Synthesis and characterization of small-sized gold nanoparticles coated by bovine serum albumin (BSA) for cancer photothermal therapy

Synchronized Chemotherapy/Photothermal Therapy/Sonodynamic Therapy of Human Triple-Negative and Estrogen Receptor-Positive Breast Cancer Cells Using a Doxorubicin-Gold Nanoclusters-Albumin Nanobioconjugate

OBJECTIVE

Novel strategies for treating triple-negative breast cancer (TNBC) are ongoing because of the lack of standard-of-care treatment. Nanoframed materials with a protein pillar are considered a valuable tool for designing multigoals of energy-absorbing/medication cargo and are a bridge to cross-conventional treatment strategies.

METHODS

Nanobioconjugates of gold nanoclusters-bovine serum albumin (AuNCs-BSA) and doxorubicin-AuNCs-BSA (Dox-AuNCs-BSA) were prepared and employed as a simultaneous double photosensitizer/sonosensitizer and triple chemotherapeutic/photosensitizer/sonosensitizer, respectively.

RESULTS

The highly stable AuNCs-BSA and Dox-AuNCs-BSA have ζ potentials of -29 and -18 mV, respectively, and represent valuable photothermal and sonodynamic activities for the combination of photothermal therapy and sonodynamic therapy (PTT/SDT) and synchronized chemotherapy/photothermal therapy/sonodynamic therapy (CTX/PTT/SDT) of human TNBC cells, respectively. The efficiency of photothermal conversion of AuNCs-BSA was calculated to be a promising value of 32.9%. AuNCs-BSA and Dox-AuNCs-BSA were activated on either laser light irradiation or ultrasound exposure with the highest efficiency on the combination of both types of radiation. CTX/PTT/SDT of MCF-7 and MDA-MB-231 breast cancer cell lines by Dox-AuNCs-BSA were evaluated with the MTT cell proliferation assay and found to progress synergistically.

CONCLUSION

Results of the MTT assay, detection of the generation of intracellular reactive oxygen species and occurrence of apoptosis in the cells confirmed that CTX/PTT/SDT by Dox-AuNCs-BSA was attained with lower needed doses of the drug and improved tumor cell ablation, which would result in the enhancement of therapeutic efficacy and overcoming of therapeutic resistance.

Use of Albumin for Drug Delivery as a Diagnostic and Therapeutic Tool

Drug delivery is an important topic that has attracted the attention of researchers in recent years. Albumin nanoparticles play a significant role in drug delivery as a carrier due to their unique characteristics. Albumin is non-toxic, biocompatible, and biodegradable. Its structure is such that it can interact with different drugs, which makes the treatment of the disease faster and also reduces the side effects of the drug. Albumin nanoparticles can be used in the diagnosis and treatment of many diseases, including cancer, diabetes, Alzheimer's, etc. These nanoparticles can connect to some compounds, such as metal nanoparticles, antibodies, folate, etc. and create a powerful nanostructure for drug delivery. In this paper, we aim to investigate albumin nanoparticles in carrier format for drug delivery application. In the beginning, different types of albumin and their preparation methods were discussed, and then albumin nanoparticles were discussed in detail in diagnosing and treating various diseases.

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.

Application of Nanoparticles in Cancer Treatment: A Concise Review

Timely diagnosis and appropriate antitumoral treatments remain of utmost importance, since cancer remains a leading cause of death worldwide. Within this context, nanotechnology offers specific benefits in terms of cancer therapy by reducing its adverse effects and guiding drugs to selectively target cancer cells. In this comprehensive review, we have summarized the most relevant novel outcomes in the range of 2010-2023, covering the design and application of nanosystems for cancer therapy. We have established the general requirements for nanoparticles to be used in drug delivery and strategies for their uptake in tumor microenvironment and vasculature, including the reticuloendothelial system uptake and surface functionalization with protein corona. After a brief review of the classes of nanovectors, we have covered different classes of nanoparticles used in cancer therapies. First, the advances in the encapsulation of drugs (such as paclitaxel and fisetin) into nanoliposomes and nanoemulsions are described, as well as their relevance in current clinical trials. Then, polymeric nanoparticles are presented, namely the ones comprising poly lactic-co-glycolic acid, polyethylene glycol (and PEG dilemma) and dendrimers. The relevance of quantum dots in bioimaging is also covered, namely the systems with zinc sulfide and indium phosphide. Afterwards, we have reviewed gold nanoparticles (spheres and anisotropic) and their application in plasmon-induced photothermal therapy. The clinical relevance of iron oxide nanoparticles, such as magnetite and maghemite, has been analyzed in different fields, namely for magnetic resonance imaging, immunotherapy, hyperthermia, and drug delivery. Lastly, we have covered the recent advances in the systems using carbon nanomaterials, namely graphene oxide, carbon nanotubes, fullerenes, and carbon dots. Finally, we have compared the strategies of passive and active targeting of nanoparticles and their relevance in cancer theranostics. This review aims to be a (nano)mark on the ongoing journey towards realizing the remarkable potential of different nanoparticles in the realm of cancer therapeutics.

