Cross-linked Matrix Research Articles

Extraction, physicochemical characterization, functionality, and excipient ability of corn fiber gum-starch isolate from corn milling industry waste

Corn processing industries generate an extensive fibrous byproduct consisting of corn fiber gum (CFG) and residual starch (S). The present study hypothesized that CFG and S could be isolated as a single crosslinked conjugate. The isolated CFG-S conjugate was acidic, with a pKa value of 11.49, and a swelling index of 99.60%. Henderson–Hasselbalch equation predicted negligible ionization throughout the gastrointestinal pH range. The DSC thermogram highlights glass transition and temperature-specific structure stabilization through the exothermic crystallization domain. FTIR, SEM & XRD confirmed the structural conjugation and integrity of the conjugate. Tablets containing Venlafaxine hydrochloride as a model drug were prepared using CFG-S (14 and 57%) as excipient by wet granulation method. Percentage cumulative drug release with low concentration was up to 99.67175 ± 0.09 % in 5 h whereas with high concentration, it was extended to 12 h (P < 0.05). Korsemayer-Peppas release exponent indicates zero order (R2 = 0.9935) kinetics with super case-II anomalous transport showing diffusion and erosion as drug release mechanisms. The results confirmed that CFG-S isolate could act as a good binding agent at low concentrations and release extending cross-linked matrix former at a higher concentration for release retardant excipient.

Triptolide attenuates pulmonary fibrosis by inhibiting fibrotic extracellular matrix remodeling mediated by MMPs/LOX/integrin

BackgroundFibrotic extracellular matrix (ECM) remodeling characterized different types of pulmonary fibrosis, and its regulation could be a potential shared treatment strategy for pulmonary fibrosis. PurposeWe aimed to investigate the effect of triptolide on pulmonary fibrosis through the inhibition of several important aspects of fibrotic ECM remodeling. MethodsBleomycin-induced pulmonary fibrosis mice and TGF-β1-induced primary lung fibroblasts were used. The effect of triptolide on pulmonary fibrosis was detected using histopathology, immunostaining, RT-qPCR, western blotting, ELISA, and protein activity assay. ResultsTriptolide significantly alleviated bleomycin-induced pulmonary fibrosis in mice. It inhibited the expression of fibrotic genes α-SMA, collagen I, fibronectin, and vimentin and blocked the TGF-β-SMAD signaling pathway both in vivo and in vitro. In addition, triptolide regulated the expression and activity of MMPs during fibrosis. Interestingly, it suppressed the expression of lysyl oxidase, which was responsible for matrix cross-linking and elevated ECM stiffness. Furthermore, triptolide blocked the biomechanical stress transduction pathway integrin-β1-FAK-YAP signaling and attenuated the pro-fibrotic feedback of fibrotic ECM on fibroblasts via integrin inhibition. ConclusionThese findings show that triptolide prevents the key linkages of fibrotic ECM remodeling, including deposition, degradation, cross-linking, and pro-fibrotic feedback and, therefore, has potential therapeutic value for pulmonary fibrosis.

Extracellular Matrix Remodeling in Vascular Disease: Defining Its Regulators and Pathological Influence.

Because of structural and cellular differences (ie, degrees of matrix abundance and cross-linking, mural cell density, and adventitia), large and medium-sized vessels, in comparison to capillaries, react in a unique manner to stimuli that induce vascular disease. A stereotypical vascular injury response is ECM (extracellular matrix) remodeling that occurs particularly in larger vessels in response to injurious stimuli, such as elevated angiotensin II, hyperlipidemia, hyperglycemia, genetic deficiencies, inflammatory cell infiltration, or exposure to proinflammatory mediators. Even with substantial and prolonged vascular damage, large- and medium-sized arteries, persist, but become modified by (1) changes in vascular wall cellularity; (2) modifications in the differentiation status of endothelial cells, vascular smooth muscle cells, or adventitial stem cells (each can become activated); (3) infiltration of the vascular wall by various leukocyte types; (4) increased exposure to critical growth factors and proinflammatory mediators; and (5) marked changes in the vascular ECM, that remodels from a homeostatic, prodifferentiation ECM environment to matrices that instead promote tissue reparative responses. This latter ECM presents previously hidden matricryptic sites that bind integrins to signal vascular cells and infiltrating leukocytes (in coordination with other mediators) to proliferate, invade, secrete ECM-degrading proteinases, and deposit injury-induced matrices (predisposing to vessel wall fibrosis). In contrast, in response to similar stimuli, capillaries can undergo regression responses (rarefaction). In summary, we have described the molecular events controlling ECM remodeling in major vascular diseases as well as the differential responses of arteries versus capillaries to key mediators inducing vascular injury.

