Ischemic stroke (IS) ranks as a leading cause of death and disability globally. The blood-brain barrier (BBB) poses significant challenges for effective drug delivery to brain tissues. Recent decades have seen the development of targeted nanomedicine and biomimetic technologies, sparking substantial interest in biomimetic drug delivery systems for treating IS. These systems are devised by utilizing or replicating natural cells and their derivatives, offering promising new pathways for detection and transport across the BBB. Their multifunctionality and high biocompatibility make them effective treatment options for IS. In addition, the incorporation of engineering techniques has provided these biomimetic drug delivery systems with active targeting capabilities, enhancing the accumulation of therapeutic agents in ischemic tissues and specific cell types. This improvement boosts drug transport and therapeutic efficacy. However, it is crucial to thoroughly understand the advantages and limitations of various engineering strategies employed in constructing biomimetic delivery systems. Selecting appropriate construction methods based on the characteristics of the disease is vital to achieving optimal treatment outcomes. This review summarizes recent advancements in three types of engineered biomimetic drug delivery systems, developed from natural cells and their derivatives, for treating IS. It also discusses their effectiveness in application and potential challenges in future clinical translation.
Humans ; Drug Delivery Systems/methods* ; Ischemic Stroke/drug therapy* ; Animals ; Blood-Brain Barrier/metabolism* ; Stroke/drug therapy*

Objective:To investigate the relationship between serum lipid levels and the risk of pulmonary embolism in patients with non-valvular atrial fibrillation.Methods:Patients with non-valvular atrial fibrillation admitted to Tianjin Chest Hospital from January 2014 to January 2019 were retrospectively analyzed.According to whether pulmonary embolism was present on CT pulmonary angiography, patients were divided into two groups, the atrial fibrillation with pulmonary embolism group(the AP group)and the control group(the AF group). Clinical data and serum lipid test results were compared between the two groups.The relationship between serum lipid levels and the risk of pulmonary embolism was evaluated.Results:Levels of apolipoprotein A1(ApoA1)and high-density lipoprotein cholesterol(HDL-C)in the AP group were(1.09±0.25)g/L and(1.03±0.28)mmol/L, which were lower than those in the AF group(1.24±0.25)g/L and(1.21±0.37)mmol/L)( t=3.255, P=0.002; t=2.972, P=0.004, respectively). Levels of very low-density lipoprotein cholesterol(VLDL-C)in the AP group were(0.41±0.24)mmol/L, which were higher than those in the AF group(0.26±0.18)mmol/L)( t=-3.761, P=0.000). The grade of cardiac function on admission in the AP group was higher than that in the AF group( χ2=13.074, P=0.004). The proportion of patients treated for atrial fibrillation in the AP group was lower than that in the AF group( χ2=5.445, P=0.020). Logistic regression analysis showed that decreased ApoA1 and left cardiac insufficiency were risk factors for pulmonary embolism in patients with non-valvular atrial fibrillation( OR=8.793, 95% CI: 1.815~42.607, P=0.007; OR=4.388, 95% CI: 1.352~14.244, P=0.014, respectively). Decreased VLDL-C and atrial fibrillation therapy were protective factors for pulmonary embolism( OR=0.180, 95% CI: 0.053~0.610, P=0.006; OR=0.268, 95% CI: 0.072~0.992, P=0.049, respectively). Conclusions:Pulmonary embolism in patients with non-valvular atrial fibrillation is related to serum lipid levels.Regulating levels of serum lipids may reduce the risk of pulmonary embolism in patients with non-valvular atrial fibrillation.

Objective To investigate the safety and feasibility of the interventional therapy on hemobilia induced by hepatic artery pseudoaneurysm(PsAn).Methods The clinical data of 28 patients with hemobilia in our department was analyzed retrospectively.All the patients were firstly treated with internal medicine,and then treated by interventional therapy.The angiography clearly displayed the shape,size and location of the PsAn,and superselective embolism was performed during the operation.The symptomatic treatment and the bile duct drainage were performed after operation.Postoperative follow-up time was 1-3 6 months,and the follow-up endpoint was the death of patient.Results 28 patients were diagnosed as hepatic artery PsAn.The interventional embolization therapy on hemobilia was completely effective.A total of 110 spring coils were applicated in the study,there was no complication related to interventional therapy.One patient with hilar cholangiocarcinoma was dead due to infection and liver failure after four weeks of operation.Two patients with choledochal carcinoma died of tumor progression after 11.5 and 14.2 months of interventional therapy,respectively.In addition,2 patients with gastric carcinoma died of tumor progression after 4 and 6.5 months of operation,respectively,and 1 patient with common bile duct stones who underwent laparoscopic surgery died of complications of coronary heart disease after 5 months of interventional therapy. The other patients all had satisfactory therapeutic effect and recovered well.Conclusion The interventional therapy has definite therapeutic effect on hemobilia induced by hepatic artery PsAn.The technique is worthy of popularized clinically due to its features of simplicity,safety and reliablity.