Functionalized Metal Nanoparticles in Cancer Therapy

Currently, there are many studies on the application of nanotechnology in therapy. Metallic nanoparticles are promising nanomaterials in cancer therapy; however, functionalization of these nanoparticles with biomolecules has become relevant as their effect on cancer cells is considerably increased by photothermal and photodynamic therapies, drug nanocarriers, and specificity by antibodies, resulting in new therapies that are more specific against different types of cancer. This review describes studies on the effect of functionalized palladium, gold, silver and platinum nanoparticles in the treatment of cancer, these nanoparticles themselves show an anticancer effect. This effect is further enhanced when the NPs are functionalized with either antibodies, DNA, RNA, peptides, proteins, or folic acid and other molecules. These NPs can penetrate the cell and accumulate in the tumor tissue, resulting in a cytotoxic effect through the generation of ROS, the induction of apoptosis, cell cycle arrest, DNA fragmentation, and a photothermal effect. NP-based therapy is a new strategy that can be used synergistically with chemotherapy and radiotherapy to achieve more effective therapies and reduce side effects.

Biomimetic Keratin-Coated Gold Nanoparticles for Photo-Thermal Therapy in a 3D Bioprinted Glioblastoma Tumor Model

Before entering human clinical studies to evaluate their safety and effectiveness, new drugs and novel medical treatments are subject to extensive animal testing that are expensive and time-consuming. By contrast, advanced technologies enable the development of animal-free models that allow the efficacy of innovative therapies to be studied without sacrificing animals, while providing helpful information and details. We report on the powerful combination of 3D bioprinting (3DB) and photo-thermal therapy (PTT) applications. To this end, we realize a 3DB construct consisting of glioblastoma U87-MG cells in a 3D geometry, incorporating biomimetic keratin-coated gold nanoparticles (Ker-AuNPs) as a photo-thermal agent. The resulting plasmonic 3DB structures exhibit a homogeneous cell distribution throughout the entire volume while promoting the localization of Ker-AuNPs within the cells. A 3D immunofluorescence assay and transmission electron microscopy (TEM) confirm the uniform distribution of fluorescent-labeled Ker-AuNPs in the volume and their capability to enter the cells. Laser-assisted (λ = 532 nm) PTT experiments demonstrate the extraordinary ability of Ker-AuNPs to generate heating, producing the highest temperature rise of about 16 °C in less than 2 min.

Bacteria-driven hypoxia targeting delivery of chemotherapeutic drug proving outcome of breast cancer

Local hypoxia is a common feature of many solid tumors and may lead to unsatisfactory chemotherapy outcomes. Anaerobic bacteria that have an affinity to hypoxic areas can be used to achieve targeted drug delivery in tumor tissues. In this study, we developed a biocompatible bacteria/nanoparticles biohybrid (Bif@DOX-NPs) platform that employs the anaerobic Bifidobacterium infantis (Bif) to deliver adriamycin-loaded bovine serum albumin nanoparticles (DOX-NPs) into breast tumors. The Bif@DOX-NPs retained the targeting ability of B. infantis to hypoxic regions, as well as the cytotoxicity of DOX. The biohybrids were able to actively colonize the hypoxic tumors and significantly increased drug accumulation at the tumor site. The DOX concentration in the tumor masses colonized by Bif@DOX-NPs was 4 times higher than that in the free DOX-treated tumors, which significantly prolonged the median survival of the tumor-bearing mice to 69 days and reduced the toxic side-effects of DOX. Thus, anaerobic bacteria-based biohybrids are a highly promising tool for the targeted treatment of solid tumors with inaccessible hypoxic regions.

