Biomimetic Engineering of a Scavenger-Free Nitric Oxide-Generating/Delivering System to Enhance Radiation Therapy

Preparation of poly(vinyl alcohol) nanofibers containing disulfiram-copper complex by electrospinning: a potential delivery system against melanoma

BACKGROUND

Melanoma poses a significant threat to human health, making the development of a safe and effective treatment a crucial challenge. Disulfiram (DS) is a proven anticancer drug that has shown effectiveness when used in combination with copper (DS-Cu complex).

OBJECTIVES

This study focuses on encapsulation of DS-copper complex into nanofiber scaffold from polyvinyl alcohol (PVA) (DS-Cu@PVA). In order to increase bioavailability towards melanoma cell lines and decrease its toxicity.

METHODS

The scaffold was fabricated through an electrospinning process using an aqueous solution, and subsequently analyzed using ART-Fourier transform infrared spectroscopy (ART-FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). Additionally, cellular cytotoxicity, flow cytometry analysis, and determination of caspase 3 activity were conducted to further characterize the scaffold.

RESULTS

The results confirmed that encapsulation of DS-Cu complex into PVA was successful via different characterization. The scanning electron microscopy (SEM) analysis revealed that the diameter of the nanofibers remained consistent despite the addition of DS-Cu. Additionally, ATR-FTIR confirmed that the incorporation of DS-Cu into PVA did not significantly alter the characteristic peaks of PVA. Furthermore, the cytotoxicity assessment of the DS-Cu@PVA nanofibrous scaffold using human normal skin cells (HFB4) demonstrated its superior biocompatibility compared to DS-Cu-free counterparts. Notably, the presence of DS-Cu maintained its effectiveness in promoting apoptosis by increasing cellular reactive oxygen species, proapoptotic gene expression, and caspase 3 activity, while simultaneously reducing glutathione levels and oncogene expression in human and mouse melanoma cell lines (A375 and B16F10, respectively). Overall, these findings suggest that the addition of DS-Cu to PVA nanofibers enhances their biocompatibility and cytotoxic effects on melanoma cells, making them a promising candidate for biomedical applications.

CONCLUSION

The findings indicate that the targeted delivery of DS-Cu onto a PVA nanofiber scaffold holds potential approach to enhance the efficacy of DS-Cu in combating melanoma.

Bioinspired Lipoproteins of Furoxans-Gemcitabine Preferentially Targets Glioblastoma and Overcomes Radiotherapy Resistance

Radiotherapy (RT) resistance is an enormous challenge in glioblastoma multiforme (GBM) treatment, which is largely associated with DNA repair, poor distribution of reactive radicals in tumors, and limited delivery of radiosensitizers to the tumor sites. Inspired by the aberrant upregulation of RAD51 (a critical protein of DNA repair), scavenger receptor B type 1 (SR-B1), and C-C motif chemokine ligand 5 (CCL5) in GBM patients, a reduction-sensitive nitric oxide (NO) donor conjugate of gemcitabine (RAD51 inhibitor) (NG) is synthesized as radio-sensitizer and a CCL5 peptide-modified bioinspired lipoprotein system of NG (C-LNG) is rationally designed, aiming to preferentially target the tumor sites and overcome the RT resistance. C-LNG can preferentially accumulate at the orthotopic GBM tumor sites with considerable intratumor permeation, responsively release the gemcitabine and NO, and then generate abundant peroxynitrite (ONOO- ) upon X-ray radiation, thereby producing a 99.64% inhibition of tumor growth and a 71.44% survival rate at 120 days in GL261-induced orthotopic GBM tumor model. Therefore, the rationally designed bioinspired lipoprotein of NG provides an essential strategy to target GBM and overcome RT resistance.

