“Stepwise Extraction” strategy-based injectable bioresponsive composite implant for cancer theranostics

Catalytic Nanoparticles in Biomedical Applications: Exploiting Advanced Nanozymes for Therapeutics and Diagnostics

Catalytic nanoparticles (CNPs) as heterogeneous catalyst reveals superior activity due to their physio-chemical features, such as high surface-to-volume ratio and unique optical, electric, and magnetic properties. The CNPs, based on their physio-chemical nature, can either increase the reactive oxygen species (ROS) level for tumor and antibacterial therapy or eliminate the ROS for cytoprotection, anti-inflammation, and anti-aging. In addition, the catalytic activity of nanozymes can specifically trigger a specific reaction accompanied by the optical feature change, presenting the feasibility of biosensor and bioimaging applications. Undoubtedly, CNPs play a pivotal role in pushing the evolution of technologies in medical and clinical fields, and advanced strategies and nanomaterials rely on the input of chemical experts to develop. Herein, a systematic and comprehensive review of the challenges and recent development of CNPs for biomedical applications is presented from the viewpoint of advanced nanomaterial with unique catalytic activity and additional functions. Furthermore, the biosafety issue of applying biodegradable and non-biodegradable nanozymes and future perspectives are critically discussed to guide a promising direction in developing span-new nanozymes and more intelligent strategies for overcoming the current clinical limitations.

Two-dimensional nanomaterials for tumor microenvironment modulation and anticancer therapy

The development of two-dimensional (2D) nanomaterials for cancer therapy has attracted increasing attention due to their high specific surface area, unique ultrathin structure, electronic and photonic properties. For biomedical applications, investigations into the family of 2D materials have been sparked by graphene and its derivatives. Many 2D nanomaterials, including layered double hydroxides, transition metal dichalcogenides, nitrides and carbonitrides, black phosphorus nanosheets, and metal-organic framework nanosheets, are extensively explored as cancer theranostic platforms. In addition to the high drug loading, 2D nanomaterials are featured with improved physiological properties of drugs, prolonged blood circulation, and increased tumor accumulation and bioavailability. As a consequence, 2D nanomaterials have been widely examined in pre-clinical tumor therapy, particularly through the tumor microenvironment (TME) modulation. This review summarizes recent progresses in developing 2D nanomaterials for TME modulating-based cancer diagnosis and therapy. It is anticipated that this review will benefit researchers to obtain a deeper understanding of interactions between 2D nanomaterials and TME components and develop rational and reliable 2D nanomedicines for pre/clinical cancer theranostics.

Exogenous Contrast Agents in Photoacoustic Imaging: An In Vivo Review for Tumor Imaging

The field of cancer theranostics has grown rapidly in the past decade and innovative ‘biosmart’ theranostic materials are being synthesized and studied to combat the fast growth of cancer metastases. While current state-of-the-art oncology imaging techniques have decreased mortality rates, patients still face a diminished quality of life due to treatment. Therefore, improved diagnostics are needed to define in vivo tumor growths on a molecular level to achieve image-guided therapies and tailored dosage needs. This review summarizes in vivo studies that utilize contrast agents within the field of photoacoustic imaging—a relatively new imaging modality—for tumor detection, with a special focus on imaging and transducer parameters. This paper also details the different types of contrast agents used in this novel diagnostic field, i.e., organic-based, metal/inorganic-based, and dye-based contrast agents. We conclude this review by discussing the challenges and future direction of photoacoustic imaging.

Recent Advances of Manganese-Based Hybrid Nanomaterials for Cancer Precision Medicine

Cancer precision medicine (CPM) could tailor the best treatment for individual cancer patients, while imaging techniques play important roles in its application. With the characteristics of noninvasion, nonionized, radiation-free, multidimensional imaging function, and real-time monitoring, magnetic resonance imaging (MRI) is an effective way for early tumor detection, and it has become a tower of strength in CPM imaging techniques. Due to linkage with nephrogenic systemic fibrosis (NSF), gadolinium (Gd)-based contrast agent (CA), which was long used in MRI, has been restricted by the Food and Drug Administration (FDA). In this review, we would like to introduce the manganese (Mn)-based CAs that could significantly increase the safety of MRI CAs by realizing more superior performance and functions simultaneously in the diagnosis and treatment of tumors. Also, recent advances in Mn-based hybrid nanomaterials for CPM are summarized and discussed.

