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1.
Angew Chem Int Ed Engl ; : e202402684, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38597346

RESUMO

Electrocatalytic urea synthesis under ambient conditions offers a promising alternative strategy to the traditional energy-intensive urea industry protocol. Limited by the electrostatic interaction, the reduction reaction of anions at the cathode in the electrocatalytic system is not easily achievable. Here, we propose a novel strategy to overcome electrostatic interaction via pulsed electroreduction. We found that the reconstruction-resistant CuSiOx nanotube, with abundant atomic Cu-O-Si interfacial sites, exhibits ultrastability in the electrosynthesis of urea from nitrate and CO2. Under a pulsed potential approach with optimal operating conditions, the Cu-O-Si interfaces achieve a superior urea production rate (1606.1 µg h-1 mgcat. -1) with high selectivity (79.01 %) and stability (the Faradaic efficiency is retained at 80 % even after 80 h of testing), outperforming most reported electrocatalytic synthesis urea catalysts. We believe our strategy will incite further investigation into pulsed electroreduction increasing substrate transport, which may guide the design of ambient urea electrosynthesis and other energy conversion systems.

2.
Int J Biol Macromol ; 265(Pt 1): 130966, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38508546

RESUMO

Bamboo, featuring fast growth rate and high cellulose content, is considered to be one of the most attractive feedstocks for degradable bio-materials as a substitute for plastics. However, those was limited to the fields of bamboo structural materials mainly by physical processes. Herein, we report a facile continuous wet extrusion strategy for scalable manufacturing of anisotropic regenerated cellulose films in alkali/urea aqueous solution for the first time. The bamboo cellulose solution was regenerated in H2SO4/Na2SO4/ZnSO4 aqueous solution to facilitate the construction of dense fibrils networks. Moreover, under the synergistic effect of shear orientations and stretching processes in wet extrusion molding, the cellulose networks promoted further orientated assembly into aligned fibrils. Therefore, these anisotropic cellulose hydrogels exhibited good mechanical properties, and the tensile strength was increased from 1.67 MPa of anisotropic cellulose hydrogel with 1.0 of stretching ration (ACH-1.0) to 2.13 MPa of ACH-1.4 with increasing stretching ratio from 1.0 to 1.4, which was about 1.34 times higher than that of the isotropic hydrogel fabricated by tape-casting. Moreover, ACH-1.4 exhibited commendable thermal stability and air barrier properties. This work demonstrated a simple and continuous bottom-up approach for fabrication of anisotropic bamboo-based cellulose hydrogels and films with excellent mechanical properties.


Assuntos
Celulose , Água , Celulose/química , Resistência à Tração , Hidrogéis
3.
Mater Horiz ; 11(6): 1560-1566, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38263927

RESUMO

Cellulose, often considered a highly promising substitute for petroleum-based plastics, offers several compelling advantages, including abundant availability, cost-effectiveness, environmental friendliness, and biodegradability. However, its inherent highly crystalline structure and extensive hydrogen-bonded network pose challenges for processing and recycling. In this study, we introduce the concept of cellulose vitrimers (CVs), wherein dynamic bonds are incorporated to reconfigure the hydrogen-bonded network, resulting in a mechanically robust, highly transparent material. CVs exhibit exceptional malleability, thermal stability, and noteworthy resistance to water and solvents. Due to the dynamic bond disassociation, CVs can be effectively chemically recycled using a well-established "dissolution-and-reforming" process. Moreover, CVs have proven successful as flexible substrate materials for organic solar cells, outperforming traditional petroleum-based polyethylene naphthalate (PEN). Given these advantages, CVs have the potential to replace conventional petroleum-based materials as recyclable and environmentally friendly alternatives, particularly within the realm of electronic devices and displays.

