Delivery Capability Research Articles

Implementing mandatory COVID-19 vaccination for Australian aged care workers.

Implementing mandatory COVID-19 vaccination for Australian aged care workers.

Effect of Direct Liquid Cooling Technology With Flow Guide Integration on Avionics Devices Thermal and Electrical Performance

Abstract With the application of various high-power electronic devices to improving aircraft comprehensive performance, there has been a significant interest in the use of high heat flux dissipation technology to maintain an effective and safe operation for electronic devices. This article presents a numerical study on the thermal and electrical performance of the avionics server module by using single-phase immersion cooling technology with flow distributor and investigates the influence of heat dissipation capacity on the thermal performance of the avionics server module and DC IR-drop of printed circuit board power distribution network (PDN). The simulation results showed that a higher dielectric fluid flowrate can be provided b flow distributor with the same pumping power, and the maximum temperature of the hot spot was 4–8 °C lower than the module without a flow distributor. The result confirmed the improved flow performance and enhances heat transfer of the hot spot for the module with a flow distributor. However, the module without the flow distributor showed better comprehensive cooling performance with about 10–15% reduction in average Nusselt number with an increase in Re. The discrepancy of PDN DC IR-drop under different Re values was constant at 3% for different design geometries, which means the effect of the flow distributor on power delivery capability can be neglected.

Microbubble-Nanoparticle Complexes for Ultrasound-Enhanced Cargo Delivery.

Targeted delivery of therapeutics to specific tissues is critically important for reducing systemic toxicity and optimizing therapeutic efficacy, especially in the case of cytotoxic drugs. Many strategies currently exist for targeting systemically administered drugs, and ultrasound-controlled targeting is a rapidly advancing strategy for externally-stimulated drug delivery. In this non-invasive method, ultrasound waves penetrate through tissue and stimulate gas-filled microbubbles, resulting in bubble rupture and biophysical effects that power delivery of attached cargo to surrounding cells. Drug delivery capabilities from ultrasound-sensitive microbubbles are greatly expanded when nanocarrier particles are attached to the bubble surface, and cargo loading is determined by the physicochemical properties of the nanoparticles. This review serves to highlight and discuss current microbubble-nanoparticle complex component materials and designs for ultrasound-mediated drug delivery. Nanocarriers that have been complexed with microbubbles for drug delivery include lipid-based, polymeric, lipid-polymer hybrid, protein, and inorganic nanoparticles. Several schemes exist for linking nanoparticles to microbubbles for efficient nanoparticle delivery, including biotin-avidin bridging, electrostatic bonding, and covalent linkages. When compared to unstimulated delivery, ultrasound-mediated cargo delivery enables enhanced cell uptake and accumulation of cargo in target organs and can result in improved therapeutic outcomes. These ultrasound-responsive delivery complexes can also be designed to facilitate other methods of targeting, including bioactive targeting ligands and responsivity to light or magnetic fields, and multi-level targeting can enhance therapeutic efficacy. Microbubble-nanoparticle complexes present a versatile platform for controlled drug delivery via ultrasound, allowing for enhanced tissue penetration and minimally invasive therapy. Future perspectives for application of this platform are also discussed in this review.

Platinum-Coordinated Dual-Responsive Nanogels for Universal Drug Delivery and Combination Cancer Therapy.

