Curcumin-loaded mesoporous polydopamine nanoparticles modified by quaternized chitosan against bacterial infection through synergistic effect.

Clinically, open wounds caused by accidental trauma and surgical lesion resection are easily infected by external bacteria, hindering wound healing. Antibacterial photodynamic therapy has become a promising treatment strategy for wound infection. In this study, a novel antibacterial nanocomposite material (QMC NPs) was synthesized by curcumin, quaternized chitosan and mesoporous polydopamine nanoparticles. The results showed that 150 µg/mL QMC NPs had good biocompatibility and exerted excellent antibacterial activity against Staphylococcus aureus and Escherichia coli after blue laser irradiation (450 nm, 1 W/cm2). In vivo, QMC NPs effectively treated bacterial infection and accelerated the healing of infected wounds in mice.

Macrophages in the process of osseointegration around the implant and their regulatory strategies.

PURPOSE/AIM OF THE STUDY: To summarize and discuss macrophage properties and their roles and mechanisms in the process of osseointegration in a comprehensive manner, and to provide theoretical support and research direction for future implant surface modification efforts. MATERIALS AND METHODS: Based on relevant high-quality articles, this article reviews the role of macrophages in various stages of osseointegration and methods of implant modification. RESULTS AND CONCLUSIONS: Macrophages not only promote osseointegration through immunomodulation, but also secrete a variety of cytokines, which play a key role in the angiogenic and osteogenic phases of osseointegration. There is no "good" or "bad" difference between the M1 and M2 phenotypes of macrophages, but their timely presence and sequential switching play a crucial role in implant osseointegration. In the implant surface modification strategy, the induction of sequential activation of the M1 and M2 phenotypes of macrophages is a brighter prospect for implant surface modification than inducing the polarization of macrophages to the M1 or M2 phenotypes individually, which is a promising pathway to enhance the effect of osseointegration and increase the success rate of implant surgery.

Driving Force Analysis of Natural Wetland in Northeast Plain Based on SSA-XGBoost Model.

Globally, natural wetlands have suffered severe ecological degradation (vegetation, soil, and biotic community) due to multiple factors. Understanding the spatiotemporal dynamics and driving forces of natural wetlands is the key to natural wetlands' protection and regional restoration. In this study, we first investigated the spatiotemporal evolutionary trends and shifting characteristics of natural wetlands in the Northeast Plain of China from 1990 to 2020. A dataset of driving-force evaluation indicators was constructed with nine indirect (elevation, temperature, road network, etc.) and four direct influencing factors (dryland, paddy field, woodland, grassland). Finally, we built the driving force analysis model of natural wetlands changes to quantitatively refine the contribution of different driving factors for natural wetlands' dynamic change by introducing the sparrow search algorithm (SSA) and extreme gradient boosting algorithm (XGBoost). The results showed that the total area of natural wetlands in the Northeast Plain of China increased by 32% from 1990 to 2020, mainly showing a first decline and then an increasing trend. Combined with the results of transfer intensity, we found that the substantial turn-out phenomenon of natural wetlands occurred in 2000-2005 and was mainly concentrated in the central and eastern parts of the Northeast Plain, while the substantial turn-in phenomenon of 2005-2010 was mainly located in the northeast of the study area. Compared with a traditional regression model, the SSA-XGBoost model not only weakened the multicollinearity of each driver but also significantly improved the generalization ability and interpretability of the model. The coefficient of determination (R2) of the SSA-XGBoost model exceeded 0.6 in both the natural wetland decline and rise cycles, which could effectively quantify the contribution of each driving factor. From the results of the model calculations, agricultural activities consisting of dryland and paddy fields during the entire cycle of natural wetland change were the main driving factors, with relative contributions of 18.59% and 15.40%, respectively. Both meteorological (temperature, precipitation) and topographic factors (elevation, slope) had a driving role in the spatiotemporal variation of natural wetlands. The gross domestic product (GDP) had the lowest contribution to natural wetlands' variation. This study provides a new method of quantitative analysis based on machine learning theory for determining the causes of natural wetland changes; it can be applied to large spatial scale areas, which is essential for a rapid monitoring of natural wetlands' resources and an accurate decision-making on the ecological environment's security.