Bioinspired Nanomodification Strategies: Moving from Chemical-Based Agrosystems to Sustainable Agriculture

Agrochemicals have supported the development of the agricultural economy and national population over the past century. However, excessive applications of agrochemicals pose threats to the environment and human health. In the last decades, nanoparticles (NPs) have been a hot topic in many fields, especially in agriculture, because of their physicochemical properties. Nevertheless, the prevalent methods for fabricating NPs are uneconomical and involve toxic reagents, hindering their extensive applications in the agricultural sector. In contrast, inspired by biological exemplifications from microbes and plants, their extract and biomass can act as a reducing and capping agent to form NPs without any toxic reagents. NPs synthesized through these bioinspired routes are cost-effective, ecofriendly, and high performing. With the development of nanotechnology, biosynthetic NPs (bioNPs) have been proven to be a substitute strategy for agrochemicals and traditional NPs in heavy-metal remediation of soil, promotion of plant growth, and management of plant disease with less toxicity and higher performance. Therefore, bioinspired synthesis of NPs will be an inevitable trend for sustainable development in agricultural fields. This critical review will demonstrate the bioinspired synthesis of NPs and discuss the influence of bioNPs on agricultural soil, crop growth, and crop diseases compared to chemical NPs or agrochemicals.

Multi-Lens Arrays (MLA)-Assisted Photothermal Effects for Enhanced Fractional Cancer Treatment: Computational and Experimental Validations

Simple Summary

Colorectal cancer is one of the most common cancers and the third leading cause of cancer-related deaths in the United States. As a non- or minimally invasive cancer treatment, photothermal therapy (PTT) has been widely used to generate irreversible thermal injuries in tumors. However, conventional PTT employs an end-firing flat fiber to deliver laser energy, leading to the incomplete removal of tumor tissues due to an uneven beam distribution over the tumor surface. Multi-lens arrays (MLA) generate multiple micro-beams to uniformly distribute laser energy on the tissue surface. Therefore, the application of MLA for PTT in cancer affords a spatially enhanced distribution of micro-beams and laser-induced temperature in the tumor. The purpose of the current study is to computationally and experimentally demonstrate the therapeutic benefits of MLA-assisted fractional PTT on colorectal cancer, in comparison to flat fiber-based PTT.

Abstract

Conventional photothermal therapy (PTT) for cancer typically employs an end-firing flat fiber (Flat) to deliver laser energy, leading to the incomplete treatment of target cells due to a Gaussian-shaped non-uniform beam profile. The purpose of the current study is to evaluate the feasibility of multi-lens arrays (MLA) for enhanced PTT by delivering laser light in a fractional micro-beam pattern. Computational and experimental evaluations compare the photothermal responses of gelatin phantoms and aqueous dye solutions to irradiations with Flat and MLA. In vivo colon cancer models have been developed to validate the therapeutic capacity of MLA-assisted irradiation. MLA yields 1.6-fold wider and 1.9-fold deeper temperature development in the gelatin phantom than Flat, and temperature monitoring identified the optimal treatment condition at an irradiance of 2 W/cm² for 180 s. In vivo tests showed that the MLA group was accompanied by complete tumor eradication, whereas the Flat group yielded incomplete removal and significant tumor regrowth 14 days after PTT. The proposed MLA-assisted PTT spatially augments photothermal effects with the fractional micro-beams on the tumor and helps achieve complete tumor removal without recurrence. Further investigations are expected to optimize treatment conditions with various wavelengths and photosensitizers to warrant treatment efficacy and safety for clinical translation.

Biomimetic keratin gold nanoparticle-mediated in vitro photothermal therapy on glioblastoma multiforme

Aim: To realize and characterize a new generation of keratin-coated gold nanoparticles (Ker-AuNPs) as highly efficient photosensitive nanosized therapeutics for plasmonic photothermal (PPT) therapy. Materials & methods: The chemical, physical, morphological and photothermal properties of Ker-AuNPs are investigated using dynamic light scattering, ζ-potential, UV-Visible, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, transmission electron microscopy and high-resolution thermography. In vitro experiments are performed on a human glioblastoma cell line (i.e., U87-MG), using viability assays, transmission electron microscopy, fluorescence microscopy, cytometric analyses and PPT experiments. Results: Experiments confirm the excellent biocompatibility of Ker-AuNPs, their efficient cellular uptake and localized photothermal heating capabilities. Conclusion: The reported structural and functional properties pointed out these Ker-AuNPs as a promising new tool in the field of biocompatible photothermal agents for PPT treatments against cancer-related diseases.