Developing a universal nanoplatform for efficient delivery of various drugs to target sites is urgent for overcoming various biological barriers and realizing combinational cancer treatment. Nanogels, with the advantages of both hydrogels and nanoparticles, may hold potential for addressing the above issue. Here, a dual-responsive nanogel platform (HPC nanogel) is constructed using β-cyclodextrin-conjugated hyaluronic acid (HA-βCD), polyethyleneimine (PEI), and cisplatin. HA-βCD and PEI compose the skeleton of the nanogel, and cisplatin molecules provide the junctions inside the skeleton, thus affording a multiple interactions-based nanogel. Besides, HA endows the nanogel with hyaluronidase (HAase)-responsiveness, and cisplatin guarantees the glutathione (GSH)-responsive ability, which make the nanogel a dual-responsive platform that can degrade and release the loaded drugs when encountering HAase or GSH. Additionally, the HPC nanogel possesses excellent small-molecule drug and protein loading and intracellular delivery capabilities. Especially, for proteins, their intracellular delivery via nanogels is not hindered by serum proteins, and the enzymes delivered into cells still maintain their catalytic activities. Furthermore, the nanogel can codeliver different cargoes to achieve "cocktail" chemotherapeutic efficacy and realize combination cancer therapy. Overall, the HPC nanogel can serve as a multifunctional platform capable of delivering desired drugs to treat cancer or other diseases.

Dynamic customer-oriented relational capabilities: how do they impact internationalizing firm performance?

PurposeThis work proposes that a multi-national service company (MNSC) needs to develop dynamic customer-oriented relational capabilities (DCRC), constituting dynamic service customization (DySC), dynamic customer integration (DyCI) and dynamic timeliness of service delivery (DyTSD) capabilities, to gain competitive advantage and performance in its internationalization efforts.Design/methodology/approachFor empirical validation of the framework, developed through qualitative interviews, this study includes multi-cross-sectional data from twelve countries, four each in the category of underdeveloped (Africa), developing (Asia) and developed economies (Europe). Covariance-based structural equation modelling is used to test the hypotheses.FindingsThe study supports that DySC, DyCI and DyTSD capabilities have a significant positive influence on firm competitive advantage and performance across economies. The levels of competition intensity and regulatory restrictions, an outcome of the type of economy, have negative intervening effects, with varying intensities across economies.Practical implicationsThis work guides the internationalization service managers to leverage DCRC across national borders keeping the state of the economy into consideration.Originality/valueThis work proposes a model of DCRC, based on the Intangibility, Heterogeneity, Inseparability and Perishability (IHIP) service framework, that enables firms to derive competitive advantage and performance across economies with varying environmental conditions.

The Behavioral Health Needs of Youth With Preexisting Psychiatric Disorders in the Aftermath of COVID-19

Children and adolescents with psychiatric disorders are a sizable population of children and youth with special health care needs. While the capabilities of behavioral health resources to meet these youth's needs were already strained, the Coronavirus Disease 2019 (COVID-19) pandemic extended resource limitations just as this subgroup of children and youth with special health care needs faced new stressors and potential exacerbations of their underlying psychiatric illnesses. In this article, we provide a brief narrative review of the factors' manifestations with an emphasis upon their disproportionate impact upon children of color and their families and particularly those from disadvantaged communities. We proceed to provide policy proposals for addressing these disparities. These include raising reimbursement for behavioral health services, increasing telehealth care delivery, reducing inter-state licensing requirements, increasing community-based services, and addressing social determinants of health. Conclusions and directions for strengthening behavioral health service delivery capabilities and addressing systemic injustices are made.

Discovery of Discrete Stages in the Oxidation of exo-Tetrahydrodicyclopentadiene (C10H16) Droplets Doped with Titanium-Aluminum-Boron Reactive Mixed-Metal Nanopowder.

Titanium (Ti), aluminum (Al), and boron (B) reactive mixed-metal nanopowders (Ti-Al-B RMNPs) represent attractive additives to hydrocarbon fuels such as exo-tetrahydrodicyclopentadiene (C10H16; JP-10) enhancing the limited volumetric energy densities of traditional hydrocarbons, but fundamental mechanisms and combustion stages in the oxidation have been obscure. This understanding is of vital significance in the development of next-generation propulsion systems and energy-generation technologies. Here, we expose distinct oxidation stages of single droplets of JP-10 doped with Ti-Al-B-RMNP exploiting innovative ultrasonic levitator technology coupled with time-resolved spectroscopic (UV-vis) and imaging diagnostics (optical and infrared). Two spatially and temporally distinct stages of combustion define a glow flame stage in which JP-10 and nanoparticles combust via a homogeneous gas phase (Al) and heterogeneous gas-surface oxidation (Ti, B) and a slower diffusion flame stage associated with the oxidation of JP-10. These findings enable the development of next-generation RMNP fuel additives with superior payload delivery capabilities.

