Transferrin-Conjugated Biodegradable Graphene for Targeted Radiofrequency Ablation of Hepatocellular Carcinoma

Peptide-Mediated Nanocarriers for Targeted Drug Delivery: Developments and Strategies

Effective drug delivery is essential for cancer treatment. Drug delivery systems, which can be tailored to targeted transport and integrated tumor therapy, are vital in improving the efficiency of cancer treatment. Peptides play a significant role in various biological and physiological functions and offer high design flexibility, excellent biocompatibility, adjustable morphology, and biodegradability, making them promising candidates for drug delivery. This paper reviews peptide-mediated drug delivery systems, focusing on self-assembled peptides and peptide-drug conjugates. It discusses the mechanisms and structural control of self-assembled peptides, the varieties and roles of peptide-drug conjugates, and strategies to augment peptide stability. The review concludes by addressing challenges and future directions.

Remotely Activated Nanoparticles for Anticancer Therapy

Cancer has nowadays become one of the leading causes of death worldwide. Conventional anticancer approaches are associated with different limitations. Therefore, innovative methodologies are being investigated, and several researchers propose the use of remotely activated nanoparticles to trigger cancer cell death. The idea is to conjugate two different components, i.e., an external physical input and nanoparticles. Both are given in a harmless dose that once combined together act synergistically to therapeutically treat the cell or tissue of interest, thus also limiting the negative outcomes for the surrounding tissues. Tuning both the properties of the nanomaterial and the involved triggering stimulus, it is possible furthermore to achieve not only a therapeutic effect, but also a powerful platform for imaging at the same time, obtaining a nano-theranostic application. In the present review, we highlight the role of nanoparticles as therapeutic or theranostic tools, thus excluding the cases where a molecular drug is activated. We thus present many examples where the highly cytotoxic power only derives from the active interaction between different physical inputs and nanoparticles. We perform a special focus on mechanical waves responding nanoparticles, in which remotely activated nanoparticles directly become therapeutic agents without the need of the administration of chemotherapeutics or sonosensitizing drugs.

Total Eradication of Bacterial Infection in Root Canal Treatment: An Electrochemical Approach

According to the American Association of Endodontists, currently 22.3 million endodontic procedures are being performed annually with the success rate of 70-95% and the average survival rate of the root canal procedure is approximately 67% after 5 years and 56% after 8 years. One of the major reason for the failure is relapse of infection. Hence, it is imperative to develop an assistive or alternative method to eradicate the bacterial infection effectively without affecting patient compliance. The application of electrochemistry has been used previously to disinfect catheters and implant disinfection. Hence, the aim of this study is to utilize the principles of electrochemistry to develop a microelectronic device to eradicate bacterial infection for root canal treatment. The electrochemical protocol includes open circuit potential (60 s) and potentiostatic scan at varying voltage (-9 to +2 V) at a different time duration (1-5 min). Enterococcus faecalis in the form of planktonic and biofilm was used in this study. After electrochemical treatment, the bacterial viability was evaluated using alamarBlue assay, colony forming units, confocal microscopy, and scanning electron microscopy. Cytotoxicity evoked by electrochemical voltage in comparison to NaOCl solution was performed using osteoblasts in 2D and 3D cell culture systems. The results of the study show that the application of -2 to +2 V at 1-5 min did not show any significant reduction in bacterial growth. However, the cathodic voltage of -9 V for 5 min showed a significant reduction (p < 0.001) in the bacterial count (80-95%). Similar results were obtained from biofilm study, which is more realistic to the in vivo condition. In contrast, the method did not induce cytotoxicity to the cells in 3D culture system (65% viability) in comparison to the highly toxic nature (0% viability) of NaOCl, indicating better patient compliance. Hence, the study provides supporting evidence to develop an electrochemically driven microelectronic device that can be a potential assistive dental instrument for endodontic procedures.

Multifunctional fluorescent iron quantum clusters for non-invasive radiofrequency ablationof cancer cells

This work reports the potential of iron quantum clusters (FeQCs) as a hyperthermia agent for cancer, by testing its in-vitro response to shortwave (MHz range), radiofrequency (RF) waves non-invasively. Stable, fluorescent FeQCs of size ∼1 nm prepared by facile aqueous chemistry from endogenous protein haemoglobin were found to give a high thermal response, with a ΔT ∼50 °C at concentrationsas low as165 μg/mL. The as-prepared nanoclusters purified by lyophilization as well as dialysis showed a concentration, power and time-dependent RF response, with the lyophilized FeQCs exhibiting pronounced heating effects. FeQCs were found to be cytocompatible to NIH-3T3 fibroblast and 4T1 cancer cells treated at concentrations upto 1000 μg/mL for 24 h. Upon incubation with FeQCs and exposure to RF waves, significant cancer cell death was observed which proves its therapeutic ability. The fluorescent ability of the clusters could additionally be utilized for imaging cancer cells upon excitation at ∼450 nm. Further, to demonstrate the feasibility of imparting additional functionality such as drug/biomolecule/dye loading to FeQCs, they were self assembled with cationic polymers to form nanoparticles. Self assembly did not alter the RF heating potential of FeQCs and additionally enhanced its fluorescence. The multifunctional fluorescent FeQCs therefore show good promise as a novel therapeutic agent for RF hyperthermia and drug loading.

