Gold laced bio-macromolecules for theranostic application

Review of Advances in Coating and Functionalization of Gold Nanoparticles: From Theory to Biomedical Application

Nanoparticles, especially gold nanoparticles (Au NPs) have gained increasing interest in biomedical applications. Used for disease prevention, diagnosis and therapies, its significant advantages in therapeutic efficacy and safety have been the main target of interest. Its application in immune system prevention, stability in physiological environments and cell membranes, low toxicity and optimal bioperformances are critical to the success of engineered nanomaterials. Its unique optical properties are great attractors. Recently, several physical and chemical methods for coating these NPs have been widely used. Biomolecules such as DNA, RNA, peptides, antibodies, proteins, carbohydrates and biopolymers, among others, have been widely used in coatings of Au NPs for various biomedical applications, thus increasing their biocompatibility while maintaining their biological functions. This review mainly presents a general and representative view of the different types of coatings and Au NP functionalization using various biomolecules, strategies and functionalization mechanisms.

A comprehensive review on nanocomposite biomaterials based on gelatin for bone tissue engineering

The creation of a suitable scaffold is a crucial step in the process of bone tissue engineering (BTE). The scaffold, acting as an artificial extracellular matrix, plays a significant role in determining the fate of cells by affecting their proliferation and differentiation in BTE. Therefore, careful consideration should be given to the fabrication approach and materials used for scaffold preparation. Natural polypeptides such as gelatin and collagen have been widely used for this purpose. The unique properties of nanoparticles, which vary depending on their size, charge, and physicochemical properties, have demonstrated potential in solving various challenges encountered in BTE. Therefore, nanocomposite biomaterials consisting of polymers and nanoparticles have been extensively used for BTE. Gelatin has also been utilized in combination with other nanomaterials to apply for this purpose. Composites of gelatin with various types of nanoparticles are particularly promising for creating scaffolds with superior biological and physicochemical properties. This review explores the use of nanocomposite biomaterials based on gelatin and various types of nanoparticles together for applications in bone tissue engineering.

Evaluation and mechanism of immune enhancement effects of Pleurotus ferulae polysaccharides-gold nanoparticles

We previously demonstrated that Pleurotus ferulae polysaccharide (PFPS) promoted dendritic cell (DC) maturation through the TLR4 signaling pathway. To improve PFPS activity and bioavailability, gold nanoparticles with PFPS (PFPS-Au NPs) were synthesized. Of note, although the polysaccharide content of PFPS-Au NPs was only one tenth of PFPS, PFPS-Au NPs enhanced the immunostimulatory activities of PFPS in the maturation and function of dendritic cells (DCs) by TLR4 and NLRP3 signaling pathways, evidenced by stronger activation of the down-stream MAPK and NF-κB pathways and NLRP3 inflammasome pathway. More importantly, PFPS-Au NPs enhanced DC migration and murine immunity, particularly in type 1 T-helper cell responses. Moreover, the half-life of PFPS-Au NPs (2.217 ± 0.187 h) was longer than that of PFPS (1.39 ± 0.257 h) in the blood and the distribution of PFPS-Au NPs (19.8 %) in the spleen was significantly increased compared with PFPS (13.3 %), indicating the improved bioavailability in vivo. PFPS-Au NPs as an adjuvant promoted antigen-specific cellular immune responses to an HPV DC-based vaccine, which significantly inhibited the growth of TC-1 tumors in mice. All results suggest that the prepared Au NPs could enhance PFPS-immunostimulatory activity, which will pave the way for PFPS-Au NPs to be applied in clinical trials.

