Biocompatible Chitosan Oligosaccharide Modified Gold Nanorods as Highly Effective Photothermal Agents for Ablation of Breast Cancer Cells

Chitosan- and hyaluronic acid-based nanoarchitectures in phototherapy: Combination cancer chemotherapy, immunotherapy and gene therapy

Cancer phototherapy has been introduced as a new potential modality for tumor suppression. However, the efficacy of phototherapy has been limited due to a lack of targeted delivery of photosensitizers. Therefore, the application of biocompatible and multifunctional nanoparticles in phototherapy is appreciated. Chitosan (CS) as a cationic polymer and hyaluronic acid (HA) as a CD44-targeting agent are two widely utilized polymers in nanoparticle synthesis and functionalization. The current review focuses on the application of HA and CS nanostructures in cancer phototherapy. These nanocarriers can be used in phototherapy to induce hyperthermia and singlet oxygen generation for tumor ablation. CS and HA can be used for the synthesis of nanostructures, or they can functionalize other kinds of nanostructures used for phototherapy, such as gold nanorods. The HA and CS nanostructures can combine chemotherapy or immunotherapy with phototherapy to augment tumor suppression. Moreover, the CS nanostructures can be functionalized with HA for specific cancer phototherapy. The CS and HA nanostructures promote the cellular uptake of genes and photosensitizers to facilitate gene therapy and phototherapy. Such nanostructures specifically stimulate phototherapy at the tumor site, with particle toxic impacts on normal cells. Moreover, CS and HA nanostructures demonstrate high biocompatibility for further clinical applications.

NIR-Responsive injectable hydrogel cross-linked by homobifunctional PEG for photo-hyperthermia of melanoma, antibacterial wound healing, and preventing post-operative adhesion

Current therapeutic approaches for skin cancer face significant challenges, including wound infection, delayed skin regeneration, and tumor recurrence. To overcome these challenges, an injectable adhesive near-infrared (NIR)-responsive hydrogel with time-dependent enhancement in viscosity is developed for combined melanoma therapy and antibacterial wound healing acceleration. The multifunctional hydrogel is prepared through the chemical crosslinking between poly(methyl vinyl ether-alt-maleic acid) and gelatin, followed by the incorporation of CuO nanosheets and allantoin. The synergistic inherent antibacterial potential of CuO nanosheets, the regenerative and smoothing effect of allantoin, the extracellular matrix-mimicking effect of gelatin, and the desirable swelling behavior of the hydrogel results in fast wound recovery after photothermal ablation of the tumor. Additionally, the hydrogel can serve as an alternative to sutures owing to its tissue adhesiveness ability, which can further render it the merits for accelerated repair of abdominal lesions while acting as a biocompatible barrier to prevent peritoneal adhesion.

Hyaluronic acid-functionalized graphene-based nanohybrids for targeted breast cancer chemo-photothermal therapy

Nanomaterials' application in cancer therapy has been driven by their ability to encapsulate chemotherapeutic drugs as well as to reach the tumor site. Nevertheless, nanomedicines' translation has been limited due to their lack of specificity towards cancer cells. Although the nanomaterials' surface can be coated with targeting ligands, such has been mostly achieved through non-covalent functionalization strategies that are prone to premature detachment. Notwithstanding, cancer cells often establish resistance mechanisms that impair the effect of the loaded drugs. This bottleneck may be addressed by using near-infrared (NIR)-light responsive nanomaterials. The NIR-light triggered hyperthermic effect generated by these nanomaterials can cause irreversible damage to cancer cells or sensitize them to chemotherapeutics' action. Herein, a novel covalently functionalized targeted NIR-absorbing nanomaterial for cancer chemo-photothermal therapy was developed. For such, dopamine-reduced graphene oxide nanomaterials were covalently bonded with hyaluronic acid, and then loaded with doxorubicin (DOX/HA-DOPA-rGO). The produced nanomaterials showed suitable physicochemical properties, high encapsulation efficiency, and photothermal capacity. The in vitro studies revealed that the nanomaterials are cytocompatible and that display an improved uptake by the CD44-overexpressing breast cancer cells. Importantly, the combination of DOX/HA-DOPA-rGO with NIR light reduced breast cancer cells' viability to just 23 %, showcasing their potential chemo-photothermal therapy.

