Factors influencing patient experience in hospital wards: a systematic review.

BACKGROUND: Patient experience plays an essential role in improving clinical effectiveness and patient safety. It's important to identify factors influencing patient experience and to improve quality of healthcare. OBJECTIVE: To identify factors that influence patient experience in hospital wards. METHODS: We conducted a systematic review including six databases; they were PubMed, CINAHL, Embase, PsycInfo, ProQuest, and Cochrane. Studies were included if they met the inclusion criteria. The JBI checklist was used to perform quality appraisal. We used 5 domains of the ecological model to organize and synthesize our findings to comprehensively understand the multi-level factors influencing the issue. RESULT: A total of 138 studies were included, and 164 factors were identified. These factors were integrated into 6 domains. All domains but one (survey-related factors) could be mapped onto the attributes of the ecological framework: intrapersonal, interpersonal, institutional, community, and public policy level factors. All factors had mixed effect on patient experience. The intrapersonal level refers to individual characteristics of patients. The interpersonal level refers to interactions between patients and healthcare providers, such as the caring time spent by a nurse. The institutional level refers to organizational characteristics, rules and regulations for operations, such as hospital size and accreditation. The community level refers to relationships among organizations, institutions, and informational networks within defined boundaries, such as a hospital located in a larger population area. Public policy level refers to local, state, national, and global laws and policies, including health insurance policies. The sixth domain, survey-related factors, was added to the framework and included factors such as survey response rate and survey response time. CONCLUSION: The factors influencing patient experience are comprehensive, ranging from intrapersonal to public policy. Providers should adopt a holistic and integrated perspective to assess patient experience and develop context-specific interventions to improve the quality of care. PROSPERO REGISTRATION NUMBER CRD42023401066.

Discovery of Preclinical Candidate AD1058 as a Highly Potent, Selective, and Brain-Penetrant ATR Inhibitor for the Treatment of Advanced Malignancies.

The ataxia telangiectasia-mutated and Rad3-related protein (ATR) plays a crucial role in regulating the cellular DNA-damage response (DDR), making it a promising target for antitumor drug development through synthetic lethality. In this study, we present the discovery and detailed characterization of AD1058, a highly potent and selective ATR inhibitor, with good preclinical pharmacokinetic profiles. AD1058 exhibits superior efficacy in inhibiting cell proliferation, disrupting the cell cycle, and inducing apoptosis compared to AZD6738. AD1058 displays potent antitumor effects as a single agent or in combination with clinically approved tumor therapies such as PARP inhibitors, ionizing radiotherapy, or chemotherapy in vivo. Considering its enhanced ability to permeate the blood-brain barrier, AD1058 is a promising clinical candidate for the treatment of brain metastases and leptomeningeal metastases in solid tumors. Additionally, among reported ATR inhibitors, AD1058 features the shortest synthesis route and the highest efficiency to date.

Bioelectret Materials and Their Bioelectric Effects for Tissue Repair: A Review.

Biophysical and clinical medical studies have confirmed that biological tissue lesions and trauma are related to the damage of an intrinsic electret (i.e., endogenous electric field), such as wound healing, embryonic development, the occurrence of various diseases, immune regulation, tissue regeneration, and cancer metastasis. As exogenous electrical signals, such as conductivity, piezoelectricity, ferroelectricity, and pyroelectricity, bioelectroactives can regulate the endogenous electric field, thus controlling the function of cells and promoting the repair and regeneration of tissues. Materials, once polarized, can harness their inherent polarized static electric fields to generate an electric field through direct stimulation or indirect interactions facilitated by physical signals, such as friction, ultrasound, or mechanical stimulation. The interaction with the biological microenvironment allows for the regulation and compensation of polarized electric signals in damaged tissue microenvironments, leading to tissue regeneration and repair. The technique shows great promise for applications in the field of tissue regeneration. In this paper, the generation and change of the endogenous electric field and the regulation of exogenous electroactive substances are expounded, and the latest research progress of the electret and its biological effects in the field of tissue repair include bone repair, nerve repair, drug penetration promotion, wound healing, etc. Finally, the opportunities and challenges of electret materials in tissue repair were summarized. Exploring the research and development of new polarized materials and the mechanism of regulating endogenous electric field changes may provide new insights and innovative methods for tissue repair and disease treatment in biological applications.