Engineering Polymer-Assisted Self-Assembly Process for High-Capacity and Cycle-Stable Si-on-Graphite Anode of Li-Ion Batteries

A facile and ready for scale-up process based on polymer-assisted solution self-assembly is developed for manufacturing high-capacity and cycle-stable silicon-on-graphite (Si@G) lithium-ion battery anode materials. The process involves first coating a polyelectrolyte poly(diallyldimethylammonium chloride, anchored by a cross-linked polyvinyl alcohol-glutaraldehyde matrix, onto micron-sized graphite particles using spray-drying. Process optimization succeeds in imparting the graphite particles with a permanent high positive zeta potential (>40 mV), which enables attracting Si nanoparticles (NPs) (zeta potential= -28.5 mV) uniformly and firmly onto the graphite surfaces in water. Collected by filtration, the resulting Si@G composite particles are finally subjected to a high-temperature (1000 oC) treatment in Ar to turn the polymer coating into a carbon layer, which engulfs the Si NPs. A Si@G composite powder containing nearly 7 wt.% Si and produced in a batch size of approximately 20 gram is demonstrated to have a high specific capacity of 605 mAh g-1, a remarkable cycle stability showing only 11% capacity loss after 300 cycles and notably high coulombic efficiencies comparable to those of a graphite electrode upon cycling. The designed polymer coating realizes charge-carrying graphite particle without damaging its surface structure and eventually leads to a surface carbon layer that prevents Si NP detachment, improves powder conductivity, and mitigates solid-electrolyte-interphase formation.

Highly stable fluorine-free slippery liquid infused surfaces

A promising Slippery Liquid Infused Surface (SLIS) has been developed, that is both easy-to-produce and environmentally friendly. Using a double replication method, a 200 µm-thick texturized cross-linked PDMS film was obtained, leading to a grid of micrometric hills and deep wells. A comparison between perfluoropolyether (PFPE) lubricant and silicone oil of different viscosities highlights the advantage of silicone oil, which penetrates the cross-linked PDMS matrix even at high viscosity. Chemical modification with OTS (octadecyltrichlorosilane) and introduction of secondary structures through plasma etching, increased the surface's shear resistance. As a result, stable sliding properties were maintained after hundreds of cycles of immersion in water and, more originally still after tests under wind blowing exposure up to 78 m/s. Furthermore, addition of water sprayed during wind blowing exposure allows partial fouling release of the surface.

Gelatine based gel polymer electrolyte towards more sustainable Lithium-Oxygen batteries

The lithium-oxygen battery has attracted wide interest thanks to its very high theoretical energy density, and as such it is considered by many as a valid battery of the future candidate. However, the challenges in its practical application are many, such as liquid electrolyte evaporation in semi-open systems, as well as solvents instability in a highly oxidizing environment. In this work, we propose to use gelatin, from cold water fish skin, a waste from the fishing industry, to prepare an efficient gel electrolyte for future Li-O2 battery applications. After a single step methacrylation in water, methacrylated gelatine is directly cross-linked in presence of liquid electrolyte through UV- initiated radical polymerization. The obtained gel polymer electrolytes present good thermal and mechanical properties, good electrochemical stability against Li metal and ionic conductivities as high as 2.51 mS cm−1 at room temperature. the Li-O2 cells assembled with this bio-renewable gel polymer electrolytes were able to perform more than 100 cycles at 0.1 mA cm−2, under constant O2 flow, at room temperature and at a fixed capacity of 0.2 mAh cm−2. Cathodes post- mortem analysis confirmed that the cross-linked gelatin matrix was able to slow down solvent degradation and therefore enhance the cell reversibility.