Chitosan-functionalized bioplatforms and hydrogels in breast cancer: immunotherapy, phototherapy and clinical perspectives

Breast cancer is the most common and malignant tumor among women. Chitosan (CS)-based nanoparticles have been introduced into breast cancer therapy as a way to increase the targeted delivery of drugs and genes to the tumor site. CS nanostructures suppress tumorigenesis by enhancing both the targeted delivery of cargo (drug and gene) and its accumulation in tumor cells. The tumor cells internalize CS-based nanoparticles through endocytosis. Moreover, chitosan nanocarriers can also induce phototherapy-mediated tumor ablation. Smart and multifunctional types of CS nanoparticles, including pH-, light- and redox-responsive nanoparticles, can be used to improve the potential for breast cancer removal. In addition, the acceleration of immunotherapy by CS nanoparticles has also been achieved, and there is potential to develop CS-nanoparticle hydrogels that can be used to suppress tumorigenesis.

Biocompatible Calcium Ion-Doped Magnesium Ferrite Nanoparticles as a New Family of Photothermal Therapeutic Materials for Cancer Treatment

Novel biocompatible and efficient photothermal (PT) therapeutic materials for cancer treatment have recently garnered significant attention, owing to their effective ablation of cancer cells, minimal invasiveness, quick recovery, and minimal damage to healthy cells. In this study, we designed and developed calcium ion-doped magnesium ferrite nanoparticles (Ca²⁺-doped MgFe₂O₄ NPs) as novel and effective PT therapeutic materials for cancer treatment, owing to their good biocompatibility, biosafety, high near-infrared (NIR) absorption, easy localization, short treatment period, remote controllability, high efficiency, and high specificity. The studied Ca²⁺-doped MgFe₂O₄ NPs exhibited a uniform spherical morphology with particle sizes of 14.24 ± 1.32 nm and a strong PT conversion efficiency (30.12%), making them promising for cancer photothermal therapy (PTT). In vitro experiments showed that Ca²⁺-doped MgFe₂O₄ NPs had no significant cytotoxic effects on non-laser-irradiated MDA-MB-231 cells, confirming that Ca²⁺-doped MgFe₂O₄ NPs exhibited high biocompatibility. More interestingly, Ca²⁺-doped MgFe₂O₄ NPs exhibited superior cytotoxicity to laser-irradiated MDA-MB-231 cells, inducing significant cell death. Our study proposes novel, safe, high-efficiency, and biocompatible PT therapeutics for treating cancers, opening new vistas for the future development of cancer PTT.

Multifunctional targeted solid lipid nanoparticles for combined photothermal therapy and chemotherapy of breast cancer

Photothermal therapy has emerged as a new promising strategy for the management of cancer, either alone or combined with other therapeutics, such as chemotherapy. The use of nanoparticles for multimodal therapy can improve treatment performance and reduce drug doses and associated side effects. Here we propose the development of a novel multifunctional nanosystem based on solid lipid nanoparticles co-loaded with gold nanorods and mitoxantrone and functionalized with folic acid for dual photothermal therapy and chemotherapy of breast cancer. Nanoparticles were produced using an economically affordable method and presented suitable physicochemical properties for tumor passive accumulation. Upon Near-Infrared irradiation (808 nm, 1.7 W cm^-2, 5 min), nanoparticles could effectively mediate a temperature increase of >20 °C. Moreover, exposure to light resulted in an enhanced release of Mitoxantrone. Furthermore, nanoparticles were non-hemolytic and well tolerated by healthy cells even at high concentrations. The active targeting strategy was found to be successful, as shown by the greater accumulation of the functionalized nanoparticles in MCF-7 cells. Finally, the combined effects of chemotherapy, light-induced drug release and photothermal therapy significantly enhanced breast cancer cell death. Overall, these results demonstrate that the developed lipid nanosystem is an efficient vehicle for breast cancer multimodal therapy.

L-Lysine-Modified pNIPAm-co-GMA Copolymer Hydrogel for pH- and Temperature-Responsive Drug Delivery and Fluorescence Imaging Applications