Curcumin loaded gold nanoparticles-chitosan/sodium alginate nanocomposite for nanotheranostic applications

A solvent casting technique was used for the preparation of biomimetic nanocomposites scaffolds at three various concentrations of Curcumin loaded gold nanoparticles (Cur-AuNPs-1, 1.5, and 2 ml) as filler materials with chitosan-sodium alginate composite. The physico-chemical properties of prepared Cu-Au NPs and biomimetic nanocomposites were analyzed using various characterization techniques. In vitro biocompatibility of biomimetic nanocomposites are determined using simulated body fluid for biomineralization property, HAp formation and phosphate buffer saline (PBS) for swelling property, protein adsorption. Antibacterial activity of Cur-Au NPs and their nanocomposites carried out against Escherichia coli (E. coli) and Staphylococcus aureus. In vitro cytotoxicity of Cur-AuNPs is identified against UC-6 and MDA-MB 231 cell lines. The use of above studies and activity of Cur-AuNPs with contain biomimetic nanocomposites can adoptable for nanotheranostics.

Functionalization strategies of polymeric nanoparticles for drug delivery in Alzheimer’s disease: Current trends and future perspectives

Alzheimer’s disease (AD), the most common form of dementia, is a progressive and multifactorial neurodegenerative disorder whose primary causes are mostly unknown. Due to the increase in life expectancy of world population, including developing countries, AD, whose incidence rises dramatically with age, is at the forefront among neurodegenerative diseases. Moreover, a definitive cure is not yet within reach, imposing substantial medical and public health burdens at every latitude. Therefore, the effort to devise novel and effective therapeutic strategies is still of paramount importance. Genetic, functional, structural and biochemical studies all indicate that new and efficacious drug delivery strategies interfere at different levels with various cellular and molecular targets. Over the last few decades, therapeutic development of nanomedicine at preclinical stage has shown to progress at a fast pace, thus paving the way for its potential impact on human health in improving prevention, diagnosis, and treatment of age-related neurodegenerative disorders, including AD. Clinical translation of nano-based therapeutics, despite current limitations, may present important advantages and innovation to be exploited in the neuroscience field as well. In this state-of-the-art review article, we present the most promising applications of polymeric nanoparticle-mediated drug delivery for bypassing the blood-brain barrier of AD preclinical models and boost pharmacological safety and efficacy. In particular, novel strategic chemical functionalization of polymeric nanocarriers that could be successfully employed for treating AD are thoroughly described. Emphasis is also placed on nanotheranostics as both potential therapeutic and diagnostic tool for targeted treatments. Our review highlights the emerging role of nanomedicine in the management of AD, providing the readers with an overview of the nanostrategies currently available to develop future therapeutic applications against this chronic neurodegenerative disease.

Polysaccharide-based substrate for surface-enhanced Raman spectroscopy

Surface-enhanced Raman spectroscopy (SERS) became a useful analytical technique with the development of appropriate metallic substrates. The need for SERS substrates that immobilize metallic nanoparticles prompted this work to search for an appropriate material. This work presents the preparation, characterization and application of a SERS substrate for crystal violet (CV) detection, as the probe molecule. The inner layer of the substrate is a thin film of the fungal β-D-glucan, botryosphaeran, covered by a thin layer of silver nanoparticles (AgNPs). The nanoparticles were produced by laser ablation, a fast and clean method for their preparation, and the layers were assembled by casting. Scanning electron and atomic force microscopies, UV-VIS and Raman spectroscopy and X-ray diffraction allowed the characterization of the surface of the substrate. Analysis by Raman spectroscopy showed promising results for SERS amplification on the substrate. Detection of CV reached enhancement factors up to 10⁶ orders of magnitude, compared to normal Raman spectra. Linearity was observed for analyses on the SERS substrate at concentration ranges of 0.005 to 1 µmol L^-1. The assembly reached the detection of 12 pmol cm^-2 of CV, which corresponds to 96 fg of the probe molecule contained in the area of the substrate effectively interacting with the laser. The substrate was more efficient than silver colloids to perform SERS.

Cyclodextrin capped gold nanoparticles (AuNP@CDs): from synthesis to applications

The synthesis of AuNP@CDs is summarized according to the type and order of bonding. The applications of AuNP@CDs are also highlighted.