Construction of proton transport channels in cross-linked composite membrane with highly sulfonated SPEEK nanofibers

A series of novel nanofiber composite proton exchange membranes were fabricated by embedding highly sulfonated poly (ether ketone) (SPEEK) nanofibers in a cross-linked SPEEK matrix, showing both high proton conductivity and excellent stability. Composite membranes were prepared with salt-form SPEEK nanofiber mats filled with acid-form SPEEK solution. After thermal treatment at 180 °C in the presence of dimethyl sulfoxide, the cross-linking reaction occurred in the acid-form SPEEK matrix but not in nanofibers. The dimensional stability, mechanical strength, and oxidative stability of the composite membrane were significantly improved due to thermal cross-linking treatment. The swelling ratio of all the cross-linked membranes was below 30% in hot water, and the maximum tensile strength reached 68 MPa. The nanofibers formed non-cross-linked regions and retained rich sulfonic acid groups to construct fast, long-range proton transport channels. The proton conductivity of the nanofiber composite cross-linked membrane reached 200 mS/cm exceeding the pristine cross-linked membrane (135 mS/cm). The fuel cell performance showed a peak power density of 485 mW/cm2 at 80 °C under 100% relative humidity.

Characteristics of halal gelatin from red snapper (Lutjanus malabaricus) bone and its potency as beta-carotene coating material

Gelatin is a material produced from the partial hydrolysis of collagen sourced from the skin and bones of farm animals such as cows and pigs. Gelatin has been used for coatings because it has high permeability and dissolves in warm conditions, so the matrix cross-links are strong. The red snapper fillet processing industry produces 11.2-15% of waste, such as bone which has not been utilized optimally. The objective of this study was to determine the characterization of red snapper bone gelatin as a source of halal gelatin and measure its ability as a coating material for β-carotene pigment microencapsulation. Results showed the characteristics of red snapper bone gelatin with a yield of 10.71%, water content of 9.63%, protein content of 34.06%, ash content of 7.62%, gelatin fat content of 0.28%, and color intensity (L: 62.6). ; a+: 13.3 and b+: 30). The obtained halal gelatin was applied as a coating material for β-carotene pigment microencapsulation through the foam-mat method. It resulted in encapsulation with a yield of 16.75%, water content 9.25%, total carotenoid content 145.49 mg/g, surface carotenoid content 2.04%, solubility 78%, encapsulation efficiency 98.22%, color intensity (L: 50; a+: 29.9 and b+: 14.6), the particle size of 1004.04 μm and irregular shape.

Characterization of extracellular matrix deposited by segmental trabecular meshwork cells

PurposeBiophysical and biochemical attributes of the extracellular matrix are major determinants of cell fate in homeostasis and disease. Ocular hypertension and glaucoma are diseases where the trabecular meshwork tissue responsible for aqueous humor egress becomes stiffer accompanied by changes in its matrisome in a segmental manner with regions of high or low flow. Prior studies demonstrate these alterations in the matrix are dynamic in response to age and pressure changes. The underlying reason for segmentation or differential response to pressure and stiffening are unknown. This is largely due to a lack of appropriate models (in vitro or ex vivo) to study this phenomena. MethodsPrimary trabecular meshwork cells were isolated from segmental flow regions, and cells were cultured for 4 weeks in the presence or absence or dexamethasone to obtain cell derived matrices (CDM). The biomechanical attributes of the CDM, composition of the matrisome, and incidence of crosslinks were determined by atomic force microscopy and mass spectrometry. ResultsData demonstrate that matrix deposited by cells from low flow regions are stiffer and exhibit a greater number of immature and mature crosslinks, and that these are exacerbated in the presence of steroid. We also show a differential response of high or low flow cells to steroid via changes observed in the matrix composition. However, no correlations were observed between elastic moduli and presence or absence of mature and immature crosslinks in the CDMs. ConclusionRegardless of a direct correlation between matrix stiffness and crosslinks, we observed distinct differences in the composition and mechanics of the matrices deposited by segmental flow cells. These results suggest distinct differences in cellular identify and likely a basis for mechanical memory post isolation and culture. Nevertheless, we conclude that although a mechanistic basis for matrix stiffness was undetermined in this study, it is a viable tool to study cell-matrix interactions and further our understanding of trabecular meshwork pathobiology.

