Caffeine-loaded gold nanoparticles conjugated with PLA-PEG-PLA copolymer for in vitro cytotoxicity and anti-inflammatory activity

Insights into the Engineered Gold Nanoparticle-Based Remedy for Supplementation Therapy of Ovarian Carcinoma

Chronic diseases, notably cancer, pose a significant global threat to human life. Oncologists and medical professionals addressing malignancies confront challenges such as toxicity and multidrug resistance. To tackle these issues, the focus has shifted toward the employment of multifunctional colloidal gold nanoparticles. This study aims to design pH-sensitive doxorubicin-loaded gold nanoparticles using polyvinylpyrrolidone. The cytotoxic efficacy of the designed gold nanoarchitecture and its doxorubicin counterpart was assessed in an in vitro model using the HeLa cell. In comparison to the free drug, experimental evaluations showed that the gold nanoarchitecture outperformed significantly lower unspecific drug leaching and efficiently delivered the payload in a controlled manner, boosting the chemotherapy outcomes. This work opens a streamlined approach for engineering gold nanoarchitecture that could be further expanded to incorporate other therapeutics and/or functional moieties that require optimized controlled delivery, offering a one-size-fits-all solution and paving the revolutionary adjustments to healthcare procedures.

Caffeine-loaded nano/micro-carriers: Techniques, bioavailability, and applications

Caffeine, as one of the most consumed bioactive compounds globally, has gained considerable attention during the last years. Considering the bitter taste and adverse effects of high levels of caffeine consumption, it is crucial to apply a strategy for masking the caffeine's bitter taste and facilitating its programmable deliverance within a long time. Other operational parameters such as food processing parameters, exposure to sunlight and oxygen, and gastrointestinal digestion could also degrade the phenolic compounds in general and caffeine in special. To overcome these challenges, various nano/micro-platforms have been fabricated, including lipid-based (e.g., nanoliposomal vehicles; nanoemulsions, double emulsions, Pickering emulsions; microemulsions; niosomal vehicles; solid lipid nanoparticles and nanostructured lipid carriers), as well as biopolymeric (e.g., nanoparticles; hydrogels, organogels, oleogels; nanofibers and nanotubes; protein-polysaccharide nanocomplexes, conjugates; cyclodextrin inclusion complexes) and inorganic (e.g., gold and silica nanoparticles) nano/micro-structures. In this review, the findings on various caffeine-loaded nano/micro-carriers and their potential applications in functional food products/supplements will be discussed. Also, the controlled release and bioavailability of encapsulated caffeine will be given, and finally, the toxicity and safety of encapsulated caffeine will be presented.

Targeted Gold Nanohybrids Functionalized with Folate-Hydrophobic-Quaternized Pullulan Delivering Camptothecin for Enhancing Hydrophobic Anticancer Drug Efficacy

This study presented a green, facile and efficient approach for a new combination of targeted gold nanohybrids functionalized with folate-hydrophobic-quaternized pullulan delivering hydrophobic camptothecin (CPT-GNHs@FHQ-PUL) to enhance the efficacy, selectivity, and safety of these systems. New formulations of spherical CPT-GNHs@FHQ-PUL obtained by bio-inspired strategy were fully characterized by TEM, EDS, DLS, zeta-potential, UV-vis, XRD, and ATR-FTIR analyses, showing a homogeneous particles size with an average size of approximately 10.97 ± 2.29 nm. CPT was successfully loaded on multifunctional GNHs@FHQ-PUL via intermolecular interactions. Moreover, pH-responsive CPT release from newly formulated-CPT-GNHs@FHQ-PUL exhibited a faster release rate under acidic conditions. The intelligent CPT-GNHs@FHQ-PUL (IC50 = 6.2 μM) displayed a 2.82-time higher cytotoxicity against human lung cancer cells (Chago-k1) than CPT alone (IC50 = 2.2 μM), while simultaneously exhibiting less toxicity toward normal human lung cells (Wi-38). These systems also showed specific uptake by folate receptor-mediated endocytosis, exhibited excellent anticancer activity, induced the death of cells by increasing apoptosis pathway (13.97%), and arrested the cell cycle at the G0-G1 phase. The results of this study showed that the delivery of CPT by smart GNHs@FHQ-PUL systems proved to be a promising strategy for increasing its chemotherapeutic effects.