Optimization of methacrylated gelatin /layered double hydroxides nanocomposite cell-laden hydrogel bioinks with high printability for 3D extrusion bioprinting.

Layered double hydroxides (LDHs) offer unique source of inspiration for design of bone mimetic biomaterials due to their superior mechanical properties, drug delivery capability and regulation cellular behaviors, particularly by divalent metal cations in their structure. Three-dimensional (3D) bioprinting of LDHs holds great promise as a novel strategy thanks to highly tunable physiochemical properties and shear-thinning ability of LDHs, which allow shape fidelity after deposition. Herein, we introduce a straightforward strategy for extrusion bioprinting of cell laden nanocomposite hydrogel bioink of gelatin methacryloyl (GelMA) biopolymer and LDHs nanoparticles. First, we synthesized LDHs by co-precipitation process and systematically examined the effect of LDHs addition on printing parameters such as printing pressure, extrusion rate, printing speed, and finally bioink printability in creating grid-like constructs. The developed hydrogel bioinks provided precise control over extrudability, extrusion uniformity, and structural integrity after deposition. Based on the printability and rheological analysis, the printability could be altered by controlling the concentration of LDHs, and printability was found to be ideal with the addition of 3 wt % LDHs. The addition of LDHs resulted in remarkably enhanced compressive strength from 652 kPa (G-LDH0) to 1168 kPa (G-LDH3). It was shown that the printed nanocomposite hydrogel scaffolds were able to support encapsulated osteoblast survival, spreading, and proliferation in the absence of any osteoinductive factors taking advantage of LDHs. In addition, cells encapsulated in G-LDH3 had a larger cell spreading area and higher cell aspect ratio than those encapsulated in G-LDH0. Altogether, the results demonstrated that the developed GelMA/LDHs nanocomposite hydrogel bioink revealed a high potential for extrusion bioprinting with high structural fidelity to fabricate implantable 3D hydrogel constructs for repair of bone defects.

A Multi-MHz Active Clamp Topology for High Cost-Performance Wireless Power Transfer

The single-switch topologies, e.g., the Class E topology, have the advantages of low component count, no shoot-through problem, simple driving circuit, which make it more suitable for high frequency low/medium-power wireless power transfer (WPT) applications. However, due to the high switch voltage stress, narrow soft switching range, bulky input choke, or ac inductor, its power delivery capability and applications are limited. In order to solve these problems, this article proposed a novel active clamp topology for high cost-performance medium-power WPT systems. The proposed topology offers low component count with no bulky inductor and low switch voltage stress, leading to high power-density, low cost, and compact size, i.e., high cost-performance for WPT applications. And the switch peak voltage can be adjusted and the soft switching operation can be achieved in a wide load range by designing the compensation capacitor and clamp capacitor. In this article, the detailed theoretical analysis and parameter design are discussed and the proposed topology is compared with the existing single-switch topology in terms of voltage stress, cost, and component count. A 120 W and 1 MHz active clamp WPT system is built and a 92.4% system efficiency is achieved with high cost-performance, which validate the feasibility of the proposed topology and the theoretical analysis.