Objective To study the efficacy of double inverted Y-shaped airway covered stent for patients with thoracostomach-right main bronchus fistula.Methods Fifteen cases with thoracostomach-right main bronchus fistula were investigated retrospectively.All patients had accepted esophageal resection and thoracostomach esophagus anastomosis,as well as radiation therapy after surgery due to esophageal cancer. All fistulas located close to the opening of right upper lobe bronchus.According to the normal tracheobronchial diameter and length of patients,two inverted Y-shaped airway covered stents were designed individually.Stenting was performed under X-ray,and the situation of fistula and clinical symptoms improvement were investigated.Results The double inverted Y-shaped airway covered stents were implanted and fistulas were closed successfully.All patients could take normal diet,and the supine cough symptoms disappeared, without complications such as airway bleeding and pneumothorax after stenting.Conclusion The stenting of double inverted Y-shaped airway covered stent may be an effective,feasible and safe treatment for thoracostomach-right main bronchus fistula.

Objective To evaluate the mid-term and long-term result of mechanical aspiration thrombectomy or combined with balloon thrombectomy,venoplasty and catheter-directed thrombolysis therapy for lower extremity deep venous thrombosis.Methods Clinical data of 1 068 admitted patients were analysed retrospectively from January 2000 to June 2010.Among these patients,271 cases were treated by thrombectomy only,537 cases received thrombectomy with arterial catheter-directed thrombolysis,260 cases were treated by thrombectomy with dorsalis pedis vein thrombolysis,492 patients with stenosis or obstruction of iliac vein underwent venoplasty treatment.Results After 36 month follow-up edema,pigmentation and chronic ulcers were 10.26％,7.28％,1.55％ respectively.The patency without reflux,patency with reflux,residual thrombus,occlusion rate of the iliofemoral vein were 84.25％,8.95％,4.3％,2.5％ respectively; The patency,residual thrombus and occlusion rate of popliteal vein were 93.32％,5.49％,1.19％.Iliac vein stent patency rate was 92.28％.Conclusions Endovascular treatment for lower extremity deep venous thrombosis was a reasonable therapy with a satisfactory mid-term and long-term result,protecting venous valve function and reducing the morbidity of post-thrombotic syndrome.

Objective To compare the clinical effect of manual aspiration thrombectomy versus systemic thrombolysis for acute lower extremity deep venous thrombosis of mixed type.Methods The clinical data of 380 patients with acute lower extremity deep venous thrombosis of nixed type was analyzed retrospectively,who were classified into two groups according to treatment methods.Group A (229 cases):the ipsilateral femoral vein was accessed under local anesthesia,a 12-14 F sheath was introduced via a guide wire to aspirate iliofenoral thrombus.As for the femoropopliteal thrombus,a Fogarty balloon catheter was introduced to pull thrombus to iliac vein,then mechanical aspiration thrombectomy was performed.One hundred and thirteen patients with stenosis or occlusion of comnon iliac vein were treated with adjunctive PTA and stenting.As for the residual thrombus bclow popliteal vein,a small dose urokinase vas given to thrombolysis and heparin anticoagulation after procedure.Group B(151 cases) were treated by systemic thrombolysis and anticoagulation with heparin.Results The swelling and pain of affected limbs of group A began to relief after operation immediately,but these times of group B was 3-7 days after operation.The thrombus was eliminated completely(Grade Ⅰ):goup A was better than group B (63.32％ vs 37.09％) (x2 =20.53,P =0.002).Conclusions The manual aspiration thrombectomy was superior to simple systemic thrombolysis in treating acute lower extremity deep venous thrombosis of mixed type,especially in protecting the normal valve function that was better than thrombolysis,aspiration thrombectomy with adjunctive iliac vein angioplasty was a more reasonable method to treat acute LEDVT.