NIR Light-Fuse Drug-Free Photothermal Armor-Piercing Microcapsule for Femoral Vein Thrombosis Therapy

Photothermal-Therapy-Based Targeting Thrombolytic Therapy

Thrombosis, a common underlying mechanism of myocardial infarction, ischemic stroke, and venous thromboembolism, is the leading cause of death in patients. Owing to their lack of targeting ability, short half-life, low utilization rate, and high risk of bleeding side effects, the current first-line thrombolytic drugs are unable to meet the requirements for effective treatment of thrombi. Photothermal therapy (PTT) represents a promising thrombolytic modality due to its precise spatiotemporal selectivity and minimal invasiveness. However, the efficacy of PTT is constrained by the limited penetration depth of conventional wavelengths, low energy conversion efficiency, and suboptimal performance of photothermal agents. Recent advancements have demonstrated that near-infrared (NIR)-mediated photothermal conversion nanomaterials exhibit significant advantages in treating thrombotic diseases. These NIR-mediated nanomaterials can rapidly convert light energy into heat via the Landau damping effect, achieving deeper tissue penetration without inducing damage, thereby enhancing the effectiveness of photothermal thrombolysis. Moreover, the modifiable nature of these nanomaterials facilitates the targeted aggregation of thrombolytic drugs at the site of thrombosis, enabling specific and effective therapy. In this review, we systematically summarize recent advances in photothermal nanomaterials with potential therapeutic applications for thrombus treatment. Specifically, we focus on composite photothermal nanomaterials that incorporate multiple components in the construction of nanocarriers. We highlight the modification technologies that utilize specific targeting ligands for enhanced thrombus treatment and the application strategies of biomimetic nanomaterials in antithrombotic therapy. Additionally, we discuss combined thrombolytic approaches such as light-triggered nitric oxide release, thrombolytic drug loading, and photodynamic therapy integration. These methods can help mitigate the risk of secondary microvascular embolization, which is crucial for comprehensive thrombus management. Collectively, these strategies offer novel insights into the treatment of thrombotic diseases.

Emerging Elastic Micro-Nano Materials for Diagnosis and Treatment of Thrombosis

Thrombus is a blood clot that forms in a blood vessel at the point of flaking. Thrombosis is closely associated with cardiovascular diseases caused by different sources and factors. However, the current clinical methods of thrombus diagnosis and treatment still have problems with targeting, permeability, stability, and biosafety. Therefore, in recent years, based on the development of micro/nano technology, researchers have tried to develop some new strategies for the diagnosis and treatment of thrombosis. Due to the unique structural characteristics, the micro-nano materials in physiological environments show excellent transport and delivery properties such as better in vivo circulation, longer life span, better targeting ability, and controllable cellular internalization. Especially, elasticity and stiffness are inherent mechanical properties of some well-designed micro-nano materials, which can make them better adapted to the needs of thrombosis diagnosis and treatment. Herein, this review first introduces the thrombotic microenvironment to characterize the thrombus development process. Then, to fine-tune the pathological occurrence and development of thrombosis, the role of elastic micro-nano materials for thrombus diagnosis and treatment is summarized. The properties, preparation methods, and biological fate of these materials have been discussed in detail. Following, the applications of elastic micro-nano materials in biomedical imaging, drug delivery, and therapy of thrombosis are highlighted. Last, the shortcomings and future design strategies of elastic micro-nano materials in diagnosis and treatment of clinical thrombosis are discussed. This review will provide new ideas for the use of nanotechnology in clinical diagnosis and treatment of thrombus in the future.

"One-Stone-Three-Birds" H2S-Photothermal Therapy for Enhanced Thrombolysis and Vascular Healing

Thrombus causes a serious condition characterized by the formation of blood clots in blood vessels or heart, potentially leading to life-threatening emergencies. Photothermal therapy (PTT) serves as a treatment for thrombosis that provides noninvasive thrombus dissolution and fewer bleeding side effects. However, the high temperatures generated by PTT can exacerbate vascular inflammation and promote thrombus recurrence. In this study, a photothermal hydrogen sulfide (H2S) nanogenerator (PSA@ADT-OH) is constructed using a perylene-cored photothermal agent (PSA) coassembled with a H2S donor ADT-OH. The system PSA@ADT-OH demonstrates outstanding targeting and accumulation efficiency against blood flow shear forces. It also provides sustained H2S release at thrombus sites, contributing to antiplatelet aggregation, reactive oxygen species clearance, and vascular healing. This approach opens up new possibilities for advanced thrombus treatment.

Optimization of photothermal therapy conditions through diffusion analysis based on the initial injection radius of AuNPs

Anticancer treatment is performed in various ways, and photothermal therapy (PTT) is gaining traction from a noninvasive treatment perspective. PTT is a treatment technique based on the photothermal effect that kills tumors by increasing their temperature. In this study, gold nanoparticles (AuNPs), which are photothermal agents, were used in numerical simulations to determine the PTT effect by considering diffusion induced changes in the distribution area of the AuNPs. The treatment effect was confirmed by varying the initial injection radius of AuNPs represented by the injection volume, the elapsed time after injection of AuNPs, and the laser intensity. The degree of maintenance of the apoptotic temperature band in the tumor was quantitatively analyzed by the apoptotic variable. Ultimately, if the initial injection radius of AuNPs is 0.7 mm or less, the optimal time to start treatment is 240 min after injection, and for 1.0 and 1.2 mm, it is optimal to start treatment when the elapsed time after injection is 90 and 30 min, respectively. This study identified the optimal treatment conditions for dosage of AuNPs and treatment start time in PTT using AuNPs, which will serve as a reference point for future PTT studies.