4.
Plast Reconstr Surg ; 153(2): 348e-360e, 2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-37171265

RESUMO

BACKGROUND: Adipose tissue engineering plays a key role in the reconstruction of soft-tissue defects. The acellular adipose matrix (AAM) is a promising biomaterial for the construction of engineered adipose tissue. However, AAM lacks sufficient adipoinduction potency because of the abundant loss of matrix-bound adipokines during decellularization. METHODS: An adipose-derived extracellular matrix collagen scaffold, "adipose collagen fragment" (ACF), was prepared using a novel mechanical method that provides sustained release of adipokines. Here, the authors used label-free proteomics methods to detect the protein components in AAM and ACF. In vivo, ACF was incorporated into AAM or acellular dermal matrix and implanted into nude mice to evaluate adipogenesis. Neoadipocytes, neovessels, and corresponding gene expression were evaluated. The effects of ACF on adipogenic differentiation of human adipose-derived stem cells and tube formation by human umbilical vein endothelial cells were tested in vitro. RESULTS: Proteomics analysis showed that ACF contains diverse adipogenic and angiogenic proteins. ACF can release diverse adipokines and induce highly vascularized, mature adipose tissue in AAM, and even in nonadipogenic acellular dermal matrix. Higher expression of adipogenic markers peroxisome proliferator-activated receptor gamma and CCAAT/enhancer-binding protein alpha and greater numbers of tubule structures were observed in ACF-treated groups in vitro. CONCLUSION: The combination of ACF and AAM could serve as a novel and promising strategy to construct mature, vascularized adipose tissue for soft-tissue reconstruction. CLINICAL RELEVANCE STATEMENT: The combined use of AAM and ACF has been proven to induce a highly vascularized, mature, engineered adipose tissue in the nude mouse model, which may serve as a promising strategy for soft-tissue reconstruction.


Assuntos
Tecido Adiposo , Engenharia Tecidual , Camundongos , Animais , Humanos , Engenharia Tecidual/métodos , Camundongos Nus , Preparações de Ação Retardada/metabolismo , Matriz Extracelular/metabolismo , Colágeno/metabolismo , Células Endoteliais da Veia Umbilical Humana , Alicerces Teciduais/química
5.
Angew Chem Int Ed Engl ; 62(51): e202315189, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-37919233

RESUMO

Thermally triggered spatial symmetry breaking in traditional ferroelectrics has been extensively studied for manipulation of the ferroelectricity. However, photoinduced molecular orbital breaking, which is promising for optical control of ferroelectric polarization, has been rarely explored. Herein, for the first time, we synthesized a homochiral fulgide organic ferroelectric crystal (E)-(R)-3-methyl-3-cyclohexylidene-4-(diphenylmethylene)dihydro-2,5-furandione (1), which exhibits both ferroelectricity and photoisomerization. Significantly, 1 shows a photoinduced reversible change in its molecular orbitals from the 3 π molecular orbitals in the open-ring isomer to 2 π and 1 σ molecular orbitals in the closed-ring isomer, which enables reversible ferroelectric domain switching by optical manipulation. To our knowledge, this is the first report revealing the manipulation of ferroelectric polarization in homochiral ferroelectric crystal by photoinduced breaking of molecular orbitals. This finding sheds light on the exploration of molecular orbital breaking in ferroelectrics for optical manipulation of ferroelectricity.

7.
J Cosmet Dermatol ; 22(12): 3387-3394, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37409535

RESUMO

BACKGROUND: The complications of large-volume fat grafting (LVFG) for breast augmentation remain unpredictable and include palpable breast nodules, oil cysts, and calcifications. AIMS: This study was aimed to provide an optimal treatment option for breast nodules after LVFG and evaluate their pathological characteristics. PATIENTS/METHODS: We effectively performed complete resection of breast nodules in 29 patients after LVFG using a minimal skin incision with the vacuum-assisted breast biopsy (VABB) system under ultrasound guidance. And we further carried on histologic examination of excised nodules and evaluated their pathological characteristics. RESULTS: The breast nodules were excised thoroughly with cosmetic effect satisfactorily. Interestingly, subsequent histologic examination showed that type I and VI collagens were strongly expressed in the fibrotic area and type IV collagen were positively expressed around the blood vessel. Furthermore, we found that the type VI collagen+ area appeared around mac2+ macrophages and α-SMA+ myofibroblasts. CONCLUSIONS: The VABB system may be the optimal treatment option for breast nodules after LVFG. And type VI collagens may serve as a biomarker of grafted adipose tissue fibrosis. The relationship between macrophages, fibroblasts, and collagen formation may be therapeutic targets for regulating fibrosis.


