Plasmonic Gold Nanorattle Impregnated Chitosan Nanocarrier for Stimulus Responsive Theranostics

NIR-Active Gold Dogbone Nanorattles Impregnated in Cationic Dextrin Nanoparticles for Cancer Nanotheranostics

Theranostic systems, which integrate therapy and diagnosis into a single platform, have gained significant attention as a promising approach for noninvasive cancer treatment. The field of image-guided therapy has revolutionized real-time tumor detection, and within this domain, plasmonic nanostructures have garnered significant attention. These structures possess unique localized surface plasmon resonance (LSPR), allowing for enhanced absorption in the near-infrared (NIR) range. By leveraging the heat generated from plasmonic nanoparticles upon NIR irradiation, target cancer cells can be effectively eradicated. This study introduces a plasmonic gold dogbone-nanorattle (AuDB NRT) structure that exhibits broad absorption in the NIR region and demonstrates a photothermal conversion efficiency of 35.29%. When exposed to an NIR laser, the AuDB NRTs generate heat, achieving a maximum temperature rise of 38 °C at a concentration of 200 μg/mL and a laser power density of 3 W/cm2. Additionally, the AuDB NRTs possess intrinsic electromagnetic hotspots that amplify the signal of a Raman reporter molecule, making them an excellent probe for surface-enhanced Raman scattering-based bioimaging of cancer cells. To improve the biocompatibility of the nanorattles, the AuDB NRTs were conjugated with mPEG-thiol and successfully encapsulated into cationic dextrin nanoparticles (CD NPs). Biocompatibility tests were performed on HEK 293 A and MCF-7 cell lines, revealing high cell viability when exposed to AuDB NRT-CD NPs. Remarkably, even at a low laser power density of 1 W/cm2, the application of the NIR laser resulted in a remarkable 80% cell death in cells treated with a nanocomposite concentration of 100 μg/mL. Further investigation elucidated that the cell death induced by photothermal heat followed an apoptotic mechanism. Overall, our findings highlight the significant potential of the prepared nanocomposite for cancer theranostics, combining effective photothermal therapy along with the ability to image cancer cells.

Cationic dextrin nanoparticles for effective intracellular delivery of cytochrome C in cancer therapy

Intracellular protein delivery shows promise as a selective and specific approach to cancer therapy. However, a major challenge is posed by delivering proteins into the target cells. Despite the development of nanoparticle (NP)-based approaches, a versatile and biocompatible delivery system that can deliver active therapeutic cargo into the cytosol while escaping endosome degradation remains elusive. In order to overcome these challenges, a polymeric nanocarrier was prepared using cationic dextrin (CD), a biocompatible and biodegradable polymer, to encapsulate and deliver cytochrome C (Cyt C), a therapeutic protein. The challenge of endosomal escape of the nanoparticles was addressed by co-delivering the synthesized NP construct with chloroquine, which enhances the endosomal escape of the therapeutic protein. No toxicity was observed for both CD NPs and chloroquine at the concentration tested in this study. Spectroscopic investigations confirmed that the delivered protein, Cyt C, was structurally and functionally active. Additionally, the delivered Cyt C was able to induce apoptosis by causing depolarization of the mitochondrial membrane in HeLa cells, as evidenced by flow cytometry and microscopic observations. Our findings demonstrate that an engineered delivery system using CD NPs is a promising platform in nanomedicine for protein delivery applications.

Optimized DOX Drug Deliveries via Chitosan-Mediated Nanoparticles and Stimuli Responses in Cancer Chemotherapy: A Review

Chitosan nanoparticles (NPs) serve as useful multidrug delivery carriers in cancer chemotherapy. Chitosan has considerable potential in drug delivery systems (DDSs) for targeting tumor cells. Doxorubicin (DOX) has limited application due to its resistance and lack of specificity. Chitosan NPs have been used for DOX delivery because of their biocompatibility, biodegradability, drug encapsulation efficiency, and target specificity. In this review, various types of chitosan derivatives are discussed in DDSs to enhance the effectiveness of cancer treatments. Modified chitosan-DOX NP drug deliveries with other compounds also increase the penetration and efficiency of DOX against tumor cells. We also highlight the endogenous stimuli (pH, redox, enzyme) and exogenous stimuli (light, magnetic, ultrasound), and their positive effect on DOX drug delivery via chitosan NPs. Our study sheds light on the importance of chitosan NPs for DOX drug delivery in cancer treatment and may inspire the development of more effective approaches for cancer chemotherapy.

