Zinc Ion-Stabilized Aptamer-Targeted Black Phosphorus Nanosheets for Enhanced Photothermal/Chemotherapy Against Prostate Cancer

Aptamer-mediated therapeutic strategies provide a potential approach for cancer

The treatment of tumors still faces considerable challenges. While conventional treatments such as surgery, chemotherapy, and radiation therapy provide some curative effects, their side effects and limitations highlight the importance of finding more precise treatment strategies. Aptamers have become an important target molecule in the field of drug delivery systems due to their good affinity and targeting, and they have gradually become an important link from basic research to clinical application. In this paper, we discussed the latest progress of aptamer-mediated nanodrugs, as well as aptamer-mediated photodynamic therapy, photothermal therapy, and immunotherapy strategies for tumor treatment, and explored the possibility of aptamer-mediated therapy for accurate tumor treatment. The purpose of this review is to provide novel insights for treating tumors with aptamer-mediated therapies by summarizing these innovative strategies, thereby ultimately enhancing the therapeutic efficacy for cancer patients.

Application of conventional metallic nanoparticles on male reproductive system - challenges and countermeasures

The application of nanotechnology in the present era has substantial impact on different industrial and medical fields. However, the advancement in nanotechnology for potential therapeutic and consumer benefits has been an anxious cause regarding the probable hazardous consequences of these molecules in biological systems and the environment. The toxic effects can perturb the physiologic system broadly and reproductive function and fertility specifically. Despite engineered nanomaterials (ENMs) having a wide range of applications, toxicological investigations of the probable ramifications of ENMs on the reproductive systems of mammals and fertility remains in its nascence. Complication in the male reproductive system is quite a pertinent issue in today's world which comprises of benign prostatic enlargement, prostate cancer, and unhealthy sperm production. The therapeutic drugs should not only be active in minimum dose but also site-specific in action, criteria being met by nanomedicines. Nanomedicine therapy is promising but encompasses the chances of adverse effects of being cytotoxic and generating oxidative stress. These hurdles can be overcome by creating coated nanoparticles with organic substances, modification of shape and size, and synthesizing biocompatible green nanoparticles. This review attempts to look into the applications of most widely used metals like zinc, titanium, silver, and gold nanoparticles in the therapy of the male reproductive system, their prospective harmful effects, and the way out to create a safe therapeutic system by specific modifications of these metal and metal oxide nanoparticles.

ROS-responsive Galactosylated-nanoparticles with Doxorubicin Entrapment for Triple Negative Breast Cancer Therapy

Background

Triple negative breast cancer (TNBC) is one of the most aggressive tumors with high metastasis and mortality, which constitutes 15~20% of all breast cancers. Chemotherapy remains main therapeutic option in the treatment of patients with TNBC.

Methods

We developed reactive oxygen species (ROS)-responsive galactosylated nanoparticles (DOX@NPs) as an efficiently targeted carrier for doxorubicin (DOX) delivery to inhibit the growth of TNBC in vitro and in vivo. DOX@NPs were composed of polyacrylate galactose and phenylboronic derivatives conjugation. The in vitro cytotoxicity, cellular uptake, cell apoptosis and cycle distribution of tumor cells treated with different formulations were investigated. Meanwhile in vivo biodistribution and antitumor effects were investigated in a 4T1 tumor-bearing mouse model.

Results

DOX@NPs showed good ROS responsiveness and rapid DOX release in the presence of H₂O₂. Furthermore, our data suggested that DOX@NPs could effectively trigger tumor cells apoptosis and cycle arrest, efficiently accumulate into tumor sites, and suppress tumor growth without adverse side effects.

Conclusion

Our results suggested DOX@NP with potent potential as a promising nanocarrier for TNBC therapy, which deserved further investigation for other cancer treatment.

Black Phosphorous Aptamer-based Platform for Biomarker Detection

Black phosphorus nanostructures (nano-BPs) mainly include BP nanosheets (BP NSs), BP quantum dots (BPQDs), and other nano-BPs-based particles at nanoscale. Firstly discovered in 2014, nano-BPs are one of the most popular nanomaterials. Different synthesis methods are discussed in short to understand the basic concepts and developments in synthesis. Exfoliated nano-BPs, i.e. nano-BPs possess high surface area, high photothermal conversion efficacy, excellent biocompatibility, high charge carrier mobility (~1000 cm^-2V^-1s^-1), thermal conductivity of 86 Wm^-1K^-1; and these properties make it a highly potential candidate for fabrication of biosensing platform. These properties enable nano-BPs to be promising photothermal/drug delivery agents as well as in electrochemical data storage devices and sensing devices; and in super capacitors, photodetectors, photovoltaics and solar cells, LEDs, super-conductors, etc. Early diagnosis is very critical in the health sector scenarios. This review attempts to highlight the attempts made towards attaining stable BP, BP-aptamer conjugates for successful biosensing applications. BP-aptamer- based platforms are reviewed to highlight the significance of BP in detecting biological and physiological markers of cardiovascular diseases and cancer; to be useful in disease diagnosis and management.