Assuntos
Mama , Mamoplastia , Humanos , Mama/diagnóstico por imagem , Mama/cirurgia , Mama/patologia , Mamoplastia/efeitos adversos , Tecido Adiposo/transplante , Biópsia por Agulha , Fibrose , Estudos Retrospectivos
8.
Int J Biol Macromol ; 246: 125649, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37394215

RESUMO

Hemicellulose removal from bleached bamboo pulp is key to produce qualified dissolving pulps. In this work, alkali/urea aqueous solution was firstly applied to remove hemicellulose in bleached bamboo pulp (BP). The effect of urea usage, time and temperature on the hemicellulose content of BP was studied. The reduction of hemicellulose content from 15.9 to 5.7 % was achieved in 6 wt% NaOH/1 wt% urea aqueous solution at 40 °C for 30 min. Cellulose carbamates (CCs) were obtained from the esterification of BP with urea. The dissolution behavior of CCs in NaOH/ZnO aqueous solutions with different degree of polymerization (DP), hemicellulose and nitrogen contents were studied by using optical microscope and rheology. The highest solubility was up to 97.7 % when the hemicellulose was 5.7 % and Mη was 6.5 × 104 (g/mol). With the decrease of hemicellulose content from 15.9 % to 8.60 % and 5.70 %, the gel temperature increased from 59.0, 69.0 to 73.4 °C. The apparent gelation time increased from 5640 to 12,120 s with the hemicellulose content increased from 8.60 % to 15.9 %. CC solution with 5.70 % hemicellulose always keeps a liquid-state (G" > G') until the test time reached 17,000 s. The results showed that the removal of hemicellulose, the decrease of DP and the increase of esterification endowed CC with higher solubility and solution stability.


Assuntos
Celulose , Óxido de Zinco , Hidróxido de Sódio , Carbamatos , Água , Ureia
9.
Int J Biol Macromol ; 245: 125395, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37330075

RESUMO

This work proposed a promising biorefinery method for the deconstruction of moso bamboo by using p-toluenesulfonic acid (P-TsOH) pretreatment to product high-purity cellulose (dissolving pulp). The cellulose pulp with high α-cellulose content (82.36 %) was successfully prepared for 60 min at low pretreatment temperature (90 °C) and atmospheric pressure. After the simple bleaching and cold caustic extraction (CCE) processes, the properties of cellulose pulp, such as α-cellulose content, polymerization, ISO brightness, all met the standard of dissolving pulp. In general, the cooking method through P-TsOH pretreatment can shorten the preparation time, which can effectively reduce energy consumption and chemical consumption. Therefore, this work may provide a new perspective for the green preparation of dissolving pulp that can be used to produce lyocell fiber after ash and metal ion treatment.


Assuntos
Celulose , Madeira , Celulose/química , Madeira/química , Benzenossulfonatos , Poaceae
10.
J Hazard Mater ; 455: 131549, 2023 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-37163896