Exploration of inorganic nanoparticles for revolutionary drug delivery applications: a critical review

The nanosystems for delivering drugs which have evolved with time, are being designed for greater drug efficiency and lesser side-effects, and are also complemented by the advancement of numerous innovative materials. In comparison to the organic nanoparticles, the inorganic nanoparticles are stable, have a wide range of physicochemical, mechanical, magnetic, and optical characteristics, and also have the capability to get modified using some ligands to enrich their attraction towards the molecules at the target site, which makes them appealing for bio-imaging and drug delivery applications. One of the strong benefits of using the inorganic nanoparticles-drug conjugate is the possibility of delivering the drugs to the affected cells locally, thus reducing the side-effects like cytotoxicity, and facilitating a higher efficacy of the therapeutic drug. This review features the direct and indirect effects of such inorganic nanoparticles like gold, silver, graphene-based, hydroxyapatite, iron oxide, ZnO, and CeO2 nanoparticles in developing effective drug carrier systems. This article has remarked the peculiarities of these nanoparticle-based systems in pulmonary, ocular, wound healing, and antibacterial drug deliveries as well as in delivering drugs across Blood-Brain-Barrier (BBB) and acting as agents for cancer theranostics. Additionally, the article sheds light on the plausible modifications that can be carried out on the inorganic nanoparticles, from a researcher's perspective, which could open a new pathway.

Polysaccharide-based gold nanomaterials: Synthesis mechanism, polysaccharide structure-effect, and anticancer activity

Polysaccharide-based gold nanomaterials have attracted great interest in biomedical fields such as cancer therapy and immunomodulation due to their prolonged residence time in vivo and enhanced immune response. This review aims to provide an up-to-date and comprehensive summary of polysaccharide-based Au NMs synthesis, including mechanisms, polysaccharide structure-effects, and anticancer activity. Firstly, research progress on the synthesis mechanism of polysaccharide-based Au NMs was addressed, which included three types based on the variety of polysaccharides and reaction environment: breaking of glycosidic bonds via Au (III) or base-mediated production of highly reduced intermediates, reduction of free hydroxyl groups in polysaccharide molecules, and reduction of free amino groups in polysaccharide molecules. Then, the potential effects of polysaccharide structure characteristics (molecular weight, composition of monosaccharides, functional groups, glycosidic bonds, and chain conformation) and reaction conditions (the reaction temperature, reaction time, pH, concentration of gold precursor and polysaccharides) on the size and shape of Au NMs were explored. Finally, the current status of polysaccharide-based Au NMs cancer therapy was summarized before reaching our conclusions and perspectives.

Chitosan functionalized gold nanostars as a theranostic platform for intracellular microRNA detection and photothermal therapy

The development of a theranostic platform that integrates both diagnostic and therapeutic capabilities is in great need for precise and personalized medicine. Here, we present a novel nanoplatform (AuNS@CS-hpDNA) formulated by chitosan functionalized gold nanostar composites and further complexed with fluorescent hairpin DNA (hpDNA) probes for tumor-related miRNA imaging and photothermal therapy (PTT). The optimized AuNS@CS-hpDNA nanoplatform mediated efficient hpDNA probe loading and intracellular delivery. Subsequently, the cytosol transfer of the hpDNA probe enabled specific hybridization using the targeted miRNA, which triggered the recovery of fluorescence for the precise detection of biomarker miR21 in living cells and realized the distinguishing cancer cell line MCF-7 and normal cells. Meanwhile, the AuNS@CS-hpDNA nanoplatform exhibited excellent photothermal conversion properties, which induced efficient cancer cell killing under laser irradiation. Thus, the developed AuNS@CS-hpDNA nanoplatform could simultaneously realize the precise detection of cancer cells and accurately initiate efficient PTT, which represents a promising strategy for precise cancer therapy.