GO-AgCl/Ag nanocomposites with enhanced visible light-driven catalytic properties for antibacterial and biofilm-disrupting applications

Nanomaterials with visible light-driven photocatalytic activity have attracted much attention due to their excellent abilities in degradation of various organic pollutants as well as inactivating bacteria. Herein, graphene oxide (GO) enwrapped silver chloride/silver (AgCl/Ag) nanocomposites with high visible light absorption were designed and fabricated as efficient antibacterial agents. AgCl NPs were synthesized in the presence of GO first and Ag NPs were coated on AgCl surface by heat reduction to form GO-AgCl/Ag nanocomposites. The as prepared nanocomposites revealed improved stability, higher absorption properties in the visible light region. The enhanced antibacterial activity was observed by quantification of colony forming units (CFU) and morphological changes of bacteria. The antibacterial mechanism of GO-AgCl/Ag was also investigated by evaluating membrane permeability and ROS level. Moreover, GO-AgCl/Ag composites can eliminate bacterial biofilms more efficiently under visible light irradiation. Our results provide new insights into the design of new multifunctional systems for antibacterial applications.

Photothermal Effect Enhanced Cascade-Targeting Strategy for Improved Pancreatic Cancer Therapy by Gold Nanoshell@Mesoporous Silica Nanorod

Pancreatic cancer, one of the leading causes of cancer-related mortality, is characterized by desmoplasia and hypovascular cancerous tissue, with a 5 year survival rate of <8%. To overcome the severe resistance of pancreatic cancer to conventional therapies, we synthesized gold nanoshell-coated rod-like mesoporous silica (GNRS) nanoparticles which integrated cascade tumor targeting (mediated by photothermal effect and molecular receptor binding) and photothermal treatment-enhanced gemcitabine chemotherapy, under mild near-infrared laser irradiation condition. GNRS significantly improved gemcitabine penetration and accumulation in tumor tissues, thus destroying the dense stroma barrier of pancreatic cancer and reinforcing chemosensitivity in mice. Our current findings strongly support the notion that further development of this integrated plasmonic photothermal strategy may represent a promising translational nanoformulation for effective treatment of pancreatic cancer with integral cascade tumor targeting strategy and enhanced drug delivery efficacy.

Recent advances in carbon based nanosystems for cancer theranostics

This review deals with four different types of carbon allotrope based nanosystems and summarizes the results of recent studies that are likely to have applications in cancer theranostics. We discuss the applications of these nanosystems for cancer imaging, drug delivery, hyperthermia, and PDT/TA/PA.

Biomedical Potential of Ultrafine Ag/AgCl Nanoparticles Coated on Graphene with Special Reference to Antimicrobial Performances and Burn Wound Healing

In recent years, researchers have proven the release of silver ions (Ag(+)) from silver nanoparticles (Ag NPs) significantly affects their toxicity to bacteria and other organisms. Due to the difficulty in maintaining a steady flux of a high concentration of Ag(+), it is still challenging to develop a highly efficient, stable, and biocompatible Ag NP-based antimicrobial material. To circumvent this issue, we developed a new Ag-based bactericide through the fabrication of sunlight-driven and ultrafine silver/silver chloride anchored on reduced graphene oxide (Ag/AgCl/rGO). This stable Ag/AgCl nanophotocatalyst with negligible release of Ag(+) generated a high amount of oxidative radicals, killing the bacteria, thus achieving both high bactericidal efficiency and stability. Moreover, functionalization of the nanomaterial with poly(diallyldimethylammonium chloride) (PDDA) gives it a highly adsorptive capacity, which allows it to capture the bacteria and possibly enhances the bactericidal activity. In vivo histopathological studies showed that the Ag/AgCl/rGO nanomaterial could obviously promote the regeneration of the epidermis, which indicated the good biomedical potential of Ag/AgCl/rGO nanomaterial in burn wound healing.

Cellular and molecular mechanistic insight into the DNA-damaging potential of few-layer graphene in human primary endothelial cells

Despite graphene being proposed for a multitude of biomedical applications, there is a dearth in the fundamental cellular and molecular level understanding of how few-layer graphene (FLG) interacts with human primary cells. Herein, using human primary umbilical vein endothelial cells as model of vascular transport, we investigated the basic mechanism underlying the biological behavior of graphene. Mechanistic toxicity studies using a battery of cell based assays revealed an organized oxidative stress paradigm involving cytosolic reactive oxygen stress, mitochondrial superoxide generation, lipid peroxidation, glutathione oxidation, mitochondrial membrane depolarization, enhanced calcium efflux, all leading to cell death by apoptosis/necrosis. We further investigated the effect of graphene interactions using cDNA microarray analysis and identified potential adverse effects by down regulating key genes involved in DNA damage response and repair mechanisms. Single cell gel electrophoresis assay/Comet assay confirmed the DNA damaging potential of graphene towards human primary cells.