Dynamics Study

Reverse nonequilibrium molecular dynamics simulations were used to study heat transport in solvated gold interfaces which have been functionalized with a low-molecular weight thiolated polyethylene glycol (PEG). The gold interfaces studied included (111), (110), and (100) facets as well as spherical nanoparticles with radii of 10 and 20 Å. The embedded atom model (EAM) and the polarizable density-readjusted embedded atom model (DR-EAM) were implemented to determine the effect of metal polarizability on heat transport properties. We find that the interfacial thermal conductance values for thiolated PEG-capped interfaces are higher than those for pristine gold interfaces. Hydrogen bonding between the thiolated PEG and solvent differs between planar facets and the nanospheres, suggesting one mechanism for enhanced transfer of energy, while the covalent gold sulfur bond appears to create the largest barrier to thermal conduction. Through analysis of vibrational power spectra, we find an enhanced population at low-frequency heat-carrying modes for the nanospheres, which may also explain the higher mean interfacial thermal conductance (G) value.

A biodegradable "one-for-all" nanoparticle for multimodality imaging and enhanced photothermal treatment of breast cancer

Silver sulfide nanoparticles (Ag 2 S-NP) have been proposed for various optical-based biomedical applications, such as near-infrared fluorescence (NIRF) imaging, photoacoustics (PA) and photothermal therapy (PTT). However, their absorbance is relatively low in the NIR window used in these applications, and previous formulations were synthesized using toxic precursors under harsh conditions and have clearance issues due to their large size. Herein, we synthesized sub-5 nm Ag 2 S-NP and encapsulated them in biodegradable, polymeric nanoparticles (AgPCPP). All syntheses were conducted using biocompatible reagents in the aqueous phase and under ambient conditions. We found that the encapsulation of Ag 2 S-NP in polymeric nanospheres greatly increases their NIR absorbance, resulting in enhanced optical imaging and photothermal heating effects. We therefore found that AgPCPP have potent contrast properties for PA and NIRF imaging, as well as for computed tomography (CT). We demonstrated the applicability of AgPCPP nanoparticles as a multimodal imaging probe that readily improves the conspicuity of breast tumors in vivo . PTT was performed using AgPCPP with NIR laser irradiation, which led to significant reduction in breast tumor growth and prolonged survival compared to free Ag 2 S-NP. Lastly, we observed a gradual decrease in AgPCPP retention in tissues over time with no signs of acute toxicity, thus providing strong evidence of safety and biodegradability. Therefore, AgPCPP may serve as a "one-for-all" theranostic agent that degrades into small components for excretion once the diagnostic and therapeutic tasks are fulfilled, thus providing good prospects for translation to clinical use.

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Adsorption and Molecular Display of a Redox-Active Protein on Gold Nanoparticle Surfaces

Engineered gold nanoparticles (AuNPs) have great potential in many applications due to their tunable optical properties, facile synthesis, and surface functionalization via thiol chemistry. When exposed to a biological environment, NPs are coated with a protein corona that can alter the NPs' biological identity but can also affect the proteins' structures and functions. Protein disulfide isomerase (PDI) is an abundant protein responsible for the disulfide formation and isomerization that contribute to overall cell redox homeostasis and signaling. Given that AuNPs are widely employed in nanomedicine and PDI plays a functional role in various diseases, the interactions between oxidized (oPDI) and reduced (rPDI) with 50 nm citrate-coated AuNPs (AuNPs) are examined in this study using various techniques. Upon incubation, PDI adsorbs to the AuNP surface, which leads to a reduction in its enzymatic activity despite limited changes in secondary structures. Partial enzymatic digestion followed by mass spectrometry analysis shows that orientation of PDI on the NP surface is dependent on both its oxidation state and the PDI:AuNP incubation ratios.

