Controlled release of vancomycin from PEGylated fibrinogen polyethylene glycol diacrylate hydrogel.

Surgical site infection (SSI) is a common issue post-surgery which often prolongs hospitalization and can lead to serious complications such as sternal wound infection following cardiac surgery via median sternotomy. Controlled release of suitable antibiotics could allow maximizing drug efficacy and safety, and therefore achieving a desired therapeutic response. In this study, we have developed a vancomycin laden PEGylated fibrinogen-polyethylene glycol diacrylate (PF-PEGDA) hydrogel system that can release vancomycin at a controlled and predictable rate to be applied in SSI prevention. Two configurations were developed to study effect of the hydrogel on drug release, namely, vancomycin laden hydrogel and vancomycin solution on top of blank hydrogel. The relationship between the rigidity of the hydrogel and drug diffusion was found to comply with a universal power law, i.e., softer hydrogels result in a greater diffusion coefficient hence faster release rate. Besides, vancomycin laden hydrogels exhibited burst release, whereas the vancomycin solution on top of blank hydrogels exhibited lag release. A mathematical model was developed to simulate vancomycin permeation through the hydrogels. The permeation of vancomycin can be predicted accurately by using the mathematical model, which provided a useful tool to customize drug loading, hydrogel thickness and stiffness for personalized medication to manage SSI. To evaluate the potential of hydrogels for bone healing applications in cardiovascular medicine, we performed a proof-of-concept median sternotomy in rabbits and applied the hydrogels. The hydrogel formulations accelerated the onset of osteo-genetic processes in rabbits, demonstrating its potential to be used in human.

Simultaneously Utilizing Excited Holes and Electrons for Piezoelectric-Enhanced Photoproduction of H2O2 from S-Scheme 2D S-Doped VOx/g-C3N4 Nanostructures.

2D/2D step-scheme (S-scheme) piezo-photocatalysts for the production of fine chemicals, such as hydrogen peroxide (H2O2), have attracted significant attention of global scientists owing to the efficiency in utilizing surface piezoelectric effects from 2D materials to overcome rapid charge recombination in photocatalytic processes. In this research, we reported the fabrication of 2D S-doped VOx deposited on 2D g-C3N4 to produce H2O2 via the piezo-photocatalytic process with high production yields at 20.19 mmol g-1 h-1, which was 1.75 and 4.87 times higher than that from solely piezo-catalytic and photocatalytic H2O2 generation. The finding pointed out that adding sulfur (S) to VOx can help to improve the catalytic outcomes by modifying the electronic properties of pristine VOx. In addition, when coupled with g-C3N4, the presence of S limits the formation of graphene in the VOx/g-C3N4 composites, causing shielding effects and pushing the cascade reactions toward water generation in the materials. Besides, the research also sheds light on the charge transport between g-C3N4 and S-VOx under irradiation and how the composites work to trigger the formation of H2O2. The presence of S in the composite systems enhances charge transfer between two semiconductors by strengthening the internal electric fields (IEF) to drive electrons moving in one direction, as demonstrated by density functional theory (DFT) calculations. Moreover, the formation of H2O2 significantly relies on the reduction of oxygen to generate oxygenic radical species at the g-C3N4 sites. Meanwhile, S-VOx provides oxidative sites in the composites to oxidize water molecules to directly or indirectly generate H2O2 or O2, which will further participate in the reactions to produce the final products. This study confirms the validation of S-scheme piezo-photocatalysts, thus encouraging further research on developing heterojunction materials with high catalytic efficiency, which can be used in practical conditions.

Recent advances in innovative osmotic membranes for resource enrichment and energy production in wastewater treatment.