The development of dual-stimuli-responsive hydrogels attracts much research interest owing to its unique stimuli-responsive characteristics. In this study, a poly-N-isopropyl acrylamide-co-glycidyl methacrylate-based copolymer was synthesized by incorporating N-isopropyl acrylamide (NIPAm) and a glycidyl methacrylate (GMA) monomer. The synthesized copolymer, pNIPAm-co-GMA was further modified with L-lysine (Lys) functional units and further conjugated with fluorescent isothiocyanate (FITC) to produce a fluorescent copolymer pNIPAAm-co-GMA-Lys hydrogel (HG). The in vitro drug loading and dual pH- and temperature-stimuli-responsive drug release behavior of the pNIPAAm-co-GMA-Lys HG was investigated at different pH (pH 7.4, 6.2, and 4.0) and temperature (25 °C, 37 °C, and 45 °C) conditions, respectively, using curcumin (Cur) as a model anticancer drug. The Cur drug-loaded pNIPAAm-co-GMA-Lys/Cur HG showed a relatively slow drug release behavior at a physiological pH (pH 7.4) and low temperature (25 °C) condition, whereas enhanced drug release was achieved at acidic pH (pH 6.2 and 4.0) and higher temperature (37 °C and 45 °C) conditions. Furthermore, the in vitro biocompatibility and intracellular fluorescence imaging were examined using the MDA-MB-231 cell line. Therefore, we demonstrate that the synthesized pNIPAAm-co-GMA-Lys HG system with temperature- and pH-stimuli-responsive features could be promising for various applications in biomedical fields, including drug delivery, gene delivery, tissue engineering, diagnosis, antibacterial/antifouling material, and implantable devices.

Enhanced Tumor Accumulation of Low-Molecular-Weight Hyaluronic Acid/Chitosan Nanocomplexes for Photothermal Therapy

Targeted phototheranostic nanosystems involving both cancer-specific near-infrared (NIR) fluorescence imaging and NIR light-induced phototherapy have shown great potential to improve cancer detection and treatment. In this study, a bifunctional nanocomplex based on low-molecular-weight hyaluronic acid (LMW-HA) and chitosan oligosaccharide lactate (COL) conjugating a zwitterionic NIR dye (ZW800-1) was rationally designed and prepared, and it was simultaneously used to enhance tumor accumulation and photothermal therapy (PTT). When HA-COL-ZW nanocomplexes were intravenously injected into mice bearing NCI-H460 tumors, HA-COL-ZW revealed increased tumor accumulation with prolonged tumor retention. Moreover, the ZW800-1 incorporated in HA-COL-ZW nanocomplexes showed excellent capability to convert NIR light into heat energy at the tumor site, acting as a PTT agent. Therefore, the targeted phototherapeutic HA-COL-ZW nanocomplex is a biocompatible and effective photothermal nanoagent, which could be a good candidate for future clinical use.

Gold nanoparticles-based photothermal therapy for breast cancer

AuNPs-mediated photothermal therapy (PTT) is gaining popularity in both laboratory research and medical applications. It has proven clear advantages in breast cancer therapy over conventional thermal ablation because of its easily-tuned features of irradiation light with inside hyperthermia ability. Notwithstanding this significant progress, the therapeutic potential of AuNPs-mediated PTT in cancer treatments is still impeded by several challenges, including inherent non-specificity, low photothermal conversion effectiveness, and the limitation of excitation light tissue penetration. Given the rapid progress of AuNPs-mediated PTT, we present a comprehensive overview of significant breakthroughs in the recent advancements of AuNPs for PTT, focusing on breast cancer cells. With the improvement of chemical synthesis technology, AuNPs of various sizes and shapes with desired properties can be synthesized, allowing breast cancer targeting and treatment. In this study, we summarized the different sizes and features of four major types of AuNPs in this review: Au nanospheres, Au nanocages, Au nanoshells, and Au nanorods, and explored their benefits and drawbacks in PTT. We also discussed the diagnostic, bioconjugation, targeting, and cellular uptake of AuNPs, which could improve the performance of AuNP-based PTT. Besides that, potential challenges and future developments of AuNP-mediated PTT for clinical applications are discussed. AuNP-mediated PTT is expected to become a highly promising avenue in cancer treatment in the near future.

Laser Ablated Albumin Functionalized Spherical Gold Nanoparticles Indicated for Stem Cell Tracking

Cell tracking in cell-based therapy applications helps distinguish cell participation among paracrine effect, neovascularization, and matrix deposition. This preliminary study examined the cellular uptake of gold nanoparticles (AuNPs), observing cytotoxicity and uptake of different sizes and AuNPs concentrations in Adipose-derived stromal cells (ASCs). ASCs were incubated for 24 h with Laser ablated Albumin functionalized spherical AuNPs (LA-AuNPs), with average sizes of 2 nm and 53 nm in diameter, in four concentrations, 127 µM, 84 µM, 42 µM, and 23 µM. Cytotoxicity was examined by Live/Dead assay, and erythrocyte hemolysis, and the effect on the cytoskeleton was investigated by immunocytochemistry for β-actin. The LA-AuNPs were internalized by the ASCs in a size and concentration-dependent manner. Clusters were observed as dispersed small ones in the cytosol, and as a sizeable perinuclear cluster, without significant harmful effects on the cells for up to 2 weeks. The Live/Dead and hemolysis percentage results complemented the observations that the larger 53 nm LA-AuNPs in the highest concentrated solution significantly lowered cell viability. The demonstrated safety, cellular uptake, and labelling persistency with LA-AuNPs, synthesized without the combination of chemical solutions, support their use for cell tracking in tissue engineering applications.