Exploring the Conformation and Thermal Stability of Human Serum Albumin Corona of Ferrihydrite Nanoparticles

In the last few years, a great amount of attention has been given to nanoparticles research due to their physicochemical properties that allow their use in analytical instruments or in promising imaging applications on biological systems. The use of ferrihydrite nanoparticles (Fh-NPs) in practical applications implies a particular control of their magnetic properties, stability, biocompatibility, interaction with the surface of the target, and low toxicity. In this study, the formation and organization of human serum albumin (HSA) molecules around the simple Fh-NPs and Fh-NPs doped with Co and Cu were examined by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) in terms of morphology and particle size. The topology of all Fh-NPs shows an organized area of HSA around each type of Fh-NP. Molecular docking studies were used in order to determine the probable location of the ferrihydrite in the HSA structure. The thermal stability of these nanohybrids was further investigated by fluorimetry, using 214-Trp residue from HSA as a spectral sensor. The denaturation temperature (T_m) was determined, and stabilization of the HSA structure in the presence of Fh-NPs was discussed. This study could be a starting point for the development of different applications targeting the structure and stability of Fh-NPs complexes with proteins.

Gold Nanoparticles as Radiosensitizers in Cancer Radiotherapy

The rapid development of nanotechnology offers a variety of potential therapeutic strategies for cancer treatment. High atomic element nanomaterials are often utilized as radiosensitizers due to their unique photoelectric decay characteristics. Among them, gold nanoparticles (GNPs) are one of the most widely investigated and are considered to be an ideal radiosensitizers for radiotherapy due to their high X-ray absorption and unique physicochemical properties. Over the last few decades, multi-disciplinary studies have focused on the design and optimization of GNPs to achieve greater dosing capability and higher therapeutic effects and highlight potential mechanisms for radiosensitization of GNPs. Although the radiosensitizing potential of GNPs has been widely recognized, its clinical translation still faces many challenges. This review analyses the different roles of GNPs as radiosensitizers in cancer radiotherapy and summarizes recent advances. In addition, the underlying mechanisms of GNP radiosensitization, including physical, chemical and biological mechanisms are discussed, which may provide new directions for the optimization and clinical transformation of next-generation GNPs.

Hydrogen-Peroxide-Responsive Protein Biomimetic Nanoparticles for Photothermal-Photodynamic Combination Therapy of Melanoma

BACKGROUND AND OBJECTIVES

Recently, there has been a rapid increase in the incidences of melanoma, which represents a serious threat to human health. Generally, tumor-microenvironment-responsive nanoparticle-based photothermal-photodynamic combination therapy (PTT-PDT) is characterized by intratumoral response and tumor targeting. In this study, we designed and synthesized hydrogen-peroxide-responsive protein biomimetic nanoparticles (MnO₂ -ICG@BSA) for the treatment of melanoma.

STUDY DESIGN/MATERIALS AND METHODS

Briefly, MnO₂ -ICG@BSA was prepared using a mild protein synthesis method by loading indocyanine green (ICG) into a bovine serum albumin-manganese dioxide complex (MnO₂ @BSA); next, its characteristics were determined. In addition, in vitro biocompatibility and antitumor efficacy were assessed using the classic cell counting kit-8 assay. Moreover, in vivo high-frequency ultrasound and thermal imaging were used to evaluate the oxygen-production capacity and photothermal conversion effect of MnO₂ -ICG@BSA at the tumor site, and Singlet Oxygen Sensor Green (SOSG) was used to measure singlet oxygen levels in the tumor. The antitumor efficacy was assessed based on relative tumor size, bodyweight, survival curves, and hematoxylin and eosin staining.

RESULTS

The results showed that MnO₂ -ICG@BSA has a high photothermal conversion efficiency, a strong singlet oxygen-generation ability, and high photothermal stability. In addition, in vitro PTT-PDT experiments showed that MnO₂ -ICG@BSA has a significant inhibitory effect on the proliferation of B16F10 melanoma cells. Meanwhile, in vivo experiments showed that MnO₂ -ICG@BSA has a significant inhibitory effect on melanoma in mice. Preliminary toxicity studies indicated that MnO₂ -ICG@BSA exhibits low toxicity.