Wastewater is a valuable resource that we can no longer afford to overlook. By recovering the nutrients and metals it contains and generating renewable energy, we can not only meet the rising demands for natural resources but also create a more sustainable and resilient future. Forward osmosis (FO) membranes are one of the most intriguing resource recovery process technologies because of their high organic retention, economical energy usage, and straightforward operation. However, the widespread adoption of FO membranes on a full-scale basis is hindered by several issues with previous membrane products. These include limited selectivity to different types of ions, insufficient water flux, and high susceptibility to membrane fouling during extended periods of operation. Hence, it is essential to either invent new FO membranes or modify the existing ones. The objective of this work is to provide a comprehensive and organized review of up-to-date advancements in the development of innovative osmotic membrane (IOM) materials for resource recovery (RR) and energy production (EP). The paper covers several aspects, including the limitations of current osmotic membrane technologies, a review of new membranes specifically designed for effective RR/EP, their applications in various industrial fields, integrated IOM systems, recent improvements in IOM fabrication processes using artificial intelligence, and a discussion of the challenges and prospects of the potential research. In general, recently developed IOMs have proven to be highly efficient in recovering organics (>99 %), nutrients (>86 %), and precious metals (>90 %). These new membranes have also demonstrated an ability to effectively harvest osmotic energy (with power output ranging from 6 to 38 W/m2) by applied pressure in the range of 8 to 30 bar. These findings suggest that IOMs is promised for efficient resource recovery and renewable energy production.

Assessing industrial wastewater effluent toxicity using boosting algorithms in machine learning: A case study on ecotoxicity prediction and control strategy development.

Trace heavy metals have a tendency to persist in the effluent of industrial wastewater treatment facilities, leading to toxic effects on downstream water bodies. Traditional assessment methods relied on animal testing, but ethical concerns have rendered them unacceptable. An alternative solution is to evaluate wastewater toxicity using trophic-level aquatic organisms as bioassays. However, these bioassay methods involve costly and time-consuming chemical and biological analytical experiments. In this study, an artificial intelligence-powered water quality assessment (AiWA) approach is proposed for predicting industrial effluent ecotoxicity to further enhance the quick and cost-effective ecotoxicity assessment process. Initially, 99 samples were collected from industrial wastewater treatment plants representing 21 different industries in the Republic of Korea. Fourteen parameters were measured, encompassing both physicochemical and ecotoxicological aspects. Boosting algorithms, especially extreme gradient boosting (XGBoost) and adaptive boosting (AdaBoost), were employed for model development. XGBoost outperformed AdaBoost in terms of model performance. Feature selection analysis revealed that conductivity, copper, lead, selenium, pH, and zinc concentrations were the most suitable inputs for training the boosting model. The innovated XGBoost-based AiWA model demonstrated significantly higher performance (i.e., up to 80%) compared to conventional models with an R2 value of exceeding 0.94 and root mean square error of 3.5 toxicity unit for predicting the integrated toxicity unit (ITU). Additionally, pH and conductivity emerged as crucial indicators for reflecting ecotoxicity levels. Specially, this case study indicated that non-toxic/directly dischargeable levels (TU ≤ 1) were achieved when the pH ranged from 6.8 to 8.4 and the conductivity remained below 1651 µS/cm. These findings are expected to facilitate rapid and cost-effective detection of heavy metal ecotoxicity in industrial wastewater effluents, aiding decision-making in wastewater management.

Fabricated magnetic adsorption - Forward osmosis membrane hybrid system for hydroponic irrigation from rich arsenic-containing heavy metal water stream.

Solidification of soluble arsenic from extremely acidic water and direct use of recovery water have been the major challenges in global water management, with the urgent need for new treatment system development. Thus, magnetic adsorption - fertilizer drawn forward osmosis (FDFO) hybrid system with a novel adsorbent and fertilizer mixture to solve the drawbacks of each process was developed with the ultimate goals of metal removal and direct reuse for hydroponic irrigation. Magnetic metal-organic framework-based adsorbent (CMM) was synthesized with various promising capabilities, i.e., wide pH range efficiency, strong pH adjustment, good stability, fast adsorption (1 h), and oxidation (40 min), high capacity (175 and 126 mg/g for As(III), As(V)), strong magnetization (75 emu/g), complete separation by a magnet, excellent interference-tolerance and reusability. In the FDFO system, a massive water volume (50 times higher than the initial draw solution with suitable nutrients for hydroponics irrigation with acceptable NaCl levels was obtained for the first time up to now. However, low As(III) rejection (50%) required the FDFO process to improve more. After integrating with magnetic adsorption, nearly 100% of As was removed. The pH of feed solutions adjusted from extremely acidic to close to neutral conditions further solidified metal by precipitation and membrane separation processes, leading to almost no detection of metals in the final draw solution. Also, favorable nutrients and excellent reusability were obtained. This hybrid process would generally offer an environmentally sustainable and high efficiency for decontaminating As-containing heavy metal water for hydroponic irrigation.

