Macrophage-modulating nanomedicine for cancer immunotherapy.

Tumor-associated macrophages (TAMs) play crucial roles in the immunosuppressive solid tumor microenvironment (TME). Despite their tumor-promoting functions, TAMs can also be therapeutically modulated to exhibit tumor-killing properties, making them attractive targets for tumor immunotherapy. This review highlights the recent advances in nanomedicine-based strategies centered around macrophages for enhanced cancer immunotherapy. Emerging nanomedicine-based strategies to modulate TAMs in cancer treatment include repolarization of the TAM phenotype, inhibition of monocyte recruitment, depletion of TAMs, and blockage of immune checkpoints. These strategies have shown great promise in significantly improving the efficacy of cancer immunotherapy. Moreover, macrophage-inspired drug delivery systems have demonstrated significant promise in inducing immunotherapeutic effects and enhancing therapeutic efficacy by facilitating evasion from the reticuloendothelial system and promoting accumulation at the tumor site. Finally, we also discuss the challenges and propose future opportunities associated with macrophage-modulating nanomedicine to enhance cancer immunotherapy.

In situ Engineering of Tumor-Associated Macrophages via a Nanodrug-Delivering-Drug (ß-Elemene@Stanene) Strategy for Enhanced Cancer Chemo-Immunotherapy.

Tumor-associated macrophages (TAMs) play a critical role in the immunosuppressive solid tumor microenvironment (TME), yet in situ engineering of TAMs for enhanced tumor immunotherapy remains a significant challenge in translational immuno-oncology. Here, we report an innovative nanodrug-delivering-drug (STNSP@ELE) strategy that leverages two-dimensional (2D) stanene-based nanosheets (STNSP) and ß-Elemene (ELE), a small-molecule anticancer drug, to overcome TAM-mediated immunosuppression and improve chemo-immunotherapy. Our results demonstrate that both STNSP and ELE are capable of polarizing the tumor-supportive M2-like TAMs into a tumor-suppressive M1-like phenotype, which acts with the ELE chemotherapeutic to boost antitumor responses. In vivo mouse studies demonstrate that STNSP@ELE treatment can reprogram the immunosuppressive TME by significantly increasing the intratumoral ratio of M1/M2-like TAMs, enhancing the population of CD4+ and CD8+ T lymphocytes and mature dendritic cells, and elevating the expression of immunostimulatory cytokines in B16F10 melanomas, thereby promoting a robust antitumor response. Our study not only demonstrates that the STNSP@ELE chemo-immunotherapeutic nanoplatform has immune-modulatory capabilities that can overcome TAM-mediated immunosuppression in solid tumors, but also highlights the promise of this nanodrug-delivering-drug strategy in developing other nano-immunotherapeutics and treating various types of immunosuppressive tumors.

Bioinspired Mild Photothermal Effect-Reinforced Multifunctional Fiber Scaffolds Promote Bone Regeneration.

Bone fractures are often companied with poor bone healing and high rates of infection. Early recruitment of mesenchymal stem cells (MSCs) is critical for initiating efficient bone repair, and mild thermal stimulation can accelerate the recovery of chronic diseases. Here, a bioinspired, staged photothermal effect-reinforced multifunctional scaffold was fabricated for bone repair. Uniaxially aligned electrospun polycaprolactone nanofibers were doped with black phosphorus nanosheets (BP NSs) to endow the scaffold with excellent near-infrared (NIR) responsive capability. Apt19S was then decorated on the surface of the scaffold to selectively recruit MSCs toward the injured site. Afterward, microparticles of phase change materials loaded with antibacterial drugs were also deposited on the surface of the scaffold, which could undergo a solid-to-liquid phase transition above 39 °C, triggering the release of payload to eliminate bacteria and prevent infection. Under NIR irradiation, photothermal-mediated up-regulation of heat shock proteins and accelerated biodegradation of BP NSs could promote the osteogenic differentiation of MSCs and biomineralization. Overall, this strategy shows the ability of bacteria elimination, MSCs recruitment, and bone regeneration promotion with the assistance of photothermal effect in vitro and in vivo, which emphasizes the design of a bioinspired scaffold and its potential for a mild photothermal effect in bone tissue engineering.