Actively targeted gold-polydopamine (PDA@Au) nanocomplex for sequential drug release and combined synergistic chemo-photothermal therapeutic effects

Multifunctional nanoparticles for treatment in cancer are getting more and more attention recently. In this study, we employed a novel polydopamine (PDA) framework-based gold nanoparticles as a carrier of an antimetabolite drug, 5-Fluorouracil (5-FU). Folic acid (FA) was embellished onto the surface of nanoparticle imparting the nanosystem with remarkable tumor-targeting abilities through its precise binding with FA receptor that is notably overexpressed in breast cancer cells. PDA served as a photothermal treatment (PTT) agent and a gatekeeper to regulate drug release since it is highly pH-sensitive and might lengthen the residency period while simultaneously enhancing water solubility and biological compatibility of nanomaterials. Gold nanoparticles (Au NPs) end up serving as both a drug delivery platform and a source of substantial photothermal effects, culminating in synergistically coupled chemo-photothermal therapy. The PDA@Au@FA nanocomplex, loaded with 5-FU, is biocompatible, features strong NIR absorption and photothermal conversion, and can control drug release in pH/NIR dual response environment. The cell viability in PDA@Au@5-FU-FA group with NIR irradiation in 48 h was only 20.1 ± 2.6%. In addition, apoptosis staining experiments revealed greater cellular uptake of PDA@Au@5-FU-FA by MCF-7 cells. Therefore, PDA@Au@5-FU-FA nanocomplex that we postulated herein may be a potential contender for effective curative treatment for breast cancer.

The Rise of Structurally Anisotropic Plasmonic Janus Gold Nanostars

Nanostructures intrinsically possessing two different structural or functional features, often called Janus nanoparticles, are emerging as a potential material for sensing, catalysis, and biomedical applications. Herein, we report the synthesis of plasmonic gold Janus nanostars (NSs) possessing a smooth concave pentagonal morphology with sharp tips and edges on one side and, contrastingly, a crumbled morphology on the other. The methodology reported herein for their synthesis - a single-step growth reaction - is different from any other Janus nanoparticle preparation involving either template-assisted growth or a masking technique. Interestingly, the coexistence of lower- and higher-index facets was found in these Janus NSs. The general paradigm for synthesizing gold Janus NSs was investigated by understanding the kinetic control mechanism with the combinatorial effect of all the reagents responsible for the structure. The optical properties of the Janus NSs were realized by corelating their extinction spectra with the simulated data. The size-dependent surface-enhanced Raman scattering (SERS) activity of these Janus NSs was studied with 1,4-BDT as the model analyte. Finite-difference time-domain simulations for differently sized particles revealed the distribution of electromagnetic hot-spots over the particles resulting in enhancement of the SERS signal in a size-dependent manner.

Plasmonic gold dogbone nanorattles sniff out trace molecules through surface enhanced Raman scattering

In this study, a highly sensitive and efficient surface-enhanced Raman spectroscopy (SERS) substrate was developed using Au dogbone nanorattles (Au-DBNRTs) deposited on a 3D wrinkled polymeric heat shrink film. The plasmonic structures of Au-DBNRTs, which possess a solid gold dogbone-shaped core and a thin, porous gold shell, and Au nanorod nanorattles (Au-NRNRTs), which have a rod-shaped core, were synthesized and their SERS performance was evaluated. Au-DBNRTs exhibited better Raman signal enhancement. The substrate was used to detect the pesticide thiabendazole with a limit of detection of up to 10-8 M. The unique optical properties and geometry of the Au-DBNRT nanoparticles, which have portruding corners in the vicinity of the metal shell, along with the shrinkage of the film after heat treatment, led to the creation of a 3D surface morphology, resulting in the generation of plasmonic electromagnetic hot spots. The fabricated substrate achieved an enhancement factor of 2.77 × 1010 for BDT, and the detection limit was 10-13 M. The current work offers a simple, cost-effective, and sensitive SERS substrate design that has great potential for sensing and detecting trace analytes.

