"Three-Bullets" Loaded Mesoporous Silica Nanoparticles for Combined Photo/Chemotherapy

Nitric Oxide-Photodelivering Materials with Multiple Functionalities: From Rational Design to Therapeutic Applications

The achievement of materials that are able to release therapeutic agents under the control of light stimuli to improve therapeutic efficacy is a significant challenge in health care. Nitric oxide (NO) is one of the most studied molecules in the fascinating realm of biomedical sciences, not only for its crucial role as a gaseous signaling molecule in the human body but also for its great potential as an unconventional therapeutic in a variety of diseases including cancer, bacterial and viral infections, and neurodegeneration. Handling difficulties due to its gaseous nature, reduced region of action due to its short half-life, and strict dependence of the biological effects on its concentration and generation site are critical questions to be solved for appropriate therapeutic uses of NO. Light-activatable NO precursors, namely, NO photodonors (NOPDs), address the above issues since they are stable in the dark and permit in a noninvasive fashion the remote-controlled delivery of NO on demand with great spatiotemporal precision. Engineering biocompatible materials with NOPDs and their combination with additional imaging, therapeutic, and phototherapeutic components leads to intriguing light-responsive multifunctional constructs exhibiting promising potential for biomedical applications. This contribution illustrates the most significant progress made over the last five years in achieving engineered materials including nanoparticles, gels, and thin films, sharing the common feature to deliver NO under the exclusive control of the biocompatible visible/near infrared light inputs. We will highlight the logical design behind the fabrication of these systems, illustrating the potential therapeutic applications with particular emphasis on cancer and bacterial infections.

Breaking boundaries in microbiology: customizable nanoparticles transforming microbial detection

The detection and identification of microorganisms are crucial in microbiology laboratories. Traditionally, detecting and identifying microbes require extended periods of incubation, significant manual effort, skilled personnel, and advanced laboratory facilities. Recent progress in nanotechnology has provided novel opportunities for detecting and identifying bacteria, viruses, and microbial metabolites using customized nanoparticles. These improvements are thought to have the ability to surpass the constraints of existing procedures and make a substantial contribution to the development of rapid microbiological diagnosis. This review article examines the customizability of nanoparticles for detecting bacteria, viruses, and microbial metabolites and discusses recent cutting-edge studies demonstrating the use of nanotechnology in biomedical research.

Recent Innovations of Mesoporous Silica Nanoparticles Combined with Photodynamic Therapy for Improving Cancer Treatment

Cancer is a global health burden and is one of the leading causes of death. Photodynamic therapy (PDT) is considered an alternative approach to conventional cancer treatment. PDT utilizes a light-sensitive compound, photosensitizers (PSs), light irradiation, and molecular oxygen (O2). This generates cytotoxic reactive oxygen species (ROS), which can trigger necrosis and/ or apoptosis, leading to cancer cell death in the intended tissues. Classical photosensitizers impose limitations that hinder their clinical applications, such as long-term skin photosensitivity, hydrophobic nature, nonspecific targeting, and toxic cumulative effects. Thus, nanotechnology emerged as an unorthodox solution for improving the hydrophilicity and targeting efficiency of PSs. Among nanocarriers, mesoporous silica nanoparticles (MSNs) have gained increasing attention due to their high surface area, defined pore size and structure, ease of surface modification, stable aqueous dispersions, good biocompatibility, and optical transparency, which are vital for PDT. The advancement of integrated MSNs/PDT has led to an inspiring multimodal nanosystem for effectively treating malignancies. This review gives an overview of the main components and mechanisms of the PDT process, the effect of PDT on tumor cells, and the most recent studies that reported the benefits of incorporating PSs into silica nanoparticles and integration with PDT against different cancer cells.

Recent Advances in Green Metallic Nanoparticles for Enhanced Drug Delivery in Photodynamic Therapy: A Therapeutic Approach

Globally, cancer is one of the leading causes of death among men and women, it is characterized by the unregulated proliferation of tumor cells. Some of the common risk factors associated with cancer development include the consistent exposure of body cells to carcinogenic agents such as alcohol, tobacco, toxins, gamma rays and alpha particles. Besides the above-mentioned risk factors, conventional therapies such as radiotherapy, and chemotherapy have also been linked to the development of cancer. Over the past decade, tremendous efforts have been invested in the synthesis of eco-friendly green metallic nanoparticles (NPs), and their medical application. Comparatively, metallic NPs have greater advantages over conventional therapies. Additionally, metallic NPs can be functionalized with different targeting moieties e.g., liposomes, antibodies, folic acid, transferrin, and carbohydrates. Herein, we review and discuss the synthesis, and therapeutic potential of green synthesized metallic NPs for enhanced cancer photodynamic therapy (PDT). Finally, the advantages of green hybridized activatable NPs over conventional photosensitizers (PSs) and the future perspectives of nanotechnology in cancer research are discussed in the review. Furthermore, we anticipate that the insights offered in this review will inspire the design and development of green nano-formulations for enhanced image-guided PDT in cancer treatment.