RESUMO

Selective capture of radioactive 99TcO4- from highly alkaline nuclear waste is highly desirable for environmental remediation and waste disposal. However, the combined features of adsorbents with excellent chemical stability and high capture selectivity for 99TcO4- have not yet been achieved. Herein, we report an ultra-stable 3D pyridinium salt-based polymeric network (TMP-TBPM) nanotrap with remarkable radiation, acid and base stability for selective capture of ReO4- via hydrophobic engineering and steric hindrance, a non-radioactive surrogate of 99TcO4-. The batch capture experiments show that TMP-TBPM has high capture capacity (918.7 mg g-1) and fast sorption kinetics (94.3 % removal in 2 min), which can be attributed to the high density of pyridinium salt-based units on the highly accessible pore channels of 3D interconnected low-density skeleton. In addition, the introduction of abundant alkyl and tetraphenylmethane units into the 3D framework not only greatly enhanced the hydrophobicity and stability of TMP-TBPM, but also significantly improved the affinity toward 99TcO4-/ReO4-, enabling reversible and selective capture of 99TcO4-/ReO4- even under highly alkaline conditions. This study exhibits the great potential of 3D pyridinium salt-based polymeric network nanotrap for 99TcO4-/ReO4- capture from highly alkaline nuclear waste, providing a new strategy to construct high-performance cationic polymeric sorbents for radioactive wastewater treatment.

11.
Polymers (Basel) ; 15(6)2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36987256

RESUMO

Bleached bamboo pulp, as a kind of natural cellulose, has received significant attention in the field of biomass materials due to its advantages of environmental protection and the abundance of raw materials. Low-temperature alkali/urea aqueous system is a green dissolution technology for cellulose, which has promising application prospects in the field of regenerated cellulose materials. However, bleached bamboo pulp, with high viscosity average molecular weight (Mη) and high crystallinity, is difficult to dissolve in an alkaline urea solvent system, restraining its practical application in the textile field. Herein, based on commercial bleached bamboo pulp with high Mη, a series of dissolvable bamboo pulps with suitable Mη was prepared using a method of adjusting the ratio of sodium hydroxide and hydrogen peroxide in the pulping process. Due to the hydroxyl radicals being able to react with hydroxyls of cellulose, molecular chains are cut down. Moreover, several regenerated cellulose hydrogels and films were fabricated in an ethanol coagulation bath or a citric acid coagulation bath, and the relationship between the properties of the regenerated materials and the Mη of the bamboo cellulose was systematically studied. The results showed that hydrogel/film had good mechanical properties, as the Mη is 8.3 × 104 and the tensile strength of a regenerated film and the film have values up to 101 MPa and 3.19 MPa, respectively. In this contribution, a simple method of a one-step oxidation of hydroxyl radicals to prepare bamboo cellulose with diversified Mη is presented, providing an avenue for a preparation of dissolving pulp with different Mη in an alkali/urea dissolution system and expanding the practical applications of bamboo pulp in biomass-based materials, textiles, and biomedical materials.

12.
J Hazard Mater ; 446: 130603, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36580784

RESUMO

Efficient extraction of radioactive 99TcO4- from strong acid/base solutions by porous adsorbents is extremely desirable but remains a great challenge. To overcome the challenge, here we report the first example of an olefin-linked cationic covalent organic framework (COF) named BDBI-TMT with excellent acid, base and radiation stability is synthesized by integrating robust imidazolium salt-based linkers with triazine building blocks. BDBI-TMT shows an ultra-fast adsorption kinetics (equilibrium is reached within 1 min) and an excellent ReO4- (a non-radioactive surrogate of 99TcO4-) capture capacity of 726 mg g-1, which can be attributed to the abundance of precisely tailored imidazolium salt-based units on the highly accessible pore walls of the ordered pore channels. Furthermore, the formation of the highly conjugated bulky alkyl skeleton enhances the hydrophobicity of BDBI-TMT, which significantly improves not only the affinity toward ReO4-/99TcO4- but also the chemical stability, allowing selective and reversible extraction of ReO4-/99TcO4- even under extreme conditions. This work demonstrates the great potential of olefin-linked cationic COFs for ReO4-/99TcO4- extraction, providing a new avenue to construct high-performance porous adsorbents for radionuclide remediation.