New Frontiers in Colorectal Cancer Treatment Combining Nanotechnology with Photo- and Radiotherapy

Colorectal cancer is the third most common cancer worldwide. Despite recent advances in the treatment of this pathology, which include a personalized approach using radio- and chemotherapies in combination with advanced surgical techniques, it is imperative to enhance the performance of these treatments and decrease their detrimental side effects on patients' health. Nanomedicine is likely the pathway towards solving this challenge by enhancing both the therapeutic and diagnostic capabilities. In particular, plasmonic nanoparticles show remarkable potential due to their dual therapeutic functionalities as photothermal therapy agents and as radiosensitizers in radiotherapy. Their dual functionality, high biocompatibility, easy functionalization, and targeting capabilities make them potential agents for inducing efficient cancer cell death with minimal side effects. This review aims to identify the main challenges in the diagnosis and treatment of colorectal cancer. The heterogeneous nature of this cancer is also discussed from a single-cell point of view. The most relevant works in photo- and radiotherapy using nanotechnology-based therapies for colorectal cancer are addressed, ranging from in vitro studies (2D and 3D cell cultures) to in vivo studies and clinical trials. Although the results using nanoparticles as a photo- and radiosensitizers in photo- and radiotherapy are promising, preliminary studies showed that the possibility of combining both therapies must be explored to improve the treatment efficiency.

pH and Thermoresponsive PNIPAm-co-Polyacrylamide Hydrogel for Dual Stimuli-Responsive Controlled Drug Delivery

The therapeutic delivery system with dual stimuli-responsiveness has attracted attention for drug delivery to target sites. In this study, we used free radical polymerization to develop a temperature and pH-responsive poly(N-isopropyl acrylamide)-co-poly(acrylamide) (PNIPAM-co-PAAm). PNIPAm-co-PAAm copolymer by reacting with N-isopropyl acrylamide (NIPAm) and acrylamide (Am) monomers. In addition, the synthesized melamine-glutaraldehyde (Mela-Glu) precursor was used as a cross-linker in the production of the melamine cross-linked PNIPAm-co-PAAm copolymer hydrogel (PNIPAm-co-PAAm-Mela HG) system. The temperature-responsive phase transition characteristics of the resulting PNIPAM-co-PAAm-Mela HG systems were determined. Furthermore, the pH-responsive drug release efficiency of curcumin was investigated under various pH and temperature circumstances. Under the combined pH and temperature stimuli (pH 5.0/45 °C), the PNIPAm-co-PAAm-Mela HG demonstrated substantial drug loading (74%), and nearly complete release of the loaded drug was accomplished in 8 h. Furthermore, the cytocompatibility of the PNIPAm-co-PAAm-Mela HG was evaluated on a human liver cancer cell line (HepG2), and the findings demonstrated that the prepared PNIPAm-co-PAAm-Mela HG is biocompatible. As a result, the PNIPAm-co-PAAm-Mela HG system might be used for both pH and temperature-stimuli-responsive drug delivery.

Gold nanoparticles loaded chitosan encapsulate 6-mercaptopurine as a novel nanocomposite for chemo-photothermal therapy on breast cancer

Background

As a promising strategy to overcome the therapeutic disadvantages of 6-mercaptopurine (6MP), we proposed the encapsulation of 6MP in chitosan nanoparticles (CNPs) to form the 6MP-CNPs complexes. The encapsulation was followed by the loading of complexes on gold nanoparticles (AuNPs) to generate a novel 6MP-CNPs-AuNPs nanocomposite to facilitate the chemo-photothermal therapeutic effect.

Methods

CNPs were produced based on the ionic gelation method of tripolyphosphate (TPP). Moreover, 6MP-CNPs composite were prepared by the modified ionic gelation method and then loaded on AuNPs which were synthesized according to the standard wet chemical method using trisodium citrate as a reducing and capping agent. The synthesized nanocomposites were characterized by UV–VIS spectroscopy, dynamic light scattering, Fourier transform infrared spectroscopy, and transmission electron microscopy. The potential cytotoxicity of the prepared nanocomposites on MCF7 cell line was carried out using Sulphorhodamine-B (SRB) assay.

