Unique characteristics, such as nontoxicity and rapid cellular internalization, allow the cell-penetrating peptides (CPPs) to transport hydrophilic macromolecules into cells, thus, enabling them to execute biological functions. However, some CPPs have limitations due to nonspecificity and easy proteolysis. To overcome such defects, the CPP amino acid sequence can be modified, replaced, and reconstructed for optimization. CPPs can also be used in combination with other drug vectors, fused with their preponderances to create novel multifunctional drug-delivery systems that increase the stability during blood circulation, and also develop novel preparations capable of targeted delivery, along with sustainable and controllable release. Further improvements in CPP structure can facilitate the penetration of macromolecules into diverse biomembrane structures, such as the blood brain barrier, gastroenteric mucosa, and skin dermis. The ability of CPP to act as transmembrane vectors improves the clinical application of some biomolecules to treat central nervous system diseases, increase oral bioavailability, and develop percutaneous-delivery dosage form.

Currently, with the rapid development of nanotechnology, novel drug delivery systems have made rapid progress, in which nanocarriers play an important role in the tumor treatment. In view of the conventional chemotherapeutic drugs with many restrictions such as non-specific systemic toxicity, short half-life and low concentration in the tumor sites, stimuli-responsive drug delivery systems can deliver anti-tumor drugs targeting to the specific sites of tumors. Owing to precise stimuli response, stimuli-responsive drug delivery systems can control drug release, so as to improve the curative effects, reduce the damage of normal tissues and organs, and decrease the side effects of traditional anti-cancer drugs. At present, according to the physicochemical properties and structures of nanomaterials, they can be divided into three categories: 1) endogenous stimuli-responsive materials, including pH, enzyme and redox responsive materials; 2) exogenous stimuli-responsive materials, such as temperature, light, ultrasound and magnetic field responsive materials; 3) multi-stimuli responsive materials. This review mainly focuses on the researches and developments of these novel stimuli-responsive drug delivery systems based on above-mentioned nanomaterials and their clinical applications.

With the continuous decline in prevalence and intensity of Schistosoma japonicum infection in China, more accurate and sensitive methods suitable for field detection become much needed for schistosomiasis control. Here, a novel rapid and visual detection method based on the combination of recombinase polymerase amplification (RPA) and lateral flow dipstick (LFD) was developed to detect S. japonicum DNA in fecal samples. The LFD-RPA assay targeting SjR2 could detect 5 fg S. japonicum DNA, which was identical to qPCR and real-time RPA assay, and showed no cross-reaction with other parasites. The detection could be finished within 15–20 min at a wide temperature range (25–45 °C), and the results could be visualized by naked eye. The diagnostic validity of LFD-RPA assay was further assessed with 14 fecal samples of infected patients diagnosed by Kato-Katz method and 31 fecal samples of healthy persons, and compared with that of Enzyme-linked immunosorbent assay (ELSIA) and Indirect Hemagglutination Assay (IHA). The LFD-RPA assay showed 92.68 % sensitivity, 100 % specificity and excellent diagnostic agreement with the gold standard Kato-Katz test (k = 0.947, Z = 6.36, P < 0.001), whereas ELISA showed 85.71 % sensitivity, 93.55 % specificity, and substantial diagnostic agreement (k = 0.793, Z = 5.31, P < 0.001), and IHA showed 78.57 % sensitivity, 83.87 % specificity, and moderate diagnostic agreement (k = 0.600, Z = 4.05, P < 0.001), indicating that the LFD-RPA was much better than the traditional methods. The LFD-RPA assay established by us is a sensitive, specific, rapid and convenient method for the diagnosis of schistosomiasis, and shows a great potency in field application.

The biggest victim of ambient air pollution is the respiratory system. Mainly because of the harmful components, especially the particulate matters with an aerodynamic diameter of ≤ 2.5µm (PM2.5), can be directly inhaled and deeply penetrate into the lung alveoli, thus causing severe lung dysfunction, including chronic cough, bronchitis and asthma, even lung cancer. Unfortunately, the toxicological mechanisms of PM2.5 associations with these adverse respiratory outcomes have still not been clearly unveiled. Here, we found that PM2.5 rapidly induced inflammatory responses, oxidative injure and cell death in human bronchial epithelium cells through upregulation of IL-6 expression, ROS production and apoptosis. Furthermore, PM2.5 specifically induced nitric oxide synthase 2 (NOS2) expression and NO generation to elevate excessive autophagy. Finally, disruption of NOS2 signaling effectively blocked autophayosome formation and the subsequent cell death. Our novel findings systemically reveled the role of autophagy-mediated cell death in PM2.5-treated human bronchial epithelium cells and provided potential strategy for future clinic intervention.

Parkinson's disease (PD) is a complex multi-system and age-related neurodegenerative disorder. The intervention targeting neuroinflammation in PD patients is one effective strategy to slow down or inhibit disease progression. Microglia-mediated inflammatory response plays an important role in Parkinson's, Alzheimer's and other cerebral diseases. Isobavachalcone is a main component of Chinese herb medicine Psoralea corylifolia, which function includes immunoregulation, anti-oxidation and the regulation of β-amyloid (Aβ42) deposited in hippocampus in Alzheimer's patients. Whether it has the therapeutic effect on Parkinson's disease, however, is unclear. In this study, we found that isobavachalcone could effectively remit Parkinson's disease induced by 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP), prolong the residence time of mice on Rota-rod and alleviate the neuronal necrosis. It also inhibited the over-activation of microglia, and decreased the expression of IL-6 and IL-1β in the brain of PD mice. In vitro, isobavachalcone could inhibit nuclear factor-kappaB (NF-κB) pathway through inhibiting the LPS-induced transfer of NF-κB subunit from cytoplasm to nucleus in BV-2 cells. Isobavachalcone decreased the LPS-induced oxidative stress and the expression of inflammatory cytokines, and provided a neuroprotective effect by antagonizing microglia-mediated inflammation. Our results indicated that isobavachalcone may be a candidated drug against Parkinson's disease with great clinical potential.

Exposure to airborne particulate matter with an aerodynamic diameter less than or equivalent to 2.5 microns (PM_2.5) easily induces acute myocardial infarction in populations with high-risk cardiovascular diseases such as hyperlipidemia, but its mechanism remains unclear. In this study, hyperlipidemic rats were used to examine the effects of PM_2.5 exposure on the cardiovascular system and the mechanism for its induction of cardiovascular events. We found that PM_2.5 exposure resulted in bigger changes in the myocardial enzyme profile (cTnI, LDH, CK, CK-MB) in hyperlipidemic rats than that of control rats, as well as a significant increase in the C-reactive protein (CRP) level and a decrease in the superoxide dismutase (SOD) activity. It promoted a hypercoagulable state, significantly increased blood pressure and heart rate, while decreased the variability of heart rate in hyperlipidemic rats. In addition, pathological test showed that PM_2.5 exposure more easily deteriorated myocardial injury in hyperlipidemic rats. It upregulated the phosphorylation levels of myocardial c-Jun NH2-terminal kinase (JNK) and P53, resulting in the elevated expression of downstream effector protein Bax and the decreased expression of Bcl-2, and then increased caspase3 level leading to cardiomyocyte apoptosis, while little change of caspase2 was observed. Taken together, PM_2.5 exposure induced more serious inflammation and oxidative stress in the circulation system of hyperlipidemic rats, promoted a hypercoagulable state and triggered cardiomyocyte apoptosis, in which JNK/P53 pathway played a key role.