Tendon-derived matrix crosslinking techniques for electrospun multi-layered scaffolds.

Tendon tears are common and healing often occurs incompletely and by fibrosis. Tissue engineering seeks to improve repair, and one approach under investigation uses cell-seeded scaffolds containing biomimetic factors. Retention of biomimetic factors on the scaffolds is likely critical to maximize their benefit, while minimizing the risk of adverse effects, and without losing the beneficial effects of the biomimetic factors. The aim of the current study was to evaluate cross-linking methods to enhance the retention of tendon-derived matrix (TDM) on electrospun poly(ε-caprolactone) (PCL) scaffolds. We tested the effects of ultraviolet (UV) or carbodiimide (EDC:NHS:COOH) crosslinking methods to better retain TDM to the scaffolds and stimulate tendon-like matrix synthesis. Initially, we tested various crosslinking configurations of carbodiimide (2.5:1:1, 5:2:1, and 10:4:1 EDC:NHS:COOH ratios) and UV (30 s 1 J/cm2 , 60 s 1 J/cm2 , and 60 s 4 J/cm2 ) on PCL films compared to un-crosslinked TDM. We found that no crosslinking tested retained more TDM than coating alone (Kruskal-Wallis: p > .05), but that human adipose stem cells (hASCs) spread most on the 60 s 1 J/cm2 UV- and 2.5:1:1 EDC-crosslinked films (Kruskal-Wallis: p < .05). Next, we compared the effects of 60 s 1 J/cm2 UV- and 2.5:1:1 EDC-crosslinked to TDM-coated and untreated PCL scaffolds on hASC-induced tendon-like differentiation. UV-crosslinked scaffolds had greater modulus and stiffness than PCL or TDM scaffolds, and hASCs spread more on UV-crosslinked scaffolds (ANOVA: p < .05). Fourier transform infrared spectra revealed that UV- or EDC-crosslinking TDM did not affect the peaks at wavenumbers characteristic of tendon. Crosslinking TDM to electrospun scaffolds improves tendon-like matrix synthesis, providing a viable strategy for improving retention of TDM on electrospun PCL scaffolds.

Competing Effects of Radio Frequency Fields on Carbon Nanotube/Resin Systems: Alignment versus Heating

AbstractThis work shows that radio‐frequency (RF) fields can simultaneously align carbon nanotubes (CNTs) dispersed in a resin and induce Joule heating to cure the resin. The timescales of alignment and curing using RF heating are numerically computed and compared at different field strengths in order to determine a temperature where alignment happens before the matrix crosslinks. Composites are experimentally fabricated at the desired target temperature and are optically analyzed and quantified; the CNT network is successfully aligned in the direction of the applied electric field. This methodology can be used to create composites where the local alignment can be varied across the sample. Composites fabricated using RF fields have higher electrical conductivity in the direction of the aligned CNTs than an oven‐cured, randomly aligned sample. Also, RF‐cured nanocomposites exhibit higher tensile strength and modulus in the direction of alignment compared to an oven‐cured sample. Finally, it is further demonstrated how this methodology can be coupled with a direct ink writing additive manufacturing process to induce alignment in any desired direction, even orthogonal to the shear forces in the extrusion direction.

Echo intensity and gray-level co-occurrence matrix analysis of soft tissue grafting biomaterials and dental implants: an in vitro ultrasonographic pilot study.

