Numerical study on the modulation of THz wave propagation by collisional microplasma photonic crystal

In order to demonstrate the modulation of terahertz wave propagation in atmospheric pressure microplasmas,in this work,the band structure and the transmission characteristics of a onedimensional collisional microplasma photonic crystal are investigated,using the transfer matrix method.For a lattice constant of 150μm and a plasma width of 100μm,three stopbands of microplasma photonic crystal are observed,in a frequency range of 0.1-5 THz.Firstly,an increase in gas pressure leads to a decrease in the central frequency of the stopband.When the gas pressure increases from 50.5 k Pa to 202 k Pa,the transmission coefficient of the THz wave first increases and then decreases at high frequency,where the wave frequency is much greater than both the plasma frequency and the collision frequency.Secondly,it is interesting to find that the central frequency and the bandwidth of the first THz stopband remain almost unchanged for electron densities of less than 10^15 cm^-3,increasing significantly when the electron density increases up to 10^16 cm^-3.A central frequency shift of 110 GHz,and a bandgap broadening of 200 GHz in the first stopband are observed.In addition,an atmospheric pressure microplasma with the electron density of 1×10^15-6×10^15 cm^-3 is recommended for the modulation of THz wave propagation by plasma photonic crystals.

A nanocleaner specifically penetrates the blood-brain barrier at lesions to clean toxic proteins and regulate inflammation in Alzheimer's disease

Insurmountable blood-brain barrier(BBB) and complex pathological features are the key factors affecting the treatment of Alzheimer's disease(AD).Poor accumulation of drugs in lesion sites and undesired effectiveness of simply reducing Aβ deposition or TAU protein need to be resolved urgently.Herein,a nanocleaner is designed with a rapamycin-loaded ROS-responsive PLGA core and surface modification with KLVFF peptide and acid-cleavable DAG peptide [R@(ox-PLGA)-KcD].DAG can enhance the targeting and internalization effect of nanocleaner towards neurovascular unit endothelial cells in AD lesions,and subsequently detach from nanocleaner in response to acidic microenvironment of endosomes to promote the transcytosis of nanocleaner from endothelial cells into brain parenchyma.Then exposed KLVFF can capture and carry Aβ to microglia,attenuating Aβ-induced neurotoxicity.Strikingly,rapamycin,an autophagy promoter,is rapidly liberated from nanocleaner in the high ROS level of lesions to improve Aβ degradation and normalize inflammatory condition.This design altogether accelerates Aβ degradation and alleviates oxidative stress and excessive inflammatory response.Collectively,our finding offers a strategy to target the AD lesions precisely and multi-pronged therapies for clearing the toxic proteins and modulating lesion microenvironment,to achieve efficient AD therapy.

GSH-responsive SN38 dimer-loaded shape-transformable nanoparticles with iRGD for enhancing chemo-photodynamic therapy

Accurate tumor targeting,deep penetration and superb retention are still the main pursuit of developing excellent nanomedicine.To achieve these requirements,a stepwise stimuli-responsive strategy was developed through co-administration tumor penetration peptide iRGD with shape-transformable and GSH-responsive SN38-dimer(d-SN38)-loaded nanoparticles(d-SN38@NPs/iRGD).Upon intravenous injection,d-SN38@NPs with high drug loading efficiency(33.92±1.33%)could effectively accumulate and penetrate into the deep region of tumor sites with the assistance of iRGD.The gathered nanoparticles simultaneously transformed into nanofibers upon 650 nm laser irradiation at tumor sites so as to promote their retention in the tumor and burst release of reactive oxygen species for photodynamic therapy.The loaded d-SN38 with disulfide bond responded to the high level of GSH in tumor cytoplasm,which consequently resulted in SN38 release and excellent chemo-photodynamic effect on tumor.In vitro,coadministering iRGD with d-SN38@NPs+laser showed higher cellular uptake,apoptosis ratio and multicellular spheroid penetration.In vivo,d-SN38@NPs/iRGD+laser displayed advanced penetration and accumulation in tumor,leading to 60.89%of tumor suppression in 4 T1 tumor-bearing mouse model with a favorable toxicity profile.Our new strategy combining iRGD with structural transformable nanoparticles greatly improves tumor targeting,penetrating and retention,and empowers anticancer efficacy.

Author correction to “A nanocleaner specifically penetrates the blood‒brain barrier at lesions to clean toxic proteins and regulate inflammation in Alzheimer’s disease” [Acta Pharmaceutica Sinica B 12, (2021) 4032e4044]

The authors regret that there were some picture errors in Fig.4A and data errors Fig.7A owing to the mistakes of copying and pasting in the process of assembling figures and making a dia-gram.The raw data of correct images of group b in Fig.4A and values of high dose in Fig.7A are provided in the supporting information,and the authors revise Figs.4 and 7 as below.The revisions do not affect any results and conclusions of the current work.The authors apologize for any inconvenience caused to the journal and readers.