Palladium Nanocapsules for Photothermal Therapy in the Near-Infrared II Biological Window

Recent developments in nanomaterials with programmable optical responses and their capacity to modulate the photothermal effect induced by an extrinsic source of light have elevated plasmonic photothermal therapy (PPTT) to the status of a favored treatment for a variety of malignancies. However, the low penetration depth of near-infrared-I (NIR-I) lights and the need to expose the human body to a high laser power density in PPTT have restricted its clinical translation for cancer therapy. Most nanostructures reported to date exhibit limited performance due to (i) activity only in the NIR-I region, (ii) the use of intense laser, (iii) need of large concentration of nanomaterials, or (iv) prolonged exposure times to achieve the optimal hyperthermia state for cancer phototherapy. To overcome these shortcomings in plasmonic nanomaterials, we report a bimetallic palladium nanocapsule (Pd Ncap)─with a solid gold bead as its core and a thin, perforated palladium shell─with extinction both in the NIR-I as well as the NIR-II region for PPTT applications toward cancer therapy. The Pd Ncap demonstrated exceptional photothermal stability with a photothermal conversion efficiency of ∼49% at the NIR-II (1064 nm) wavelength region at a very low laser power density of 0.5 W/cm2. The nanocapsules were further surface-functionalized with Herceptin (Pd Ncap-Her) to target the breast cancer cell line SK-BR-3 and exploited for in vitro PPTT applications using NIR-II light. Pd Ncap-Her caused more than 98% cell death at a concentration of just 50 μg/mL and a laser power density of 0.5 W/cm2 with an output power of only 100 mW. Flow cytometric and microscopic analyses revealed that Pd Ncap-Her-induced apoptosis in the treated cancer cells during PPTT. Additionally, Pd Ncaps were found to have reactive oxygen species (ROS) scavenging ability, which can potentially reduce the damage to cells or tissues from ROS produced during PPTT. Also, Pd Ncap demonstrated excellent in vivo biocompatibility and was highly efficient in photothermally ablating tumors in mice. With a high photothermal conversion and killing efficiency at very low nanoparticle concentrations and laser power densities, the current nanostructure can operate as an effective phototherapeutic agent for the treatment of different cancers with ROS-protecting ability.

Gold Nanoblackbodies-based Multifunctional Nanocomposite for Multimodal Cancer Therapy

Multifunctional nanocomposites are of potential use to achieve complete tumor elimination and, thus, to avoid tumor recurrence. Herein, polydopamine (PDA)-based gold nanoblackbodies (AuNBs) loaded with indocyanine green (ICG) and Doxorubicin (DOX) termed as A-P-I-D nanocomposite were investigated for multimodal plasmonic photothermal-photodynamic-chemotherapy. Upon near-infrared (NIR) irradiation, A-P-I-D nanocomposite showed enhanced photothermal conversion efficiency of 69.2% compared to bare AuNBs (62.9%) due to the presence of ICG, along with ROS (¹O₂) generation as well as enhanced DOX release. On assessment of therapeutic effects on breast cancer (MCF-7) and melanoma (B16F10) cell lines, A-P-I-D nanocomposite showed significantly lower cell viabilities of 45.5% and 24% compared to 79.3% and 76.8% for AuNBs. Fluorescence images of stained cells revealed characteristic signs of apoptotic mode of cell death, with almost complete damage on A-P-I-D nanocomposite+NIR treated cells. Further, on evaluation of photothermal performance through breast tumor-tissue mimicking phantoms, A-P-I-D nanocomposite provided required thermal ablation temperatures within the tumor along with the potential for the elimination of residual cancerous cells through photodynamic therapy and chemotherapy. Overall, this study demonstrates that A-P-I-D nanocomposite+NIR provides better therapeutic outcome on cell lines and enhanced photothermal performance on breast tumor-tissue mimicking phantoms to be a promising agent for multimodal cancer therapy.