13.
Polymers (Basel) ; 16(1)2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38201679

RESUMO

Super-wetting interface materials have shown great potential for applications in oil-water separation. Hydrogel-based materials, in particular, have been extensively studied for separating water from oily wastewater due to their unique hydrophilicity and excellent anti-oil effect. In this study, a superhydrophilic and underwater superoleophobic bamboo cellulose hydrogel-coated mesh was fabricated using a feasible and eco-friendly dip-coating method. The process involved dissolving bamboo cellulose in a green alkaline/urea aqueous solvent system, followed by regeneration in ethanol solvent, without the addition of surface modifiers. The resulting membrane exhibited excellent special wettability, with superhydrophilicity and underwater superoleophobicity, enabling oil-water separation through a gravity-driven "water-removing" mode. The super-wetting composite membrane demonstrated a high separation efficiency of higher than 98% and a permeate flux of up to 9168 L·m-2·h-1 for numerous oil/water mixtures. It also maintained a separation efficiency of >95% even after 10 cycles of separation, indicating its long-term stability. This study presents a green, simple, cost-effective, and environmentally friendly approach for fabricating superhydrophilic surfaces to achieve oil-water separation. It also highlights the potential of bamboo-based materials in the field of oil-water separation.

14.
Polymers (Basel) ; 14(23)2022 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-36501555

RESUMO

Water is an indispensable strategic resource for biological and social development. The problem of oily wastewater pollution originating from oil spillages, industrial discharge and domestic oil pollution has become an extremely serious international challenge. At present, numerous superwetting materials have been applied to effectively separate oil and water. However, most of these materials are difficult to scale and their large-scale application is limited by cost and environmental protection. Herein, a simple, environmentally friendly strategy including sol-gel, freeze-drying and surface hydrophobic modification is presented to fabricate a bamboo cellulose foam with special wetting characteristics. The bamboo cellulose foam is superhydrophobic, with a water contact angle of 160°, and it has the superoleophilic property of instantaneous oil absorption. Owing to the synergistic effect of the three-dimensional network structure of the superhydrophobic bamboo cellulose foam and its hydrophobic composition, it has an excellent oil-absorption performance of 11.5 g/g~37.5 g/g for various types of oil, as well as good recyclability, with an oil (1,2-dichloroethane) absorption capacity of up to 31.5 g/g after 10 cycles. In addition, the prepared cellulose-based foam exhibits an outstanding performance in terms of acid and alkali corrosion resistance. Importantly, owing to bamboo cellulose being a biodegradable, low-cost, natural polymer material that can be easily modified, superhydrophobic/superoleophilic bamboo cellulose foam has great application potential in the field of oily wastewater treatment.

15.
Aesthet Surg J ; 42(5): NP337-NP350, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-36413201

RESUMO

BACKGROUND: Skin filler is an option for treating skin aging and wrinkles; however, currently used fillers are limited by poor biocompatibility, rapid degradation, and possible hypersensitivity reactions. Autologous adipose tissue-derived products have been recognized as promising options for skin rejuvenation. OBJECTIVES: This study aimed to develop a novel adipose-derived product for skin filling. METHODS: Adipose collagen fragment (ACF) was prepared through pulverization, filtration, and centrifugation. The macrography, structure, types of collagen, and cell viability of ACF were evaluated by immunostaining, western blotting, and cell culture assays. ACF, nanofat, and phosphate-buffered saline (9 spots/side, 0.01 mL/spot) were intradermally injected in the dorsal skin of 36 female BALB/c nude mice; the skin filling capacity and the collagen remodeling process were then investigated. Twenty-one female patients with fine rhytides in the infraorbital areas were enrolled and received clinical applications of ACF treatment. Therapeutic effects and patients' satisfaction scores were recorded. RESULTS: The mean [standard deviation] yield of ACF from 50 mL of Coleman fat was 4.91 [0.25] mL. ACF contained nonviable cells and high levels of collagen I, collagen IV, and laminin. Fibroblasts and procollagen significantly increased in ACF and ACF-treated dermis (P < 0.05). Overall, 85.7% of patients were satisfied with the therapy results, and no infections, injection site nodules, or other unwanted side effects were observed. CONCLUSIONS: ACF significantly improved dermal thickness and collagen synthesis and may serve as a potential autologous skin filler.


