Vascular Endothelial Growth Factor Release Research Articles

Metastasis and angiogenesis in cervical cancer: key aspects of purinergic signaling in platelets and possible therapeutic targets.

Cervical cancer ranks as the fourth most common and fatal cancer among women worldwide. Studies have demonstrated a strong association between purinergic platelet signaling and tumor progression in this type of cancer. The literature shows that neoplastic cells, when in the bloodstream, secrete adenosine triphosphate (ATP) and adenosine nucleotide diphosphate (ADP) that act on their corresponding platelet P2Y and P2X receptors. The interaction of these nucleotides with their receptors results in platelet activation and degranulation, ensuing several consequences, such as vascular endothelial growth factor (VEGF), platelet-derived growth factor, matrix metalloproteinases, ADP, and ATP. These molecules play essential roles in angiogenesis and tumor metastasis in cervical cancer. Several purinergic receptors are found in endothelial cells. Their activation, especially P2Y2, by the nucleotides released by platelets can induce relaxation of the endothelial barrier and consequent extravasation of tumor cells, promoting the development of metastases. Cancer cells that enter the bloodstream during the metastatic process are also subject to high shear stress and immune surveillance. In this context, activated platelets bind to circulating tumor cells and protect them against shear stress and the host's immune system, especially against natural killer cells, facilitating their spread throughout the body. Furthermore, activation of the P2Y12 receptor present on the platelet surface promotes the release of VEGF, the main inducer of angiogenesis in cervical cancer, in addition to increasing the concentration of several other pro-angiogenic molecules. Therefore, this review will address the role of platelet purinergic signaling in tumor progression of cervical cancer and propose possible therapeutic targets.

Computational Insights into the Interplay of Mechanical Forces in Angiogenesis.

This study employs a meshless computational model to investigate the impacts of compression and traction on angiogenesis, exploring their effects on vascular endothelial growth factor (VEGF) diffusion and subsequent capillary network formation. Three distinct initial domain geometries were defined to simulate variations in endothelial cell sprouting and VEGF release. Compression and traction were applied, and the ensuing effects on VEGF diffusion coefficients were analysed. Compression promoted angiogenesis, increasing capillary network density. The reduction in the VEGF diffusion coefficient under compression altered VEGF concentration, impacting endothelial cell migration patterns. The findings were consistent across diverse simulation scenarios, demonstrating the robust influence of compression on angiogenesis. This computational study enhances our understanding of the intricate interplay between mechanical forces and angiogenesis. Compression emerges as an effective mediator of angiogenesis, influencing VEGF diffusion and vascular pattern. These insights may contribute to innovative therapeutic strategies for angiogenesis-related disorders, fostering tissue regeneration and addressing diseases where angiogenesis is crucial.

Theoretical modeling of tumor angiogenesis: the opposing effects of vascular endothelial growth factor and angiopoietin-2

Tumor microvascular networks are highly unstable, disorganized structures that obstruct cancer therapeutics by poorly distributing blood flow and oxygen. The elevated release of vascular endothelial growth factor (VEGF) by solid tumors has been widely implicated in pathological angiogenesis, or the growth of new blood vessels. However, how VEGF overexpression leads to the malformation of vascular networks is incompletely understood. Angiopoietin-2 (Ang2) is a destabilization factor that has been shown to promote sprouting in the presence of VEGF with hypoxia, but regression in its absence. Here, we hypothesize that the tumor environment, which sustains VEGF production under conditions of normoxia, also promotes Ang2-induced regression. A theoretical model is developed representing the 3-dimensional growth, remodeling, and pruning of microvascular networks in early-stage tumors to investigate the combined effects of VEGF and Ang2. Oxygen transport by the growing vascular network is simulated. VEGF production is induced by hypoxia and also elevated independent of oxygen levels in the expanding tumor region. Angiogenesis is stimulated in response to elevated VEGF levels. The model predicts that the release of VEGF in normoxic regions without counteracting factors results in very high tumor vascular densities compared to normal tissue, which is not observed experimentally. Introducing the regressive effects of Ang2 limits vascular density and produces greater variability in oxygen levels in the tumor region. Vascular networks in the tumor generated from the model show comparable densities to surrounding tissue, in which an elevated rate of sprouting is balanced by Ang2-induced regression. In this state, continuous turnover of vessels is predicted, while a relatively constant vascular density is maintained. These simulations suggest that the destabilizing role of Ang2 is an important factor that should be included in theoretical models for tumor angiogenesis. While Ang2 activity is already targeted in a number of clinical trials, clarifying the dynamic role of Ang2 may help advance angiogenesis-based therapeutic approaches. Supported by NIH grant HL034555. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Electrospun silk fibroin/polylactic acid conduit filled with proangiogenic carboxylated silk fibroin/chitosan hydrogel facilitates peripheral nerve regeneration