Cellulose-Based Metallogels-Part 3: Multifunctional Materials

The incorporation of the metal phase into cellulose hydrogels, resulting in the formation of metallogels, greatly expands their application potential by introducing new functionalities and improving their performance in various fields. The unique antiviral, antibacterial, antifungal, and anticancer properties of metal and metal oxide nanoparticles (Ag, Au, Cu, CuxOy, ZnO, Al2O3, TiO2, etc.), coupled with the biocompatibility of cellulose, allow the development of composite hydrogels with multifunctional therapeutic potential. These materials can serve as efficient carriers for controlled drug delivery, targeting specific cells or pathogens, as well as for the design of artificial tissues or wound and burn dressings. Cellulose-based metallogels can be used in the food packaging industry to provide biodegradable and biocidal materials to extend the shelf life of the goods. Metal and bimetallic nanoparticles (Au, Cu, Ni, AuAg, and AuPt) can catalyze chemical reactions, enabling composite cellulose hydrogels to be used as efficient catalysts in organic synthesis. In addition, metal-loaded hydrogels (with ZnO, TiO2, Ag, and Fe3O4 nanoparticles) can exhibit enhanced adsorption capacities for pollutants, such as dyes, heavy metal ions, and pharmaceuticals, making them valuable materials for water purification and environmental remediation. Magnetic properties imparted to metallogels by iron oxides (Fe2O3 and Fe3O4) simplify the wastewater treatment process, making it more cost-effective and environmentally friendly. The conductivity of metallogels due to Ag, TiO2, ZnO, and Al2O3 is useful for the design of various sensors. The integration of metal nanoparticles also allows the development of responsive materials, where changes in metal properties can be exploited for stimuli-responsive applications, such as controlled release systems. Overall, the introduction of metal phases augments the functionality of cellulose hydrogels, expanding their versatility for diverse applications across a broad spectrum of industries not envisaged during the initial research stages.

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.

Photo-Chemical Stimulation of Neurons with Organic Semiconductors

Recent advances in light-responsive materials enabled the development of devices that can wirelessly activate tissue with light. Here it is shown that solution-processed organic heterojunctions can stimulate the activity of primary neurons at low intensities of light via photochemical reactions. The p-type semiconducting polymer PDCBT and the n-type semiconducting small molecule ITIC (a non-fullerene acceptor) are coated on glass supports, forming a p-n junction with high photosensitivity. Patch clamp measurements show that low-intensity white light is converted into a cue that triggers action potentials in primary cortical neurons. The study shows that neat organic semiconducting p-n bilayers can exchange photogenerated charges with oxygen and other chemical compounds in cell culture conditions. Through several controlled experimental conditions, photo-capacitive, photo-thermal, and direct hydrogen peroxide effects on neural function are excluded, with photochemical delivery being the possible mechanism. The profound advantages of low-intensity photo-chemical intervention with neuron electrophysiology pave the way for developing wireless light-based therapy based on emerging organic semiconductors.

Porphyrin as a Cryoprotectant for Graphene Oxide-Coated Gold Nanorods to Produce Conjugated Product with Improved Stability and Opto-Phototherapeutic Properties

Graphene oxide (GO) as a coating material for gold nanorods (AuNRs) has gained interest in reducing toxicity and improving the photothermal profiling of AuNRs. However, there is still a challenge regarding the storage of colloidal suspensions of GO-coated AuNRs (GO@AuNRs). Hence, the conjugation of GO@AuNRs to meso-tetra-(4-sulfonatophenyl)porphyrin (TPPS4), an anionic water-soluble porphyrin, has been reported to enhance their re-dispensability and improve their phototherapeutic properties. The AuNRs and GO were synthesised using seed-mediated and Hummers' methods, respectively. The GO@AuNRs were conjugated to TPPS4 and characterised using ultraviolet-visible-near-infrared (UV-Vis-NIR) spectroscopy, zeta analyser, dynamic light scattering (DLS), photoluminescence spectroscopy (PL), x-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and Fourier-transform infrared spectroscopy (FTIR) before freeze-drying. The results showed that the AuNRs were sandwiched between GO and TPPS4. After freeze-drying, the freeze-dried conjugate was dispensed in deionised water without adding cryoprotectants and its properties were compared to those of the unfreeze-dried conjugate. The results showed that the freeze-dried conjugate contained similar optical properties to the unfreeze-dried conjugate. However, the bare GO@AuNRs showed a change in the optical properties after freeze-drying. These results revealed that porphyrin is an excellent additive to reduce the freeze-drying stress tolerance of GO@AuNRs. The freeze-dried conjugate also showed both singlet oxygen and photothermal properties of GO@AuNRs and porphyrin. These results indicated that the freeze-dried conjugate is a promising dual photodynamic and photothermal agent, and porphyrin can act as a cryoprotectant.

GM-CSF augmented the photothermal immunotherapeutic outcome of self-driving gold nanoparticles against a mouse CT-26 colon tumor model

BACKGROUND

Hypoxia is a frequent characteristic observed in solid tumors and is strongly associated with tumor metastasis, angiogenesis, and drug resistance. While the vasculature of hypoxic tumor tissues poses obstacles to the efficient administration of conventional drugs, it may prove advantageous in sustaining hyperthermia. Photothermal therapy (PTT) offers a promising treatment strategy that utilizes the activation of photosensitizers to produce heat, thus facilitating the selective ablation of tumor tissues.

METHOD

To enhance the accumulation of photothermal agents in tumor tissue and improve the effectiveness of PTT, we developed a self-propelled hybrid called Bif@PAu-NPs. This hybrid consists of polydopamine (PDA)-coated gold nanoparticles (Au-NPs) loaded onto the anaerobic Bifidobacterium infantis (Bif).