CONCLUSION

From the results, we can conclude that MnO₂ -ICG@BSA could be used in PTT-PDT to treat melanoma, making it a good candidate material for PTT-PDT. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Laser enhancement of cancer cell destruction by photothermal therapy conjugated glutathione (GSH)-coated small-sized gold nanoparticles

The current study presents the employment of glutathione (GSH)-modified small-sized gold nanoparticles (AuNPs) ~ 3 nm in photothermal therapy (PTT), to evaluate the targeting and the toxic effect of cancer rather than normal cells. GSH is pH-sensitive surfaces that exhibit a fast response to the variation in pH conditions between normal (~ 7.4) and cancer cells (6-6.5). Results showed a considerable toxic impact via GSH-AuNP accumulation in cancer cells by both green and NIR laser irradiation. A proportional relation of cellular death to AuNP concentration, exposure time, and light-to-heat conversion efficiency has been demonstrated. The small-sized GSH-AuNPs represent promising agents for developing the safety issues of photothermal cancer treatment by the selective targeting of cancer rather than normal cells, reducing the NP toxicity by their size overlapping with the renal clearance barrier of kidney filtration (~ 5.5 nm), and promoting the photothermal performance in the NIR region, in which light penetration into deep cancer regions is more interested.

Capping gold nanoparticles with albumin to improve their biomedical properties

Nanotechnology is an emerging field which has created great opportunities either through the creation of new materials or by improving the properties of existing ones. Nanoscale materials with a wide range of applications in areas ranging from engineering to biomedicine have been produced. Gold nanoparticles (AuNPs) have emerged as a therapeutic agent, and are useful for imaging, drug delivery, and photodynamic and photothermal therapy. AuNPs have the advantage of ease of functionalization with therapeutic agents through covalent and ionic binding. Combining AuNPs and other materials can result in nanoplatforms, which can be useful for biomedical applications. Biomaterials such as biomolecules, polymers and proteins can improve the therapeutic properties of nanoparticles, such as their biocompatibility, biodistribution, stability and half-life. Serum albumin is a versatile, non-toxic, stable, and biodegradable protein, in which structural domains and functional groups allow the binding and capping of inorganic nanoparticles. AuNPs coated with albumin have improved properties such as greater compatibility, bioavailability, longer circulation times, lower toxicity, and selective bioaccumulation. In the current article, we review the features of albumin, as well as its interaction with AuNPs, focusing on its biomedical applications.

Synthesis and biological evaluation of 2.4 nm thiolate-protected gold nanoparticles conjugated to Cetuximab for targeting glioblastoma cancer cells via the EGFR

Therapeutic monoclonal antibodies benefit to patients and the conjugation to gold nanoparticles (AuNPs) might bring additional activities to these macromolecules. However, the behavior of the conjugate will largely depend on the bulkiness of the AuNP and small sizes are moreover preferable for diffusion. Water-soluble thiolate-protected AuNPs having diameters of 2-3 nm can be synthesized with narrow polydispersity and can selectively react with incoming organic thiols via a S_N2-like mechanism. We therefore synthesized a mixed thionitrobenzoic acid- , thioaminobenzoic acid-monolayered AuNP of 2.4 nm in diameter and developed a site-selective conjugation strategy to link the AuNP to Cetuximab, an anti-epidermal growth factor receptor (EGFR) antibody used in clinic. The water-soluble 80 kDa AuNP was fully characterized and then reacted to the hinge area of Cetuximab, which was selectively reduced using mild concentration of TCEP. The conjugation proceeded smoothly and could be analyzed by polyacrylamide gel electrophoresis, indicating the formation of a 1:1 AuNP-IgG conjugate as the main product. When added to EGFR expressing glioblastoma cells, the AuNP-Cetuximab conjugate selectively bound to the cell surface receptor, inhibited EGFR autophosphorylation and entered into endosomes like Cetuximab. Altogether, we describe a simple and robust protocol for a site-directed conjugation of a thiolate-protected AuNP to Cetuximab, which could be easily monitored, thereby allowing to assess the quality of the product formation. The conjugated 2.4 nm AuNP did not majorly affect the biological behavior of Cetuximab, but provided it with the electronic properties of the AuNP. This offers the ability to detect the tagged antibody and opens application for targeted cancer radiotherapy.

