ThePreparation of Electrospun PVDF/TBAC Multimorphology Nanofiber Membrane and Its Application in Direct Contact Membrane Distillation.

Microporous membrane with a hydrophobic surface, high porosity, and narrow pore size distribution is the ideal membrane distillation (MD) membrane. The electrospun membranes for MD are a new type and effective way to seawater desalination. Herein, a novel polyvinylidene fluoride (PVDF)/tetrabutylammonium chloride (TBAC) electrospun nanofiber membrane (ENMs) fabricated apply to for direct contact membrane distillation (DCMD). Combine with the spinning condition, the characteristic and content of TBAC significant effect on the multimorphology structure of nanofiber. Therefore, the porous structure and morphology of PVDF/TBAC ENMs can be well-designed by optimizing relative humidity and TBAC concentration in spinning process, three different structure nanofiber membranes are obtained. Lab-scale setup is used to test membrane separation performance. The result indicates that the ultrafine ENMs with 0.025 mol L-1 TBAC presented a steady water flux of about 20.6 L m-2 h-1 and a high-efficiency salt rejection rate of over 99%. PVDF/TBAC ENMs are expected to provide a solution for development of efficient water treatment membrane.

Research Progress of Polydopamine Hydrogel in the Prevention and Treatment of Oral Diseases.

Oral diseases represent one of the most prevalent diseases globally and are associated with serious health and economic burdens, greatly altering the quality of life of affected individuals. Various biomaterials play important roles in the treatment of oral diseases. To some extent, the development of biomaterials has promoted progress in clinically available oral medicines. Hydrogels have unique tunable advantages that make them useful in the next generation of regenerative strategies and have been widely applied in both oral soft and hard tissues repair. However, most hydrogels lack self-adhesive properties, which may result in low repair efficacy. Polydopamine (PDA), the primary adhesive component, has attracted increasing attention in recent years. PDA-modified hydrogels exhibit reliable and suitable adherence to tissues and easily integrate into tissues to promote repair efficiency. This paper reviews the latest research progress on PDA hydrogels and elaborates on the mechanism of the reaction between PDA functional groups and hydrogels, and summarizes the biological properties and the applications of PDA hydrogels in the prevention and treatment of the field of oral diseases. It is also proposed that in future research we should simulate the complex microenvironment of the oral cavity as much as possible, coordinate and plan various biological events rationally, and realize the translation from scientific research to clinical practice.

Stabilization of Bio-Oss® particulates using photocurable hydrogel to enhance bone regeneration by regulating macrophage polarization.

Bone substitutes are widely used in maxillofacial and oral surgeries. However, in clinical practice, bone substitutes with various forms, including separated particulates, powders, and blocks, have exhibited poor handling properties and space maintenance characteristics, resulting in long surgery procedures and unstable volume of the newly formed bone. Movable separated particulates with high stiffness have induced local inflammatory responses that hinder bone regeneration. The present study aimed to develop a new method to enhance the stability and operability of bone substitutes commonly used in dentistry by premixing with photocurable hydrogel GelMA. The GelMA-encapsulated particulate had a strong capacity to aggregate separated particulates and firmly attach to the host bone defect after photocuring compared to particulates alone. Additionally, macrophages at the surface of the GelMA-stabilized particulates tended to present a more M2-like phenotype than those at the surface of Bio-Oss®, leading to more MMR+ multinucleated giant cell formation and the induction of blood vessel invasion and new bone formation. In conclusion, this hydrogel-coated bone substitute strategy facilitates bone regeneration with increased operability, a stable volume of osteogenic space, and a favorable osteogenic microenvironment, indicating its potential value in the field of maxillofacial and oral surgeries when bone substitutes are needed.

Multidynamic Osteogenic Differentiation by Effective Polydopamine Micro-Arc Oxide Manipulations.

Introduction: The nanostructural modification of the oral implant surface can effectively mimic the morphology of natural bone tissue, allowing osteoblasts to achieve both proliferation and differentiation capabilities at the bone interface of the dental implant. To improve the osteoinductive activity on the surface of titanium implants for rapid osseointegration, we prepared a novel composite coating (MAO-PDA-NC) by micro-arc oxidation technique and immersion method and evaluated the proliferation, adhesion, and osteogenic differentiation of osteoblasts on this coating. Methods: The coatings were prepared by micro-arc oxidation (MAO) technique and immersion method, and characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) for different coatings; the loading of PDA was examined using Fourier transform infrared spectroscopy (FTIR); the ion release capacity of the coatings was determined by inductively coupled plasma emission spectrometry (ICP-OES); the interfacial bonding of the coatings was examined using nanoscratch experiment strength. The cytotoxicity of the coating was examined by live/dead staining kit; cell proliferation viability was examined by CCK-8 kit; adhesion and osteogenic effect of the coating were examined by immunofluorescence staining and RT-PCR; osteogenic differentiation was examined by alkaline phosphatase staining. Results: The surface morphology of titanium implants was modified by micro-arc oxidation technology, and a new MAO-PDA-NC composite coating was successfully prepared. The results showed that the MAO-PDA-NC coating not only optimized the physical and chemical properties of the titanium implant surface but also significantly stimulated the biological properties of osteoblast adhesion, proliferation, and osteogenic differentiation on the coating surface. Conclusion: These results show that MAO-PDA-NC composite coating can significantly improve the surface properties of titanium implants and achieve a stable bond between implant and bone tissue, thus accelerating early osseointegration.