In Situ Forming of Nitric Oxide and Electric Stimulus for Nerve Therapy by Wireless Chargeable Gold Yarn-Dynamos

Endogenous signals, namely nitric oxide (NO) and electrons, play a crucial role in regulating cell fate as well as the vascular and neuronal systems. Unfortunately, utilizing NO and electrical stimulation in clinical settings can be challenging due to NO's short half-life and the invasive electrodes required for electrical stimulation. Additionally, there is a lack of tools to spatiotemporally control gas release and electrical stimulation. To address these issues, an "electromagnetic messenger" approach that employs on-demand high-frequency magnetic field (HFMF) to trigger NO release and electrical stimulation for restoring brain function in cases of traumatic brain injury is introduced. The system comprises a NO donor (poly(S-nitrosoglutathione), pGSNO)-conjugated on a gold yarn-dynamos (GY) and embedded in an implantable silk in a microneedle. When subjected to HFMF, conductive GY induces eddy currents that stimulate the release of NO from pGSNO. This process significantly enhances neural stem cell (NSC) synapses' differentiation and growth. The combined strategy of using NO and electrical stimulation to inhibit inflammation, angiogenesis, and neuronal interrogation in traumatic brain injury is demonstrated in vivo.

Advanced Nitric Oxide Generating Nanomedicine for Therapeutic Applications

Nitric oxide (NO), a gaseous transmitter extensively present in the human body, regulates vascular relaxation, immune response, inflammation, neurotransmission, and other crucial functions. Nitrite donors have been used clinically to treat angina, heart failure, pulmonary hypertension, and erectile dysfunction. Based on NO's vast biological functions, it further can treat tumors, bacteria/biofilms and other infections, wound healing, eye diseases, and osteoporosis. However, delivering NO is challenging due to uncontrolled blood circulation release and a half-life of under five seconds. With advanced biotechnology and the development of nanomedicine, NO donors packaged with multifunctional nanocarriers by physically embedding or chemically conjugating have been reported to show improved therapeutic efficacy and reduced side effects. Herein, we review and discuss recent applications of NO nanomedicines, their therapeutic mechanisms, and the challenges of NO nanomedicines for future scientific studies and clinical applications. As NO enables the inhibition of the replication of DNA and RNA in infectious microbes, including COVID-19 coronaviruses and malaria parasites, we highlight the potential of NO nanomedicines for antipandemic efforts. This review aims to provide deep insights and practical hints into design strategies and applications of NO nanomedicines.

Fluorescent Self-Reporting Lipid Nanoparticles for Nitric Oxide/Gene Co-Delivery and Combination Therapy

The combination cancer therapy of nitric oxide (NO) with gene therapy is a promising method for tumor treatment. However, efficient co-delivery of gas and therapeutic genes to tumor cells remains a challenge. Herein, we designed a nano-sized ultraviolet (UV) light-responsive cationic lipid vector DPNO(Zn). Fluorescence spectroscopy and confocal imaging experiments revealed that DPNO(Zn) lipid nanoparticles (LNPs) could rapidly release NO under low-power UV light irradiation. Moreover, the fluorescence turn-on might take place along with the release of NO, indicating the self-reporting ability. Gene delivery experiments showed that DPNO(Zn) LNPs had good gene transfection ability, making such materials a good candidate for gas/gene combination therapy. In vitro antitumor assay demonstrated that the co-delivery system was more effective in inhibiting tumor cell proliferation than individual NO or pTrail treatment. Studies on the mechanism of tumor cell apoptosis induced by NO/pTrail co-delivery showed that NO could not only effectively increase the accumulation of p53 protein in tumor cells, thereby promoting the activation of caspase-3, but also induce mitochondrial damage. On the other hand, the Trail protein expressed by pTrail gene could enhance the degree of NO-induced caspase-3 activation, indicating the synergistic effect. These results proved that DPNO(Zn) LNP may serve as a multifunctional nanocarrier for potential tumor therapy.