To characterize different allogeneic and xenogeneic soft tissue graft substitutes and to assess their echo intensity and grayscale texture-related outcomes by using high-frequency ultrasonography (HFUS). Ten samples from each of the following biomaterials were scanned using HFUS: bilayered collagen matrix (CM), cross-linked collagen matrix (CCM), multilayered cross-linked collagen matrix (MCCM), human-derived acellular dermal matrix (HADM), porcine-derived acellular dermal matrix (PADM), collagen tape dressing (C) and dental implants (IMPs). The obtained images were then imported in a commercially available software for grayscale analysis. First-order grayscale outcomes included mean echo intensity (EI), standard deviation, skewness, and kurtosis, while second-order grayscale outcomes comprised entropy, contrast, correlation, energy and homogeneity derive from the gray-level co-occurrence matrix analysis. Descriptive statistics were performed for visualization of results, and one-way analysis of variance with Bonferroni post-hoc tests were performed to relative assessments of the biomaterials. The statistical analysis revealed a statistically significant difference among the groups for EI (p < .001), with the group C showing the lowest EI, and the IMP group presenting with the greatest EI values. All groups showed significantly higher EI when compared with C (p < .001). No significant differences were observed for energy, and correlation, while a statistically significant difference among the groups was found in terms of entropy (p < 0.01), contrast (p < .001) and homogeneity (p < .001). IMP exhibited the highest contrast, that was significantly higher than C, HADM, PADM, CCM and CM. HFUS grayscale analysis can be applied to characterize the structure of different biomaterials and holds potential for translation to in-vivo assessment following soft tissue grafting-related procedures.

Orbitalization of Ethmoidal Sinus With Stacked Cross-linked Acellular Dermal Matrix: A New Strategy to Reconstruct Medial Orbital Wall Fracture.

The use of an acellular dermal matrix (ADM) has not been reported in medial orbital wall fracture reconstruction previously. This study aimed to share our early experience with the cross-linked ADM as an allograft material for medial orbital wall reconstruction. In this study, the author evaluated the medical records and serial facial computed tomography scans of 27 patients with pure medial orbital wall fractures reconstructed by a single surgeon between May 2021 and March 2023. The author routinely approached the medial orbital wall with a retrocaruncular incision. Five out of 27 patients were reconstructed with trimmed, multiple folded, 1.0-mm-thick cross-linked ADM (MegaDerm; L&C Bio, South Korea). All cases reconstructed with cross-linked ADM improved clinically and radiologically without complications. The serial computed tomography findings revealed that implanted cross-linked ADM successfully covered the defect while providing a significant volumizing effect. This is the first study to show the efficacy of cross-linked ADM for orbital medial wall fracture reconstruction. Our strategy of orbitalization of ethmoidal sinus with stacked cross-linked ADM would be an excellent surgical option.

Prevention and Resolution of Silicone Implant-Related Problems in Secondary Rhinoplasty Using a Cross-Linked Human Acellular Dermal Matrix.

Silicone implant augmentation rhinoplasty along with various tip plasties are commonly performed in Asian patients, but a revision rhinoplasty is frequently required because of various problems. Secondary rhinoplasties are often performed using silicone, dermofat, costal cartilage block, or diced rib cartilage, but often result in unsatisfactory outcomes. This study assessed the surgical outcomes and complications of cross-linked acellular dermal matrix (ADM) as an alternative biological substitute for silicone implant in secondary rhinoplasty. The authors prospectively studied 56 patients with a minimum follow-up of 1 year among 104 patients who underwent secondary rhinoplasty in their clinic between January of 2015 and December of 2018. Silicone implant, capsule, and scar tissue removal; dorsal augmentation with ADM; and tip plasty using autogenous cartilage were performed for all of them. The results were assessed using the modified Rhinoplasty Outcome Evaluation, consisting of a 10-item questionnaire completed preoperatively, 6 months postoperatively, and over 1 year postoperatively. One infection and three cases of excessive resorption were noted, with no other major complications. The mean modified Rhinoplasty Outcome Evaluation score was 31.7 on preoperative evaluation, 77.3 at 6 months postoperatively, and 81.4 at 1 year postoperatively (mean difference, 45.6 and 49.7, respectively; P < 0.001). Various problems that occur after primary rhinoplasty using silicone implants can be resolved successfully with secondary rhinoplasty by dorsal augmentation using the cross-linked human ADM along with various nasal tip work using autogenous cartilage. Surgical outcome showed favorable resolution of contracture deformities, a low infection rate, firm fixation of the implant, good skin texture/thickness of the skin/soft-tissue envelope, and gain of desired height and dorsal line. Therapeutic, IV.