A Review on Toxicity and Challenges in Transferability of Surface-functionalized Metallic Nanoparticles from Animal Models to Humans

Abstract The unique size and surface morphology of nanoparticles (NPs) have substantially influenced all aspects of human life, making nanotechnology a novel and promising field for various applications in biomedical sciences. Metallic NPs have gained immense interest over the last few decades due to their promising optical, electrical, and biological properties. However, the aggregation and the toxic nature of these NPs have restricted their utilization in more optimized applications. The optimum selection of biopolymers and biological macromolecules for surface functionalization of metallic NPs will significantly improve their biological applicability and biocompatibility. The present mini-review attempts to stress the overview of recent strategies involved in surface functionalization of metallic NPs, their specific biomedical applications, and comparison of their in vitro, ex vivo, and in vivo toxicities with non-functionalized metallic NPs. In addition, this review also discusses the various challenges for metallic NPs to undergo human clinical trials.

Caffeine-loaded gold nanoparticles: antibiofilm and anti-persister activities against pathogenic bacteria

The formation of biofilms by bacterial pathogens and the presence of persister cells in biofilms have become major concerns in the health sector, owing to their antibiotic resistance and tolerance. The transformation of bacterial pathogens into persister cells, either stochastically or due to stressful environmental factors, results in recalcitrant and recurring infections. Here, we sought to prepare gold nanoparticles from naturally occurring caffeine and explore their inhibitory action against biofilm formation and persister cells. Fourier transform infrared spectroscopy, UV-visible absorption spectroscopy, field emission transmission electron microscopy, energy-dispersive X-ray diffraction, and dynamic light scattering were used to characterize the gold nanoparticles obtained from caffeine (Caff-AuNPs). The Caff-AuNPs were found to exhibit a number of properties, including the ability to prevent biofilm formation, disperse mature biofilms, and kill different types of persister of gram-positive (Staphylococcus aureus and Listeria monocytogenes) and gram-negative (Pseudomonas aeruginosa and Escherichia coli) pathogenic bacteria. Microscopic analysis of the aforementioned bacterial cells, treated with Caff-AuNPs, revealed the bactericidal effect of Caff-AuNPs, although the underlying mechanism remains unknown. Collectively, the Caff-AuNPs synthesized in this study may be used as potential drugs to combat chronic infections caused by biofilm-forming pathogenic bacteria. KEY POINTS: • Biofilm and persister cells are clinically relevant, as they either prolong or completely resist antibiotic treatments. • Caffeine is used in the green synthesis of Caff-AuNPs, which have antibacterial and antibiofilm properties. • Caff-AuNPs are effective against various pathogenic bacterial persister cells.

New organic/inorganic nanohybrids of targeted pullulan derivative/gold nanoparticles for effective drug delivery systems

This study aimed to develop new organic/inorganic nanohybrids of targeted pullulan derivative/gold nanoparticles (FA-PABA-Q188-PUL@AuNPs) to improve the selectivity and efficacy of drugs. The chemical structure of targeted pullulan derivative, folic acid-decorated para-aminobenzoic acid-quat188-pullulan (FA-PABA-Q188-PUL), was designed for reducing, stabilizing, capping, and functionalizing AuNPs. Here, the key factors, including pH, temperature, and FA-PABA-Q188-PUL concentrations, were systematically optimized to control the morphology, size, and functionalization of multifunctional FA-PABA-Q188-PUL@AuNPs. Spherical FA-PABA-Q188-PUL@AuNPs obtained by a green, simple, and bio-inspired strategy under the optimum conditions were thoroughly characterized and had an average size of 12.6 ± 1.5 nm. The anticancer drug DOX was successfully loaded on monodispersed FA-PABA-Q188-PUL@AuNPs and the system exhibited excellent intracellular uptake, specificity, and physicochemical properties. The pH-responsive DOX release from FA-PABA-Q188-PUL@AuNPs-DOX showed fast release (85% after 72 h) under acidic conditions. Furthermore, FA-PABA-Q188-PUL@AuNPs-DOX enhanced the anticancer activity of DOX toward Chago-k1 cancer cells up to 4.8-fold and showed less cytotoxicity toward normal cells than free DOX. The FA-PABA-Q188-PUL@AuNPs-DOX induced the death of cells by increasing late apoptotic cells (26.4%) and arresting the cell cycle at S-G2/M phases. These results showed that innovative FA-PABA-Q188-PUL@AuNPs should be considered as new candidate platforms for anticancer drug delivery systems.