Supramolecular Nitric Oxide Depot for Hypoxic Tumor Vessel Normalization and Radiosensitization

In cancer radiotherapy, the lack of fixed DNA damage by oxygen in hypoxic microenvironment of solid tumors often leads to severe radioresistance. Nitric oxide (NO) is a potent radiosensitizer that acts in two ways. It can directly react with the radical DNA thus fixing the damage. It also normalizes the abnormal tumor vessels, thereby increasing blood perfusion and oxygen supply. To achieve these functions, the dosage and duration of NO treatment need to be carefully controlled, otherwise it will lead to the exact opposite outcomes. However, a delivery method that fulfills both requirements is still lacking. A NO depot is designed for the control of NO releasing both over quantity and duration for hypoxic tumor vessel normalization and radiosensitization. In B16-tumor-bearing mice, the depot can provide low dosage NO continuously and release large amount of NO immediately before irradiation for a short period of time. These two modes of treatment work in synergy to reverse the radioresistance of B16 tumors more efficiently than releasing at single dosage.

Black Phosphorus-Synergic Nitric Oxide Nanogasholder Spatiotemporally Regulates Tumor Microenvironments for Self-Amplifying Immunotherapy

The lack of tumor immunogenicity coupled with the presence of tumor immunosuppression severely hinders antitumor immunity, especially in the treatment of "immune cold" tumors. Here, we have developed a drug-free and NIR-enabled nitric oxide (NO)-releasing nanogasholder (NO_PS@BP) composed of an outer cloak of nitrate-containing polymeric NO donor and an inner core of black phosphorus (BP) as the energy converter to spatiotemporally regulate NO-mediated tumor microenvironment remodeling and achieve multimodal therapy. Following NIR-irradiation, BP-induced photothermia and its intrinsic reducing property accelerate NO release from the outer cloak, by which the instantaneous NO burst concomitant with mild photothermia, on the one hand, induces immunogenic cell death (ICD), thereby provoking antitumor responses such as the maturation of dendritic cells (DCs) and the infiltration of cytotoxic T lymphocytes (CTLs); on the other hand, it reverses tumor immunosuppression via Treg inhibition, M2 macrophage restraint, and PD-L1 downregulation, further strengthening antitumor immunity. Therefore, this drug-free NO_PS@BP by means of multimodal therapy (NO gas therapy, immune therapy, photothermal therapy) realizes extremely significant curative effects against primary and distant tumors and even metastasis in B16F10 tumor models, providing a new modality to conquer immune cold tumors by NO-potentiated ICD and immunosuppression reversal.

On-Demand Generation of Peroxynitrite from an Integrated Two-Dimensional System for Enhanced Tumor Therapy

Nanosystem-mediated tumor radiosensitization strategy combining the features of X-ray with infinite penetration depth and high atomic number elements shows considerable application potential in clinical cancer therapy. However, it is difficult to achieve satisfactory anticancer efficacy using clinical radiotherapy for the majority of solid tumors due to the restrictions brought about by the tumor hypoxia, insufficient DNA damage, and rapid DNA repair during and after treatment. Inspired by the complementary advantages of nitric oxide (NO) and X-ray-induced photodynamic therapy, we herein report a two-dimensional nanoplatform by the integration of the NO donor-modified LiYF₄:Ce scintillator and graphitic carbon nitride nanosheets for on-demand generation of highly cytotoxic peroxynitrite (ONOO^-). By simply adjusting the Ce³⁺ doping content, the obtained nanoscintillator can realize high radioluminescence, activating photosensitive materials to simultaneously generate NO and superoxide radical for the formation of ONOO^- in the tumor. Obtained ONOO^- effectively amplifies therapeutic efficacy of radiotherapy by directly inducing mitochondrial and DNA damage, overcoming hypoxia-associated radiation resistance. The level of glutamine synthetase (GS) is downregulated by ONOO^-, and the inhibition of GS delays DNA damage repair, further enhancing radiosensitivity. This work establishes a combinatorial strategy of ONOO^- to overcome the major limitations of radiotherapy and provides insightful guidance to clinical radiotherapy.