Fabrication of a modified bacterial cellulose with different alkyl chains and its prevention of abdominal adhesion.

Abdominal hernia mesh is a common product which is used for prevention of abdominal adhesion and repairing abdominal wall defect. Currently, designing and preparing a novel bio-mesh material with prevention of adhesion, promoting repair and good biocompatibility simultaneously remain a great bottleneck. In this study, a novel siloxane-modified bacterial cellulose (BC) was designed and fabricated by chemical vapor deposition silylation, then the effects of different alkyl chains length of siloxane on surface properties and cell behaviors were explored. The effect of preventing of abdominal adhesion and repairing abdominal wall defect in rats with the siloxane-modified BC was evaluated. As the grafted alkyl chains become longer, the surface of the siloxane-modified BC can be transformed from super hydrophilic to hydrophobic. In vivo results showed that BC-C16 had good long-term anti-adhesion effect, good tissue adaptability and histocompatibility, which is expected to be used as a new anti-adhesion hernia repair material in clinic.

Injectable and in situ foaming shape-adaptive porous Bio-based polyurethane scaffold used for cartilage regeneration.

Irregular articular cartilage injury is a common type of joint trauma, often resulting from intense impacts and other factors that lead to irregularly shaped wounds, the limited regenerative capacity of cartilage and the mismatched shape of the scaffods have contributed to unsatisfactory therapeutic outcomes. While injectable materials are a traditional solution to adapt to irregular cartilage defects, they have limitations, and injectable materials often lack the porous microstructures favorable for the rapid proliferation of cartilage cells. In this study, an injectable porous polyurethane scaffold named PU-BDO-Gelatin-Foam (PUBGF) was prepared. After injection into cartilage defects, PUBGF forms in situ at the site of the defect and exhibits a dynamic microstructure during the initial two weeks. This dynamic microstructure endows the scaffold with the ability to retain substances within its interior, thereby enhancing its capacity to promote chondrogenesis. Furthermore, the chondral repair efficacy of PUBGF was validated by directly injecting it into rat articular cartilage injury sites. The injectable PUBGF scaffold demonstrates a superior potential for promoting the repair of cartilage defects when compared to traditional porous polyurethane scaffolds. The substance retention ability of this injectable porous scaffold makes it a promising option for clinical applications.

Stimuli-responsive microcarriers and their application in tissue repair: A review of magnetic and electroactive microcarrier.

Microcarrier applications have made great advances in tissue engineering in recent years, which can load cells, drugs, and bioactive factors. These microcarriers can be minimally injected into the defect to help reconstruct a good microenvironment for tissue repair. In order to achieve more ideal performance and face more complex tissue damage, an increasing amount of effort has been focused on microcarriers that can actively respond to external stimuli. These microcarriers have the functions of directional movement, targeted enrichment, material release control, and providing signals conducive to tissue repair. Given the high controllability and designability of magnetic and electroactive microcarriers, the research progress of these microcarriers is highlighted in this review. Their structure, function and applications, potential tissue repair mechanisms, and challenges are discussed. In summary, through the design with clinical translation ability, meaningful and comprehensive experimental characterization, and in-depth study and application of tissue repair mechanisms, stimuli-responsive microcarriers have great potential in tissue repair.

Risk factors of chronic postoperative pain after total knee arthroplasty: a systematic review.