A modified habitat quality model to incorporate the effects of ecological restoration

Ecosystem restoration has the potential to improve the ecological environment, increase ecosystem service delivery capability, and promote biodiversity conservation. Although habitat quality (HQ) is being widely used as a metric for large-scale biodiversity conservation, it is poorly understood and measured in areas with significant vegetation restoration (VR). This study proposes a modified approach based on the InVEST-HQ module by coupling Normalized Difference Vegetation Index to measure the HQ in the Yellow River Basin (YRB) with extensive VR in recent decades. The results show that the VR area with significant increases in both Leaf Area Index and net primary production accounts for 29.7% of the total area of the YRB. The original and modified modules were compared. Based on the InVEST-HQ module, the results show that HQ has a tendency for very small changes in the years 2000, 2010, and 2020, with first a small increase and then a small decrease; however, HQ based on the modified method has a significantly increasing trend, which is consistent with the ecological restoration status of the study area and the trend of key ecosystem parameters. The modified method effectively expresses HQ changes with VR, making it more appropriate for usage in areas where nature conservation and ecosystem restoration are important management actions, allowing for realistic decision-making and data support for regional biodiversity conservation and habitat management.

Corrosion-Resistant Plug Materials for Geothermal Well Fluid Control.

Conventional cements and plugs are challenged by corrosion in CO2-rich and extreme geothermal environments, due to the hostile chemistry and high temperatures. Thermite-based sealing and well intervention technologies are being applied in the oil and gas industry, combining the energy delivery capability of thermite materials with the sealing characteristics of low melt temperature alloys. The thermite reaction products (ceramics) and the sealing alloys used in these plugs both have very attractive corrosion properties, and their operating envelopes extend into geothermal conditions. Thermite plugs and platforms, without supplemental sealing materials, have been considered for nuclear waste isolation, carbon sequestration, and geothermal applications due to the geochemical stability of the ceramic product and its very high service temperature. This study addresses corrosion resistance of the thermite reaction products. A range of engineered thermite systems which yield thermite reaction products including pure aluminum oxide, feldspar, or aluminosilicate solid solutions (in addition to the iron produced in thermite reactions) was developed. These materials were evaluated for their strong acid resistance (pH 1), carbonate resistance (sodium carbonate) and thermal shock resistance (600 °C heating → cold water quenching repeated three times). Performance of different materials was evaluated based on the changes in mechanical properties, water-fillable porosity, phase changes under stress conditions. The aluminosilicate product exhibited very good corrosion resistance, both from material loss and strength perspectives, while the other products performed with varying degrees of stability. This paper presents the results of the thermite corrosion studies and describes the novel tools being deployed, and under development, to satisfy challenging barrier and intervention applications.

Ingestible Functional Magnetic Robot with Localized Flexibility (MR-LF).

The integration of an ingestible dosage form with sensing, actuation, and drug delivery capabilities can enable a broad range of surgical-free diagnostic and treatment strategies. However, the gastrointestinal (GI) tract is a highly constrained and complex luminal construct that fundamentally limits the size of an ingestible system. Recent advancements in mesoscale magnetic crawlers have demonstrated the ability to effectively traverse complex and confined systems by leveraging magnetic fields to induce contraction and bending-based locomotion. However, the integration of functional components (e.g., electronics) in the proposed ingestible system remains fundamentally challenging. Herein, the creation of a centralized compartment in a magnetic robot by imparting localized flexibility (MR-LF) is demonstrated. The centralized compartment enables MR-LF to be readily integrated with modular functional components and payloads, such as commercial off-the-shelf electronics and medication, while preserving its bidirectionality in an ingestible form factor. The ability of MR-LF to incorporate electronics, perform drug delivery, guide continuum devices such as catheters, and navigate air-water environments in confined lumens is demonstrated. The MR-LF enables functional integration to create a highly-integrated ingestible system that can ultimately address a broad range of unmet clinical needs.