Cancer nanomedicine in preoperative therapeutics: Nanotechnology-enabled neoadjuvant chemotherapy, radiotherapy, immunotherapy, and phototherapy.

Surgical resection remains a mainstay in the treatment of malignant solid tumors. However, the use of neoadjuvant treatments, including chemotherapy, radiotherapy, phototherapy, and immunotherapy, either alone or in combination, as a preoperative intervention regimen, have attracted increasing attention in the last decade. Early randomized, controlled trials in some tumor settings have not shown a significant difference between the survival rates in long-term neoadjuvant therapy and adjuvant therapy. However, this has not hampered the increasing use of neoadjuvant treatments in clinical practice, due to its evident downstaging of primary tumors to delineate the surgical margin, tailoring systemic therapy response as a clinical tool to optimize subsequent therapeutic regimens, and decreasing the need for surgery, with its potential for increased morbidity. The recent expansion of nanotechnology-based nanomedicine and related medical technologies provides a new approach to address the current challenges of neoadjuvant therapy for preoperative therapeutics. This review not only summarizes how nanomedicine plays an important role in a range of neoadjuvant therapeutic modalities, but also highlights the potential use of nanomedicine as neoadjuvant therapy in preclinical and clinic settings for tumor management.

Living Leukocyte-Based Drug Delivery Systems.

Leukocytes play a vital role in immune responses, including defending against invasive pathogens, reconstructing impaired tissue, and maintaining immune homeostasis. When the immune system is activated in vivo, leukocytes accomplish a series of orderly and complex regulatory processes. While cancer and inflammation-related diseases like sepsis are critical medical difficulties plaguing humankind around the world, leukocytes have been shown to largely gather at the focal site, and significantly contribute to inflammation and cancer progression. Therefore, the living leukocyte-based drug delivery systems have attracted considerable attention in recent years due to the innate and specific targeting effect, low immunogenicity, improved therapeutic efficacy, and low reverse effect. In this review, the recent advances in the development of living leukocyte-based drug delivery systems including macrophages, neutrophils, and lymphocytes as promising treatment strategies for cancer and inflammation-related diseases are introduced. The advantages, current challenges, and limitations of these delivery systems are also discussed, as well as perspectives on the future development of precision and targeted therapy in the clinics are provided. Collectively, it is expected that such kind of living cell-based drug delivery system is promising to improve or even revolutionize the treatments of cancers and inflammation-related diseases in the clinics.

Cancer nanomedicine toward clinical translation: Obstacles, opportunities, and future prospects.

With the integration of nanotechnology into the medical field at large, great strides have been made in the development of nanomedicines for tackling different diseases, including cancers. To date, various cancer nanomedicines have demonstrated success in preclinical studies, improving therapeutic outcomes, prolonging survival, and/or decreasing side effects. However, the translation from bench to bedside remains challenging. While a number of nanomedicines have entered clinical trials, only a few have been approved for clinical applications. In this review, we highlight the most recent progress in cancer nanomedicine, discuss current clinical advances and challenges for the translation of cancer nanomedicines, and provide our viewpoints on accelerating clinical translation. We expect this review to benefit the future development of cancer nanotherapeutics specifically from the clinical perspective.

The marriage of Xenes and hydrogels: Fundamentals, applications, and outlook.

Hydrogels have blossomed as superstars in various fields, owing to their prospective applications in tissue engineering, soft electronics and sensors, flexible energy storage, and biomedicines. Two-dimensional (2D) nanomaterials, especially 2D mono-elemental nanosheets (Xenes) exhibit high aspect ratio morphology, good biocompatibility, metallic conductivity, and tunable electrochemical properties. These fascinating characteristics endow numerous tunable application-specific properties for the construction of Xene-based hydrogels. Hierarchical multifunctional hydrogels can be prepared according to the application requirements and can be effectively tuned by different stimulation to complete specific tasks in a spatiotemporal sequence. In this review, the synthesis mechanism, properties, and emerging applications of Xene hydrogels are summarized, followed by a discussion on expanding the performance and application range of both hydrogels and Xenes.