Plasmonic 3-D wrinkled polymeric shrink film-based SERS substrates for pesticide detection on real-world surfaces

The continuous and excessive use of agrochemicals for crop improvement and protection has raised widespread concern, as they exert adverse effects on human health and the local environment. Surface Enhanced Raman Spectroscopy (SERS) provides a method for the quick identification and detection of such hazardous substances in a short amount of time due to its properties of being robust, accurate, sensitive and non-destructive. Despite the fact that several SERS substrates have been developed, the bulk of them are ineffective in terms of sample collection or providing reproducible results. In this study, we showed that a 3-D wrinkled polymeric heat-shrink film coated with Au bead@Ag nanorods (silver nanorods) serves as a potential SERS substrate for trace analysis. The surface of the heat-shrink film became wrinkled after heating, and this, along with the spatial arrangement of nanoparticles, significantly enhances the Raman signal of the analytes. The fabricated SERS substrate was able to sense two model analytes 1,4-benzenedithiol (BDT) and 2-naphthalenethiol (NT) up to 10^-13 M and 10^-11 M concentrations. The fabricated substrate was also effective in sensing thiram down to 10^-13 M concentration. Additionally, the SERS substrate was applied in a real-world setting for the detection of the pesticide thiram spiked onto apple skin surfaces. To collect the thiram residues, the substrate was simply swabbed across the surface of the apple. This allowed for the detection of thiram at concentrations as low as 10^-9 M (1 ppb). The fabricated SERS substrate can thus detect analytes in an efficient, sensitive, dependable and accurate manner, allowing for the sensing of trace analytes like pesticides in a real-world environment.

Synthesis of Zinc Oxide (ZnO)-Titanium Dioxide (TiO2)-Chitosan-Farnesol Nanocomposites and Assessment of Their Anticancer Potential in Human Leukemic MOLT-4 Cell Line

Leukemia is the most prevalent cancer in children and one of the most common and deadly cancers that affect adults. Several metal oxide nanoparticles, biopolymers, and phytochemicals have been discovered to target cancer cells selectively while inflicting low to no damage to healthy cells. Among the existing nanoparticle synthesis methodologies, biologically synthesized nanoparticles using phytochemicals have emerged as a straightforward, economical, and environmentally sound strategy. The synergistic antitumor potential of ZnO-TiO2-chitosan-farnesol nanocomposites (NCs) against leukemia MOLT-4 cells was investigated in the current study. After synthesizing the NCs, characterization of the same was carried out using XRD, DLS, FESEM, TEM, PL, EDX, and FTIR spectroscopy. To analyze its anticancer activity, MOLT-4 cells were cultured and treated at diverse dosages of NCs. The cell viability upon treatment was examined by MTT assay. The morphological and nuclear modifications were observed by dual staining. ROS and MMP levels were observed by DCFH-DA staining and Rh-123 dye, respectively. Furthermore, the caspase 3, 8, and 9 levels were examined by performing ELISA. The XRD patterns exhibited a hexagonal structure of the NCs. In the DLS spectrum, the hydrodynamic diameter of the NCs was observed to be 126.2 nm. The electrostatic interface between the ZnO-TiO2-chitosan-farnesol NCs was confirmed by the FTIR spectra. A significant loss of cell viability in a dosage-dependent trend confirmed the cytotoxic effect of the NCs. An elevated ROS level and MMP depletion suggested apoptosis-associated cell death via the intrinsic pathway, which was confirmed by elevated expressions of caspase 3, 8, and 9 markers. Thus, the results showed that the synthesized NCs demonstrated a remarkable anticancer potential against leukemic cells and can be potentially valuable in cancer treatments. The findings from this study conclude that this is a new approach for modifying the physicochemical characteristics of ZnO-TiO2-chitosan-farnesol composites to increase their properties and synergistically exhibit anticancer properties in human leukemic cancer cells.