Chemistry of Advanced Nanomedicines in Cancer Cell Metabolism Regulation

Tumors reprogram their metabolic pathways to meet the bioenergetic and biosynthetic demands of cancer cells. These reprogrammed activities are now recognized as the hallmarks of cancer, which not only provide cancer cells with unrestricted proliferative and metastatic potentials, but also strengthen their resistance against stress conditions and therapeutic challenges. Although recent progress in nanomedicine has largely promoted the developments of various therapeutic modalities, such as photodynamic therapy, photothermal therapy, nanocatalytic therapy, tumor-starving/suffocating therapy, etc., the therapeutic efficacies of nanomedicines are still not high enough to achieve satisfactory tumor-suppressing effects. Therefore, researchers are obliged to look back to the essence of cancer cell biology, such as metabolism, for tailoring a proper therapeutic regimen. In this work, the characteristic metabolic pathways of cancer cells, such as aerobic respiration, glycolysis, autophagy, glutaminolysis, etc. are reviewed, to summarize the very recent advances in the smart design of nanomedicines that can regulate tumor metabolism for enhancing conventional therapeutic modalities. The underlying chemistry of these nanomedicines by which tumor metabolism is harnessed, is also discussed in a comprehensive manner. It is expected that by harnessing tumor metabolism cancer nanotherapeutics will be substantially improved in the future.

The pharmaceutical solvent N-methyl-2-pyrollidone (NMP) attenuates inflammation through Krüppel-like factor 2 activation to reduce atherogenesis

N-methyl-2-pyrrolidone (NMP) is a versatile water-miscible polar aprotic solvent. It is used as a drug solubilizer and penetration enhancer in human and animal, yet its bioactivity properties remain elusive. Here, we report that NMP is a bioactive anti-inflammatory compound well tolerated in vivo, that shows efficacy in reducing disease in a mouse model of atherosclerosis. Mechanistically, NMP increases the expression of the transcription factor Kruppel-like factor 2 (KLF2). Monocytes and endothelial cells treated with NMP express increased levels of KLF2, produce less pro-inflammatory cytokines and adhesion molecules. We found that NMP attenuates monocyte adhesion to endothelial cells inflamed with tumor necrosis factor alpha (TNF-α) by reducing expression of adhesion molecules. We further show using KLF2 shRNA that the inhibitory effect of NMP on endothelial inflammation and subsequent monocyte adhesion is KLF2 dependent. Enhancing KLF2 expression and activity improves endothelial function, controls multiple genes critical for inflammation, and prevents atherosclerosis. Our findings demonstrate a consistent effect of NMP upon KLF2 activation and inflammation, biological processes central to atherogenesis. Our data suggest that inclusion of bioactive solvent NMP in pharmaceutical compositions to treat inflammatory disorders might be beneficial and safe, in particular to treat diseases of the vascular system, such as atherosclerosis.

Applications of Two-Dimensional Nanomaterials in Breast Cancer Theranostics

Breast cancer is the leading cause of cancer-related mortality among women. Early stage diagnosis and treatment of this cancer are crucial to patients' survival. In addition, it is important to avoid severe side effects during the process of conventional treatments (surgery, chemotherapy, hormonal therapy, and targeted therapy) and increase the patients' quality of life. Over the past decade, nanomaterials of all kinds have shown excellent prospects in different aspects of oncology. Among them, two-dimensional (2D) nanomaterials are unique due to their physical and chemical properties. The functional variability of 2D nanomaterials stems from their large specific surface area as well as the diversity of composition, electronic configurations, interlayer forces, surface functionalities, and charges. In this review, the current status of 2D nanomaterials in breast cancer diagnosis and therapy is reviewed. In this respect, sensing of the tumor biomarkers, imaging, therapy, and theranostics are discussed. The ever-growing 2D nanomaterials are building blocks for the development of a myriad of nanotheranostics. Accordingly, there is the possibility to explore yet novel properties, biological effects, and oncological applications.