Results

Optimization of CNPs, 6MP-CNPs, and 6MP-CNPs-AuNPs revealed 130 ± 10, 200 ± 20, and 25 ± 5 nm particle size diameters with narrow size distributions and exhibited high stability with zeta potential 36.9 ± 4.11, 37, and 44.4 mV, respectively. The encapsulation efficiency of 6MP was found to be 57%. The cytotoxicity of 6MP-CNPs and 6MP-CNPs-AuNPs on breast cell line MCF7 was significantly increased and reached IC50 of 9.3 and 8.7 µM, respectively. The co-therapeutic effect of the nanocomposites resulted in an improvement of the therapeutic efficacy compared to the individual effect of chemo- and photothermal therapy. Irradiation of 6MP-CNPs and 6MP-CNPs-AuNPs with a diode laser (DPSS laser, 532 nm) was found to have more inhibition on cell viability with a decrease in IC50 to 5 and 4.4 µM, respectively.

Conclusion

The Chemo-Photothermal co-therapy treatment with novel prepared nanocomposite exhibits maximum therapeutic efficacy and limits the dosage-related side effects of 6MP.

Graphical Abstract

Controllable preparation of chitosan oligosaccharides via a recombinant chitosanase from marine Streptomyces lydicus S1 and its potential application on preservation of pre-packaged tofu

Chitosan oligosaccharides (COSs) are widely applied in many areas due to its various biological activities. Controllable preparation of COSs with desired degree of polymerization (DP) via suitable chitosanase is of great value. Herein, a novel glycoside hydrolase (GH) family 46 chitosanase (SlCsn46) from marine Streptomyces lydicus S1 was prepared, characterized and used to controllably produce COSs with different DP. The specific activity of purified recombinant SlCsn46 was 1,008.5 U/mg. The optimal temperature and pH of purified SlCsn46 were 50°C and 6.0, respectively. Metal ions Mn2+ could improve the stability of SlCsn46. Additionally, SlCsn46 can efficiently hydrolyze 2% and 4% colloidal chitosan to prepare COSs with DP 2–4, 2–5, and 2–6 by adjusting the amount of SlCsn46 added. Moreover, COSs with DP 2–4, 2–5, and 2–6 exhibited potential application value for prolonging the shelf-life of pre-packaged Tofu. The water-holding capacity (WHC), sensorial properties, total viable count (TVC), pH and total volatile base nitrogen (TVB-N) of pre-packed tofu incorporated with 4 mg/mL COSs with DP 2–4, 2–5, and 2–6 were better than those of the control during 15 days of storage at 10°C. Thus, the controllable hydrolysis strategy provides an effective method to prepare COSs with desired DP and its potential application on preservation of pre-packed tofu.

Gold Nanoparticles as Photothermal Agent in Cancer Therapy: Theoretical Study of Concentration and Agglomeration Effects on Temperature

One promising cancer therapy is related to the treatment of diseased cells through thermal ablation by an individual or an agglomeration of nanoparticles acting as photothermal agents. The main principle of such a therapy consists in the photo-energy absorption by the nanoparticles and its conversion into heat in order to kill the biological media/cells in the neighboring regions of such a photothermal agent. Nevertheless, such a therapy must preserve the surrounding healthy cells (or biological media). In case of agglomerates of nanoparticles, the local concentrations of nanoparticles may increase the temperature locally. In this paper, we use the finite element method to calculate the temperature elevation for agglomerations of nanoparticles in a biological medium/cell. The positions of nanoparticles, forming the agglomerates, are randomly generated. The temperature elevation for such agglomerations of nanoparticles is then analyzed. We show that the control of the concentration of nanoparticles can preserve the efficiency of the thermal agent, but with limited risk of damage to the surrounding biological media/cells.

Gold-based hybrid nanostructures: more than just a pretty face for combinational cancer therapy

The early diagnosis together with an efficient therapy of cancer is essential to treat cancer patients and to enhance their quality of life. The use of nanostructures, as a newer technology, has demonstrated proven benefits as efficient cancer theranostic agents in numerous recent studies. Having a tunable surface plasmon resonance, gold nanostructures have been the subject of many recent studies as excellent imaging and photothermal therapy agents. However, the potential cytotoxicity and weak stability of gold nanostructures necessitate further modifications using biocompatible materials for biological applications. Based on the composition of the final structure, these gold-based hybrid nanostructures (GHNs) could be divided into five major groups; each of which has specific pros and cons. Understanding the strengths and weaknesses of each group helps scientists to optimize GHN designs with multiple functions by synergizing the benefits of different groups. This review aims to summarize the advancements in GHN design and provide a perspective view of future requirements for successful GHN-based targeted combinational cancer theranostic platforms.