Designing a multifunctional nanoplatform based on PEGylated cobalt ferrite magnetic nanoparticles containing capecitabine for cancer theranostics

Anticancer drugs can be delivered more efficiently to tumor sites with fewer side effects by utilizing magnetic nanoparticles. In this research detailed examinations of the effect of polyethylene glycol (PEG) on microstructure, size distribution, morphology, magnetic performance and coating of cobalt ferrite nanoparticles (CFO) were conducted. CFO nanoparticles were functionalized by PEG under different conditions, using a facile co-precipitation process. X-ray diffraction (XRD) patterns confirmed that all detected peaks were related to the cubic single-phase spinel structure. Fourier transform infrared spectroscopy (FTIR) revealed the chemical interactions between CFO and PEG. The results of field emission scanning electron microscopy (FE-SEM) showed a uniform spherical morphology with a mean size of 24, 32, and 40 nm at PEG molecular weights of 600, 1500 and 6000, respectively. Furthermore, vibrating sample magnetometer (VSM) revealed that saturation magnetization of nanoparticles decreased by coating with PEG. Results also confirmed that PEG with a higher molecular weight created a thicker coating on CFO. Estimation of capecitabine anticancer drug loading in CFO-PEG nanoparticles investigated by UV-VIS spectroscopy indicated that composite nanoparticles with a PEG molecular weight of 6000 had the highest loading efficiency of 13.67%. Over 40% of capecitabine was released in tumor-like acidic pH (5.5) compared to 23% in normal tissue pH (7.4). Nanoparticles proved blood biocompatible in terms of hemolysis up to a high concentration of 800 μg/ml. Eventually, magnetic resonance imaging (MRI) analyses displayed that CFO-PEG6000 nanoparticles with a relaxivity of 81.12 mM−1 S−1 can be successfully used as an MRI contrast agent. Overall, the developed multifunctional CFO-PEG nanoparticle with potential localized and efficient drug delivery and favorable imaging capability is a promising candidate as a cancer theranostic nanoplatform.

Gentamicin-loaded polyvinyl alcohol/whey protein isolate/hydroxyapatite 3D composite scaffolds with drug delivery capability for bone tissue engineering applications

Bone defects caused by diseases such as bone diseases, tumours, and traumas negatively affect the lives of millions of people around the world. Bone tissue engineering offers a new approach to repairing bone defects. Here, a novel bioactive Polyvinyl alcohol (PVA)/ Whey protein isolate (WPI)/ Hydroxyapatite (HA) composite scaffolds with Gentamicin (GEN)-loaded at varying rates were successfully fabricated by 3D printing technology. The strong interaction between PVA, WPI, HA, and GEN were proved with Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). When the scanning electron microscopy (SEM) images of the produced 3D composite scaffolds were evaluated, it can be said that 3D composite scaffolds with the desired porosity and structure for bone tissue engineering applications were obtained. The 3D PVA/WPI/HA/12GEN composite scaffold was fabricated excellently with its 675 µm pore size. Compression tests revealed that the 3D composite scaffold had a compressive strength of 1.28–1.22 MPa and strain of % 12.89–8.70 and thus met the mechanical desirables of human trabecular bone. Moreover, the compressive strength and strain values of the scaffolds were decreased slightly due to adding the GEN drug. According to the Differential scanning calorimetry (DSC) analysis, it was determined that the highly crystalline structure of PVA was disrupted by adding GEN to the composite scaffolds. It was also observed that the addition of GEN to the scaffold did not significantly affect the swelling and degradation behaviour, and the scaffolds degraded by approximately 55% on the 10th day. The scaffolds exhibited a controlled release profile up to 240 and 264 h and were released with the Korsmeyer-Peppas kinetic model according to the highest correlation number. Cell analysis revealed that biocompatible structures were produced, and osteoblasts formed filopodia extensions, resulting in healthy cell attachment. According to these results, 3D GEN-loaded PVA/WPI/HA composite scaffolds may be a promising innovation for bone defect repair in bone tissue engineering applications.

Nanotechnology-based cell-mediated delivery systems for cancer therapy and diagnosis.