Magnetic Responsive Release of Nitric Oxide from an MOF-Derived Fe3O4@PLGA Microsphere for the Treatment of Bacteria-Infected Cutaneous Wound

Nitric oxide (NO) is an essential endogenous signaling molecule regulating multifaceted physiological functions in the (cardio)vascular, neuronal, and immune systems. Due to the short half-life and location-/concentration-dependent physiological function of NO, translational application of NO as a novel therapeutic approach, however, awaits a strategy for spatiotemporal control on the delivery of NO. Inspired by the magnetic hyperthermia and magneto-triggered drug release featured by Fe₃O₄ conjugates, in this study, we aim to develop a magnetic responsive NO-release material (MagNORM) featuring dual NO-release phases, namely, burst and steady release, for the selective activation of NO-related physiology and treatment of bacteria-infected cutaneous wound. After conjugation of NO-delivery [Fe(μ-S-thioglycerol)(NO)₂]₂ with a metal-organic framework (MOF)-derived porous Fe₃O₄@C, encapsulation of obtained conjugates within the thermo-responsive poly(lactic-co-glycolic acid) (PLGA) microsphere completes the assembly of MagNORM. Through continuous/pulsatile/no application of the alternating magnetic field (AMF) to MagNORM, moreover, burst/intermittent/slow release of NO from MagNORM demonstrates the AMF as an ON/OFF switch for temporal control on the delivery of NO. Under continuous application of the AMF, in particular, burst release of NO from MagNORM triggers an effective anti-bacterial activity against both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). In addition to the magneto-triggered bactericidal effect of MagNORM against E. coli-infected cutaneous wound in mice, of importance, steady release of NO from MagNORM without the AMF promotes the subsequent collagen formation and wound healing in mice.

Multifunctional Mitochondria-Targeting Nanosystems for Enhanced Anticancer Efficacy

Mitochondria, a kind of subcellular organelle, play crucial roles in cancer cells as an energy source and as a generator of reactive substrates, which concern the generation, proliferation, drug resistance, and other functions of cancer. Therefore, precise delivery of anticancer agents to mitochondria can be a novel strategy for enhanced cancer treatment. Mitochondria have a four-layer structure with a high negative potential, which thereby prevents many molecules from reaching the mitochondria. Luckily, the advances in nanosystems have provided enormous hope to overcome this challenge. These nanosystems include liposomes, nanoparticles, and nanomicelles. Here, we summarize the very latest developments in mitochondria-targeting nanomedicines in cancer treatment as well as focus on designing multifunctional mitochondria-targeting nanosystems based on the latest nanotechnology.

PLGA Core-Shell Nano/Microparticle Delivery System for Biomedical Application

Core-shell particles are very well known for their unique features. Their distinctive inner core and outer shell structure allowed promising biomedical applications at both nanometer and micrometer scales. The primary role of core-shell particles is to deliver the loaded drugs as they are capable of sequence-controlled release and provide protection of drugs. Among other biomedical polymers, poly (lactic-co-glycolic acid) (PLGA), a food and drug administration (FDA)-approved polymer, has been recognized for the vehicle material. This review introduces PLGA core-shell nano/microparticles and summarizes various drug-delivery systems based on these particles for cancer therapy and tissue regeneration. Tissue regeneration mainly includes bone, cartilage, and periodontal regeneration.

Synergistic Therapy Using Doxorubicin-Loading and Nitric Oxide-Generating Hollow Prussian Blue Nanoparticles with Photoacoustic Imaging Potential Against Breast Cancer

Introduction

Traditional antitumor chemotherapy faces great challenges, such as multi-drug resistance (MDR) and poor penetration into tumor tissues. The newly emerging nitric oxide (NO)-based gas therapy has been recognized to reduce MDR and has improved permeation into tumor tissue.