BACKGROUND: There is a lack of relevant studies to grade the evidence on the risk factors of chronic pain after total knee arthroplasty (TKA), and only quantitative methods are used for systematic evaluation. The review aimed to systematically identify risk factors of chronic postoperative pain following TKA and to evaluate the strength of the evidence underlying these correlations. METHODS: PubMed, Web of Science, Cochrane Library, Embase, and CINAHL databases were searched from initiation to September 2023. Cohort studies, case-control studies, and cross-sectional studies involving patients undergoing total knee replacement were included. A semi-quantitative approach was used to grade the strength of the evidence-based on the number of investigations, the quality of the studies, and the consistency of the associations reported by the studies. RESULTS: Thirty-two articles involving 18,792 patients were included in the final systematic review. Ten variables were found to be strongly associated with postoperative pain, including Age, body mass index (BMI), comorbidities condition, preoperative pain, chronic widespread pain, preoperative adverse health beliefs, preoperative sleep disorders, central sensitization, preoperative anxiety, and preoperative function. Sixteen factors were identified as inconclusive evidence. CONCLUSIONS: This systematic review clarifies which risk factors could be involved in future research on TKA pain management for surgeons and patients. It highlights those factors that have been controversial or weakly correlated, emphasizing the need for further high-quality studies to validate them. Most crucially, it can furnish clinicians with vital information regarding high-risk patients and their clinical attributes, thereby aiding in the development of preventive strategies to mitigate postoperative pain following TKA. TRIAL REGISTRATION: This systematic review has been registered on the PROSPERO platform (CRD42023444097).

Diffusion tensor imaging combined with chemical shift-encoded sequence to quantify the adaptive changes of calf muscles in amateur marathoners.

PURPOSE: Calf muscles play an important role in marathon race, and the incidence of injury is high in this process. This study prospectively quantified diffusion tensor metrics, muscle fat fraction (MFF) and cross-sectional area (CSA) of calf muscles induced by endurance exercise in amateur marathoners, and the potential mechanisms underlying the changes in these parameters were analyzed. METHOD: In this prospective study, 35 marathoners (27 males, 8 females; mean age (standard deviation, SD), 38.92 (4.83) years) and 26 controls (18 males, 8 females; mean age (SD), 38.35 (6.75) years) underwent magnetic resonance imaging (MRI) from September 2022 to March 2023. The diffusion tensor eigenvalues (λ1, λ2, λ3), radial diffusivity (RD), fractional anisotropy (FA), MFF and CSA of calf muscles were compared between marathoners and controls. A binary logistic regression model with gender correction was performed analyze the relationship between marathon exercise and DTI parameters, CSA and MFF of calf muscles. RESULTS: Interobserver agreement was good (κ = 0.71). The results of binary logistic regression model with gender correction showed that the regression coefficients of FA values in anterior group of calf (AC), soleus (SOL), medial gastrocnemius (MG) and lateral gastrocnemius (LG) were negative, and the odds ratios (OR) were 0.33, 0.45, 0.35, 0.05, respectively (P < 0.05). The OR of RD in SOL and λ2 in external group of calf (EC) were relatively higher, 3.74 and 3.26, respectively (P < 0.05). CSA was greater in SOL of marathoners, with an OR value of 1.00(P < 0.05). The MFF in AC and LG was lower in marathoners and OR of two indexes were -0.69 and -0.59, respectively (P < 0.05). CONCLUSIONS: Diffusion tensor imaging (DTI) combined with chemical shift-encoded sequence can noninvasively detect and quantify the adaptive changes of calf muscle morphology, microstructure and tissue composition induced by long-term running training in amateur marathoners.

Identification and quantification of nanoplastics in different crops using pyrolysis gas chromatography-mass spectrometry.