Mn2+ modified black phosphorus nanosheets with enhanced DNA adsorption and affinity for robust sensing

To develop various biosensors, several 2D nanomaterials adsorb DNA probes (aptamers) via π-π stacking interactions. However, interference from DNA displacement by external non-targeted ligands has precluded their practical applications for specific detection and imaging at high protein concentrations. Metal coordination is an attractive strategy for biomolecular crosslinking and functional molecular self-assembly. Herein, a robust 2D biosensor nanoplatform was developed to enhance DNA adsorption and affinity using Mn²⁺-modified black phosphorus nanosheets (BPNS@Mn²⁺) via metal coordination. The Mn²⁺ can simultaneously coordinate with the lone pair electrons (π bonds) of the BPNS and nucleotide bases to provide binding sites for DNA nucleobases on the BPNS surface, which greatly enhances the stability of the inner BPNS and improves DNA adsorption and affinity. The DNA adsorption mechanism of BPNS@Mn²⁺ was also characterized, and is extensively discussed. Without any further modification, this BPNS@Mn²⁺/DNA biosensor specifically detected single-stranded DNA (linear range: 10-200 nM, detection limit: 5.76 nM) and thrombin (linear range: 20-180 nM, detection limit: 2.39 nM) in 100 nM bovine serum albumin solution. The nonspecific ligands in the environment did not affect the detection performance of the robust biosensor. In addition, the expression levels of microRNA-21 can be imaged and analyzed in living cells using this biosensor, which is consistent with the results of the polymerase chain reaction. This study highlights the potential of metal coordination in surface modification and provides new opportunities for biomedical applications of 2D nanomaterials with superior DNA-adsorption capacity, facilitating the development of biosensor design and nucleic acid/drug delivery.

Multivalent Aptamer Approach: Designs, Strategies, and Applications

Aptamers are short and single-stranded DNA or RNA molecules with highly programmable structures that give them the ability to interact specifically with a large variety of targets, including proteins, cells, and small molecules. Multivalent aptamers refer to molecular constructs that combine two or more identical or different types of aptamers. Multivalency increases the avidity of aptamers, a particularly advantageous feature that allows for significantly increased binding affinities in comparison with aptamer monomers. Another advantage of multivalency is increased aptamer stabilities that confer improved performances under physiological conditions for various applications in clinical settings. The current study aims to review the most recent developments in multivalent aptamer research. The review will first discuss structures of multivalent aptamers. This is followed by detailed discussions on design strategies of multivalent aptamer approaches. Finally, recent developments of the multivalent aptamer approach in biosensing and biomedical applications are highlighted.

Polymeric Indoximod Based Prodrug Nanoparticles with Doxorubicin Entrapment for Inducing Immunogenic Cell Death and Improving Immunotherapy for Breast caner

Immunotherapy using host immunity has emerged as a powerful therapeutic strategy in tumor treatment. However, facilitating immune system against tumor often fails to obtain a durable immune response due to...

Zinc-Loaded Black Phosphorus Multifunctional Nanodelivery System Combined With Photothermal Therapy Have the Potential to Treat Prostate Cancer Patients Infected With COVID-19

Since 2019, coronavirus disease 2019 (COVID-19) has swept the world and become a new virus threatening the health of all mankind. The survey found that prostate cancer accounts for one in three male cancer patients infected with COVID-19. This undoubtedly makes prostate cancer patients face a more difficult situation. Prostate cancer is the second most harmful malignant tumor in men because of its insidious onset, easy metastasis, and easy development into castration-resistant prostate cancer even after treatment. Due to its high immunogenicity and a small number of specific infiltrating T cells with tumor-associated antigens in the tissue, it is difficult to obtain a good therapeutic effect with immune checkpoint blocking therapy alone. Therefore, in the current study, we developed a platform carrying Doxorubicin (DOX)-loaded black phosphate nanometer combined with photothermal therapy (PTT) and found this drug combination stimulated the immungentic cell death (ICD) process in PC-3 cells and DC maturation. More importantly, zinc ions have a good immunomodulatory function against infectious diseases, and can improve the killing ability of the nanosystem against prostate cancer cells. The introduction of Aptamer (Apt) enhances the targeting of the entire nanomedicine. We hope that this excellent combination will lead to effective treatment strategies for prostate cancer patients infected with COVID-19.