Effect of wetting and drying cycles on mechanical strength of cement-natural rubber latex stabilized recycled concrete aggregate

In this study, natural rubber latex (NRL) was used as a polymer additive to modify the durability against wetting and drying (w-d) cycles of the cement-stabilized recycled concrete aggregate (RCA) when used as a pavement base/subbase material. This research investigated the performance of cement-stabilized RCA and cement-NRL stabilized RCA at various dry rubber-to-cement (r/c) ratios against w-d cycles. The weight loss, unconfined compressive strength (UCS), rate of deterioration, modulus of elasticity, and microstructural analysis of the studied samples before and after being subjected to w-d cycles were performed. The r/c ratio of 10% was found to be the optimum r/c ratio for cement-NRL stabilized RCA, which provided the best performance for all test results. The weight loss was found to increase, while the UCS value subsequently decreased with an increase of w-d cycles for all studied samples. At the optimum r/c ratio, the UCS results of cement-NRL stabilized after 12 w-d cycles were still higher than the minimum requirement (UCS > 2.413 MPa) for a high-volume traffic road. In addition, its modulus of elasticity was higher than that of cement-stabilized RCA samples. This indicated that the NRL additive could enhance the ductility of cement-stabilized RCA. The microstructural analysis illustrated that the formation of a stable cross-linked matrix between the cement hydration products and NRL films could improve the durability against the w-d cycles of cement-stabilized RCA as a pavement base material.

Perovskite‐Organic Coupling WLED: Progress and Perspective

AbstractPerovskite shows great potential in lighting and display owing to its advantages of low cost, high efficiency, and whole visible light tunability. However, how to realize high‐efficiency white perovskite light‐emitting diodes (WPeLEDs) still faces challenges such as the stability of devices and the energy regulation between different emission centers. In recent years, some organic molecules are introduced into the perovskite system because of their role in stabilizing perovskite crystals and enhancing photoelectric properties. In this review, the strategy of perovskite‐organic combination and coupling emission are emphasized, hoping to promote the development of high‐efficiency WPeLEDs. First, the research status of perovskite‐organic coupling WLEDs (POC‐WLEDs) is summarized in detail. Then, the development direction and possibility of POC‐WLEDs are proposed by combining them with some recent reports on POC methods. Finally, an outlook on POC‐WLEDs is proposed. It is a considerable strategy to introduce organic luminescent molecules into perovskite systems as ligands or A‐site organic cations for coupling emission with perovskite. In addition, the technologies of the organic polymer matrix, interfacial exciplex, and organic crosslinking are noteworthy exploration directions. They will promote the development of POC‐WLEDs in improving the stability of perovskite electroluminescence and regulating the energy transfer efficiency between perovskite/organic‐molecule emitting centers.

Tableting-induced mechanochemical matrix crosslinking: Towards non-disintegrating chitosan-based sustained delivery tablets

BackgroundMechanochemistry involves the application of mechanical force to induce chemical changes in the material solid state. Mechanochemistry promises to overcome many drawbacks in pharmaceutical formulation. Chitosan (CS), a semisynthetic polymer obtained by N-deacetylation of chitin, has attracted attention in various biomedical and pharmaceutical applications. MethodsCS was grafted with 2,4-dichlorophenoxyacetic acid (2,4-D), a significantly hydrophobic and safe substituent, to promote facile adsorption of CO2. Physical mixtures and corresponding tablets comprised of model drugs and CS-2,4-D were prepared and characterized by DSC, XRD, and IR, and were compared with pure drugs and their mixtures with unmodified CS. Tensile strength and drug-release profiles of CS-2,4-D tablets were evaluated and compared with counterparts prepared from unmodified CS. ResultsAdsorbed CO2 promoted the formation of powerful and extensive carbamate crosslinks within CS-2,4-D upon mechanochemical stress induced by mixing the new polymer with model drugs followed by tableting. Corresponding tablets showed increased tensile strength, sustained drug release and resistance to disintegration over 72 h of exposure to dissolution media. MTT bioassay indicated CS-2,4-D to be less cytotoxic than unmodified CS. Conclusionsthe current study provided a proof-of-principle on tableting mediated mechanochemical matrix crosslinking.