Physics-informed neural network-based serial hybrid model capturing the hidden kinetics for sulfur-driven autotrophic denitrification process.

Sulfur-driven autotrophic denitrification (SdAD) is a biological process that can remove nitrate from low carbon/nitrogen (C/N) ratio wastewater. Although this process has been intensively researched, the mechanism whereby its intermediates (i.e., elemental sulfur and nitrite ions) are generated and accumulated remains elusive. Existing mathematical models developed for SdAD cannot accurately predict the intermediates in SdAD because of the incomplete knowledge of process kinetic resulting from changes in the environmental conditions and electron competition during SdAD. To address this limitation, we proposed a novel serial hybrid model structure based on a physics-informed neural network (PINN) to capture the dynamics of the process kinetics and predict the substrate concentrations in SdAD. In this study, we evaluated the model through numerical experiments and applied it to real case studies involving batch and continuous-flow reactor scenarios. By leveraging the PINN approach, the hybrid model yielded accurate predictions at both the state (i.e. substrate concentration) and kinetic levels in the numerical experiments and performed better than both mechanistic and purely data-driven models in the case studies. Furthermore, we used the trained hybrid model to design control strategies for SdAD and a novel integrated process involving SdAD and anammox for energy-efficient nitrogen removal. Finally, we discuss the advantages and application scope of the PINN-based hybrid model.

Revisiting the roles of dopants in g-C3N4 nanostructures for piezo-photocatalytic production of H2O2: a case study of selenium and sulfur.

The sustainable production of hydrogen peroxide (H2O2) from oxygen and water has become an exciting research hotspot in the scientific community due to the importance of this fine chemical in various fields. Besides, piezo-photocatalysis is an emerging star for generating H2O2 from these green reagents. For developing catalysts for this specific application, doping heteroatoms into carbon-based materials such as graphitic carbon nitrides (g-C3N4) is a growing fascination among worldwide scientists. However, systematic study on the effects of doping precursors on the catalytic results is still rare. Herein, we fabricated sulfur (S) and selenium (Se) doped g-C3N4 with various doping precursors to evaluate the effects of these agents on the production of H2O2 under light and ultrasound irradiation. Based on the results, Se-doped g-C3N4 gave an outstanding catalytic performance compared to S-doped g-C3N4, even in a significantly low quantity of Se. In order to fully understand the chemical, physical, optical, and electronic properties of pristine g-C3N4 and its derivatives, the as-prepared materials were thoroughly analyzed with various tools. Thus, this study would give more profound insights into doping techniques for carbon-based materials and encourage further research on the design and development of piezo-photocatalysts for practical applications.

Investigating PEGDA and GelMA Microgel Models for Sustained 3D Heterotypic Dermal Papilla and Keratinocyte Co-Cultures.

Hair follicle morphogenesis is heavily dependent on reciprocal, sequential, and epithelial-mesenchymal interaction (EMI) between epidermal stem cells and the specialized cells of the underlying mesenchyme, which aggregate to form the dermal condensate (DC) and will later become the dermal papilla (DP). Similar models were developed with a co-culture of keratinocytes and DP cells. Previous studies have demonstrated that co-culture with keratinocytes maintains the in vivo characteristics of the DP. However, it is often challenging to develop three-dimensional (3D) DP and keratinocyte co-culture models for long term in vitro studies, due to the poor intercellular adherence between keratinocytes. Keratinocytes exhibit exfoliative behavior, and the integrity of the DP and keratinocyte co-cultured spheroids cannot be maintained over prolonged culture. Short durations of culture are unable to sufficiently allow the differentiation and re-programming of the keratinocytes into hair follicular fate by the DP. In this study, we explored a microgel array approach fabricated with two different hydrogel systems. Using poly (ethylene glycol) diacrylate (PEGDA) and gelatin methacrylate (GelMA), we compare their effects on maintaining the integrity of the cultures and their expression of important genes responsible for hair follicle morphogenesis, namely Wnt10A, Wnt10B, and Shh, over prolonged duration. We discovered that low attachment surfaces such as PEGDA result in the exfoliation of keratinocytes and were not suitable for long-term culture. GelMA, on the hand, was able to sustain the integrity of co-cultures and showed higher expression of the morphogens overtime.