Shortwave Infrared InGaAs Detectors On-Chip Integrated with Subwavelength Polarization Gratings.

Shortwave infrared polarization imaging can increase the contrast of the target to the background to improve the detection system's recognition ability. The division of focal plane polarization indium gallium arsenide (InGaAs) focal plane array (FPA) detector is the ideal choice due to the advantages of compact structure, real-time imaging, and high stability. However, because of the mismatch between nanostructures and photosensitive pixels as well as the crosstalk among the different polarization directions, the currently reported extinction ratio (ER) of superpixel-polarization-integrated detectors cannot meet the needs of high-quality imaging. In this paper, a 1024 × 4 InGaAs FPA detector on-chip integrated with a linear polarization grating (LPG) was realized and tested. The detector displayed good performance throughout the 0.9-1.7 um band, and the ERs at 1064 nm, 1310 nm and 1550 nm reached up to 22:1, 29:1 and 46:1, respectively. For the crosstalk investigation, the optical simulation of the grating-integrated InGaAs pixel was carried out, and the limitation of the ER was calculated. The result showed that the scattering of incident light in the InP substrate led to the crosstalk. Moreover, the deviation of the actual grating morphology from the designed structure caused a further reduction in the ER.

Modulation of two-dimensional palladium nanozyme activity to enhance chemodynamic/photothermal combined therapy for melanoma.

Nanozymes are artificial enzymes that mimic natural enzyme-like activities and exhibit tremendous potential for tumor chemodynamic therapy. However, the development of novel nanozymes with superior catalytic activities for nanotheranostics remains a formidable challenge. Herein, we report a facile synthesis of monodisperse palladium nanosheets (Pd nanosheets) and their assembly on graphene oxide (GO) that enhances the catalytic activities of Pd nanoparticles. Simultaneously, the obtained nanocomposites (rGO-Pd) could be applied as a smart near-infrared (NIR) light-responsive nanotheranostic for near infrared imaging-guided chemodynamic/photothermal combined therapy. Notably, rGO-Pd exhibited high peroxidase mimicking activities, which could catalyze the conversion of intratumoral H2O2 to ˙OH. Impressively, the reactive oxygen species (ROS) generation of rGO-Pd was further remarkably enhanced by the endogenous acidity of the tumor microenvironment and the exogenous NIR light-responsive photothermal effect. These collective properties of the rGO-Pd nanozyme enabled it to be a ROS generation accelerator for photothermally enhanced tumor chemodynamic therapy. Thus, the as-developed rGO-Pd may represent a promising new type of high-performance nanozyme for multifunctional nanotheranostics toward cancer.

Chitosan Grafted with Thermoresponsive Poly(di(ethylene glycol) Methyl Ether Methacrylate) for Cell Culture Applications.

Chitosan is a polysaccharide extracted from animal sources such as crab and shrimp shells. In this work, chitosan films were modified by grafting them with a thermoresponsive polymer, poly(di(ethylene glycol) methyl ether methacrylate) (PMEO2MA). The films were modified to introduce functional groups useful as reversible addition-fragmentation chain transfer (RAFT) agents. PMEO2MA chains were then grown from the films via RAFT polymerization, making the chitosan films thermoresponsive. The degree of substitution of the chitosan-based RAFT agent and the amount of monomer added in the grafting reaction were varied to control the length of the grafted PMEO2MA chain segments. The chains were cleaved from the film substrates for characterization using 1H NMR and a gel permeation chromatography analysis. Temperature-dependent contact angle measurements were used to demonstrate that the hydrophilic-hydrophobic nature of the film surface varied with temperature. Due to the enhanced hydrophobic character of PMEO2MA above its lower critical solution temperature (LCST), the ability of PMEO2MA-grafted chitosan films to serve as a substrate for cell growth at 37 °C (incubation temperature) was tested. Interactions with cells (fibroblasts, macrophages, and corneal epithelial cells) were assessed. The modified chitosan films supported cell viability and proliferation. As the temperature is lowered to 4 °C (refrigeration temperature, below the LCST), the grafted chitosan films become less hydrophobic, and cell adhesion should decrease, facilitating their removal from the surface. Our results indicated that the cells were detached from the films following a short incubation period at 4 °C, were viable, and retained their ability to proliferate.