Quantitative studies of nanoplastics (NPs) abundance on agricultural crops are crucial for understanding the environmental impact and potential health risks of NPs. However, the actual extent of NP contamination in different crops remains unclear, and therefore insufficient quantitative data are available for adequate exposure assessments. Herein, a method with nitric acid digestion, multiple organic extraction combined with pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) quantification was used to determine the chemical composition and mass concentration of NPs in different crops (cowpea, flowering cabbage, rutabagas, and chieh-qua). Recoveries of 74.2-109.3% were obtained for different NPs in standard products (N = 6, RSD <9.6%). The limit of detection (LOD) and the limit of quantitation (LOQ) were 0.02-0.5 µg and 0.06-1.5 µg, respectively. The detection method for NPs exhibited good external calibration curves and linearity with 0.99. The results showed that poly (vinylchloride) (PVC), poly (ethylene terephthalate) (PET), polyethylene (PE), and polyadiohexylenediamine (PA66) NPs could be detected in crop samples, although the accumulation levels associated with the various crops varied significantly. PVC (N.D.-954.3 mg kg-1, dry weight (DW)) and PE (101.3-462.9 mg kg-1, DW) NPs were the dominant components in the samples of all four crop species, while high levels of PET (414.3-1430.1 mg kg-1, DW) NPs were detected in cowpea samples. Furthermore, there were notable differences in the accumulation levels of various edible crop parts, such as stems (60.2%) > leaves (39.8%) in flowering cabbage samples and peas (58.8%) > pods (41.2%) in cowpea samples. This study revealed the actual extent of NP contamination in different types of crops and provided crucial reference data for future research.

Bio-Inspired Neural Network for Real-Time Evasion of Multi-Robot Systems in Dynamic Environments.

In complex and dynamic environments, traditional pursuit-evasion studies may face challenges in offering effective solutions to sudden environmental changes. In this paper, a bio-inspired neural network (BINN) is proposed that approximates a pursuit-evasion game from a neurodynamic perspective instead of formulating the problem as a differential game. The BINN is topologically organized to represent the environment with only local connections. The dynamics of neural activity, characterized by the neurodynamic shunting model, enable the generation of real-time evasive trajectories with moving or sudden-change obstacles. Several simulation and experimental results indicate that the proposed approach is effective and efficient in complex and dynamic environments.

Paeoniflorin increases the anti-tumor efficacy of sorafenib in tumor-bearing mice with liver cancer via suppressing the NF-κb/PD-l1 axis.

Background: Sorafenib (Sor) represents a first-line therapy for hepatocellular carcinoma (HCC); however, its efficacy is constrained by secondary failure, which limits its clinical use. Recent studies have indicated that the suppression of Programmed cell death-Ligand 1 (PD-L1) may potentiate Sor's anti-liver cancer effects; furthermore, PD-L1 expression is known to be regulated by NF-κB. Previous research has demonstrated that paeoniflorin (PF) downregulates the NF-κB axis, nevertheless, current research has not yet determined whether PF can synergistically enhance the efficacy of Sor against HCC by modulating the NF-κB/PD-L1 pathway. Methods: The study employed a H22 hepatoma-bearing mouse model, which was treated with PF, Sor, and their combination over a period of 12 days. The impact of PF and Sor on tumor growth, proliferation, apoptosis, T-cell subsets, IL-2 and IFN-γ production, and NF-κB and PD-L1 expression was assessed. Moreover, Splenic lymphocyte from normal mice and tumor cells from model mice were co-cultured in vitro, and the tumor-specific cytotoxic T lymphocyte activity was analyzed. In the final phase of the study, Huh-7 cells were stimulated with PF in combination with an NF-κB activator or inhibitor, and the subsequent production of NF-κB and PD-L1 was investigated. Results: PF and Sor exhibit a synergistic anti-tumor effect, compared to the use of Sor alone, the combined use of PF and Sor significantly increased the number of CD4+ and CD8+ T cells in tumor tissue, markedly enhanced the cytotoxic activity of tumor-specific cytotoxic T lymphocytes, and reversed the depletion of interleukin-2 and the increase in PD-L1 expression following Sor intervention. This combination also further reduced the level of IFN-γ in peripheral blood and the expression of NF-κB and PD-L1 in tumor tissue. Additionally, in vitro experiments confirmed that PF reduces the expression of PD-L1 in Huh-7 liver cancer cells by inhibiting NF-κB. Conclusions: PF plays a synergistic role of Sor inhibiting HCC progression by regulating the NF-κB/PD-L1 pathway.

Intelligent Fish-Inspired Foraging of Swarm Robots with Sub-Group Behaviors Based on Neurodynamic Models.