Immobilized nanoneedle-like structures for intracellular delivery, biosensing and cellular surgery.

The rapid advancements of nanotechnology over the recent years have reformed the methods used for treating human diseases. Nanostructures including nanoneedles, nanorods, nanowires, nanofibers and nanotubes have exhibited their potential roles in drug delivery, biosensing, cancer therapy, regenerative medicine and intracellular surgery. These high aspect ratio structures enhance targeted drug delivery with spatiotemporal control while also demonstrating their role as an efficient intracellular biosensor with minimal invasiveness. This review discusses the history and emergence of these nanostructures and their fabrication methods. This review also provides an overview of the different applications of nanoneedle systems, further highlighting the importance of greater investigation into these nanostructures for future medicine.

Utilization of Response Surface Methodology in Optimization of Polysaccharides Extraction from Vietnamese Red Ganoderma lucidum by Ultrasound-Assisted Enzymatic Method and Examination of Bioactivities of the Extract.

Red Ganoderma lucidum (G. lucidum) is a popular medicinal herb commonly used in Vietnamese traditional remedies due to its potential value for health. In this study, polysaccharides were extracted from G. lucidum using ultrasound-assisted enzymatic extraction method. The response surface methodology and Box-Behnken design were employed to investigate the effects of pH, extraction temperature, extraction time, and ultrasonic power on the content of polysaccharides. Based on ultraviolet-visible spectroscopy analysis, the highest content of polysaccharides in the extract was 32.08 mg/g under optimum experimental parameters including enzyme concentration of 3%, pH of 5.5, extraction temperature of 45°C, extraction time of 30 min, and ultrasonic power of 480 W. The Fourier-transform infrared spectroscopy was also used to identify the functional groups in the extracts. The molecular weights of polysaccharides were determined by gel permeation chromatography. The obtained extract was then evaluated for anticancer activities by using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, showing the anticancer activities with the half-maximal inhibitory concentration value of more than 512 µg/mL. This result suggested that UAEE could be considered as an appropriate and effective extraction method for bioactive crude polysaccharides from G. lucidum.

On-pump transapical cardioscopic mitral valve replacement with cardiac arrest: short-term results in a porcine survival model.

OBJECTIVES: Favourable outcomes with mitral annuloplasty have been achieved with transapical cardioscopic (TAC) surgery in a survival animal model. In addition, experimental TAC on a non-survival animal model also showed adequate access to remove the native mitral valve and implant a prosthetic valve, but the surgical procedure took a long time and lacked follow-up data. The goal of this study was to develop a clinically translatable TAC mitral valve replacement (MVR) procedure using technical and instrumental refinements to reduce the surgical time and to evaluate functional recovery and short-term durability using a survival porcine model. We hypothesized that MVR could be achieved with subannular implantation of the bioprosthesis via the TAC approach. METHODS: TAC MVR using the Hancock II™ (Medtronic)® mitral prosthesis was performed in 6 pigs via an incision over the xiphoid process, under cardiopulmonary bypass and cardiac arrest. COR-KNOT® and minimally invasive cardiac surgery instruments were used. Haemodynamics, echocardiography, cardiac computed tomography, ventriculography and electrocardiography were used to evaluate the function of the mitral prosthesis and left ventricle, coronary system and conduction system in the perioperative period and 4 weeks later. RESULTS: A postimplant examination showed that the mitral prosthesis was competent, without a paravalvular leak. The left ventricular ejection fraction was comparable to preoperative values (65.2 ± 4.1 vs 67.2 ± 7.9). The bypass, cross-clamp and implant times were 177.2 ± 44.2 min, 135.3 ± 47.6 min and 94.0 ± 41.2 min, respectively. The prosthesis was in a good position. The apical scar was intact and not aneurysmal 4 weeks after the implant. The valve was properly sutured to the annulus, without a postimplant paravalvular leak. All animals recovered after 1 month of follow-up with preserved ventricular function and normal wall motion. CONCLUSIONS: We successfully managed to replace the mitral valve with a biological prosthesis via the apex with encouraging bypass and cross-clamp times. This technique may provide an alternative for a selected group of patients with diseased mitral valves who have indications for MVR and still in a high-risk redo setting with conventional sternotomy or minimally invasive cardiac surgery-MVR.