Stimuli Responsive Nitric Oxide-Based Nanomedicine for Synergistic Therapy

Gas therapy has received widespread attention from the medical community as an emerging and promising therapeutic approach to cancer treatment. Among all gas molecules, nitric oxide (NO) was the first one to be applied in the biomedical field for its intriguing properties and unique anti-tumor mechanisms which have become a research hotspot in recent years. Despite the great progress of NO in cancer therapy, the non-specific distribution of NO in vivo and its side effects on normal tissue at high concentrations have impaired its clinical application. Therefore, it is important to develop facile NO-based nanomedicines to achieve the on-demand release of NO in tumor tissue while avoiding the leakage of NO in normal tissue, which could enhance therapeutic efficacy and reduce side effects at the same time. In recent years, numerous studies have reported the design and development of NO-based nanomedicines which were triggered by exogenous stimulus (light, ultrasound, X-ray) or tumor endogenous signals (glutathione, weak acid, glucose). In this review, we summarized the design principles and release behaviors of NO-based nanomedicines upon various stimuli and their applications in synergistic cancer therapy. We also discuss the anti-tumor mechanisms of NO-based nanomedicines in vivo for enhanced cancer therapy. Moreover, we discuss the existing challenges and further perspectives in this field in the aim of furthering its development.

Current trends in smart mesoporous silica-based nanovehicles for photoactivated cancer therapy

Photoactivated therapeutic strategies (photothermal therapy and photodynamic therapy), due to the adjusted therapeutic area, time and light dosage, have prevailed for the fight against tumors. Currently, the monotherapy with limited treatment effect and undesired side effects is gradually replaced by multimodal and multifunctional nanosystems. Mesoporous silica nanoparticles (MSNs) with unique physicochemical advantages, such as huge specific surface area, controllable pore size and morphology, functionalized modification, satisfying biocompatibility and biodegradability, are considered as promising candidates for multimodal photoactivated cancer therapy. Excitingly, the innovative nanoplatforms based on the mesoporous silica nanoparticles provide more and more effective treatment strategies and display excellent antitumor potential. Given the rapid development of antitumor strategies based on MSNs, this review summarizes the current progress in MSNs-based photoactivated cancer therapy, mainly consists of (1) photothermal therapy-related theranostics; (2) photodynamic therapy-related theranostics; (3) multimodal synergistic therapy, such as chemo-photothermal-photodynamic therapy, phototherapy-immunotherapy and phototherapy-radio therapy. Based on the limited penetration of irradiation light in photoactivated therapy, the challenges faced by deep-seated tumor therapy are fully discussed, and future clinical translation of MSNs-based photoactivated cancer therapy are highlighted.

Porous materials as carriers of gasotransmitters towards gas biology and therapeutic applications

This review highlights the strategies employed to load and release gasotransmitters such as NO, CO and H₂S from different kinds of porous materials, including zeolites, mesoporous silica, metal–organic frameworks and protein assemblies.

Nitric Oxide-Releasing Polymeric Materials for Antimicrobial Applications: A Review

Polymeric materials releasing nitric oxide have attracted significant attention for therapeutic use in recent years. As one of the gaseous signaling agents in eukaryotic cells, endogenously generated nitric oxide (NO) is also capable of regulating the behavior of bacteria as well as biofilm formation in many metabolic pathways. To overcome the drawbacks caused by the radical nature of NO, synthetic or natural polymers bearing NO releasing moiety have been prepared as nano-sized materials, coatings, and hydrogels. To successfully design these materials, the amount of NO released within a certain duration, the targeted pathogens and the trigger mechanisms upon external stimulation with light, temperature, and chemicals should be taken into consideration. Meanwhile, NO donors like S-nitrosothiols (RSNOs) and N-diazeniumdiolates (NONOates) have been widely utilized for developing antimicrobial polymeric agents through polymer-NO donor conjugation or physical encapsulation. In addition, antimicrobial materials with visible light responsive NO donor are also reported as strong and physiological friendly tools for rapid bacterial clearance. This review highlights approaches to delivery NO from different types of polymeric materials for combating diseases caused by pathogenic bacteria, which hopefully can inspire researchers facing common challenges in the coming 'post-antibiotic' era.