Review on marine carbohydrate-based gold nanoparticles represented by alginate and chitosan for biomedical application

Gold nanoparticles (AuNPs) have been attracted considerable attention in cancer therapy, drug delivery and other applications due to their unique physical, chemical, and optical properties. Marine carbohydrates are important biological macromolecules that widely exist in marine algae and animals, such as alginate, carrageenan, porphyran, fucoidan, ulvan, agarose, and chitosan. Their excellent properties, such as biocompatibility, biodegradability and no irritation, make them widely used in biomedicine and nanomaterials fields. More importantly, they can be easily modified by functional groups, such as sulfation, acetylation, and carboxylation, to further extend their applications. The marine carbohydrates functionalized AuNPs can increase their biocompatibility and targeting in a green preparation method. Here, we review recent advances on marine carbohydrate-based AuNPs for cancer therapy, imaging, drug delivery and other biomedical fields. The topics of selective surface modification in different carbohydrates and further biomedical applications of AuNPs are also discussed.

Exploring the Gelation Mechanisms and Cytocompatibility of Gold (III)-Mediated Regenerated and Thiolated Silk Fibroin Hydrogels

Accelerating the gelation of silk fibroin (SF) solution from several days or weeks to minutes or few hours is critical for several applications (e.g., cell encapsulation, bio-ink for 3D printing, and injectable controlled release). In this study, the rapid gelation of SF induced by a gold salt (Au3+) as well as the cytocompatibility of Au3+-mediated SF hydrogels are reported. The gelation behaviors and mechanisms of regenerated SF and thiolated SF (tSF) were compared. Hydrogels can be obtained immediately after mixing or within three days depending on the types of silk proteins used and amount of Au3+. Au3+-mediated SF and tSF hydrogels showed different color appearances. The color of Au-SF hydrogels was purple-red, whereas the Au-tSF hydrogels maintained their initial solution color, indicating different gelation mechanisms. The reduction of Au3+ by amino groups and further reduction to Au by tyrosine present in SF, resulting in a dityrosine bonding and Au nanoparticles (NPs) production, are proposed as underlying mechanisms of Au-SF gel formation. Thiol groups of the tSF reduced Au3+ to Au+ and formed a disulfide bond, before a formation of Au+-S bonds. Protons generated during the reactions between Au3+ and SF or tSF led to a decrease of the local pH, which affected the chain aggregation of the SF, and induced the conformational transition of SF protein to beta sheet. The cytocompatibility of the Au-SF and tSF hydrogels was demonstrated by culturing with a L929 cell line, indicating that the developed hydrogels can be promising 3D matrices for different biomedical applications.

One-Minute Synthesis of Size-Controlled Fucoidan-Gold Nanosystems: Antitumoral Activity and Dark Field Imaging

Gold nanoparticles (AuNPs) are one of the most studied nanosystems with great potential for biomedical applications, including cancer therapy. Although some gold-based systems have been described, the use of green and faster methods that allow the control of their properties is of prime importance. Thus, the present study reports a one-minute microwave-assisted synthesis of fucoidan-coated AuNPs with controllable size and high antitumoral activity. The NPs were synthesized using a fucoidan-enriched fraction extracted from Fucus vesiculosus, as the reducing and capping agent. The ensuing monodispersed and spherical NPs exhibit tiny diameters between 5.8 and 13.4 nm for concentrations of fucoidan between 0.5 and 0.05% (w/v), respectively, as excellent colloidal stability in distinct solutions and culture media. Furthermore, the NPs present antitumoral activity against three human tumor cell lines (MNT-1, HepG2, and MG-63), and flow cytometry in combination with dark-field imaging confirmed the cellular uptake of NPs by MG-63 cell line.