The global prevalence of cancer is increasing, necessitating new additions to traditional treatments and diagnoses to address shortcomings such as ineffectiveness, complications, and high cost. In this context, nano and microparticulate carriers stand out due to their unique properties such as controlled release, higher bioavailability, and lower toxicity. Despite their popularity, they face several challenges including rapid liver uptake, low chemical stability in blood circulation, immunogenicity concerns, and acute adverse effects. Cell-mediated delivery systems are important topics to research because of their biocompatibility, biodegradability, prolonged delivery, high loading capacity, and targeted drug delivery capabilities. To date, a variety of cells including blood, immune, cancer, and stem cells, sperm, and bacteria have been combined with nanoparticles to develop efficient targeted cancer delivery or diagnosis systems. The review paper aimed to provide an overview of the potential applications of cell-based delivery systems in cancer therapy and diagnosis.

Engineered microneedles arrays for wound healing

• The advances of engineered microneedles arrays for wound healing were reviewed. • The design strategies, advanced applications and advantages of engineered microneedles arrays were summarized. • The challenges, further orientations and prospects were discussed. Wound healing is the regenerative process of original skin structure after destructing by different damage sources. Due to their transdermal delivery capability and high specific surface area, microneedles arrays (MAs) have been recognized as encouraging biomaterials for wound healing. In this review, we have outlined the engineered MAs used for tissue regeneration and wound healing. Engineered MAs were first classified by design methodologies such as bionic design, intelligent-responsive design, actively-triggered design, matrix materials innovation, and composite smart design. Then, the MAs were divided into two categories based on the different loading substances: drug-loaded MAs and living component-loaded MAs. Finally, we have summed up the important elements of the preceding discussions and forecasted their future evolution.

Evidence For Sustained Physiological Adaptation From A Single Exercise Bout At Simulated Altitude

Intermittent exposures to normobaric or hypobaric hypoxia have been used to provide enhancements to oxygen delivery capabilities in athletes and in some patient populations as well as in the pre-acclimatization of individuals. The body is capable of very rapid adjustments to this type of environmental stress. However, it is somewhat unclear if an acute exposure to this type of environmental stress is enough to produce evidence of adaptations. PURPOSE: To examine evidence for physiological adaptation after a single bout of exercise at simulated altitude (Stratosphere Hypobaric Training Chamber) as determined from heart rate (HR), peripheral oxygen saturation (SpO2) and the ratio of hemoglobin O2 (oxygen) saturation in the circulating peripheral blood relative to HR (SpO2/HR) response. METHODS: 11 subjects (6 male, 5 female, age 36.5 ± 12.9 yrs, height 173.6 ± 9.2 cm, weight 75.7 ± 14.5 kg) completed 2 hypobaric chamber visits. During both visits, subjects performed a 30 min bout of exercise on a cycle ergometer at the same simulated altitude (2 km n = 1, 3 km n = 2, 4 km n = 8). Based on subjects previous VO2max test results, the exercise was divided into a light to moderate intensity for the first 15 min (target 50-60% WMax), immediately followed by a higher intensity (target 70-80% WMax) for the second 15 min. There was an average of 10 ± 6 days between each testing visit. Statistical analyses included paired samples t-test (p ≤ 0.05). RESULTS: There were no significant changes in workload (p = 0.28) or SpO2 (p = 0.67) between the two visits. However, there was a significant difference in HR (p < 0.001) and SpO2/HR (p < 0.001). There was an average decrease in HR of 19 bpm (12%) from visit 1 (155 ± 17 bpm) to visit 2 (136 ± 26 bpm), along with a 16% average increase in SpO2/HR from visit 1 (0.55 ± 0.06) to visit 2 (0.64 ± 0.13). The average workload across both intensity levels and altitudes were 97 ± 38 W for Visit 1 and 103 ± 39 W for Visit 2, with an average SpO2 of 84 ± 5% for both visits. CONCLUSION: These findings indicate an adaptive response to a short aerobic exercise bout during simulated altitude exposure that appears to be sustained greater than one week after the initial visit. Whether this is linked to oxygen sensing, neurally mediated or suggests early adjustments in oxygen delivery pathways is unclear, but appear unrelated to age, sex or fitness level.