Chitosan: A versatile bio-platform for breast cancer theranostics

Breast cancer is considered one of the utmost neoplastic diseases globally, with a high death rate of patients. Over the last decades, many approaches have been studied to early diagnose and treat it, such as chemotherapy, hormone therapy, immunotherapy, and MRI and biomarker tests; do not show the optimal efficacy. These existing approaches are accompanied by severe side effects, thus recognizing these challenges, a great effort has been done to find out the new remedies for breast cancer. Main finding: Nanotechnology opened a new horizon to the treatment of breast cancer. Many nanoparticulate platforms for the diagnosis of involved biomarkers and delivering antineoplastic drugs are under either clinical trials or just approved by the Food and Drug Administration (FDA). It is well known that natural phytochemicals are successfully useful to treat breast cancer because these natural compounds are safer, available, cheaper, and have less toxic effects. Chitosan is a biocompatible and biodegradable polymer. Further, it has outstanding features, like chemical functional groups that can easily modify our interest with an exceptional choice of promising applications. Abundant studies were directed to assess the chitosan derivative-based nanoformulation's abilities in delivering varieties of drugs. However, the role of chitosan in diagnostics and theranostics not be obligated. The present servey will discuss the application of chitosan as an anticancer drug carrier such as tamoxifen, doxorubicin, paclitaxel, docetaxel, etc. and also, its role as a theranostics (i.e. photo-responsive and thermo-responsive) moieties. The therapeutic and theranostic potential of chitosan in cancer is promising and it seems that to have a good potential to get to the clinic.

Enhanced Intracellular Delivery of Curcumin by Chitosan-Lipoic Acid as Reduction-Responsive Nanoparticles

AIMS

Enhancement of anti-tumor activity of the chemotherapeutic agent CUR by redoxsensitive nanoparticle to get a deeper insight into cancer therapy.

BACKGROUND

Tumor targetability and stimulus are widely used to study the delivery of drugs for cancer diagnosis and treatment because poor cellular uptake and inadequate intracellular drug release lead to inefficient delivery of anticancer agents to tumor tissue.

OBJECTIVE

Studies distinguishing between tumor and normal tissues or redox-sensitive systems using glutathione (GSH) as a significant signal.

METHODS

In this study, we designed Chitosan-Lipoic acid Nanoparticles (CS-LANPs) to improve drug delivery for breast cancer treatment by efficient delivery of Curcumin (CUR). The properties of blank CS-LANPs were studied in detail. The size and the Polydispersity Index (PDI) of the CS-LANPs were optimized.

RESULTS

The results indicate the mean size and PDI of the blank CS-LANPs were around 249 nm and 0.125, respectively. However, the Drug Loading (DL) and Encapsulation Efficiency (EE) of the CSLANPs were estimated to be about 18.22% and 99.80%, respectively. Compared to non-reductive conditions, the size of reduction-sensitive CS-LANPs increased significantly under reductive conditions. Therefore, the drug release of CS-LANPs in the presence of glutathione was much faster than that of non-GSH conditions .Moreover, the antitumor effect of CS-LANPs on MCF-7 cells was determined in vitro by MTT assay, cell cytotoxicity, Caspase-3 Assay, detection of mitochondrial membrane potential and quantification of apoptosis incidence.

CONCLUSION

CS-LANPs showed a remarkably increased accumulation in tumor cells and had a better tumor inhibitory activity in vitro. CS-LANPs could successfully deliver drugs to cancer cells and revealed better efficiency than free CUR.

Gold nanostructures as mediators of hyperthermia therapies in breast cancer

Breast cancer is the leading cause of cancer-related deaths among women. Due to the limitations of the current therapeutics, new treatment options are needed. Hyperthermia is a promising approach to improve breast cancer therapy, particularly when combined with chemo and radiotherapy. This area has gained more attention following association with nanotechnology, with the emergence of modalities, such as photothermal therapy (PTT). PTT is a simple, minimally invasive technique that requires a near infrared (NIR) light source and a PTT agent. Gold nanostructures are excellent PTT agents as they offer biocompatibility, versatility, high photothermal conversion efficiency, imaging contrast and an easily-modified surface. In this review, we describe the molecular basis and the current clinical aspects of hyperthermia-based therapies. The emergent area of nanoparticle-induced hyperthermia will be explored, in particular gold nanostructure-mediated PTT, focusing on recent preclinical studies for breast cancer management.