Augmenting Tumor-Starvation Therapy by Cancer Cell Autophagy Inhibition

It was recently recognized that cancer therapeutic efficacy may be greatly compromised by an intrinsic protective mechanism called autophagy, by which cancer cells survive in harsh conditions such as starvation. Here, a synergetic strategy is described for cancer treatment by suppressing such a protective mechanism for augmenting tumor-starvation therapy. The synergetic therapy is achieved by restraining glucose metabolism using an antiglycolytic agent to predispose cancer cells to severe energy deprivation; concurrently the downstream autophagic flux and compensatory energy supplies are blocked by the autophagy inhibitor black phosphorus nanosheet. Cancer cells fail to extract their own nutrient to feed themselves, finally succumbing to therapeutic interventions and starving to death. Both in vitro and in vivo results evidence the cooperative effect between the autophagy inhibitor and antiglycolytic agent, which leads to remarkable synergetic antineoplastic outcome. It is expected that such a combinational approach by concurrently blocking exogenous and endogenous nutrition supplies will be beneficial to the design of effective tumor-specific cancer therapies in the future.

Nanocatalytic Medicine

Catalysis and medicine are often considered as two independent research fields with their own respective scientific phenomena. Promoted by recent advances in nanochemistry, large numbers of nanocatalysts, such as nanozymes, photocatalysts, and electrocatalysts, have been applied in vivo to initiate catalytic reactions and modulate biological microenvironments for generating therapeutic effects. The rapid growth of research in biomedical applications of nanocatalysts has led to the concept of "nanocatalytic medicine," which is expected to promote the further advance of such a subdiscipline in nanomedicine. The high efficiency and selectivity of catalysis that chemists strived to achieve in the past century can be ingeniously translated into high efficacy and mitigated side effects in theranostics by using "nanocatalytic medicine" to steer catalytic reactions for optimized therapeutic outcomes. Here, the rationale behind the construction of nanocatalytic medicine is eludicated based on the essential reaction factors of catalytic reactions (catalysts, energy input, and reactant). Recent advances in this burgeoning field are then comprehensively presented and the mechanisms by which catalytic nanosystems are conferred with theranostic functions are discussed in detail. It is believed that such an emerging catalytic therapeutic modality will play a more important role in the field of nanomedicine.

Biomedical and bioimaging applications of 2D pnictogens and transition metal dichalcogenides

Multifunctional platforms will play a key role and gain more prominence in the field of personalized healthcare worldwide in the near future due to the ever-increasing number of patients suffering from cancer. Along with the development of efficient techniques for cancer treatment, a considerable effort should be devoted toward the exploration of an emerging class of materials with unique properties that might be beneficial in this context. Currently, 2D post-carbon materials, such as pnictogens (phosphorene, antimonene), transition metal dichalcogenides, and boron nitride, have become popular due to their efficient photothermal behavior, drug-loading capability, and low toxicity. This review underlines the recent progresses made in the abovementioned 2D materials for photothermal/photodynamic cancer therapies and their applicability in bioimaging applications.

Manganese-phenolic network-coated black phosphorus nanosheets for theranostics combining magnetic resonance/photoacoustic dual-modal imaging and photothermal therapy

In this work, we directly coated a layer of tannic acid (TA)-Mn2+ chelate networks on black phosphorus (BP) nanosheets (BPNSs) via a simple one-step method. The as-synthesized TA-Mn2+ chelate-coated BPNSs (BPNS@TA-Mn) have excellent T1 MRI contrast enhancement capability, good photoacoustic imaging performance, and high photothermal conversion efficiency, showing great potential in imaging-guided photothermal therapy.