Protein A/G-based surface plasmon resonance biosensor for regenerable antibody-mediated capture and analysis of nanoparticles

Characterization of nanoparticles (NPs) and their subpopulations in heterogeneous samples is of utmost importance, for example, during the initial design of targeted NP therapies and the different phases of their production cycle. Biological NPs such as extracellular vesicles (EVs) have shown promise in improving the drug delivery capabilities compared to traditional NP-based therapies, for example, in treating cancer and neurodegenerative diseases. This work presents a general antibody-mediated surface capture and analysis protocol for NPs using a Protein A/G-functionalized surface plasmon resonance biosensor. The use of anti-streptavidin antibodies allows regenerable capture of biotin-containing NPs such as large unilamellar vesicles commonly used as drug delivery vehicles. Furthermore, the use of antibodies directed against glycophorin A and B (CD235a and b) enabled diffusion-limited specific surface capture of red blood cell-derived extracellular vesicles (RBC EVs). RBC EVs showed the efficacy of the biosensor in the determination of size and bulk concentration of NP subpopulations isolated from a complex biological matrix. The mean size of the surface-captured RBC EVs was comparable to the corresponding sizes derived for the entire EV population measured with well-established NP sizing techniques, namely, nanoparticle tracking analysis and dynamic light scattering. Taken together, the Protein A/G-functionalized biosensor provides a generic alternative to the existing NP-capturing sensors based on, for example, covalent antibody attachment, hydrophobic surfaces or biotin-capped self-assembled monolayers.

Polycaprolactone triol-based polyurethane film conjugated ibuprofen to sustained release: Synthesis, physicochemical, cytotoxic, and release studies

Polyurethanes are among the most ubiquitous materials in the biomedical and pharmaceutical areas. Thus, in this study, polycaprolactone-triol-based polyurethane conjugated ibuprofen (coded as PU-ibu) was synthesized by a two-step condensation method and characterized according to composition, morphological, thermal, and mechanical. In addition to wettability, hemocompatibility, cytotoxicity, and in vitro release. In addition to wettability, hemocompatibility, cytotoxicity, and in vitro release. The synthesized PU film had a smoother surface and superior mechanical properties compared to PU-ibu film.Moreover, PU was capable of swelling in PBS while PU-ibu film exhibited a surprising “de-swelling” behavior. Additionally, PU-ibu film not only had adequate wettability, excellent hemocompatibility, and sustained delivery capability but also greatly enhanced the proliferation of fibroblast cells. Therefore, the PU-ibu film provides a potential novel system for sustained drug delivery.

Red blood cell membrane-camouflaged vancomycin and chlorogenic acid-loaded gelatin nanoparticles against multi-drug resistance infection mice model

Misuse of antibiotics leads to the emergence of multidrug-resistant (MDR) bacterial infection globally. Vancomycin (V), the so-called last line defense against methicillin resistance Staphylococcus aureus (MRSA), declines its therapeutic effect each year due to high-level of resistance. Stewardships, drug-combination, development of antibiotic delivery and biomimetic systems are the current practical strategies to reduce the resistance emergence. In this study, red blood cell membrane (RBCM) and bacterial exotoxins-responsive supramolecular gelatin nanoparticles (SGNPs) loading vancomycin and chlorogenic acid (C) are used to construct the VC-SGNPs-R drug delivery system to inhibit MRSA infection both in vitro and in vivo. RBCM coating evade the immune system, prolong circulation and neutralize exotoxins in an infection-microenvironment. Moreover, excellent in vivo inflammation healing, wound repairing and MRSA eradication were confirmed by leg and skin infection mice model. The intense fluorescence molecular tomography (FMT) measurement of VC-SGNPs-R, tissue quantification and successful wound healing shows its capability for on-demand antibiotic delivery and responsiveness in an infection-microenvironment.This approach develops a biomimetic drug delivery system of VC-SGNPs-R with long circulation and synergistic effect against MDR bacteria.