Manipulation of Macrophage Uptake by Controlling the Aspect Ratio of Graft Copolymer Micelles.

Nanostructures of drug carriers play a crucial role in nanomedicine due to their ability to influence drug delivery. There is yet no clear consensus regarding the optimal size and shape (e.g., aspect ratio) of nanoparticles for minimizing macrophage uptake, given the difficulties in controlling the shape and size of nanoparticles while maintaining identical surface properties. Here, we employed graft copolymer self-assembly to prepare polymer micelles with aspect ratios ranging from 1.0 (spherical) to 10.8 (cylindrical) and closely matched interfacial properties. Notably, our findings emphasize that cylindrical micelles with an aspect ratio of 2.4 are the least susceptible to macrophage uptake compared with both their longer counterparts and spherical micelles. This reduced uptake of the short cylindrical micelles results in a 3.3-fold increase in blood circulation time compared with their spherical counterparts. Controlling the aspect ratio of nanoparticles is crucial for improving drug delivery efficacy through better nanoparticle design.

Molecular Bottlebrushes for Immunostimulatory CpG ODN Delivery: Relationship among Cation Density, Complex Formation Ability, and Cytotoxicity.

Artificially designed short single-stranded DNA sequences containing unmethylated CG (CpG ODNs) are agonists for toll-like receptor 9 (TLR9); thus, they have great potential as vaccine adjuvants for cancer immunotherapy and preventing infectious diseases. To deliver effectively CpG ODNs into cells bearing TLR9, nanoparticle polyion complexes of cationic polymers that are able to ingest multiple CpG ODN molecules have been developed; however, their structures and synthesized polycations are hard to control and bioincompatible, respectively. To solve these issues, we designed cationic molecular bottlebrushes (CMBs) with branches that are made from copolymers of 2-methacryloyloxyethyl phosphorylcholine and 2-methacryloyloxyethyl trimethylammonium chloride. Several instrumental methods were carried out to determine the structure of a CMB and its complex with CpG ODNs. The complexation did not change the overall shape of the original CMB, and the bound CpG ODNs were captured by the outer layer of the CMB. The moderation of cations was important to reduce toxicity and improve secretion of inflammatory cytokines.

Impact of Zwitterionic Polymers on the Tumor Permeability of Molecular Bottlebrush-Based Nanoparticles.

Biocompatible polymers possessing antifouling properties for biomolecules are necessary to be combined with nanoparticles for cancer chemotherapy to improve their retention in blood and subsequent tumor accumulation. However, these properties simultaneously lead to poor affinity to cells, and low tumor tissue permeability subsequently, which is one of the major barriers in achieving efficient anticancer efficacy. To address this, we try to elucidate the tumor permeability of nanoparticles using molecular bottlebrushes (MBs) as model polymeric nanoparticles composed of various biocompatible polymers. An MB comprising nonionic poly[(ethylene glycol) methyl ether methacrylate] (PEGMA) shows no tumor permeability at all, whereas zwitterionic MBs composed of poly(phosphobetaine methacrylate), poly(sulfobetaine methacrylate), or poly(carboxybetaine methacrylate) penetrate deeply into tumor tissues. The carboxybetaine-based MBs showed an efficient cellular uptake into cancer cells while the other MBs did not, which enable them to penetrate into tumor tissues via the transcytosis pathway. Additionally, their permeability is based on intercellular or intracellular pathways, which might be related to the zwitterionic betaine properties that recognize protein transporters on cancer cells. Surprisingly, incorporating only 10 mol % of the zwitterionic betaine polymers into PEGMA-based MBs significantly enhances their tissue permeability. This platform technology enables us to redesign the PEG-based nanoparticles developed for cancer chemotherapy in clinical applications.

Kurort Health Walking Preferentially Decreases Higher Blood Pressure and Improves Mood.