Methods

In this study, NO-generating prodrug sodium nitroprusside (SNP) was doped to hollow mesoporous Prussian blue (PB) nanoparticles to fabricate NO-generating nanoparticles (NO-PB), which was further loaded with doxorubicin (DOX).

Results

DOX loaded NO-PB (DOX-NO-PB) was released quicker at pH 6 compared with neutral pH, suggesting NO-PB may facilitate the release of loaded drug in acidic tumor tissue. The capacity of NO production by NO-PB was measured, and the results showed the presence of NO in the culture medium from 4T1 cells incubated with NO-PB and inside the cells. NP-PB could be detected by photoacoustic imaging (PAI) in tumor tissue in 4T1 tumor bearing mice, suggesting this nanoparticle may serve as contrast agent for the noninvasive diagnosis of tumor tissues. NO-PB suppressed the growth of tissues in 4T1 tumor bearing mice. DOX-NO-PB showed more potent anti-tumor effects in 4T1 cells and tumor bearing mice compared with free DOX and NO-PB alone, indicating that the combination of DOX and NO-PB exhibited synergistic effects on tumor suppression.

Conclusion

This study provides a novel nanocarrier for gas therapy with additional PAI imaging capacity. This nanocarrier can be utilized for combination therapy of NO and chemotherapeutics which may serve as theranostic agents.

Advanced and Innovative Nano-Systems for Anticancer Targeted Drug Delivery

The encapsulation of therapeutic agents into nano-based drug delivery system for cancer treatment has received considerable attention in recent years. Advancements in nanotechnology provide an opportunity for efficient delivery of anticancer drugs. The unique properties of nanoparticles not only allow cancer-specific drug delivery by inherent passive targeting phenomena and adopting active targeting strategies, but also improve the pharmacokinetics and bioavailability of the loaded drugs, leading to enhanced therapeutic efficacy and safety compared to conventional treatment modalities. Small molecule drugs are the most widely used anticancer agents at present, while biological macromolecules, such as therapeutic antibodies, peptides and genes, have gained increasing attention. Therefore, this review focuses on the recent achievements of novel nano-encapsulation in targeted drug delivery. A comprehensive introduction of intelligent delivery strategies based on various nanocarriers to encapsulate small molecule chemotherapeutic drugs and biological macromolecule drugs in cancer treatment will also be highlighted.

Mitochondria-targeted and ultrasound-responsive nanoparticles for oxygen and nitric oxide codelivery to reverse immunosuppression and enhance sonodynamic therapy for immune activation

Background: Sonodynamic therapy (SDT) is a promising strategy to inhibit tumor growth and activate antitumor immune responses for immunotherapy. However, the hypoxic and immunosuppressive tumor microenvironment limits its therapeutic efficacy and suppresses immune response. Methods: In this study, mitochondria-targeted and ultrasound-responsive nanoparticles were developed to co-deliver oxygen (O2) and nitric oxide (NO) to enhance SDT and immune response. This system (PIH-NO) was constructed with a human serum albumin-based NO donor (HSA-NO) to encapsulate perfluorodecalin (FDC) and the sonosensitizer (IR780). In vitro, the burst release of O2 and NO with US treatment to generate reactive oxygen species (ROS), the mitochondria targeting properties and mitochondrial dysfunction were evaluated in tumor cells. Moreover, in vivo, tumor accumulation, therapeutic efficacy, the immunosuppressive tumor microenvironment, immunogenic cell death, and immune activation after PIH-NO treatment were also studied in 4T1 tumor bearing mice. Results: PIH-NO could accumulate in the mitochondria and relive hypoxia. After US irradiation, O2 and NO displayed burst release to enhance SDT, generated strongly oxidizing peroxynitrite anions, and led to mitochondrial dysfunction. The release of NO increased blood perfusion and enhanced the accumulation of the formed nanoparticles. Owing to O2 and NO release with US, PIH-NO enhanced SDT to inhibit tumor growth and amplify immunogenic cell death in vitro and in vivo. Additionally, PIH-NO promoted the maturation of dendritic cells and increased the number of infiltrating immune cells. More importantly, PIH-NO polarized M2 macrophages into M1 phenotype and depleted myeloid-derived suppressor cells to reverse immunosuppression and enhance immune response. Conclusion: Our findings provide a simple strategy to co-deliver O2 and NO to enhance SDT and reverse immunosuppression, leading to an increase in the immune response for cancer immunotherapy.