A health concern regarding the protein corona, aggregation and disaggregation

Nanoparticle (NP)-protein complexes exhibit the "correct identity" of NP in biological media. Therefore, protein-NP interactions should be closely explored to understand and modulate the nature of NPs in medical implementations. This review focuses mainly on the physicochemical parameters such as dimension, surface chemistry, morphology of NPs, and influence of pH on the formation of protein corona and conformational changes of adsorbed proteins by different kinds of techniques. Also, the impact of protein corona on the colloidal stability of NPs is discussed. Uncontrolled protein attachment on NPs may bring unwanted impacts such as protein denaturation and aggregation. In contrast, controlled protein adsorption by optimal concentration, size, pH, and surface modification of NPs may result in potential implementation of NPs as therapeutic agents especially for disaggregation of amyloid fibrils. Also, the effect of NPs-protein corona on reducing the cytotoxicity and clinical implications such as drug delivery, cancer therapy, imaging and diagnosis will be discussed. Validated correlative physicochemical parameters for NP-protein corona formation frequently derived from protein corona fingerprints of NPs which are more valid than the parameters obtained only on the base of NP features. This review may provide useful information regarding the potency as well as the adverse effects of NPs to predict their behavior in vivo.

Performance Evaluation of Miniature Integrated Electrochemical Cells Fabricated Using LTCC Technology

Miniaturized and integrated analytical devices, including chemical sensors, are at the forefront of modern analytical chemistry. The construction of novel analytical tools takes advantage of contemporary micro- and nanotechnologies, as well as materials science and technology. Two electrochemical techniques were used in experiments: electrochemical impedance spectroscopy and cyclic voltammetry. The goal of this study was to investigate electron transfer resistance in a model solution containing Fe2+/3+ ions and protein adsorption using integrated electrochemical cells with different geometry. Tests performed at various Fe2+/3+ concentration allowed to verify that these cells work properly. The influence of bovine serum albumin adsorbing to the surface of the integrated electrochemical cells was investigated. In electrochemical impedance spectroscopy, the value of Rct increased with protein adsorption and the relative change of Rct was in range 21% to 55%. In cyclic voltammetry the decreasing amperometric response of the working electrode was used as evidence of protein adsorption on the electrode.

Biocompatible quantum dot-antibody conjugate for cell imaging, targeting and fluorometric immunoassay: crosslinking, characterization and applications

Quantum dots (QDs) are important fluorescent probes that offer great promise for bio-imaging research due to their superior optical properties. However, QDs for live cell imaging and the tracking of cells need more investigation to simplify processing procedures, improving labeling efficiency, and reducing chronic toxicity. In this study, QDs were functionalized with bovine serum albumin (BSA) via a chemical linker. Anti-human immunoglobulin antibodies were oxidized by sodium periodate to create reactive aldehyde groups for a spontaneous reaction with the amine groups of BSA-modified QDs. An antibody-labeled QD bioconjugate was characterized using agarose gel electrophoresis, dynamic light scattering, and zeta potential. Using fluorescence spectroscopy, we found that the fluorescence of QDs was retained after multiple conjugation steps. The cell-labeling function of the QD bioconjugate was confirmed using an image analyzer and confocal microscopy. The QD bioconjugate specifically targeted human immunoglobulin on the membrane surface of recombinant cells. In addition, the QD bioconjugate applied in fluorometric immunoassay was effective for the quantitative analysis of human immunoglobulin in an enzyme-linked immunosorbent assay. The developed QD bioconjugate may offer a promising platform to develop biocompatible tools to label cells and quantify antibodies in the immunoassay.

A layer-by-layer covalent strategy is developed including the modification of QDs using BSA as a stabilizing agent and then anti-human immunoglobulin antibody as a targeting moiety.

