Nanomaterials for stroke diagnosis and treatment

Nanomaterials and nanotechnology innovations possess unique physicochemical properties that present new opportunities in the realm of stroke detection, diagnosis, and treatment. This comprehensive review explores the utilization of nanomaterials in the diagnosis and treatment of strokes, encompassing recent advancements in computed tomography (CT), magnetic resonance imaging (MRI) and magnetic particle imaging (MPI), as well as groundbreaking applications of nanomaterials and bionanomaterials in drug delivery systems and brain tissue repair. Additionally, this review meticulously examines significant challenges such as biocompatibility toxicity and long-term safety, proposing potential strategies to surmount these obstacles. Moreover, this review delves into the application of nanomaterials to improve the clinical diagnosis of stroke patients, elucidates the potential of nanotechnology in post-stroke therapy, and identifies future research directions and potential clinical applications.

Lactylation of nuclear receptor coactivator 4 promotes ferritinophagy and glycolysis of neuronal cells after cerebral ischemic injury

Ischemic stroke remains a major cause of disability and mortality. Nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy is involved in cerebral ischemic injury. Additionally, lactylation regulates the progression of ischemia injury. This study aimed to investigate the impact of NCOA4 on ferritinophagy and glycolysis of hippocampal neuron cells and its lactylation modification. Middle cerebral artery occlusion (MCAO) mouse and oxygen-glucose deprivation (OGD)-treated HT22 cell models were generated. Ferritinophagy was evaluated via detecting ferrous iron (Fe 2+ ), glutathione, malondialdehyde, and protein levels. Glycolysis was assessed by examining the glucose consumption, lactate production, and extracellular acidification rate. The lactylation was evaluated using immunoprecipitation and immunoblotting. Brain injury in vivo was analyzed by measuring brain infarct and neurological function. The results showed that NCOA4 expression was increased in the blood of patients with acute ischemia stroke, the peri-infarct region of the brain in MCAO mice (increased percentage: 142.11%) and OGD-treated cells (increased percentage: 114.70%). Knockdown of NCOA4 inhibited ferritinophagy and glycolysis of HT22 cells induced by OGD. Moreover, OGD promoted the lactylation of NCOA4 at lysine (K)450 sites, which enhanced NCOA4 protein stability. Additionally, interfering with NCOA4 attenuated brain infarction and neurological dysfunction in MCAO mice. Lactylation of NCOA4 at K450 sites promotes ferritinophagy and glycolysis of hippocampal neuron cells, thereby accelerating cerebral ischemic injury. These findings suggest a novel pathogenesis of ischemic stroke.

Neuronal injuries in cerebral infarction and ischemic stroke: From mechanisms to treatment (Review)

Stroke is the leading cause of disabilities and cognitive deficits, accounting for 5.2% of all mortalities worldwide. Transient or permanent occlusion of cerebral vessels leads to ischemic strokes, which constitutes the majority of strokes. Ischemic strokes induce brain infarcts, along with cerebral tissue death and focal neuronal damage. The infarct size and neurological severity after ischemic stroke episodes depends on the time period since occurrence, the severity of ischemia, systemic blood pressure, vein systems and location of infarcts, amongst others. Ischemic stroke is a complex disease, and neuronal injuries after ischemic strokes have been the focus of current studies. The present review will provide a basic pathological background of ischemic stroke and cerebral infarcts. Moreover, the major mechanisms underlying ischemic stroke and neuronal injuries are summarized. This review will also briefly summarize some representative clinical trials and up-to-date treatments that have been applied to stroke and brain infarcts.

Temperature-sensitive liposome-mediated delivery of thrombolytic agents

BACKGROUND

Clinical efficacy of thrombolytic drugs is limited by lack of specific delivery and requires large therapeutic doses which increase toxicity. Encapsulating these drugs in temperature-sensitive liposomes and applying hyperthermia to deliver thrombolytic agents locally to thrombus might theoretically favourably alter the therapeutic window. The objectives of this study were to formulate liposomes encapsulating thrombolytics and assess thrombolytic activity following hyperthermia.

METHODS

Three liposome formulations were investigated: temperature-sensitive liposome (TSL, DPPC:DSPE-PEG2000 (mol% 95:5)), low temperature-sensitive liposome (LTSL, DPPC:MSPC:DSPE-PEG2000 (mol% 85.3:9.7:5)), and traditional temperature-sensitive liposome (TTSL, DPPC:HSPC:Chol:DSPE-PEG2000 (mol% 55:25:15:5)). To characterise temperature-dependent release of high molecular weight cargo from each formulation, fluorescein-conjugated dextrans (70 kDa) were loaded and release was quantified via spectrophotometry. Staphylokinase (SAK), urokinase, and tissue-type plasminogen activator were also loaded individually into each liposome formulation. Leakage at 37 °C and release at 38-44 °C were quantified via chromogenic enzymatic activity assay. Clot lysis was evaluated by measuring mass of blood clots before and after thrombolytic liposome treatment.

RESULTS

The LTSL formulation had optimal release characteristics with maximum release at 41.3 °C. Release of dextrans from LTSLs was observed to be 11.5 ± 1.5%, 79.7 ± 1.6%, and 93.6 ± 3.7% after 15 min in plasma at 37°, 39°, and 41.3 °C, respectively. The SAK LTSL had the highest release/leakage ratio and demonstrated greater clot lysis.

CONCLUSIONS

The SAK LTSL achieves significant clot lysis in vitro. When combined with local hyperthermia, the SAK LTSL potentially produces sufficient thrombolysis while minimising systemic side effects.