Near infrared II laser controlled free radical releasing nanogenerator for synergistic nitric oxide and alkyl radical therapy of breast cancer

Recently, alkyl radicals have attracted much attention in cancer therapy due to their oxygen-independent generation property. For the first time, alkyl radical and nitric oxide (NO) combined therapy is demonstrated as an effective strategy for tumor inhibition. As a proof of concept, a biocompatible free radical nanogenerator with near-infrared (NIR) II laser-induced simultaneous NO and alkyl radical release property was elaborately fabricated. In particular, an NIR II molecule (IR 1061), NO donor (BNN6) and alkyl radical initiator (AIPH) were firstly encapsulated in a natural lecithin stabilized phase change material, and then further functionalized by an amphiphile of DSPE-PEG-RGD with specific tumor targeting ability, finally obtaining biocompatible P(IR/BNN6/AIPH)@Lip-RGD. Upon NIR II laser irradiation, the photothermal effect generated from IR 1061 could trigger the phase change of the nanogenerator by releasing the encapsulated BNN6 and AIPH, and subsequently decompose them to generate highly active NO and alkyl radicals. Remarkably, NO and alkyl radical release profiles of P(IR/BNN6/AIPH)@Lip-RGD could be precisely controlled using intermittent NIR II laser irradiation. Moreover, P(IR/BNN6/AIPH)@Lip-RGD displayed a synergistic NO and alkyl radicals' anticancer effect by significantly inhibiting the growth of breast tumors, upon NIR II laser exposure. Furthermore, an in depth mechanistic study revealed that synergistic NO and alkyl radical effect induced cancer cell apoptosis through a mitochondria-mediated apoptotic pathway. The synergistic effect jointly caused a burst generation of mitochondrial ROS, which significantly down-regulated Bcl-2 protein expression, accelerated cytochrome c release and triggered a cascade of apoptosis-related proteins of Caspase-3 and Caspase-9.

Gaseous microenvironmental remodeling of tumors for enhanced photo-gas therapy and real-time tracking

The gaseous microenvironment (GME) of tumors is rapidly becoming a new concern for nanotechnology-mediated oncotherapy. Here, we constructed a tumor/near-infrared (NIR) light-responsive nanoplatform to generate O₂ and NO for remodeling the GME of tumors and phototherapy. The biocompatible and pyrolytic polydopamine was used to load indocyanine green, NONOate, and MnO₂ NPs as a nanoenzyme (PINM). Then, HA was modified on the PINM to form the final nanoplatform (PINMH). PINMH can target tumors favorably due to the modification of HA. Under the NIR light irradiation, PINM converts the light and O₂ to hyperpyrexia (58.5 °C) and cytotoxic ¹O₂. MnO₂ NPs catalyze the H₂O₂ overexpressed in tumors to O₂, which increases the amount of ¹O₂. Moreover, NONOate decomposes to NO (100 μM) under hyperpyrexia, thus leading to the gas therapy. The results verified that the responsive nanoplatform with precise gaseous regulation and phototherapy exhibited a superior anti-tumor effect (V/V₀ = 1.2) and biosafety. In addition, PINMH can be tracked in real-time via magnetic resonance imaging. In this study, an intelligent nano-platform integrated with diagnosis and treatment was developed, which used the phototherapy technology to reshape GME and achieve good anti-tumor effects, aiming to provide an innovative and reasonable strategy for the development of tumor treatment.