Ultra-small but ultra-effective: Folic acid-targeted gold nanoclusters for enhancement of intracranial glioma tumors' radiation therapy efficacy

The aim of the present study is to investigate folic acid and BSA decorated gold nanoclusters (FA-AuNCs) effect on the enhancement of intracranial C6 glioma tumors radiation therapy (RT) efficacy. Inductively coupled plasma optical emission spectrometry (ICP-OES) measurements exhibited about 2.5 times more FA-AuNCs uptake by C6 cancer cells (32.8 ng/10⁶ cells) than the normal cells. FA-AuNCs had significantly higher concentration in the brain tumors (8.1 μg/mg) in comparison with surrounding normal brain tissue (4.3 μg/mg). Moreover, FA-AuNCs exhibited dose enhancement factor (DEF) of 1.6. The glioma-bearing rats' survival times were almost doubled at radiation therapy + FA-AuNCs (25.0 ± 1.5 days) in comparison with no-treatment group (12.8 ± 0.7 days). The Ki-67 labeling index was 48.89% ± 9.93 for control, 29.98% ± 8.32 for RT, and 11.53% ± 7.65 for RT + FA-AuNCs. Therefore, FA-AuNCs can be effective radiosensitizers for intracranial glioma tumors RT.

Fabrication of Chlorophyll-Incorporated Nanogels for Potential Applications in Photothermal Cancer Therapy

Nanogels have been widely used in biomedical applications, such as carriers for hyperthermia cancer treatment, drug delivery, and imaging. Owing to the enhanced permeability and retention effect, nanogels have shown a great potential in cancer therapy. In this study, sodium copper chlorophyllin (SCC), a low cytotoxicity and biodegradable photothermal agent, was copolymerized with a nanogel of N-[3-(dimethylamino)propyl]methacrylamide. The nanogels could produce heat under exposure to a green laser with a 532 nm wavelength. The positively charged nature of the nanogels enhanced the endocytosis of the nanogels. The cell mortality was greatly enhanced with the treatment of the SCC-containing nanogels and green light illumination. Our results suggest the potential of SCC-containing nanogels in photothermal cancer therapy.

AS1411 aptamer-targeted gold nanoclusters effect on the enhancement of radiation therapy efficacy in breast tumor-bearing mice

AIM

Herein, the AS1411 aptamer-targeted ultrasmall gold nanoclusters (GNCs) were assessed at different aspects as a radiosensitizer.

MATERIALS & METHODS

AS1411 aptamer-conjugated gold nanoclusters (Apt-GNCs) efficacy was evaluated at cancer cells targeting, radiosensitizing effect, tumor targeting, and biocompatibility in breast tumor-bearing mice.

RESULTS

Flow cytometry and fluorescence microscopy exhibited more cellular uptake for Apt-GNCs in comparison with GNCs. In addition, inductively coupled plasma optical emission spectrometry results demonstrated its effective tumor targeting as the tumors' gold content for GNCs and Apt-GNCs were 8.53 and 15.33 μg/g, respectively. Apt-GNCs significantly enhanced radiotherapy efficacy as mean tumors' volume decreased about 39% and 9 days increase in the mice survival was observed. Both GNCs and Apt-GNCs were biocompatible.

CONCLUSION

The Apt-GNCs is a novel and efficient  radiosensitizer.

Gold nanoparticles-mediated photothermal therapy and immunotherapy

Cancer has been a significant threat to human health with more than eight million deaths each year in the world. Therefore, there is a significant need for novel technologies to effectively treat cancer and ultimately reduce cancer recurrences, treatment costs, number of radical cystectomies and mortality. A promising therapeutic platform for cancer is offered by nanoparticle-mediated therapy. This review highlights the development and applications of various nanoparticle platforms for photo-induced hyperthermia and immunotherapy. Taking advantage of gold's high biocompatibility, gold nanoparticles (GNPs) can be injected intravenously and accumulate preferentially in cancer cells due to the enhanced permeability and retention effect. Various gold nanoplatforms including nanospheres, nanoshells, nanorods, nanocages and nanostars have been used for effective photothermal treatment of various cancers. GNPs have also been used in immunotherapies, involving cancer antigen and immune adjuvant delivery as well as combination therapies with photothermal therapy. Among GNPs platforms, gold nanostars (GNS) have great therapeutic potential due to their unique star-shaped geometry that dramatically enhances light absorption and provides high photon-to-heat conversion efficiency due to the plasmonic effect. This photothermal process can be exploited to specifically ablate tumors and, more importantly, to amplify the antitumor immune response following the highly immunogenic thermal death of cancer cells. GNS-mediated photothermal therapy combined with checkpoint immunotherapy has been found to reverse tumor-mediated immunosuppression, thereby leading to the treatment of not only primary tumors but also cancer metastasis, as well as to induce effective long-lasting immunity, in other words, an anticancer ‘vaccine’ effect.