Chitosan-based nanoscale systems for doxorubicin delivery: Exploring biomedical application in cancer therapy

Green chemistry has been a growing multidisciplinary field in recent years showing great promise in biomedical applications, especially for cancer therapy. Chitosan (CS) is an abundant biopolymer derived from chitin and is present in insects and fungi. This polysaccharide has favorable characteristics, including biocompatibility, biodegradability, and ease of modification by enzymes and chemicals. CS-based nanoparticles (CS-NPs) have shown potential in the treatment of cancer and other diseases, affording targeted delivery and overcoming drug resistance. The current review emphasizes on the application of CS-NPs for the delivery of a chemotherapeutic agent, doxorubicin (DOX), in cancer therapy as they promote internalization of DOX in cancer cells and prevent the activity of P-glycoprotein (P-gp) to reverse drug resistance. These nanoarchitectures can provide co-delivery of DOX with antitumor agents such as curcumin and cisplatin to induce synergistic cancer therapy. Furthermore, co-loading of DOX with siRNA, shRNA, and miRNA can suppress tumor progression and provide chemosensitivity. Various nanostructures, including lipid-, carbon-, polymeric- and metal-based nanoparticles, are modifiable with CS for DOX delivery, while functionalization of CS-NPs with ligands such as hyaluronic acid promotes selectivity toward tumor cells and prevents DOX resistance. The CS-NPs demonstrate high encapsulation efficiency and due to protonation of amine groups of CS, pH-sensitive release of DOX can occur. Furthermore, redox- and light-responsive CS-NPs have been prepared for DOX delivery in cancer treatment. Leveraging these characteristics and in view of the biocompatibility of CS-NPs, we expect to soon see significant progress towards clinical translation.

Recent advances in nanoparticle-based photothermal therapy for breast cancer

Breast cancer is one of the most common cancers among women that is associated with high mortality. Conventional treatments including surgery, radiotherapy, and chemotherapy, which are not effective enough and have disadvantages such as toxicity and damage to healthy cells. Photothermal therapy (PTT) of cancer cells has been took great attention by researchers in recent years due to the use of light radiation and heat generation at the tumor site, which thermal ablation is considered a minimally invasive method for the treatment of breast cancer. Nanotechnology has opened up a new perspective in the treatment of breast cancer using PTT method. Through NIR light absorption, researchers applied various nanostructures because of their specific nature of penetrating and targeting tumor tissue, increasing the effectiveness of PTT, and combining it with other treatments. If PTT is used with common cancer treatments, it can dramatically increase the effectiveness of treatment and reduce the side effects of other methods. PTT performance can also be improved by hybridizing at least two different nanomaterials. Nanoparticles that intensely absorb light and increase the efficiency of converting light into heat can specifically kill tumors through hyperthermia of cancer cells. One of the main reasons that have increased the efficiency of nanoparticles in PTT is their permeability and durability effect and they can accumulate in tumor tissue. Targeted PTT can be provided by incorporating specific ligands to target receptors expressed on the surface of cancer cells on nanoparticles. These nanoparticles can specifically target cancer cells by maintaining the surface area and increasing penetration. In this study, we briefly introduce the performance of light therapy, application of metal nanoparticles, polymer nanoparticles, carbon nanoparticles, and hybrid nanoparticles for use in PTT of breast cancer.

Polysaccharide-Based Theranostic Systems for Combined Imaging and Cancer Therapy: Recent Advances and Challenges

Designing novel systems for efficient cancer treatment and improving the quality of life for patients is a prime requirement in the healthcare sector. In this regard, theranostics have recently emerged as a unique platform, which combines the benefits of both diagnosis and therapeutics delivery. Theranostics have the desired contrast agent and the drugs combined in a single carrier, thus providing the opportunity for real-time imaging to monitor the therapy results. This helps in reducing the hazards related to treatment overdose or underdose and gives the possibility of personalized therapy. Polysaccharides, as natural biomolecules, have been widely explored to develop theranostics, as they act as a matrix for simultaneously loading both contrast agents and drugs for their utility in drug delivery and imaging. Additionally, their remarkable physicochemical attributes (biodegradability, satisfactory safety profile, abundance, and diversity in functionality and charge) can be tuned via postmodification, which offers numerous possibilities to develop theranostics with desired characteristics. Hence, we provide an overview of recent advances in polysaccharide matrix-based theranostics for drug delivery combined with magnetic resonance imaging, computed tomography, positron emission tomography, single photon emission computed tomography, and ultrasound imaging. Herein, we also summarize the toxicity assessment of polysaccharides, associated contrast agents, and nanotoxicity along with the challenges and future research directions.