Assuntos
Preenchedores Dérmicos , Camundongos , Animais , Feminino , Camundongos Nus , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Tecido Adiposo
16.
Angew Chem Int Ed Engl ; 61(50): e202214142, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36225162

RESUMO

It is well known that charge separation is crucial for efficient photocatalytic solar conversion. Although some covalent-organic frameworks (COFs) exhibit visible-light harvest, the large exciton binding energies reduce their photocatalytic efficiencies. Herein, we developed a novel method to post-treat the olefin-linked COFs with end-capping polycyclic aromatic hydrocarbons (PAHs) for spontaneous charge separation. Interestingly, a type-II heterostructure is constructed in our perylene-modified COFs which displays drastically enhanced performance for photocatalytic CO2 reduction, with an efficiency of 8-fold higher than that of unmodified COF. A combination of electrochemical, steady-state, and time-resolved spectroscopic measurements indicates that such drastically enhanced performance should be attributed to photoinduced spontaneous charge separation in the heterostructure. These results illustrate the feasibility of engineering the charge-separation properties of crystalline porous frameworks at a molecular level for artificial photosynthesis.

17.
FASEB J ; 36(10): e22550, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36098482

RESUMO

Clinical unpredictability and variability following fat grafting remain non-negligible problems due to the unknown mechanism of grafted fat retention. The role of the extracellular matrix (ECM), which renders cells with structural and biochemical support, has been ignored. This study aimed to clarify the ECM remodeling process, related cellular events, and the spatiotemporal relationship between ECM remodeling and adipocyte survival and adipogenesis after fat grafting. Labeled Coleman fat by the matrix-tracing technique was grafted in nude mice. The ECM remodeling process and cellular events were assessed in vivo. The related cytokines were evaluated by qRT-PCR. An in vitro cell migration assay was performed to verify the chemotactic effect of M2-like macrophages on fibroblasts. The results demonstrated that in the periphery, most of the adipocytes of the graft survived or regenerated, and the graft-derived ECM was gradually replaced by the newly-formed ECM. In the central parts, most adipocytes in the grafts died shortly after, and a small part of the graft-derived and newly-formed ECM was expressed with irregular morphology. Adipose ECM remodeling is associated with increased infiltration of macrophages and fibroblasts, as well as up-regulated expression of cytokines in the adipose tissue. To sum up, our results describe the various preservation mode of fat grafts after transplantation and underscore the importance of macrophage-mediated ECM remodeling in graft preservation after fat grafting. The appreciation and manipulation of underlying mechanisms that are operant in this setting stand to explore new therapeutic approaches and improve clinical outcomes of fat grafting.


Assuntos
Tecido Adiposo , Matriz Extracelular , Animais , Citocinas , Macrófagos , Camundongos , Camundongos Nus
18.
Langmuir ; 38(40): 12179-12188, 2022 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-36170049

RESUMO

Lead ion (Pb2+) is one of the most common water pollutants. Herein, with bamboo as the raw material, we fabricate a thin-walled hollow ellipsoidal carbon-based adsorbent (CPCs900) containing abundant O-containing groups and carbon defects and having a specific surface area as large as 730.87 m2 g-1. CPCs900 shows a capacity of 37.26 mg g-1 for adsorbing Pb2+ in water and an efficiency of 98.13% for removing Pb2+ from water. This is much better than the activated carbon commonly used for removing Pb2+ from water (12.19 mg g-1, 30.48%). The bond interaction of Pb2+ with the O-containing groups on CPCs900 and the electrostatic interaction of Pb2+ with the electron-rich carbon defects on CPCs900 could be the main forces to drive Pb2+ adsorption on CPCs900. The outstanding adsorption performance of CPCs900 could be due to the abundant O-containing groups and carbon defects as well as the large specific surface area of CPCs900. Bamboo has a large reserve and a low price. The present work successfully converts bamboo into adsorbents with outstanding performances in removing Pb2+ from water. This is of great significance for meeting the huge industrial demand on highly efficient adsorbents for removing toxic metal ions from water.