Antibacterial properties of antimicrobial peptide HHC36 modified polyetheretherketone.

Introduction: Polyetheretherketone (PEEK) is considered to be a new type of orthopedic implant material due to its mechanical properties and biocompatibility. It is becoming a replacement for titanium (Ti) due to its near-human-cortical transmission and modulus of elasticity. However, its clinical application is limited because of its biological inertia and susceptibility to bacterial infection during implantation. To solve this problem, there is an urgent need to improve the antibacterial properties of PEEK implants. Methods: In this work, we fixed antimicrobial peptide HHC36 on the 3D porous structure of sulfonated PEEK (SPEEK) by a simple solvent evaporation method (HSPEEK), and carried out characterization tests. We evaluated the antibacterial properties and cytocompatibility of the samples in vitro. In addition, we evaluated the anti-infection property and biocompatibility of the samples in vivo by establishing a rat subcutaneous infection model. Results: The characterization test results showed that HHC36 was successfully fixed on the surface of SPEEK and released slowly for 10 days. The results of antibacterial experiments in vitro showed that HSPEEK could reduce the survival rate of free bacteria, inhibit the growth of bacteria around the sample, and inhibit the formation of biofilm on the sample surface. The cytocompatibility test in vitro showed that the sample had no significant effect on the proliferation and viability of L929 cells and had no hemolytic activity on rabbit erythrocytes. In vivo experiments, HSPEEK can significantly reduce the bacterial survival rate on the sample surface and the inflammatory reaction in the soft tissue around the sample. Discussion: We successfully loaded HHC36 onto the surface of SPEEK through a simple solvent evaporation method. The sample has excellent antibacterial properties and good cell compatibility, which can significantly reduce the bacterial survival rate and inflammatory reaction in vivo. The above results indicated that we successfully improved the antibacterial property of PEEK by a simple modification strategy, making it a promising material for anti-infection orthopedic implants.

Enhanced corrosion resistance in an inflammatory environment and osteogenic properties of silicalite-1 coated titanium alloy implants.

The corrosion resistance and osteogenic property of titanium-based implants are crucial for their clinical application. Although they have good stability in standard physiological solutions, limited corrosion resistance in the inflammatory environment is still an unavoidable problem. Herein, the calcined and uncalcined silicalite-1 coatings were synthesized on titanium alloy (Ti-6Al-4 V). The corrosion resistance was investigated by simulating an inflammatory environment in vitro, and osteogenic potential was also evaluated. Here, the uncalcined silicalite-1 coating had the highest corrosion protection efficiency (PE) for Ti-6Al-4 V, which inhibited the metal ion release, surface damage and mass loss in the short-term (7 days) and long-term (30 days). Moreover, positive cell responses, including adhesion, proliferation and osteogenic differentiation of MC3T3-E1 cells, were observed in the uncalcined silicalite-1 coating system, supporting its favorable biocompatibility and osteogenic property. Therefore, these findings indicate that the uncalcined silicalite-1 may be a promising coating strategy for the surface modification of Ti-6Al-4 V implants.

Retinoschisin deficiency induces persistent aberrant waves of activity affecting neuroglial signaling in the retina.

Genetic disorders which present during development make treatment strategies particularly challenging because there is a need to disentangle primary pathophysiology from downstream dysfunction caused at key developmental stages. To provide a deeper insight into this question, we studied a mouse model of X-linked juvenile retinoschisis (XLRS), an early-onset inherited condition caused by mutations in the Rs1 gene encoding retinoschisin (RS1) and characterized by cystic retinal lesions and early visual deficits. Using an unbiased approach in expressing the fast intracellular calcium indicator GCaMP6f in neuronal, glial, and vascular cells of the retina of RS1-deficient male mice, we found that initial cyst formation is paralleled by the appearance of aberrant spontaneous neuro-glial signals as early as postnatal day 15, when eyes normally open. These presented as glutamate-driven wavelets of neuronal activity and sporadic radial bursts of activity by Müller glia, spanning all retinal layers and disrupting light-induced signaling. This study confers a role to RS1 beyond its function as an adhesion molecule, identifies an early onset for dysfunction in the course of disease, establishing a potential window for disease diagnosis and therapeutic intervention.Significance StatementDevelopmental disorders make it difficult to distinguish pathophysiology due to ongoing disease from pathophysiology due to disrupted development. Here, we investigated a mouse model for X-linked retinoschisis (XLRS), a well-defined monogenic degenerative disease caused by mutations in the Rs1 gene, which codes for the protein retinoschisin. We evaluated the spontaneous activity of explanted retinas lacking retinoschisin at key stages of development using the unbiased approach of ubiquitously expressing GCaMP6f in all retinal neurons, vasculature and glia. In mice lacking RS1, we found an array of novel phenotypes which present around eye-opening, are linked to glutamatergic neurotransmission, and affect visual processing. These data identify novel pathophysiology linked to RS1, and define a window where treatments might be best targeted.