Superior Peroxidase-Like activity of Gold Nanorattles in Ultrasensitive H2O2 Sensing and Antioxidant Screening

Nanozymes are artificial enzyme systems which are easy to produce, highly stable and cost-effective in comparison to natural enzymes. Herein, we evaluated the peroxidase like activity of gold nanorattles (AuNRTs) having a solid gold octahedron core and thin, porous cubic gold shell. We also prepared solid gold nanocube and nanosphere of similar sizes and surface charge as that of AuNRTs and compared its activity with standard horse radish peroxidase (HRP) enzyme. All the prepared nanostructures followed Michaelis-Menten kinetics as observed from their substrate vs initial reaction velocity plot using 3',5,5'-tetramethylbenzidine (TMB) as a substrate. The kinetic parameters demonstrated that AuNRTs possess the best nanozymatic activity with lowest K M and highest catalytic efficiency (K cat /K M ). The better activity of AuNRTs compared with other nanostructures and HRP could be attributed to the hollow porous structure with a solid core where different surfaces are available for the nanozymatic reaction. AuNRTs, being the best amongst the tested nanozymes were further used for the sensing of hydrogen peroxide (H 2 O 2 ) and it was able to sense H 2 O 2 down to 0.5 μM concentration. Further, two naturally occurring antioxidants, tannic acid and ascorbic acid showed inhibitory effect on the peroxidase like activity of AuNRTs in a concentration dependent manner which can be further be used for screening of antioxidants or for determining the antioxidant potential.

Recent advancements in synthesis and drug delivery utilization of polysaccharides-based nanocomposites: The important role of nanoparticles and layered double hydroxides

Drug delivery systems are explained as methods to deliver a specific drug to desired organs, tissues, and cells for drug release to diseases treatment. Recently, considerable development has been interested in stimuli-responsive nano-systems, which respond to the essential pathological and physicochemical issues in diseased sites. During the last decades, researchers in the world presented, investigated, and implemented novel different nanomaterials with a focus on developing drug delivery. Polysaccharides including chitosan, alginate, hyaluronic acid, gums, and cellulose, as natural bio-materials, are suitable candidates for designing and formulations of these nano-systems because of the outstanding merits such as bio-compatibility, bio-degradability, non-toxicity, and gelling characteristics. On the other side, nanoparticles including metals (Au, Ag), metal oxides (Fe₃O₄, ZnO, CuO), or non-metal oxides (SiO₂) and also, layered double hydroxides nanostructures have appealed significant consideration in the fields of biomedical therapeutics and cancer therapy owing to the bio-compatibility, great surface area, good chemical and mechanical features, and also proper magnetic characteristics. This comprehensive review provides an overview of current advancements in drug delivery strategies, and manufacturing methods using chitosan, alginate, hyaluronic acid, gums, and also, metals, metal oxides, non-metal oxides, and LDHs for delivery system uses.

Facile In-Situ Fabrication of a Ternary ZnO/TiO2/Ag Nanocomposite for Enhanced Bactericidal and Biocompatibility Properties

This paper presents for the first time a successful fabrication of ternary ZnO/TiO2/Ag nanocomposites consisting of zinc oxide (ZnO), titania (TiO2) and silver (Ag) nanoparticles (NPs) synthesised using Morinda citrifolia fruit (MCF) extract. ZnONPs were synthesised using the co-precipitation method, and TiO2 and Ag were introduced into the precursor solutions under microwave irradiation to obtain ZnO/TiO2/Ag nanocomposites (NCs). This material demonstrated enhanced bactericidal effect towards bacterial pathogens compared to that of the binary TiO2/Ag, Ag and TiO2 alone. In vitro cytotoxicity results of the as-synthesised ZnO/TiO2/AgNCs on RAW 264.7 macrophages and A549 cell lines revealed a negative role in cytotoxicity, but contributed astoundingly towards antimicrobials as compared of Ag alone and binary Ag/TiO2. This study shows that the resultant ternary metal/bi-semiconductor nanocomposites may provide a therapeutic strategy for the eradication of bacterial pathogens without affecting the healthy mammalian cells.