Photon-Responsive Antibacterial Nanoplatform for Synergistic Photothermal-/Pharmaco-Therapy of Skin Infection

Abuse of antibiotics and their residues in the environment results in the emergence and prevalence of drug-resistant bacteria and leads to serious health problems. Herein, a photon-controlled antibacterial platform that can efficiently kill drug-resistant bacteria and avoid the generation of new bacterial resistance was designed by encapsulating black phosphorus quantum dots (BPQDs) and pharmaceuticals inside a thermal-sensitive liposome. The antibacterial platform can release pharmaceuticals in a spatial-, temporal-, and dosage-controlled fashion because the BPQDs can delicately generate heat under near-infrared light stimulation to disrupt the liposome. This user-defined delivery of drug can greatly reduce the antibiotic dosage, thus avoiding the indiscriminate use of antibiotics and preventing the generation of superbugs. Moreover, by coupling the photothermal effect with antibiotics, this antibacterial platform achieved a synergistic photothermal-/pharmaco-therapy with significantly improved antibacterial efficiency toward drug-resistant bacteria. The antibacterial platform was further employed to treat antibiotic-resistant bacteria-caused skin abscess and it displayed excellent antibacterial activity in vivo, promising its potential clinical applications. Additionally, the antibacterial mechanism was further investigated. The developed photon-controlled antibacterial platform can open new possibilities for avoiding bacterial resistance and efficiently killing antibiotic-resistant bacteria, making it valuable in fields ranging from antiinfective therapy to precision medicine.

Exosome Biochemistry and Advanced Nanotechnology for Next-Generation Theranostic Platforms

Recent marked technological advances in the field of exosome nanotechnology have provided unprecedented opportunities to bloom the developments of exosome-related biology, chemistry, pathology, and therapeutics, which have laid a solid basis for scientific community to design exosome-based nanotheranostic platforms. The unique structural/compositional/morphological characteristics of exosomes as natural nanocarriers, as well as their fascinating physicochemical/biochemical properties, which underpin their special physiopathological roles, have triggered the concept that these cell-derived nanovesicles with intrinsic biological functions can be highly competent for the establishment of next-generation nanomedicine. Herein, efforts are made to give a comprehensive overview on the recent advances of exosome nanotechnology based on the representative examples of the current state of the art of exosome-based research, ranging from their formation, biological function, preparation, and characterization to their extensive nanomedical applications. It is highly expected that the better and clearer elucidation of the fundamental principles for advanced nanotechnology in constructing exosome-based theranostic nanoplatforms, as well as integrating the intrinsic advantages of exosomes as endogenous cell-derived nanocarriers with the advanced design methodology of traditional nanomedicine, will help to unlock the innate powers of exosomes for the establishment of next-generation theranostic nanoplatforms.

Exogenous/Endogenous-Triggered Mesoporous Silica Cancer Nanomedicine

Recent advances in nanomedicine-based theranostic platforms have catalyzed the generation of new theranostic modalities for pathological abnormalities, such as cancer. Mesoporous silica-based nanomedicines, which feature unique physicochemical properties and specific applicability, are extensively explored for numerous oncological applications. Due to the well-defined morphology, specific surface area, and pore volume, mesoporous silica nanoparticle (MSN)-based theranostic platforms have provided unprecedented opportunities for the development of next-generation cancer nanomedicine. However, current understanding on the underlying mechanisms of how these feasible theranostic platforms interact with exogenous/endogenous triggers and how this unique responsiveness for optimized cancer therapy can be taken advantage of is still preliminary. In this progress report, efforts are made to give a comprehensive overview of the development of MSN-based "smart" theranostic platforms, from exogenous physical irradiation-triggered platforms for localized therapy to endogenous biological stimulus-triggered platforms for tumor microenvironment responsiveness. It is highly expected that these elaborately fabricated MSN-based nanoformulations will play an indispensable role in the efficient cancer therapy based on their high therapeutic outcome and reduced side effects.

3D printing and coating to fabricate a hollow bullet-shaped implant with porous surface for controlled cytoxan release

Intratumoral implants have aroused great interests for local chemotherapy of cancer, however, how to efficiently control drug release from implants is still a great challenge. Herein, we designed and prepared a new hollow bullet-shaped implant with porous surface by 3D printing, loaded chemotherapeutic agent cytoxan (CTX) with tetradecyl alcohol or lecithin as matrix and coated it with poly (lactic acid) to obtain a CTX implant, which has a highly tuned drug release property with a drug release time from 4 h to more than 1 month. The drug release from the implant can be easily controlled by changing pore sizes, kinds of matrices, and coating thickness.