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Ischemic stroke caused by a thrombus clog and ischemia is one of the most lethal and disabling cerebrovascular diseases. A sequentially targeted delivery system is highly desired to deliver thrombolytics and neuroprotectant to the site of the thrombus and ischemic penumbra, respectively, to pursue a maximized combinational effect. Inspired by the vital roles that platelets play in thrombus formation, herein, we develop a bioengineered “nanoplatelet” (tP-NP-rtPA/ZL006e) for sequentially site-specific delivery of recombinant tissue plasminogen activator (rtPA) and neuroprotectant (ZL006e) for ischemic stroke treatment. The tP-NP-rtPA/ZL006e consists of a ZL006e-loaded dextran derivative polymeric nanoparticle core and platelet membrane shell conjugated with thrombin-cleavable Tat-peptide-coupled rtPA. Mediated by the cloak of the platelet membrane, tP-NP-rtPA/ZL006e targets the thrombus site and rtPA is triggered to release by the upregulated thrombin. Subsequently, the in situexposed Tat peptide enhanced penetration of the “nanoplatelet” across the blood–brain barrier into ischemic brain for ZL006e site-specific delivery. From the in vitroand in vivoevaluation, tP-NP-rtPA/ZL006e is demonstrated to significantly enhance the anti-ischemic stroke efficacy in the rat model  with middle cerebral artery occlusion, showing a 63 and 72% decrease in ischemic area and reactive oxygen species level compared to that with free drug combination, respectively.

Ischemic stroke is a leading cause of long-term disability and death worldwide. Current drug delivery vehicles for the treatment of ischemic stroke are less than satisfactory, in large part due to their short circulation lives, lack of specific targeting to the ischemic site, and poor controllability of drug release. In light of the upregulation of reactive oxygen species (ROS) in the ischemic neuron, we herein developed a bioengineered ROS-responsive nanocarrier for stroke-specific delivery of a neuroprotective agent, NR2B9C, against ischemic brain damage. The nanocarrier is composed of a dextran polymer core modified with ROS-responsive boronic ester and a red blood cell (RBC) membrane shell with stroke homing peptide (SHp) inserted. These targeted “core–shell” nanoparticles (designated as SHp-RBC-NP) could thus have controlled release of NR2B9C triggered by high intracellular ROS in ischemic neurons after homing to ischemic brain tissues. The potential of the SHp-RBC-NP for ischemic stroke therapy was systematically evaluated in vitroand in rat models of middle cerebral artery occlusion (MCAO). In vitroresults showed that the SHp-RBC-NP had great protective effects on glutamate-induced cytotoxicity in PC-12 cells. In vivopharmacokinetic (PK) and pharmacodynamic (PD) testing further demonstrated that the bioengineered nanoparticles can drastically prolong the systemic circulation of NR2B9C, enhance the active targeting of the ischemic area in the MCAO rats, and reduce ischemic brain damage.

Glioblastoma multiforme (GBM) presents one of the most lethal brain tumor with a dismal prognosis. And nanodrug delivery system (nano-DDS) have raised a lot of concern, while the conventional nanoformulations addressed many limitations, especially the low drug loading capacity and poor stability in vivo. Herein, we proposed PTX prodrug (PTX-SS-C18) conjugate self-assembled nanoparticles (PSNPs) functionalized with Pep-1, glioma homing peptide, to overcome the blood brain tumor barrier (BBTB) via interleukin 13 receptor α2 (IL-13Rα2)-mediated endocytosis for targeting GMB. This nanocarrier was with ultrahigh drug loading capacity (56.03%) and redox-sensitivity to the up-expression of glutathione in glioma tumors. And compared with PEG-PSNPs, Pep-PSNPs could significantly enhance cellular uptake in U87MG cells via IL-13Rα2-mediated endocytosis. Enhanced cytotoxicity of Pep-PSNPs against U87MG cells and BCEC cells pretreated with glutathione monoester (GSH-OEt) confirmed that this nanosystem was sensitive to reduction environment, and there was significant difference between targeting and nontargeting groups in MTT assay. Real-time fluorescence image of intracranialU87MG glioma-bearing mice revealed that Pep-PSNPs could more efficiently accumulate at tumor site and improve the penetration. Furthermore, the ex vivo fluorescence imaging and corresponding semiquantitative results displayed that the glioma fluorescence intensity of Pep-PSNPs group was 1.74-fold higher than that of nontargeting group. Pep-PSNPs exhibited remarkable antiglioblastoma efficacy with an extended median survival time. In conclusion, Pep-PSNPs had a promising perspective as a targeting drug delivery system of PTX for glioma treatment.

Combining treatment of anticancer cells and antiangiogenesis is considered to be a potential targeted strategy for brain glioblastoma therapy. In this study, by utilizing the overexpression of Interleukin 13 receptor α2 (IL-13Rα2) on the glioma cells and heparan sulfate on neovascular endothelial cells, we developed a paclitaxel (PTX) loaded Pep-1 and CGKRK peptide-modified PEG–PLGA nanoparticle (PC-NP-PTX) for glioma cells and neovasculature dual-targeted chemotherapy to enhance the antiglioma efficacy. There were significant differences both on the enhancement of cellular uptake in HUVEC and C6 cells and on the improvement of in vitroantiglioma activity in the respect of proliferation, tumor spheroid growth, tube formation, and migration between PC-NP-PTX and Taxol and NP-PTX. As for C6 cells, the IC50were 3.59 ± 0.056, 2.37 ± 0.044, 1.38 ± 0.028, 1.82 ± 0.035, and 1.00 ± 0.016 μg/mL of Taxol, NP-PTX, Pep-NP-PTX, CGKRK-NP-PTX, and PC-NP-PTX, and for HUVEC cells, the IC50were 0.44 ± 0.006, 0.33 ± 0.005, 0.25 ± 0.005, 0.19 ± 0.004, and 0.16 ± 0.004 μg/mL of Taxol, NP-PTX, Pep-NP-PTX, CGKRK-NP-PTX, and PC-NP-PTX, respectively. In vivodistribution assays confirmed that PC-NP-PTX targeted and accumulated effectively at glioma site. PC-NP-PTX showed a longer median survival time of 61 days when compared with Taxol (22 days), NP-PTX (24 days), Pep-NP-PTX (32 days), and CGKRK-NP-PTX (34 days). The in vivoantiglioma efficacy and safety evaluation showed PC-NP-PTX significantly enhanced the antiglioma efficacy and displayed negligible acute toxicity.

A novel candidate named 5-(3,5-dichloro-2-hydroxybenzylamino)-2- hydroxybenzoic acid (ZL006) can effectively treat focal cerebral ischemic stroke. However, the application potential of ZL006 was compromised by its poor solubility. In this study, ZL006 was loaded effectively into liposomes to improve the solubility and bioavailability. The particle size of ZL006-loaded liposomes (LPs) was about 115.5 nm with acceptable polydispersity index. The in vitro release profiles indicated that ZL006 could keep sustained release from LPs for more than 48 h. The results of pharmacokinetics study proved that the mean residence time of LPs group was 1.5-fold (P < 0.05) higher than that of free ZL006 group. Besides, the results of tissue distribution showed that the accumulation of ZL006 in brain tissue was significantly improved compared with the free ZL006 group at 1 h time after intravenous. Anti- ischemic stroke results showed that LPs could significantly enhance neuroprotection of ischemic stroke on middle cerebral artery occlusion (MCAO) rats model. In conclusion, LPs had been demonstrated to be a promising drug delivery system for ZL006 to treat ischemic stroke.