Intrinsically Bioactive Manganese-Eumelanin Nanocomposites Mediated Antioxidation and Anti-Neuroinflammation for Targeted Theranostics of Traumatic Brain Injury.

Overproduced reactive oxygen species and the induced oxidative stress and neuroinflammation often result in secondary injury, which is associated with unfavorable prognosis in traumatic brain injury (TBI). Unfortunately, current medications cannot effectively ameliorate the secondary injury at traumatic sites. Here, it is reported that intrinsically bioactive multifunctional nanocomposites (ANG-MnEMNPs-Cur, AMEC) mediate antioxidation and anti-neuroinflammation for targeted TBI theranostics, which are engineered by loading the neuroprotective agent curcumin on angiopep-2 functionalized and manganese doped eumelanin-like nanoparticles. After intravenous delivery, efficient AMEC accumulation is observed in lesions of TBI mice models established by controlled cortical impact method, evidenced by T1 -T2 magnetic resonance and photoacoustic dual-modal imaging. Therapeutically, AMEC effectively alleviates neuroinflammation, protects blood-brain barrier integrity, relieves brain edema, reduces brain tissue loss, and improves the cognition of TBI mice. Mechanistically, following the penetration into the traumatic tissues via angiopep-2 mediated targeting effect, the efficacy of AMEC is synergistically improved by combined functional moieties of curcumin and eumelanin. This is achieved by the alleviation of oxidative stress, inhibition of neuroinflammation via M1-to-M2 macrophage reprogramming, and promotion of neuronal regeneration. The as-developed AMEC with well-defined mechanisms of action may represent a promising targeted theranostics strategy for TBI and other neuroinflammation-associated intracranial diseases.

The antibacterial property of zinc oxide/graphene oxide modified porous polyetheretherketone againstS. sanguinis, F. nucleatumandP. gingivalis.

About 30% failures of implant are caused by peri-implantitis. Subgingival plaque, consisting of S. sanguinis, F. nucleatum,P. gingivalis et al, is the initiating factor of peri-implantitis. Polyetheretherketone (PEEK) is widely used for the fabrication of implant abutment, healing cap and temporary abutment in dental applications. As a biologically inert material, PEEK has shown poor antibacterial properties. To promote the antibacterial activity of PEEK, we loaded ZnO/GO on sulfonated PEEK. We screened out that when mass ratio of ZnO/GO was 4:1, dip-coating time was 25 min, ZnO/GO modified SPEEK shown the best physical and chemical properties. At the meantime, the ZnO/GO-SPEEK samples possess a good biocompatibility. The ZnO/GO-SPEEK inhibitsP. gingivalisobviously, and could exert an antibacterial activity toS. sanguinisin the early stage, prevents biofilm formation effectively. With the favorablein vitroperformances, the modification of PEEK with ZnO/GO is promising for preventing peri-implantitis.

mSLA-based 3D printing of acrylated epoxidized soybean oil - nano-hydroxyapatite composites for bone repair.