Assuntos
Poluentes Químicos da Água , Poluentes da Água , Adsorção , Carvão Vegetal/química , Concentração de Íons de Hidrogênio , Íons , Cinética , Chumbo , Água , Poluentes Químicos da Água/análise
19.
J Nonlinear Sci ; 32(6): 80, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36089998

RESUMO

In this study, we propose an explicit adaptive finite difference method (FDM) for the Cahn-Hilliard (CH) equation which describes the process of phase separation. The CH equation has been successfully utilized to model and simulate diverse field applications such as complex interfacial fluid flows and materials science. To numerically solve the CH equation fast and efficiently, we use the FDM and time-adaptive narrow-band domain. For the adaptive grid, we define a narrow-band domain including the interfacial transition layer of the phase field based on an undivided finite difference and solve the numerical scheme on the narrow-band domain. The proposed numerical scheme is based on an alternating direction explicit (ADE) method. To make the scheme conservative, we apply a mass correction algorithm after each temporal iteration step. To demonstrate the superior performance of the proposed adaptive FDM for the CH equation, we present two- and three-dimensional numerical experiments and compare them with those of other previous methods.

20.
Acta Biomater ; 151: 106-117, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35970482

RESUMO

Extracellular matrix (ECM)-mimicking biomaterials are considered effective tissue-engineered scaffolds for regenerative medicine because of their biocompatibility, biodegradability, and bioactivity. ECM-mimicking biomaterials preserve natural microstructures and matrix-related bioactive components and undergo continuous matrix remodeling upon transplantation. The interaction between host immune cells and transplanted ECM-mimicking biomaterials has attracted considerable attention in recent years. Transplantation of biomaterials may initiate injuries and early pro-inflammation reactions characterized by infiltration of neutrophils and M1 macrophages. Pro-inflammation reactions may lead to degradation of the transplanted biomaterial and drive the matrix into a fetal-like state. ECM degradation leads to the release of matrix-related bioactive components that act as signals for cell migration, proliferation, and differentiation. In late stages, pro-inflammatory cells fade away, and anti-inflammatory cells emerge, which involves macrophage polarization to the M2 phenotype and leukocyte activation to T helper 2 (Th2) cells. These anti-inflammatory cells interact with each other to facilitate matrix deposition and tissue reconstruction. Deposited ECM molecules serve as vital components of the mature tissue and influence tissue homeostasis. However, dysregulation of matrix remodeling results in several pathological conditions, such as aggressive inflammation, difficult healing, and non-functional fibrosis. In this review, we summarize the characteristics of inflammatory responses in matrix remodeling after transplantation of ECM-mimicking biomaterials. Additionally, we discuss the intrinsic linkages between matrix remodeling and tissue regeneration. STATEMENT OF SIGNIFICANCE: Extracellular matrix (ECM)-mimicking biomaterials are effectively used as scaffolds in tissue engineering and regenerative medicine. However, dysregulation of matrix remodeling can cause various pathological conditions. Here, the review describes the characteristics of inflammatory responses in matrix remodeling after transplantation of ECM-mimicking biomaterials. Additionally, we discuss the intrinsic linkages between matrix remodeling and tissue regeneration. We believe that understanding host immune responses to matrix remodeling of transplanted biomaterials is important for directing effective tissue regeneration of ECM-mimicking biomaterials. Considering the close relationship between immune response and matrix remodeling results, we highlight the need for studies of the effects of clinical characteristics on matrix remodeling of transplanted biomaterials.


Assuntos
Materiais Biocompatíveis , Engenharia Tecidual , Anti-Inflamatórios/metabolismo , Materiais Biocompatíveis/metabolismo , Materiais Biocompatíveis/farmacologia , Matriz Extracelular/metabolismo , Humanos , Inflamação/metabolismo , Medicina Regenerativa , Engenharia Tecidual/métodos , Alicerces Teciduais/química
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