This paper proposes a novel intelligent approach to swarm robotics, drawing inspiration from the collective foraging behavior exhibited by fish schools. A bio-inspired neural network (BINN) and a self-organizing map (SOM) algorithm are used to enable the swarm to emulate fish-like behaviors such as collision-free navigation and dynamic sub-group formation. The swarm robots are designed to adaptively reconfigure their movements in response to environmental changes, mimicking the flexibility and robustness of fish foraging patterns. The simulation results show that the proposed approach demonstrates improved cooperation, efficiency, and adaptability in various scenarios. The proposed approach shows significant strides in the field of swarm robotics by successfully implementing fish-inspired foraging strategies. The integration of neurodynamic models with swarm intelligence not only enhances the autonomous capabilities of individual robots, but also improves the collective efficiency of the swarm robots.

Injury of flexor halluics longus tendon in amateur marathon runners results in abnormal plantar pressure distribution: observational study.

OBJECTIVE: To analyze the changes of plantar pressure in amateur marathon runners with flexor halluics longus (FHL) tendon injury using the Medtrack-Gait plantar pressure measurement system, and to explore whether the plantar pressure data can be used as an index for the diagnosis of injury. METHODS: A total of 39 healthy amateur marathon runners without any ankle joint symptoms were recruited. Dynamic and static plantar pressure data were measured using the pressure plate of Medtrack-Gait. According to MRI imaging findings, whether the FHL tendon was injured or not was judged, and the dynamic and static data were divided into the injury group and control group. The data with statistically significant differences between the two groups were used to make the receiver operating characteristic (ROC) curve. RESULT: The maximum contact area (PA) of the first metatarsal(M1) region, the maximum load-bearing peak value (PW) and the time pressure integral (PMPTI) of the second metatarsal(M2) region in the injury group were lower than those in the control group, respectively (P < 0.05). The maximum contact area (PA) of the fifth metatarsal(M5) region was higher than that in the control group (P < 0.05). The area under curve (AUC) value of the ROC curve of the PA of M1 region, the PW and PMPTI of M2 region were statistically (P < 0.05). CONCLUSION: FHL tendon injury resulted in decreased PA in M1, decreased PW and PMPTI in M2, and increased PA in the M5 region, suggesting that FHL tendon injury resulted in a force shift from the medial to the lateral side of the foot. The PA of M1, PW and PMPTI of M2 have certain diagnostic value for early FHL injury in amateur marathon runners.

A reproducibility study of knee cartilage volume and thickness values derived by fully automatic segmentation based on three-dimensional dual-echo in steady state data from 1.5 T and 3 T magnetic resonance imaging.

OBJECTIVE: To evaluate the repeatability of cartilage volume and thickness values at 1.5 T MRI using a fully automatic cartilage segmentation method and reproducibility of the method between 1.5 T and 3 T data. METHODS: The study included 20 knee joints from 10 healthy subjects with each subject having undergone double-knee MRI. All knees were scanned at 1.5 T and 3 T MR scanners using a three-dimensional (3D) high-resolution dual-echo in steady state (DESS) sequence. Cartilage volume and thickness of 21 subregions were quantified using a fully automatic cartilage segmentation research application (MR Chondral Health, version 3.0, Siemens Healthcare, Erlangen, Germany). The volume and thickness values derived from fully automatically computed segmentation masks were analyzed for the scan-rescan data from the same volunteers. The accuracy of the automatic segmentation of the cartilage in 1.5 T images was evaluated by the dice similarity coefficient (DSC) and Hausdorff distance (HD) using the manually corrected segmentation as a reference. The volume and thickness values calculated from 1.5 T and 3 T were also compared. RESULTS: No statistically significant differences were found for cartilage thickness or volume across all subregions between the scan-rescanned data at 1.5 T (P > 0.05). The mean DSC between the fully automatic and manually corrected knee cartilage segmentation contours at 1.5 T was 0.9946. The average value of HD was 2.41 mm. Overall, there was no statistically significant difference in the cartilage volume or thickness in most-subregions between the two field strengths (P > 0.05) except for the medial region of femur and tibia. Bland-Altman plot and intraclass correlation coefficient (ICC) showed high consistency between results obtained based on same and different scanning sequences. CONCLUSION: The cartilage segmentation software had high repeatability for DESS images obtained from the same device. In addition, the overall reproducibility of the images obtained from equipment of two different field strengths was satisfactory.