Gold nanoclusters modified mesoporous silica coated gold nanorods: Enhanced photothermal properties and fluorescence imaging

Photothermal therapy (PTT) is a non-invasive therapy that is widely used in cancer treatment. Gold nanorods (AuNRs) are particularly suitable as a photothermal reagent due to their unique localized surface plasmon resonance (LSPR) properties. However, bare gold nanorods are not stable enough during radiation to collect enough energy to kill tumor cells. In addition, they showed some biologically toxic originated from the poor colloidal stability and surfactants cetyltrimethyl ammonium bromide (CTAB), making it difficult to apply them directly to clinical research. To solve these problems, a novel nanocomposite was structured by coating silica shell and gold nanocluster on the outer layer of the gold nanorod (AuNRs@SiO₂@AuNCs). Compared with the bare gold nanorod, the nanocomposite with the core-shell structure showed superior photothermal effect. The photothermal conversion temperature reached 63 °C under a lower irradiation power. The photothermal conversion efficiency was enhanced to 77.6%. Its photothermal performance remained constant after five cycles of near-infrared laser irradiation, indicating excellent photothermal stability. In vitro cell imaging experiments show that AuNRs@SiO₂@ AuNCs can effectively enter tumor cells. By 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis, cancer cells can be effectively killed when exposed to a near-infrared laser. During the synthesis process, the silica and gold nanoclusters replaced the toxic CTAB molecular layer on the surface of AuNRs. Therefore, AuNRs@SiO₂@AuNCs has good biocompatibility and fluorescence characteristics. These results suggest that such AuNRs@SiO₂@AuNCs nanocomposite shows great potential in imaging guided photothermal therapy for cancer.

Near-infra-red fluorescent chitosan oligosaccharide lactate for targeted cancer imaging and photothermal therapy

Photothermal therapy (PTT) is a promising approach for effective cancer treatment because of its non-invasive procedure, low toxicity to normal tissues, and high tumour ablation efficiency. Developing a PTT agent with precise tumour imaging capabilities is an essential prerequisite for effective PTT. In this study, we developed a bifunctional near-infra-red (NIR) fluorescent conjugate consisting of chitosan oligosaccharide lactate (COL) and the ZW800-1 NIR fluorophore (COL-ZW). We demonstrate that this conjugate is easy to use and that it is an effective theranostic agent for fluorescence-guided photothermal treatment. The temperature of COL-ZW increased by 62.3 °C after NIR laser irradiation (1.1 W/cm²) for 5 min in HT-29 tumour-bearing mice. The HT-29 tumours targeted by COL-ZW showed a remarkable decrease in tumour volume until a week after photothermal treatment. These in vivo results demonstrate that the bifunctional COL-ZW generates strong fluorescence and light-triggered PTT in tumour sites, indicating successful fluorescence-guided PTT. Importantly, no tumour recurrence or treatment-induced toxicity was observed after a single dose of COL-ZW with laser irradiation. Therefore, a combinatorial treatment with COL-ZW and NIR laser irradiation could serve as a promising strategy for photothermal cancer therapy.

Synthesis, Characterization, and Evaluation of Redox-Sensitive Chitosan Oligosaccharide Nanoparticles Coated with Phycocyanin for Drug Delivery

In this paper, a type of phycocyanin (PC)-functionalized and curcumin (CUR)-loaded biotin-chitosan oligosaccharide-dithiodipropionic acid-curcumin (BCSC) nanoparticles, called CUR-BCSC@PCs, were designed to enhance the biocompatibility of CUR. The structure of BCSC was confirmed using ¹H-NMR. In CUR-BCSC@PCs with an average hydrodynamic diameter of 160.3 ± 9.0 nm, the biomimetic protein corona gave the nanoparticles excellent stability and the potential to avoid protein adsorption in blood circulation. The in vitro release experiment verified that CUR-BCSC@PCs with redox responsive shells were sensitive to high concentrations of glutathione. In addition, CUR-BCSC@PCs were effective at increasing the inhibitory activity on the proliferation of A549 cells by enhancing the intracellular uptake of CUR. These results indicated that CUR-BCSC@PCs have great application prospects in cancer therapy as effective drug delivery carriers.