Structural bone allografts are used to treat critically sized segmental bone defects (CSBDs) as such defects are too large to heal naturally. Development of biomaterials with competent mechanical properties that can also facilitate new bone formation is a major challenge for CSBD repair. 3D printed synthetic bone grafts are a possible alternative to structural allografts if engineered to provide appropriate structure with sufficient mechanical properties. In this work, we fabricated a set of novel nanocomposite biomaterials consisting of acrylated epoxidized soybean oil (AESO), polyethylene glycol diacrylate (PEGDA) and nanohydroxyapatite (nHA) by using masked stereolithography (mSLA)-based 3D printing. The nanocomposite inks possess suitable rheological properties and good printability to print complex, anatomically-precise, 'by design' grafts. The addition of nHA to the AESO/PEGDA resin improved the tensile strength and fracture toughness of the mSLA printed nanocomposites, presumably due to small-scale reinforcement. By adding 10 vol% nHA, tensile strength, modulus and fracture toughness (KIc) were increased to 30.8 ± 1.2 MPa (58% increase), 1984.4 ± 126.7 MPa (144% increase) and 0.6 ± 0.1 MPa·m1/2 (42% increase), respectively (relative to the pure resin). The nanocomposites did not demonstrate significant hydrolytic, enzymatic or oxidative degradation when incubated for 28 days, assuring chemical and mechanical stability at early stages of implantation. Apatite nucleated and covered the nanocomposite surfaces within 7 days of incubation in simulated body fluid. Good viability and proliferation of differentiated MC3T3-E1 osteoblasts were also observed on the nanocomposites. Taken all together, our nanocomposites demonstrate excellent bone-bioactivity and potential for bone defect repair.

Near-Infrared Light Enhanced Peroxidase-Like Activity of PEGylated Palladium Nanozyme for Highly Efficient Biofilm Eradication.

The overall eradication of biofilm-mode growing bacteria holds significant key to the answer of a series of infection-related health problems. However, the extracellular matrix of bacteria biofilms disables the traditional antimicrobials and, more unfortunately, hampers the development of the anti-infectious alternatives. Therefore, highly effective antimicrobial agents are an urgent need for biofilm-infection control. Herein, a PEGylated palladium nanozyme (Pd-PEG) with peroxidase (POD)-like activity for highly efficient biofilm infection control is reported. Pd-PEG also shows the intrinsic photothermal effect as well as near-infrared (NIR) light-enhanced POD-like activity in the acidic environment, thereby massively destroying the biofilm matrix and killing the adhering bacteria. Importantly, the antimicrobial mechanism of the synergistic treatment based on Pd-PEG+H2O2+NIR combination was disclosed. In vitro and in vivo results illustrated the designed Pd-PEG+H2O2 +NIR treatment reagent possessed outstanding antibacterial and biofilms elimination effects with negligible biotoxicity. This work hopefully facilitates the development of metal-based nanozymes in biofilm related infectious diseases.

[Effects of Straw Mulching and Nitrogen Reduction on the Distribution of Soil Nitrogen and Groundwater Nitrogen Pollution].

To explore the effects of straw mulching and reduced nitrogen fertilization on the temporal and spatial patterns of soil nitrogen, groundwater nitrogen pollution, and summer maize yield, field experiments were carried out in the Hetao irrigation district in 2017 and 2018. The experiment involved the following seven treatments:a control (CK) treatment involving conventional fertilization and traditional tillage, and conventional nitrogen applications reduced by 30% (N1), 20% (N2), and 10% (N3) coupled with either straw surface covering (B) or deep straw burial (S). The results showed that the distribution of soil nitrogen in the CK treatment varied depending on soil depth, with an overall decreasing trend. In the 0-20 cm soil layer under straw surface covering (B) treatments, soil nitrogen was superficially accumulated. NO3--N and NH4+-N content increased by an average of 22.2% and 42.7% compared to the CK treatment, respectively, which decreased significantly at first and then increased slightly with depth. In the 20-40 cm deep soil layer under the deep straw burial (S) treatments, soil nitrogen accumulated and the content of NO3--N and NH4+-N increased by an average of 29.8% and 48.1%, respectively, compared to the CK treatment. Nitrogen accumulation first and then decreased significantly with depth. Nitrogen accumulation under the different straw mulching regimes increased with an increase in the application of reduced nitrogen. After the harvest of summer maize, the accumulation of NO3--N and NH4+-N in the >80 cm soil layer under the B treatments was 19.9%-58.2% and 31.1%-61.7% lower than that of the CK treatment, respectively. This compared to reductions of 36.7%-70.9% and 82.6%-89.2% for the S treatments, respectively. Only the BN3 treatment increased accumulation compared with CK by 0.4% on average, while the SN2 treatment resulted in a 9.3% increase. Summer maize yield and relative indexes were also improved relative to the other treatments. Nonlinear fitting of yield and application reduction showed that deep straw burial was better than surface covering at increasing summer maize production. The effect of deep straw burial and 14%-20% application reduction was better. Straw mulching with reduced nitrogen fertilization can limit nitrogen leaching and thereby reduce the risk of groundwater pollution. After the harvest, groundwater quality was classified in the Ⅱ class, with the risk of nitrogen contamination being lowest under deep straw burial with>20% reduced nitrogen fertilization. These observations show that deep straw deep alongside 14%-20% application reduction could effectively alleviate nitrogen leaching and reduce the risk of nitrogen pollution in groundwater. This approach can help improve the ecological environment and summer maize yields in the Hetao irrigation district.