A soil fumigant increases American ginseng (Panax quinquefolius L.) survival and growth under continuous cropping by affecting soil microbiome assembly: a 4-year in situ field experiment.

IMPORTANCE: Numerous reports of soil fumigants and fungicides on annual crops exist; however, it is unclear whether the single application to perennial plants persistently improves plant growth and controls disease or whether it has a long-lasting impact on soil microbes. We found that soil fumigation enhances ginseng growth and suppresses root rot disease by reshaping the soil microbial community. Our findings benefit the agricultural development of ginseng and provide a theoretical basis for the prevention of ginseng diseases.

Enhancing Cutting Rates in Multi-Channel HSWEDM of Metal Materials with a Novel Decoupling Circuit.

Multi-channel high-speed wire electrical discharge machining (HSWEDM) has shown great potential in enhancing the cutting rate of metal workpieces. However, the mechanism of multi-channel discharges in this technique remains unclear. In this paper, the equivalent circuit and processing model of the multi-channel HSWEDM were developed to investigate the discharge characteristics. It was found that the equipotential between electrodes is the primary factor causing electrical signal coupling between channels, hindering the achievement of synchronous discharge. To address this issue, a novel power supply with a decoupling circuit was devised. By utilizing the combined effect of electrode wire resistance and current limiting resistance (Rc), a potential difference was induced between electrodes in different channels, enabling electrical signal decoupling and facilitating synchronous discharge. The impact of Rc on synchronous discharge was examined, revealing that a reduction in Rc can increase the gap voltage of non-breakdown channels, thereby enhancing the discharge ratio. Finally, cutting rate experiments were conducted. When the new power supply was used for electrical signal decoupling, the cutting rates of multi-channel WEDM were significantly improved. Compared to single-channel HSWEDM, the cutting rates of two-channel and four-channel HSWEDM are enhanced by 84.06% and 247.83%, respectively.

Application of double-layer detector spectral CT calcicum supression technique in the diagnosis of traumatic bone marrow edema in the knee.

Objective: To investigate the accuracy of calcicum supression (CaSupp) technique derived from double-layer detector spectral computed tomography (DSCT) in the diagnosis of traumatic bone marrow edema in the knee. Methods: Twenty-three patients with trauma in the knee who underwent DSCT and Magnetic Resonance Imaging (MRI) in the Third Hospital of Hebei Medical University from October 2021 to March 2022 were retrospectively collected. To make the evaluation more detailed and accurate, each knee was divided into 10 partitions. Bone marrow edema in each partition of the knee was evaluated by two physicians (physician A and B) using CaSupp images combined with conventional CT-CaSupp fusion false-color images. MRI results were used as the gold standard and the accuracy of the CaSupp technique was analyzed in the diagnosis of traumatic bone marrow edema in the knee. The CaSuppCT values of the normal bone marrow area and the bone marrow edema area were delineated, and receiver operating curve (ROC curve) was drawn to find the optimal cut-off value of CaSuppCT as the quantitative parameter for the diagnosis of bone marrow edema. Results: The diagnostic sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of physician A were 83.1 %, 98.1 %, 95.5 % and 92.1 %, respectively; those of physician B were 93.5 %, 97.4 %, 94.7 % and 96.8 %, respectively. The CaSuppCT values in the bone marrow edema areas were higher than those in the normal areas, and the difference was statistically significant. The area under the receiver operating characteristic curve (AUC) of the CaSuppCT values was 0.979, and the cut-off value was 7.05Hu*. The corresponding diagnostic sensitivity was 87.0 %, and specificity was 100.0 %. Conclusion: The CaSupp technique derived from DSCT has high sensitivity and specificity in the detection of traumatic bone marrow edema in the knee, and can provide more imaging information for clinical practice.