Preparation of Centella asiatica loaded gelatin/chitosan/nonwoven fabric composite hydrogel wound dressing with antibacterial property.

Antibiotics abuse and the emergence of massive drug-resistant bacteria have become the major obstacles in the medical system. Thus, designing an antibiotic-free wound dressing with antibacterial activity and decent biocompatibility is urgently desired. Herein, the sandwich-like composite hydrogel wound dressings were developed by intercalating nonwoven fabrics (NF) as the middle layer, gelatin and chitosan (Gel-CS) hydrogel loaded with Centella asiatica (CA) as the base materials. In addition, soaking strategy was employed to improve the mechanical properties of hydrogels. The hydrogels exhibited uniform microporous structure, stable mechanical property, high water absorbency, as well as water vapor transmission rate. After loading with CA, the composite wound dressing showed the sustained drug release properties in vitro and excellent antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The cytotoxicity results demonstrated that the composite hydrogels had good biocompatibility. This work indicates that the nonwoven composite hydrogels have broad application prospects in the field of medical care in the future.

Synthetic hydrogel nanoparticles for sepsis therapy.

Sepsis is a life-threatening condition caused by the extreme release of inflammatory mediators into the blood in response to infection (e.g., bacterial infection, COVID-19), resulting in the dysfunction of multiple organs. Currently, there is no direct treatment for sepsis. Here we report an abiotic hydrogel nanoparticle (HNP) as a potential therapeutic agent for late-stage sepsis. The HNP captures and neutralizes all variants of histones, a major inflammatory mediator released during sepsis. The highly optimized HNP has high capacity and long-term circulation capability for the selective sequestration and neutralization of histones. Intravenous injection of the HNP protects mice against a lethal dose of histones through the inhibition of platelet aggregation and migration into the lungs. In vivo administration in murine sepsis model mice results in near complete survival. These results establish the potential for synthetic, nonbiological polymer hydrogel sequestrants as a new intervention strategy for sepsis therapy and adds to our understanding of the importance of histones to this condition.

In vitro and in vivo evaluation of targeting tumor with folate-based amphiphilic multifunctional stabilizer for resveratrol nanosuspensions.

Resveratrol (RSV) nanosuspensions, with long term stability and targeting delivery ability, were designed and demonstrated by in vitro and in vivo model. The folate modified distearoylphosphatidyl ethanolamine-polyethylene glycol (DSPE-PEG-FA), as target delivery carrier, was synthesized and confirmed by FTIR and 1H NMR. D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and DSPE-PEG-FA used as stabilizers formed two RSV nanosuspensions (RSV-NA and RSV-NB), which were prepared by anti-solvent precipitation method and optimized by central composite design-response surface model (CCD-RSM). The morphology of RSV nanosuspensions showed flake shapes and spherical shapes by SEM. And the distribution of particles was uniform by TEM and AFM. The two RSV nanosuspensions displayed an amorphous state, by XRPD and DSC determination. At room temperature, the optimum RSV nanosuspensions showed long term stability for 20days. The cell proliferation and morphology study revealed that the RSV nanosuspensions significantly enhanced the in vitro cytotoxicity against A549 cells in a dose- and time-dependent manner. The recommended safe concentration was 5µM for in vitro study. In vivo studies of the two nanosuspensions also displayed higher antitumor efficacy by reduced tumor volume and weight. Compared with the saline group, the tumor inhibition ratio of the RSV-NA was 61.53±18.36% and RSV-NB was 64.61±21.13%. The mice weight of the RSV-NA group and RSV-NB group was also maintained constant increasing. These results demonstrated that TPGS and DSPE-PEG-FA could be used as stabilizers for stable RSV nanosuspensions formulation with the potentiality for targeting delivery to human alveolar carcinoma cells with high stability and efficacy.

Effect of PEGylated chitosan as multifunctional stabilizer for deacetyl mycoepoxydience nanosuspension design and stability evaluation.

Here a series of multifunctional stabilizers was designed and used in a nanosuspension stability enhancement study. Methoxypolyethylene glycol (M PEG)-grafted chitosan, accompanied by space steric hindrance, an electrostatic repulsion function, and a solvation effect, is a multifunctional stabilizer. Deacetyl mycoepoxydience (DM) nanosuspension was prepared using the anti-solvent precipitation approach. The effects of the DM and the multifunctional stabilizer concentration, solvent to anti-solvent ratio, crystallization and storage temperature, and ultrasonic time on drug particle formation during the anti-solvent processing were investigated and the nanosuspension stability was studied. The nanosuspension showed dendritic-like nanostructures and a crystalline state in a morphology and crystalline state study. The optimized drug and multifunctional stabilizer concentration range were selected through the response surface optimization method. The most appropriate and stable nanosuspension could be obtained through the optimal parameters. This study demonstrated that M PEG-grafted chitosan (M PEGC) could be used as a multifunctional stabilizer to control particle size and improve nanosuspension stability.