RESULTS

The Bif@PAu-NPs actively aggregated at the tumor site because the ability of Bif can target hypoxic regions, and PAu-NPs achieved precise PTT due to their high photothermal conversion efficiency (η = 67.8%). The tumor tissues were ablated by PTT, resulting in the release of antigens through immunogenic cell death (ICD), which stimulates an immune response. The inclusion of GM-CSF enhanced the immune response by recruiting dendritic cells and initiating long-term anti-tumor immunity.

CONCLUSION

The Bif@PAu-NPs hybrid effectively suppressed the growth of both primary tumors and re-challenged tumors. The utilization Bif@PAu-NPs in conjunction with GM-SCF exhibits great potential as a photothermal-immunotherapeutic strategy for precisely treating solid tumors. In this study, the bacterial Bif@PAu-NPs biohybrid is exploited the self-driving ability of anaerobic Bifidobacterium infantis to deliver polydopamine-modified gold nanoparticles to hypoxic region of tumor. Under irradiation with 808 nm NIR laser, the hybrid exerts precise photothermal therapy to stimulate the immune response, which is further enhanced by GM-CSF, leading to recruitment of dendritic cells and initiation of a long-term anti-tumor immunity remember to prevent tumor recurrence.

Encapsulins: Nanotechnology's future in a shell

Encapsulins, virus capsid-like bacterial nanocompartments have emerged as promising tools in medicine, imaging, and material sciences. Recent work has shown that these protein-bound icosahedral 'organelles' possess distinct properties that make them exceptionally usable for nanotechnology applications. A key factor contributing to their appeal is their ability to self-assemble, coupled with their capacity to encapsulate a wide range of cargos. Their genetic manipulability, stability, biocompatibility, and nano-size further enhance their utility, offering outstanding possibilities for practical biotechnology applications. In particular, their amenability to engineering has led to their extensive modification, including the packaging of non-native cargos and the utilization of the shell surface for displaying immunogenic or targeting proteins and peptides. This inherent versatility, combined with the ease of expressing encapsulins in heterologous hosts, promises to provide broad usability. Although mostly not yet commercialized, encapsulins have started to demonstrate their vast potential for biotechnology, from drug delivery to biofuel production and the synthesis of valuable inorganic materials. In this review, we will initially discuss the structure, function and diversity of encapsulins, which form the basis for these emerging applications, before reviewing ongoing practical uses and highlighting promising applications in medicine, engineering and environmental sciences.

Heavy Metal-Based Nanoparticles as High-Performance X-ray Computed Tomography Contrast Agents

X-ray computed tomography (CT) contrast agents offer extremely valuable tools and techniques in diagnostics via contrast enhancements. Heavy metal-based nanoparticles (NPs) can provide high contrast in CT images due to the high density of heavy metal atoms with high X-ray attenuation coefficients that exceed that of iodine (I), which is currently used in hydrophilic organic CT contrast agents. Nontoxicity and colloidal stability are vital characteristics in designing heavy metal-based NPs as CT contrast agents. In addition, a small particle size is desirable for in vivo renal excretion. In vitro phantom imaging studies have been performed to obtain X-ray attenuation efficiency, which is a critical parameter for CT contrast agents, and the imaging performance of CT contrast agents has been demonstrated via in vivo experiments. In this review, we focus on the in vitro and in vivo studies of various heavy metal-based NPs in pure metallic or chemical forms, including Au, Pt, Pd, Ag, Ce, Gd, Dy, Ho, Yb, Ta, W, and Bi, and provide an outlook on their use as high-performance CT contrast agents.

Functional material-mediated wireless physical stimulation for neuro-modulation and regeneration

Nerve injuries and neurological diseases remain intractable clinical challenges. Despite the advantages of stem cell therapy in treating neurological disorders, uncontrollable cell fates and loss of cell function in vivo are still challenging. Recently, increasing attention has been given to the roles of external physical signals, such as electricity and ultrasound, in regulating stem cell fate as well as activating or inhibiting neuronal activity, which provides new insights for the treatment of neurological disorders. However, direct physical stimulations in vivo are short in accuracy and safety. Functional materials that can absorb energy from a specific physical field exerted in a wireless way and then release another localized physical signal hold great advantages in mediating noninvasive or minimally invasive accurate indirect physical stimulations to promote the therapeutic effect on neurological disorders. In this review, the mechanism by which various physical signals regulate stem cell fate and neuronal activity is summarized. Based on these concepts, the approaches of using functional materials to mediate indirect wireless physical stimulation for neuro-modulation and regeneration are systematically reviewed. We expect that this review will contribute to developing wireless platforms for neural stimulation as an assistance for the treatment of neurological diseases and injuries.