Background: Kurort is a German term from the words kur (cure) and ort (area), and refers to improvements in patients' health in areas full of nature. We investigated the effect of kurort health walking in the 2 urban-style kurort health walking courses opened in Gifu City on systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate, and mood. Methods and Results: The subjects were 454 people (136 males, 318 females; mean [±SD] age 61.7±9.9 years) taking part in kurort health walking for the first time. SBP, DBP, and heart rate were measured before and after kurort health walking. Mood was assessed using a 10-item checklist after kurort health walking. Kurort health walking significantly decreased SBP and DBP and increased heart rate. The decrease in SBP was significantly greater in the SBP ≥140 than <140 mmHg group, indicating that SBP before Kurort health walking was inversely correlated with the change in SBP. Similarly, the decrease in DBP was significantly greater in the DBP ≥90 than <90 mmHg group, indicating that DBP before kurort health walking was also inversely correlated with the change in DBP. All 10 items on the mood assessment were significantly improved after kurort health walking. Conclusions: Kurort health walking preferentially decreases higher blood pressure and improves mood.

Phosphorylcholine-Grafted Molecular Bottlebrush-Doxorubicin Conjugates: High Structural Stability, Long Circulation in Blood, and Efficient Anticancer Activity.

Controlling the particle structure of tumor-targeting nanomedicines in vivo remains challenging but must be achieved to control their in vivo fate and functions. Molecular bottlebrushes (MBs), where brush side chains are densely grafted from a main chain, have recently received attention as building blocks of polymer-based prodrugs because their rigid structure would be expected to demonstrate high structural stability in vivo. Here, we synthesized a poly(methacryloyloxyethyl phosphorylcholine) (pMPC)-grafted molecular bottlebrush (PCMB) conjugated with a cancer drug, doxorubicin (DOX), via an acid-cleavable hydrazone bond. A pMPC-based linear polymer (LP) conjugated with DOX was also prepared for comparison. We confirmed the lack of structural transition in the PCMB between before and after conjugation with DOX using small-angle light and X-ray scattering techniques, whereas the structure of LP was significantly influenced by DOX conjugation and transformed from a random-coil structure to a large agglomerate via hydrophobic interactions among DOXs. Although PCMB-DOX and LP-DOX showed comparable tissue permeability, pharmacokinetics, and ability to accumulate in tumor tissues, the antitumor efficacy of PCMB-DOX was better than that of LP-DOX. This was presumably due to the formation of LP-DOX agglomerates. The diffusion of cleaved DOX would be restricted in the hydrophobic core of the agglomerate, resulting in the DOX release at the tumor site being compromised. In contrast to LP-DOX, DOX release from PCMB-DOX was not compromised after accumulation in tumor tissues because it did not form such an agglomerate, resulting in the strong antitumor effect. We have demonstrated the potential of MBs as building blocks of drug carriers and believe that these findings can contribute to the design of polymer-based nanomedicines.

Characterizing an siRNA-Containing Lipid-Nanoparticle Prepared by a Microfluidic Reactor: Small-Angle X-ray Scattering and Cryotransmission Electron Microscopic Studies.

A new cationic-lipid/siRNA particle that was designed to deliver siRNA was investigated by the combination of small-angle X-ray scattering (SAXS), asymmetric field flow fractionation coupled with multiangle light scattering, and cryotransmission electron microscopy (cryo-TEM). The particle was prepared through two-step mixing using a microfluidic technique. In the first step, siRNA was premixed with a cationic lipid in an EtOH-rich solution. In the second step, the premixed solution was mixed with other lipids, followed by solvent exchange with water. SAXS showed formation of a siRNA/cationic lipid pair in the first step, and this pair consisted of the major part of the core in the final particle. The relationship between the hydrodynamic radius and the radius of gyration indicated the formation of a densely packed core and PEG-rich shell, confirming a well-known core-shell model. SAXS and cryo-TEM showed that the ordering of the core structure enhanced as the siRNA content increased.

[Endogenous endophthalmitis following staphylococcus aureus meningitis].