Prophylactic effect of rectal indomethacin plus nitroglycerin administration for preventing pancreatitis after endoscopic retrograde cholangiopancreatography in female patients.

BACKGROUND: Prophylactic pancreatic stent placement (PSP) and rectal indomethacin suppository are recommended to prevent post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) in high-risk cases. Clinical trials on the use of nitroglycerin to reduce PEP have reached no definitive conclusion. Our study aimed to determine whether treatment with rectal indomethacin plus nitroglycerin could eliminate the need for PSP in patients. METHODS: In this randomized clinical trial, patients were allocated into groups using a random number table, with each patient receiving a pre-made envelope containing their intervention prior to ERCP. The three treatment groups were: the placebo group, the indomethacin + nitroglycerin group, and the PSP group. The subjects were assessed for PEP and its severity by a panel of independent and blinded adjudicators. RESULTS: A total of 526 patients were eligible for inclusion. The placebo group included 176 patients, the indomethacin + nitroglycerin group included 176 patients and the PSP group included 174.A diagnosis of PEP was made in 64 (12.2%) cases. The rate of PEP in the three study groups placebo group, indomethacin + nitroglycerin group and the PSP group was 19.3%, 5.1%, and 12.1%, respectively. CONCLUSIONS: The risk of post-ERCP pancreatitis in the indomethacin + nitroglycerin group was 7% lower than that in the PSP. Indomethacin + nitroglycerin is superior to PSP in preventing and relieving the severity of post-ERCP pancreatitis in patients with difficult intubation. Indomethacin plus nitroglycerin can avoid the need for PSP in the prevention of post-ERCP pancreatitis. TRIAL REGISTRATION: Current Controlled Trials ChiCTR2000033944.

Highly Anisotropic Corncob as an Efficient Solar Steam-Generation Device with Heat Localization and Rapid Water Transportation.

Solar steam generation is receiving considerable interest because of its potential application in wastewater treatment and desalination. Many devices with various photothermal materials and structures have been demonstrated to be solar steam evaporators by improving their light absorption, heat loss, water transportation, and vapor escape. However, developing a biomass-based evaporator with heat localization and rapid water transportation is highly desired yet still challenging. Here, corncobs, a kind of agricultural waste with vascular bundle and "vesiculose" structures, are used to fabricate solar steam-generation devices. After high-temperature treatment, the carbonized corncobs maintain the highly anisotropic porous framework and favorable hydrophilicity and thereby have excellent thermal management and water transportation. With efficient solar absorption, heat localization, and rapid water transportation, the lightweight carbonized corncobs can float on water and generate water vapor with a high steam generation efficiency of 86.7% under 1 sun.

Injectable hydrogel-loaded nano-hydroxyapatite that improves bone regeneration and alveolar ridge promotion.

In stomatology, the promotion of alveolar bone regeneration while preventing the reduction of ridge absorption remains a challenge. In this work, we designed and prepared bio-mimetic polysaccharide hydrogels that are multi-functional in terms of being injectable, promote self-healing, degradable, porous structure, et al. After introducing nano-hydroxyapatite particles, the composite scaffold of hydrogel/hydroxyapatite (GH) stent was obtained. When GH material was injected into the mandibular incisors of rats following tooth extraction, the new bone area was enhanced more than 50%, while the alveolar ridge was promoted in excess of 60% after 4 weeks. What's more, the wound soft tissue was healed within 1 week. Overall, our results indicate that this optimized GH stent has the potential to both maintain dimensional alveolar ridge, as well as to promote soft tissue healing. Moreover, using the hydroxyapatite-containing hydrogel platform has the potential to promote bone and soft tissue regeneration.