Establishing in vivo and ex vivo chick embryo models to investigate fetal tendon healing

Injured adult tendons heal fibrotically and possess high re-injury rates, whereas fetal tendons appear to heal scarlessly. However, knowledge of fetal tendon wound healing is limited due in part to the need for an accessible animal model. Here, we developed and characterized an in vivo and ex vivo chick embryo tendon model to study fetal tendon healing. In both models, injury sites filled rapidly with cells and extracellular matrix during healing, with wound closure occurring faster in vivo. Tendons injured at an earlier embryonic stage improved mechanical properties to levels similar to non-injured controls, whereas tendons injured at a later embryonic stage did not. Expression levels of tendon phenotype markers, collagens, collagen crosslinking regulators, matrix metalloproteinases, and pro-inflammatory mediators exhibited embryonic stage-dependent trends during healing. Apoptosis occurred during healing, but ex vivo tendons exhibited higher levels of apoptosis than tendons in vivo. Future studies will use these in vivo and ex vivo chick embryo tendon injury models to elucidate mechanisms of stage-specific fetal tendon healing to inform the development of therapeutic approaches to regeneratively heal adult tendons.

CD11b Deficiency Favors Cartilage Calcification via Increased Matrix Vesicles, Apoptosis, and Lysyl Oxidase Activity.

Pathological cartilage calcification is a hallmark feature of osteoarthritis, a common degenerative joint disease, characterized by cartilage damage, progressively causing pain and loss of movement. The integrin subunit CD11b was shown to play a protective role against cartilage calcification in a mouse model of surgery-induced OA. Here, we investigated the possible mechanism by which CD11b deficiency could favor cartilage calcification by using naïve mice. First, we found by transmission electron microscopy (TEM) that CD11b KO cartilage from young mice presented early calcification spots compared with WT. CD11b KO cartilage from old mice showed progression of calcification areas. Mechanistically, we found more calcification-competent matrix vesicles and more apoptosis in both cartilage and chondrocytes isolated from CD11b-deficient mice. Additionally, the extracellular matrix from cartilage lacking the integrin was dysregulated with increased collagen fibrils with smaller diameters. Moreover, we revealed by TEM that CD11b KO cartilage had increased expression of lysyl oxidase (LOX), the enzyme that catalyzes matrix crosslinks. We confirmed this in murine primary CD11b KO chondrocytes, where Lox gene expression and crosslinking activity were increased. Overall, our results suggest that CD11b integrin regulates cartilage calcification through reduced MV release, apoptosis, LOX activity, and matrix crosslinking. As such, CD11b activation might be a key pathway for maintaining cartilage integrity.

Scalable silicon@sulfur-doped carbon composites via a low-cost facile method for high-performance lithium-ion battery anodes

The development of facile and low-cost fabrication methods for silicon/carbon (Si/C) composites with stable cycle performance is urgent requirement for the development of high-energy-density lithium-ion batteries. Exploring carbon materials with good mechanical properties and electrochemical stability for the fabrication of Si/C materials can overcome the extreme volume changes and unstable electrochemical stability of Si anodes. Herein, [email protected] carbon ([email protected]) composites were successfully synthesized by simple solvent evaporation and carbonization of inexpensive and readily available petroleum pitch (PP) and amorphous sulfur. Various sulfur-containing functional groups enhanced the material strength of composite by increasing the chemical crosslinking of the carbon matrix to adapt to the Si volume changes. In addition, the larger carbon layer spacing and defects derived from sulfur doping can promote Li+ diffusion and electrode reaction. As a result, the optimized [email protected] exhibited stable interfacial electrode stability and moderate cycle performance, delivering a specific capacity of 681.6 mAh·g−1 and 79.1% capacity retention at 0.5 A g−1 after 700 cycles. This synthesis strategy for [email protected] composites is meaningful for scalable and low-cost fabrication as well as for understanding the effect of sulfur-doped carbon in Si/C anodes.