Gold embedded chitosan nanoparticles with cell membrane mimetic polymer coating for pH-sensitive controlled drug release and cellular fluorescence imaging

Recent studies on proteins and polysaccharides-based pH-responsive fluorescent materials

Polymer-based pH-responsive fluorescent materials have the characteristics of fast response, real-time monitoring, visualisation, and easy forming. Consequently, they have attracted widespread attention in wound healing, sweat monitoring, security and anti-counterfeiting, freshness detection of aquatic products, metal-ion sensing and bioimaging. This paper analyses the preparation principles and characteristics of pH-responsive fluorescent materials based on cellulose, chitosan and proteins. It then outlines the fluorescence properties, environmental response mechanisms and applications of various luminescent materials. Next, the research indicates that amines, N-heterocyclic rings, carboxyl groups and amino plasmonic groups on the fluorescent molecule structure and polymer skeleton appear to change the degree of ionisation under acid or alkali stimulation, which affects the light absorption ability of chromophore electrons, thus producing fluorescence changes in fluorescent materials under different pH stimuli. On this basis, the challenges and growth encountered in the development of proteins and polysaccharides-based pH-responsive fluorescent materials were prospected to provide theoretical references and technical support for constructing pH-responsive fluorescent materials with high stability, high sensitivity, long-lasting pH-response and wide detection range.

Gold Nanoparticles: Construction for Drug Delivery and Application in Cancer Immunotherapy

Cancer immunotherapy is an innovative treatment strategy to enhance the ability of the immune system to recognize and eliminate cancer cells. However, dose limitations, low response rates, and adverse immune events pose significant challenges. To address these limitations, gold nanoparticles (AuNPs) have been explored as immunotherapeutic drug carriers owing to their stability, surface versatility, and excellent optical properties. This review provides an overview of the advanced synthesis routes for AuNPs and their utilization as drug carriers to improve precision therapies. The review also emphasises various aspects of AuNP-based immunotherapy, including drug loading, targeting strategies, and drug release mechanisms. The application of AuNPs combined with cancer immunotherapy and their therapeutic efficacy are briefly discussed. Overall, we aimed to provide a recent understanding of the advances, challenges, and prospects of AuNPs for anticancer applications.

Enhanced photocatalytic activity of modified black phosphorus-incorporated PANi/PAN nanofibers

Enhancement of the photocatalytic activity of black phosphorus (BP) is a highly challenging proposition. The fabrication of electrospun composite nanofibers (NFs) through the incorporation of modified BP nanosheets (BPNs) into conductive polymeric NFs has been recently introduced as a newer strategy not only to enhance the photocatalytic activity of BPNs but also to overcome their drawbacks including ambient instability, aggregation, and hard recycling, which exist in their nanoscale powdered forms. The proposed composite NFs were prepared through the incorporation of silver (Ag)-modified BPNs, gold (Au)-modified BPNs, and graphene oxide (GO)-modified BPNs into polyaniline/polyacrylonitrile (PANi/PAN) NFs by an electrospinning process. The successful preparation of the modified BPNs and electrospun NFs was confirmed by the characterization techniques of Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis), powder X-ray diffraction (PXRD), and Raman spectroscopy. The pure PANi/PAN NFs exhibited high thermal stability with a main weight loss of ∼23% for the temperature range of 390-500 °C, and the thermal stability of NFs was enhanced after their incorporation with the modified BPNs. The BPNs@GO-incorporated PANi/PAN NFs indicated improved mechanical properties compared to the pure PANi/PAN NFs with tensile strength (TS) of 1.83 MPa and elongation at break (EAB) of 24.91%. The wettability of the composite NFs was measured in the range of 35-36°, which exhibited their good hydrophilicity. The photodegradation performance was found in the sequence of BPNs@GO > BPNs@Au > BPNs@Ag > bulk BP ∼BPNs > red phosphorus (RP) for methyl orange (MO) and in the sequence of BPNs@GO > BPNs@Ag > BPNs@Au > bulk BP > BPNs > RP for methylene blue (MB), accordingly. The composite NFs degraded the MO and MB dyes more efficiently relative to the modified BPNs and pure PANi/PAN NFs.