Transapical cardioscopic mitral annuloplasty: a short-term survival study in a porcine model.

OBJECTIVES: The transapical approach provides concurrent surgical access to the mitral and the aortic valves, the root of the aorta and the left atrium. We previously showed the feasibility of transapical cardioscopic (TAC) surgery in a non-survival porcine model. However, reproducibility and feasibility of ring implantation using TAC have not been reported. Therefore, in this study, we hypothesized that implantation of a mitral annuloplasty ring can be feasibly and safely carried out endoscopically via the apex of the heart. METHODS: Using a porcine model in a short-term survival study, TAC mitral annuloplasty was performed in 6 pigs via an incision over the xyphoid, under cardiopulmonary bypass and cardiac arrest. A mitral annuloplasty ring was implanted via the apex to a normal mitral annulus, using a customized set of instruments and techniques. Haemodynamics, echocardiography, cardiac computed tomography, ventriculography, electrocardiography and histopathology studies were used to evaluate the function of the mitral valve and the left ventricle, coronary system and conduction system in the perioperative period and 4 weeks later. RESULTS: All 6 animals survived and recovered from the TAC annuloplasty procedure. Postimplantation examination showed that the mitral valve was competent, left ventricular ejection fraction was 63 ± 4%, left ventricular length was 6.2 ± 0.5 cm and left ventricular end-diastolic volume was 80 ± 10 ml, which were comparable to preoperative values. Apart from a dense scar at the apex, no significant injury was noticed on the ventricle, the chordae and the mitral leaflets. The bypass, cross-clamp and implantation times were 181 ± 55 min, 130 ± 37 min and 47 ± 6 min, respectively. CONCLUSIONS: Despite long surgical times due to the initial learning curve, successful execution of mitral ring annuloplasty could be safely achieved using the TAC approach, via a small incision without the involvement of sternum or the right pleural cavity, thereby potentially expanding the indication to patients with high-risk full sternotomy or right thoracotomy.

Drug permeation through skin is inversely correlated with carrier gel rigidity.

Controlled release plays an essential role in formulating topical and transdermal drug delivery systems. In this study, we correlated the skin permeation of Sesamin, a lipophilic drug, with the rheological properties of two different organogel carriers, i.e., low molecular weight gelling agent N-lauroyl-l-glutamic acid di-n-butylamide (GP-1) and Carbopol polymeric gels. Although these two gels have distinct network structures, they share the same trend: the more rigid the gel network and the higher the gelator concentration, the lower the steady flux of Sesamin through skin. This negative correlation lies in the fact that organogel network hinders the diffusion of drug to the gel-skin interface; as a result, the depletion zone near the interface is non-negligible and contributes to the resistance of the whole diffusion system, and thus, the permeation flux is reduced. More interestingly, the dependence of the steady flux against gel complex modulus at the linear viscoelastic region followed a "universal" power law regardless of the gel types, i.e., 1/J = 1/J0 + a(G*)(ε)/C0 with a = 11.25, ε = 0.21 ± 0.03 for GP-1 gels, and a = 0.16, ε = 1.05 ± 0.06 for Carbopol gels, J0 is the steady flux without gel (G* = 0), and C0 is the initial concentration of drug in gels. The empirical formulae are crucial in developing transdermal organogel systems with controlled release of drug content through readily obtainable data of their rheological properties. The explanation for the power law dependence of the steady flux on gel complex modulus is discussed.