Immunoactive polysaccharide functionalized gold nanocomposites promote dendritic cell stimulation and antitumor effects

Aim: To investigate the immune responses and antitumor efficacy of immunoactive polysaccharide functionalized gold nanocomposites (APS-AuNP). Materials & methods: Immunoregulation of APS-AuNP on dendritic cells/T cells in vitro was evaluated by flow cytometry and their inhibitions against primary/metastatic tumors were determined on 4T1-bearing mice model. Results & conclusion: APS-AuNP exhibited remarkable capability to induce dendritic cells maturation through phenotypic markers with functional changes, which further promoted T-cell proliferation and enhanced cytotoxicity against 4T1 tumor cells. The inhibitory rate of APS-AuNP against 4T1 primary tumor growth and pulmonary metastasis in mice was higher than paclitaxel-treated group. In addition, APS-AuNP exhibited strong capability to increase the population of CD4+/CD8+ T lymphocytes as well as effector memory cells rather than central memory cells.

Combining Cellulose and Cyclodextrins: Fascinating Designs for Materials and Pharmaceutics

Cellulose and cyclodextrins possess unique properties that can be tailored, combined, and used in a considerable number of applications, including textiles, coatings, sensors, and drug delivery systems. Successfully structuring and applying cellulose and cyclodextrins conjugates requires a deep understanding of the relation between structural, and soft matter behavior, materials, energy, and function. This review focuses on the key advances in developing materials based on these conjugates. Relevant aspects regarding structural variations, methods of synthesis, processing and functionalization, and corresponding supramolecular properties are presented. The use of cellulose/cyclodextrin conjugates as intelligent platforms for applications in materials science and pharmaceutical technology is also outlined, focusing on drug delivery, textiles, and sensors.

In vitro hemocompatability evaluation of gold nanoparticles capped with Lactobacillus plantarum derived lipase1

BACKGROUND

Gold nanoparticles (GNPs) are key diagnostic and therapeutic agents in biomedical sciences. Several studies have been carried out in different therapeutic areas such as in cancer treatment, antibacterial topical agents, imaging agents etc. There is a necessity to evaluate the gold nanoparticles cytotoxicity at all fronts. Since blood is the first point of contact in any therapy, it is required to have a thorough in vitro investigation of gold nanoparticles to avoid any adverse effects.

OBJECTIVE

The objective of the current study is to evaluate the effect of gold nanoparticles capped with lipase on blood clotting factors, platelets, coagulation time and blood clotting strength.

METHODS

Whole blood samples were drawn from healthy volunteers. Plasma and plasma with platelets were isolated from the blood and all the samples were treated with lipase capped gold nanoparticles, except control. Plasma fibrinogen formed in the blood coagulation process after contacting with nanoparticles was quantitatively evaluated. In addition, platelet aggregation, blood clotting kinetics, strength of the blood clot and time were evaluated post nanoparticle treatment.

RESULTS

The work primarily explores the effect of GNPs on blood with changing concentrations of lipase capping. Plasma fibrinogen levels of plasma samples were found to be moderately elevated, however, there is no significant effect on blood clotting kinetics, strength, and platelet aggregation. Also, the study showed that lipase capped GNPs did not result in aggregation upon interaction with plasma components and remained stable for 1 hour after incubation.

CONCLUSIONS

Our study revealed that lipase capped GNPs synthesized using NaBH4 approach were stable and hemocompatible. There is an increase in fibrinogen levels after the exposure to nanoparticles, an observation which is consistent with other studies. However, the functional consequences of such increase are unknown. The results of no significant platelet aggregation, change in blood clotting time, kinetics, and clot strength revealed the non-toxic effect of lipase capped GNPs towards blood components, which is essential for any in vivo applications.

Recent advances in cell-mediated nanomaterial delivery systems for photothermal therapy

Cell-mediated “Trojan Horse” delivery vehicles overcome the drug delivery barriers to transport nano-agents enhancing the efficiency of photothermal therapy.