A capillary electrophoresis strategy to sensitively detect dynamic properties of coiled coil polypeptides.

The self-assembly behavior of polypeptides plays an essential role to form biological and functional macromolecules, which have attracted a lot of attention due to their excellent characters. Understanding the polypeptide self-assembly systems and dynamic behaviors is fundamental to improve the potential of biomedical applications. In this work, coiled coil polypeptides PC10 and PC10 P were designed and biosynthesized. PC10 and PC10 P could form nanogels when the concentration of polypeptides was less than 2% (m/v). The dynamic behaviors of PC10 and PC10 P were measured by Förster resonance energy transfer method based on a capillary electrophoresis system. The Förster resonance energy transfer efficiency of this system was 60.4%, and the distance of self-assembled domains in the polypeptides was calculated as 6.14 nm, demonstrating that the exchange behavior occurred between two different polypeptides containing the same coiled coil region.

Design and fabrication of an InGaAs focal plane array integrated with linear-array polarization grating.

Polarization imaging plays a crucial role in modern photonic applications such as remote sensing, material classification, and reconnaissance. A novel InGaAs focal plane array integrated with linear-array polarization grating is proposed and fabricated to meet the practical needs of near-infrared polarization imaging. In order to accurately evaluate the polarization performance of a fabricated detector, the improved test system is used to measure the transmittance and extinction ratio (ER). The results show that the detectivity reaches ${1}.{06}\; \times \;{{10}^{12}}\;{{\rm cm}\cdot{\rm Hz}^{1/2}}/{\rm W}$1.06×1012cm⋅Hz1/2/W, and the operable pixel factor is more than 99.8%. The transmittance of more than 55% and the ER of greater than 21:1 are realized, which indicates that the fabricated detector has excellent capability for near-infrared polarization imaging.

Ultrasound-Switchable Nanozyme Augments Sonodynamic Therapy against Multidrug-Resistant Bacterial Infection.

Ultrasound (US)-driven sonodynamic therapy (SDT) has demonstrated wide application prospects in the eradication of deep-seated bacterial infections due to its noninvasiveness, site-confined irradiation, and high-tissue-penetrating capability. However, the ineffective accumulation of sonosensitizers at the infection site, the hypoxic microenvironment, as well as rapid depletion of oxygen during SDT greatly hamper the therapeutic efficacy of SDT. Herein, an US-switchable nanozyme system was proposed for the controllable generation of catalytic oxygen and sonosensitizer-mediated reactive oxygen species during ultrasound activation, thereby alleviating the hypoxia-associated barrier and augmenting SDT efficacy. This nanoplatform (Pd@Pt-T790) was easily prepared by bridging enzyme-catalytic Pd@Pt nanoplates with the organic sonosensitizer meso-tetra(4-carboxyphenyl)porphine (T790). It was really interesting to find that the modification of T790 onto Pd@Pt could significantly block the catalase-like activity of Pd@Pt, whereas upon US irradiation, the nanozyme activity was effectively recovered to catalyze the decomposition of endogenous H2O2 into O2. Such "blocking and activating" enzyme activity was particularly important for decreasing the potential toxicity and side effects of nanozymes on normal tissues and has potential to realize active, controllable, and disease-loci-specific nanozyme catalytic behavior. Taking advantage of this US-switchable enzyme activity, outstanding accumulation in infection sites, as well as excellent biocompatibility, the Pd@Pt-T790-based SDT nanosystem was successfully applied to eradicate methicillin-resistant Staphylococcus aureus (MRSA)-induced myositis, and the sonodynamic therapeutic progression was noninvasively monitored by photoacoustic imaging and magnetic resonance imaging. The developed US-switchable nanoenzyme system provides a promising strategy for augmenting sonodynamic eradication of deep-seated bacterial infection actively, controllably, and precisely.