A Fluorescent Aptasensor Based on Assembled G-Quadruplex and Thioflavin T for the Detection of Biomarker VEGF165

VEGF165, a regulator of angiogenesis, has been widely used as a serum biomarker for a number of human diseases, including cancer, rheumatoid arthritis, bronchial asthma, and diabetic eye disease. The rapid, accurate, and convenient detection of VEGF165 is a crucial step in effective healthcare monitoring, disease diagnosis, and prognosis assessment. In this study, a fluorescent aptasensor based on an assembled G-quadruplex and the signal molecule ThT was developed for VEGF165 detection. First, G-rich DNA fragments were assembled at both ends of the anti-VEGF165 aptamer, and the B-DNA form was converted into a G-quadruplex structure aptamer (G4-Apt). Then, ThT was introduced, and the G-quadruplex significantly enhanced the fluorescence intensity of the bound ThT. When VEGF165 was present, the higher affinity of the aptamer to the target protein allowed the G4-Apt/VEGF165 complex to form and release ThT, which emitted only weak fluorescence in the free state. Therefore, the aptasensor exhibited a good linear detection window from 1.56 to 25 nM VEGF165, with a limit of detection of 0.138 nM. In addition, the aptasensor was applied to detect VEGF165 in clinical serum samples, showing good accuracy, reproducibility, and stability. These results indicate that our developed fluorescent aptasensor can potentially be a reliable, convenient, and cost-effective approach for the sensitive, specific, and rapid detection of the VEGF165 biomarker.

2D Nanosheets-A New Class of Therapeutic Formulations against Cancer

Researchers in cancer nanomedicine are exploring a revolutionary multifaceted carrier for treatment and diagnosis, resulting in the proposal of various drug cargos or "magic bullets" in this past decade. Even though different nano-based complexes are registered for clinical trials, very few products enter the final stages each year because of various issues. This prevents the formulations from entering the market and being accessible to patients. In the search for novel materials, the exploitation of 2D nanosheets, including but not limited to the highly acclaimed graphene, has created extensive interest for biomedical applications. A unique set of properties often characterize 2D materials, including semiconductivity, high surface area, and their chemical nature, which allow simple decoration and functionalization procedures, structures with high stability and targeting properties, vectors for controlled and sustained release of drugs, and materials for thermal-based therapies. This review discusses the challenges and opportunities of recently discovered 2D nanosheets for cancer therapeutics, with special attention paid to the most promising design technologies and their potential for clinical translation in the future.

Biomimetic Black Phosphorus Nanosheet-Based Drug Delivery System for Targeted Photothermal-Chemo Cancer Therapy

As a biodegradable material, black phosphorus (BP) has been considered as an efficient agent for cancer photothermal therapy. However, its systemic delivery faces several hurdles, including rapid degradation in blood circulation, quick clearance by the immune system, and low delivery sufficiency to the tumor site. Here, we developed a biomimetic nanoparticle platform for in vivo tumor-targeted delivery of BP nanosheets (BP NSs). Through a biomimetic strategy, BP NSs were utilized to coordinate with the active species of oxaliplatin (1,2-diaminocyclohexane) platinum (II) (DACHPt) complexions, and the nanoparticles were further camouflaged with mesenchymal stem cell (MSC)–derived membranes. We showed that the incorporation of DACHPt not only decelerated the BP degradation but also enhanced the antitumor effect by combining the photothermal effect with chemotoxicity. Furthermore, MSC membrane coating increased the stability, dispersibility, and tumor-targeting properties of BP/DACHPt, significantly improving the antitumor efficacy. In short, our work not only provided a new strategy for in vivo tumor-targeted delivery of BP NSs but also obtained an enhanced antitumor effect by combining photothermal therapy with chemotherapy.

Microstructure and Mechanical Properties of Zinc Matrix Biodegradable Composites Reinforced by Graphene

This work used spark plasma sintering (SPS) to prepare graphene nanosheets (GNS) reinforced zinc matrix composites. The influence of GNS on the microstructure and mechanical properties of zinc matrix composites was studied. The results show that the GNS/Zn composites prepared by SPS have a dense structure and good interface bonding, and GNS are uniformly distributed in the zinc matrix. Adding GNS can significantly improve the mechanical properties of the zinc matrix. When 0.7 wt% GNS are added, the comprehensive mechanical properties of the composite material are improved. The ultimate tensile strength is 254 MPa, and the Vickers hardness is 65 HV, which are 126 and 20.3% higher than those of pure zinc (112 MPa and 54 HV), respectively. The strengthening mechanisms of GNS/Zn composites are mainly load transfer of GNS and dislocation strengthening caused by coefficient of thermal expansion (CTE) mismatch. In addition, the biodegradability of GNS/Zn composites was evaluated by electrochemical measurement and immersion test. The results show that adding GNS to the zinc matrix will accelerate the degradation rate of the composite material. But the degradation rate can be controlled by the content of GNS. Its degradation rate is in the range of 69–301 μm/a, an ideal degradation rate as an orthopedic implant material.