Metal-Based Nanostructures/PLGA Nanocomposites: Antimicrobial Activity, Cytotoxicity, and Their Biomedical Applications

Among the different synthetic polymers developed for biomedical applications, poly(lactic-co-glycolic acid) (PLGA) has attracted considerable attention because of its excellent biocompatibility and biodegradability. Nanocomposites based on PLGA and metal-based nanostructures (MNSs) have been employed extensively as an efficient strategy to improve the structural and functional properties of PLGA polymer. The MNSs have been used to impart new properties to PLGA, such as antimicrobial properties and labeling. In the present review, the different strategies available for the fabrication of MNS/PLGA nanocomposites and their applications in the biomedical field will be discussed, beginning with a description of the preparation routes, antimicrobial activity, and cytotoxicity concerns of MNS/PLGA nanocomposites. The biomedical applications of these nanocomposites, such as carriers and scaffolds in tissue regeneration and other therapies are subsequently reviewed. In addition, the potential advantages of using MNS/PLGA nanocomposites in treatment illnesses are analyzed based on in vitro and in vivo studies, to support the potential of these nanocomposites in future research in the biomedical field.

Development of Polymer Coacersome Structure with Enhanced Colloidal Stability for Therapeutic Protein Delivery

Poly(ethylene arginyl aspartate diglyceride) (PEAD) polycation is widely used to prepare coacervate particles by electrostatic complexation with an anionic heparin (HEP) in aqueous environments, for controlled release of therapeutic proteins. However, coacervate complexes aggregate randomly due to particle-particle charge interactions. Herein, a new term "coacersome" is introduced to represent a stable polyplex formed by complexation of mPEGylated PEAD and HEP. Methoxy polyethylene glycol (mPEG)-b-cationic PEAD diblock copolymers are synthesized and complexed with HEP to create a stable "coacersome" structure. Water-soluble mPEG moiety assembles on the surface of coacersomes in aqueous conditions and creates a steric barrier to avoid aggregation of coacersomes. The coacersomes are able to maintain their initial spherical morphology and size for longer durations in the presence of competing ions, such as 0.3 m NaCl. Additionally, the coacersomes exhibit biocompatibility toward human dermal fibroblasts, a high loading efficiency (>96%) for encapsulation of bone morphogenetic protein 2 (BMP-2), and a sustained release profile up to 28 days. The BMP-2-loaded coacersomes further exhibit increased osteogenic differentiation of human mesenchymal stem cells (hMSCs). The developed coacersome structures have the potential to be utilized as effective carriers for therapeutic protein delivery.

Development of Folate-Thioglycolate-Gold Nanoconjugates by Using Citric Acid-PEG Branched Polymer for Inhibition of MCF-7 Cancer Cell Proliferation

Development of folate (FA)-functionalized gold nanoparticles (AuNPs) has greatly increased in recent years due to their potential in cancer treatment. As surface functionalization of polymer-free AuNPs with thiol groups could result in agglomeration and precipitation, AuNPs should be stabilized with an efficient polymer. In this study, citric acid-PEG branched polymer (CPEG) acted as a reducing as well as stabilizing agent in the synthesis of AuNPs. The thiol group of thioglycolic acid (TGA) attached to CPEG-stabilized AuNPs and interacted with the free carboxylic acid group on the surface of TGA-AuNP nanoconjugates. Stable TGA-AuNP nanoconjugates were obtained only with CPEG-stabilized AuNPs and not with citrate-stabilized AuNPs. The carboxylic acid group on the surface of AuNPs was used to attach FA via an EDC/NHS coupling reaction to obtain FA-TGA-AuNP nanoconjugates. In vitro cytotoxicity studies indicated that FA-TGA-AuNPs were not toxic to normal cells up to a concentration of 200 μg/mL. However, FA-TGA-AuNP nanoconjugates effectively inhibited proliferation of MCF-7 cancer cells at a low concentration of 25 μg/mL after 3 days of incubation. The anticancer activity of FA-TGA-AuNPs was enhanced by incorporating the anticancer drug 5-fluorouracil into the nanoconjugates, which exhibited sustained drug release up to 5 days. Hence, the developed biocompatible FA-TGA-AuNPs could be used for specific killing of breast cancer cells.