Chitosan/polydopamine/octacalcium phosphate composite microcarrier simulates natural bone components to induce osteogenic differentiation of stem cells.

Natural polymers and minerals can be combined to simulate natural bone for repairing bone defects. However, bone defects are often irregular and pose challenges for their repair. To overcome these challenges, we prepared Chitosan/Polydopamine/Octacalcium phosphate (CS/PDA/OCP) microcarriers that mimic bone composition and micro-size to adapt to different bone defect defects. CS/PDA microspheres were prepared by emulsion phase separation method and PDA in-situ polymerization. Finally, it was used to adsorb and immobilize OCP particles, resulting in the preparation of CS/PDA/OCP composite microcarriers. The microcarriers maintain an interconnected porous structure and appropriate porosity, which promotes cell adhesion, proliferation, and nutrient exchange. Subsequently, the protein adsorption capacity, simulated degradation, cell adhesion and proliferation capacity of the composite microcarriers were investigated. Additionally, their ability to simulate mineralization and induce osteogenic differentiation of BMSCs was characterized. The results demonstrated that the composite microcarrier had good biocompatibility and was conducive to cell adhesion and proliferation. Moreover, ALP and ARS staining revealed that the addition of OCP significantly enhanced the osteogenic differentiation of BMSCs. These results indicate that the composite microcarrier has promising prospects for bone repair applications.

The controlled degradation of bacterial cellulose in simulated physiological environment by immobilization and release of cellulase.

Bacterial cellulose (BC) has good network structure, biocompatibility, and excellent mechanical properties, and is widely used in the field of biomaterials. The controllable degradation of BC can further broaden its application. Oxidative modification and cellulases may endow BC with degradability, but these methods inevitably lead to the obvious reduction of its initial mechanical properties and uncontrolled degradation. In this paper, the controllable degradation of BC was realized for the first time by using a new controlled release structure that combines the immobilization and release of cellulase. The immobilized enzyme has higher stability and is gradually released in the simulated physiological environment, and its load can control the hydrolysis rate of BC well. Furthermore, the BC-based membrane prepared by this method retains the favorable physicochemical performance of the original BC, including flexibility and great biocompatibility, and holds good application prospects in drug control release or tissue repair.

Ultrasonic/electrical dual stimulation response nanocomposite bioelectret for controlled precision drug release.

Electret materials have attracted extensive attention because of their permanent polarization and electrostatic effect. However, it is one of problem that needs to be solved in biological application to manipulate the change of surface charge of electret by external stimulation. In this work, a drug-loaded electret with flexibility and no cytotoxicity was prepared under relatively mild conditions. The electret can release the charge through stress change and ultrasonic stimulation, and the drug release can be accurately controlled with the help of ultrasonic and electric double stimulation response. Here, the dipoles like particles of carnauba wax nanoparticles (nCW) are fixed in the matrix based on the interpenetrating polymer network structure, and "frozen" oriented dipolar particles that are treated by thermal polarization and cooled at high field strength. Subsequently, the charge density of the prepared composite electret can reach 101.1 â€‹nC/m2 at the initial stage of polarization and 21.1 â€‹nC/m2 after 3 weeks. In addition, the stimulated change of electret surface charge flow under cyclic tensile stress and cyclic compressive stress can generate a current of 0.187 â€‹nA and 0.105 â€‹nA at most. The ultrasonic stimulation results show that when the ultrasonic emission power was 90% (Pmax â€‹= â€‹1200 â€‹W), the current of 0.472 â€‹nA can be generated. Finally, the drug release characteristics and biocompatibility of the nCW composite electret containing curcumin were tested. The results showed that it not only had the ability to accurately control the release by ultrasound, but also triggered the electrical effect of the material. The prepared drug loaded composite bioelectret provides a new way for the construction, design and testing of the bioelectret. Its ultrasonic and electrical double stimulation response can be accurately controlled and released as required, and it has broad application prospects.