Chitosan-Imidazolium Core-Shell Nanoparticles of Gd-Mn-Mo Polyoxometalate as Novel Potential MRI Nano-Agent for Breast Cancer Detection

Polyoxometalates (POMs) are mineral nanoclusters with many advantages in various diagnostic fields, in particular cancer detection. This study aimed to synthesize and evaluate the performance of gadolinium-manganese-molybdenum polyoxometalate (Gd-Mn-Mo; POM) nanoparticles coated with chitosan-imidazolium (POM@CSIm NPs) for detecting 4T1 breast cancer cells by magnetic resonance imaging in vitro and in vivo. The POM@Cs-Im NPs were fabricated and characterized by FTIR, ICP-OES, CHNS, UV-visible, XRD, VSM, DLS, Zeta potential, and SEM. Cytotoxicity, cellular uptake, and MR imaging in vivo and in vitro of L929 and 4T1 cells were also assessed. The efficacy of nanoclusters was demonstrated using MR images of BALB/C mice bearing a 4T1 tumor in vivo. The evaluation of the in vitro cytotoxicity of the designed NPs showed their high biocompatibility. In fluorescence imaging and flow cytometry, NPs had a higher uptake rate by 4T1 than L929 (p < 0.05). Furthermore, NPs significantly increased the signal strength of MR images, and its relaxivity (r1) was calculated as 4.71 mM^-1 s^-1. MR imaging also confirmed the attachment of nanoclusters to cancer cells and their selective accumulation in the tumor region. Overall, the results showed that fabricated POM@CSIm NPs have considerable potential as an MR imaging nano-agent for early 4T1 cancer detection.

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.

Research update on cell membrane camouflaged nanoparticles for cancer therapy

Cell membrane-camouflaged biomimetic functionalization of nanoparticles has emerged as a promising strategy for cancer theranostics. These cell membranes used for camouflaging are generally isolated from natural or engineered erythrocytes, neutrophils, macrophages, T lymphatic cells, stem cells, and cancer cells. The camouflaging strategy of coating nanoparticles with cell membranes allows for tumor homotypic targeting through self-recognition as source cells, immune evasion, and a prolonged blood circulation time, thereby improving the effective payload delivery and tumor therapy. More so, some engineered cell membranes with functionalized peptides, proteins and moieties on membrane surface can be transferred for therapy in the same time. In this review, we summarize the latest research on various types of cell membrane-camouflaged nanoparticles aimed at anti-cancer therapy, focusing on the biological advantages of different cell membranes, constitutions of nanoparticles, fabrication processes, key findings, potential therapies, and discuss the major challenges and future opportunities.

Laser Enhanced Combinatorial Chemo-photothermal Therapy of Green Synthesis Gold Nanoparticles Loaded with 6Mercaptopurine on Breast Cancer Model

Purpose

We tend to evaluated a method for loading 6Mercaptopurine (6MP) on green synthesized hybrid chitosan gold nanoparticles (AuNPs) forming 6MP-AuNPs nanocomposite for the first time in combinatorial chemo-photothermal therapy.

Methods

The AuNPs were synthesized using chitosan as a reducing and capping agent. Different concentrations of 6MP were mixed AuNPs. Cells were incubated with 6MP and 6MP loaded AuNPs for 48 h and then exposed to laser.

Results

AuNPs and 6MP-AuNPs nanocomposite have small sizes of 18 ± 4 and 25 ± 5 nm and exhibit high stability with Zeta potential of 55.9 ± 6.3 and 57 ± 4 mV. 6MP-AuNPs nanocomposite irradiated with Diode Pumped Solid State (DPSS) laser showed a maximum inhibition in cell viability reaching 63% at 1.25 µM.

Conclusions

A hybrid chitosan gold nanoparticle is a powerful anti-cancer drug carrier as well as photothermal agent in combinatorial chemo-photothermal therapy.

Mesoporous silica@chitosan@gold nanoparticles as "on/off" optical biosensor and pH-sensitive theranostic platform against cancer