Thiol chitosan-wrapped gold nanoshells for near-infrared laser-induced photothermal destruction of antibiotic-resistant bacteria

Developing new antibacterial nanomaterials and novel therapeutic strategies for the destruction of human pathogenic bacteria that cause infectious diseases is becoming more crucial, because infections caused by antibiotic-resistant bacteria are becoming more and more difficult to be effectively cured with commercially available antibiotics. In this study, we successfully developed new thiol chitosan-wrapped gold nanoshells (TC-AuNSs) as an antibacterial agent for the near-infrared (NIR) laser-triggered photothermal destruction of antibiotic-resistant pathogens, such as Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli), owing to their high water solubility, biocompatibility, strong NIR absorption, and outstanding photothermal properties. More interestingly, TC-AuNSs (115 μg/mL) were capable of completely destroying S. aureus, P. aeruginosa, and E.coli within 5 min of NIR laser irradiation, and no bacterial growth was detected on the tryptic soy agar (TSA) plate after 48 h of laser irradiation, indicating that TC-AuNSs along with laser irradiation are highly efficient and can kill bacteria quickly and prevent bacterial regrowth. We believe that TC-AuNSs deserve much more attention as an antibacterial agent, to be used in effectively combating pathogenic bacteria associated with public health problems and monitoring of environmental pollution for hygiene and safety.

Effective control of biofilms by photothermal therapy using a gold nanorod hydrogel

Biofilms are matrices synthesized by bacteria containing polysaccharides, DNA, and proteins. The development of biofilms in infectious processes can induce a chronic inflammatory response that may progress to the destruction of tissues. The treatment of biofilms is difficult because they serve as a bacterial mechanism of defense and high doses of antibiotics are necessary to treat these infections with limited positive results. It has been demonstrated that photothermal therapy using gold nanorods (AuNRs) is an attractive treatment because of its anti-biofilm activity. The purpose of this work was to generate a novel chitosan-based hydrogel embedded with AuNRs to evaluate its anti-biofilm activity. AuNRs were synthesized by the seed-mediated growth method and mixed with the chitosan-based hydrogel. Hydrogels were characterized and tested against two bacterial strains by irradiating the produced biofilm in the presence of the nanoformulation with a laser adjusted at the near infrared spectrum. In addition, the safety of the nanoformulation was assessed with normal human gingival fibroblasts. Results showed that a significant bacterial killing was measured when biofilms were exposed to an increase of 10°C for a short time of 2 min. Moreover, no cytotoxicity was measured when normal gingival fibroblasts were exposed to the nanoformulation using the bactericidal conditions. The development of the reported formulation can be used as a direct application to treat periodontal diseases or biofilm-produced bacteria that colonize the oral cavity.

Anisotropic Gold Nanoparticles in Biomedical Applications

Gold nanoparticles (AuNPs) play a crucial role in the development of nanomedicine, principally due to their unique photophysical properties and high biocompatibility. The possibility to tune and customize the localized surface plasmon resonance (LSPR) toward near-infrared region by modulating the AuNP shape is one of the reasons for the huge widespread use of AuNPs. The controlled synthesis of no-symmetrical nanoparticles, named anisotropic, is an exciting goal achieved by the scientific community which explains the exponential increase of the number of publications related to the synthesis and use of such type of AuNPs. Even with such steps forward and the AuNP translation in clinic being done, some key issues are still remain and they are related to a reliable and scalable production, a full characterization, and to the development of nanotoxicology studies on the long run. In this review we highlight the very recent advances on the synthesis of the main classes of anisotropic AuNPs (nanorods, nanourchins and nanocages) and their use in the biomedical fields, in terms of diagnosis and therapeutics.

Gold Nanoparticles as a Photothermal Agent in Cancer Therapy: The Thermal Ablation Characteristic Length

In cancer therapy, the thermal ablation of diseased cells by embedded nanoparticles is one of the known therapies. It is based on the absorption of the energy of the illuminating laser by nanoparticles. The resulting heating of nanoparticles kills the cell where these photothermal agents are embedded. One of the main constraints of this therapy is preserving the surrounding healthy cells. Therefore, two parameters are of interest. The first one is the thermal ablation characteristic length, which corresponds to an action distance around the nanoparticles for which the temperature exceeds the ablation threshold. This critical geometric parameter is related to the expected conservation of the body temperature in the surroundings of the diseased cell. The second parameter is the temperature that should be reached to achieve active thermal agents. The temperature depends on the power of the illuminating laser, on the size of nanoparticles and on their physical properties. The purpose of this paper is to propose behavior laws under the constraints of both the body temperature at the boundary of the cell to preserve surrounding cells and an acceptable range of temperature in the target cell. The behavior laws are deduced from the finite element method, which is able to model aggregates of nanoparticles. We deduce sensitivities to the laser power and to the particle size. We show that the tuning of the temperature elevation and of the distance of action of a single nanoparticle is not significantly affected by variations of the particle size and of the laser power. Aggregates of nanoparticles are much more efficient, but represent a potential risk to the surrounding cells. Fortunately, by tuning the laser power, the thermal ablation characteristic length can be controlled.