Endogenous endophthalmitis is a rare complication of acute meningitis. A healthy 82-year-old woman suddenly developed septic bacteremia and meningitis owing to Staphylococcus aureus (methicillin-susceptible Staphylococcus aureus); she presented with a high fever and drowsiness. Improvement of these initial symptoms unveiled impaired bilateral visual acuity. Detailed ophthalmological assessments diagnosed it as probable endogenous endophthalmitis, which was immediately treated with vitrectomy. Subsequently, the patient totally recovered without any neurologic or ophthalmic sequela.

[Delayed posthypoxic leukoencephalopathy: case reports].

Delayed posthypoxic leukoencephalopathy (DPL) is a rare and less well known complication of hypoxic brain injury. Although it is well known that anoxic or hypoxic injury produces acute neurologic deficits, DPL typically manifests days to weeks after apparent recovery from an obtunded state, and patients with DPL demonstrate cognitive impairment, high brain dysfunction, parkinsonism, or psychosis. MRI findings of the brain demonstrate deep white matter abnormalities. We report 2 cases of DPL after hypoxia due to benzodiazepine overdose. Both of our patients had normal arylsulfatase A activity. Although DPL is seen in carbon monoxide poisoning, pseudodeficiency of arylsulfatase A activity, or drug overdose with heroin or morphine, there are only some previous studies of DPL caused by an overdose with benzodiazepine. It is unclear whether neurotoxicity from the drug in addition to hypoxia alone is involved, however, it is important to note that overdose of common drugs as sleeping medicine can cause DPL. Since DPL may often be misdiagnosed and be subjected to unnecessary treatments, it is also important to understand its unique clinical course and MRI findings. With prompt recognition of DPL, we expect that more cases of DPL caused by overdose with benzodiazepine will be diagnosed, because benzodiazepine overdoses are common.

Clinical features of late-onset poststroke seizures.

BACKGROUND: Compared to the patients with early-onset seizures (ES), those with late-onset seizures (LS) have a high risk of epilepsy that is a feared complication after stroke. However, few studies have described detailed clinical features of LS in Japanese patients. METHODS: To elucidate the clinical features of LS, a series of 448 stroke patients (cerebral infarction n = 286; cerebral hemorrhage n = 162) in our hospital were retrospectively examined in this study. Stroke location was determined by computed tomographic and/or magnetic resonance imaging scans. Lesion size was evaluated using the Alberta Stroke Program Early Computed Tomographic Score. We examined occurrence rate, onset time, and recurrence rate of LS. In addition, clinical features of the infarction of LS and non-LS group were compared on age, gender, laterality, location, and extent, respectively. RESULTS: LS occurred in 18 patients (4.0%). Of these, 17 experienced LS within 1.5 years after stroke. While epilepsy developed in none of the patients with ES, it developed in 33% of those with LS. Patients with cortical and a larger infarction involving the middle cerebral artery had at significantly greater risk of LS (P < .05). CONCLUSIONS: Patients with cortical and a larger infarction involving the middle cerebral artery should be carefully observed because of a high risk of LS.

[Clinical characteristics of status epilepticus in an emergency hospital: importance of nonconvulsive status epilepticus].

Although nonconvulsive status epilepticus (NCSE) is a major neurological emergency, its frequency and clinical course are not well clarified. We investigated the clinical characteristics of status epilepticus focusing on the significance of NCSE. One thousand seven hundred twenty-three patients were admitted as neurological emergency cases in our hospital between October 2003 and September 2006. Of these cases, 94 (5.5%) were diagnosed as status epilepticus of which, 24 (25.5%) were diagnosed with NCSE on admission. Moreover, 8 patients who presented with convulsive status epilepticus on admission had episodes of NCSE during hospitalization. Thus, 32 patients (34.0%) suffered from NCSE during their clinical course. We analyzed the prognostic factors of status epilepticus using the Glasgow Outcome Scale. Poor outcome was significantly correlated with NCSE (p = 0.003) and acute cerebrovascular disease (p = 0.010), independent of age, sex, history of epilepsy, and other etiologies. Our study revealed that NCSE is not a rare condition and results in a poor outcome. Careful EEG evaluation of patients with consciousness disturbance might increase the diagnostic accuracy of NCSE, and aggressive treatment of patients with NCSE should be necessary to improve the prognosis of NCSE.