A cancer nanotheranostic system was fabricated based on mesoporous silica@chitosan@gold (MCM@CS@Au) nanosystem targeted by aptamer toward the MUC-1 positive tumor cells. Subsequently, curcumin as an efficient herbal anticancer drug was first encapsulated into chitosan-triphosphate nanoparticles and then the resulted nanoparticle was loaded into the nanosystem (MCM@CS@Au-Apt). The nanosystem successful fabrication was approved at each synthesis step through FTIR, XRD, BET, DLS, FE-SEM, HRTEM, and fluorescence spectroscopy. Besides, the interaction between aptamer and curcumin was evaluated using full atomistic molecular dynamics simulations. The mechanism of curcumin release was likewise investigated through different kinetic models. Afterwards, the potential of the designed nanosystem in targeted imaging, and drug delivery was evaluated using fluorescence microscopy and flow cytometry. It was found that the energy transfer between the base pairs in the hairpin of double strands of DNA aptamer acts as a quencher for MCM@CS@Au fluorescence culminating in an "on/off" optical biosensor. On the other hand, the presence of pH-sensitive chitosan nanoparticles creates smart nanosystem to deliver more curcumin into the desired cells. Indeed, when the aptamer specifically binds to the MUC-1 receptor, its double strands separate under the low pH condition, leading to the drug release and the recovery of the fluorescence ("On" state). Based on the toxicity results, this nanosystem had more toxicity toward the MUC-1-positive tumor cells than MUC-1-negative cells, representing its selective targeting. Therefore, this nanosystem could be introduced as a smart anticancer nanotheranostic system for tracing particular biomarkers (MUC-1), non-invasive fluorescence imaging, and targeted curcumin delivery.

Green Metallic Nanoparticles for Cancer Therapy: Evaluation Models and Cancer Applications

Metal-based nanoparticles are widely used to deliver bioactive molecules and drugs to improve cancer therapy. Several research works have highlighted the synthesis of gold and silver nanoparticles by green chemistry, using biological entities to minimize the use of solvents and control their physicochemical and biological properties. Recent advances in evaluating the anticancer effect of green biogenic Au and Ag nanoparticles are mainly focused on the use of conventional 2D cell culture and in vivo murine models that allow determination of the half-maximal inhibitory concentration, a critical parameter to move forward clinical trials. However, the interaction between nanoparticles and the tumor microenvironment is not yet fully understood. Therefore, it is necessary to develop more human-like evaluation models or to improve the existing ones for a better understanding of the molecular bases of cancer. This review provides recent advances in biosynthesized Au and Ag nanoparticles for seven of the most common and relevant cancers and their biological assessment. In addition, it provides a general idea of the in silico, in vitro, ex vivo, and in vivo models used for the anticancer evaluation of green biogenic metal-based nanoparticles.

Biosynthesis of chitosan-coated iron oxide (Fe3O4) hybrid nanocomposites from leaf extracts of Brassica oleracea L. and study on their antibacterial potentials

In this study, we prepared chitosan (CS)-coated iron oxide (Fe₃O₄) nanocomposites (NCs) by employing the aqueous leaf extract of Brassica oleracea L. and evaluated its antimicrobial potential. The characterization of hybrid CS-Fe₃O₄ NCs was performed using Fourier-transform infrared spectroscopy (FTIR) analysis to evaluate the chemical bonding of chitosan to nanoparticles (NPs). X-ray photoelectron spectroscopy (XPS) studies revealed the presence of oxidation state elements Fe 2p, O 1s, N 1s, and C 1s, and the zeta potential analysis was found to have well-colloidal stability (+ 76.9 mV) of NCs. Transmission electron microscopy (TEM) analysis determined that CS-Fe₃O₄ NCs were spherical with an average particle size of 27 nm. The X-ray diffractometer (XRD) spectrum ascertained the crystallinity of the hybrid NCs and the vibrating sample magnetometer (VSM) inferred the ferromagnetic behavior of the synthesized NCs. Furthermore, the significant antibacterial efficacy of NPs was demonstrated against foodborne bacterial pathogens, such as Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), and the highest zone of inhibition was observed to be 11.5 mm and 13.5 mm in CS-Fe₃O₄ NCs, respectively. In comparison with Fe₃O₄ NPs, synergistic impacts of CS-Fe₃O₄ NCs displayed great antibacterial potential as exhibited by a clearly enlarged zone. Thus, CS-Fe₃O₄ NCs could be used as efficacious antimicrobial agents in food packaging and food preservation fields.

Roles of Chitosan in Green Synthesis of Metal Nanoparticles for Biomedical Applications

Chitosan (CS) is a well-known stabilizer for metal nanoparticles in biomedical engineering. However, very few studies have explored other important roles of CS including reducing, shape-directing, and size-controlling. This review aims to provide the latest and most comprehensive overview of the roles of CS in the green synthesis of metal nanoparticles for biomedical applications. To the best of our knowledge, this is the first review that highlights these potentialities of CS. At first, a brief overview of the properties and the bioactivity of CS is presented. Next, the benefits of CS for enhancing the physicochemical behaviors of metal nanoparticles are discussed in detail. The representative biomedical applications of CS-metal nanoparticles are also given. Lastly, the review outlines the perceptual vision for the future development of CS-metal nanoparticles in the biomedicine field.