Angiogenesis plays a crucial role in peripheral nerve regeneration after injury. We introduce a proangiogenic hydrogel-filled nerve conduit, designed to promote peripheral nerve regeneration. The hydrogel was synthesized by chemically crosslinking carboxylated silk fibroin (cSF) and chitosan (CS), enriched with vascular endothelial growth factor (VEGF) to initiate angiogenesis. Complementarily, a nerve conduit was fabricated using coaxial electrospinning of poly-lactic acid (PLA), silk fibroin (SF), and ibuprofen (IBU) was incorporated to further support nerve regeneration. The hydrogel exhibited optimal properties including rapid gelation, uniform porosity and full biodegradation within four weeks. The nerve conduit, on the other hand, displayed enhanced mechanical strength, elasticity, and controlled biodegradability. In vitro assays demonstrated a sustained release of VEGF and IBU, which significantly enhanced cell adhesion, proliferation, migration and angiogenesis in Human umbilical vein endothelial cells (HUVEC), as well as promoted adhesion and proliferation in rat Schwann cells (RSC96). This proangiogenic hydrogel-filled nerve conduit thus emerged as a potent candidate for advancing peripheral nerve regeneration.

BDNF- and VEGF-Responsive Stimulus to an NGF Mimic Cyclic Peptide with Copper Ionophore Capability and Ctr1/CCS-Driven Signaling.

Neurotrophins are a family of growth factors that play a key role in the development and regulation of the functioning of the central nervous system. Their use as drugs is made difficult by their poor stability, cellular permeability, and side effects. Continuing our effort to use peptides that mimic the neurotrophic growth factor (NGF), the family model protein, and specifically the N-terminus of the protein, here we report on the spectroscopic characterization and resistance to hydrolysis of the 14-membered cyclic peptide reproducing the N-terminus sequence (SSSHPIFHRGEFSV (c-NGF(1-14)). Far-UV CD spectra and a computational study show that this peptide has a rigid conformation and left-handed chirality typical of polyproline II that favors its interaction with the D5 domain of the NGF receptor TrkA. c-NGF(1-14) is able to bind Cu2+ with good affinity; the resulting complexes have been characterized by potentiometric and spectroscopic measurements. Experiments on PC12 cells show that c-NGF(1-14) acts as an ionophore, influencing the degree and the localization of both the membrane transporter (Ctr1) and the copper intracellular transporter (CCS). c-NGF(1-14) induces PC12 differentiation, mimics the protein in TrkA phosphorylation, and activates the kinase cascade, inducing Erk1/2 phosphorylation. c-NGF(1-14) biological activities are enhanced when the peptide interacts with Cu2+ even with the submicromolar quantities present in the culture media as demonstrated by ICP-OES measurements. Finally, c-NGF(1-14) and Cu2+ concur to activate the cAMP response element-binding protein CREB that, in turn, induces the brain-derived neurotrophic factor (BDNF) and the vascular endothelial growth factor (VEGF) release.

Mechanically reinforced hydrogel vehicle delivering angiogenic factor for beta cell therapy

Type 1 diabetes mellitus (T1DM) is a chronic disease affecting millions worldwide. Insulin therapy is currently the golden standard for treating T1DM; however, it does not restore the normal glycaemic balance entirely, which increases the risk of secondary complications. Beta-cell therapy may be a possible way of curing T1DM and has already shown promising results in the clinic. However, low retention rates, poor cell survival, and limited therapeutic potential are ongoing challenges, thus increasing the need for better cell encapsulation devices. This study aimed to develop a mechanically reinforced vascular endothelial growth factor (VEGF)-delivering encapsulation device suitable for beta cell encapsulation and transplantation. Poly(l-lactide-co-ε-caprolactone) (PLCL)/gelatin methacryloyl (GelMA)/alginate coaxial nanofibres were produced using electrospinning and embedded in an alginate hydrogel. The encapsulation device was physically and biologically characterised and was found to be suitable for INS-1E beta cell encapsulation, vascularization, and transplantation in terms of its biocompatibility, porosity, swelling ratio and mechanical properties. Lastly, VEGF was incorporated into the hydrogel and the release kinetics and functional studies revealed a sustained release of bioactive VEGF for at least 14 days, making the modified alginate system a promising candidate for improving the beta cell survival after transplantation.

Morphological peculiarities of regeneration phases and dynamics of growth factor levels at using 2-ethyl-6-methyl-3-hydroxypyridinium n-acetyl-6-aminohexanoate for rat skin burns repairation

BACKGROUND: It was found that new derivatives of acexamic acid — N-acetyl-6-aminohexanoate of silver and 2-ethyl-6-methyl-3-hydroxypyridinium N-acetyl-6-aminohexanoate stimulate regeneration and mineralization of bone tissues in osteoporosis. However, to date, the effect of 2-ethyl-6-methyl-3-hydroxypyridinium N-acetyl-6-aminohexanoate on the features of reparative histogenesis and the relationship of its stages with the levels of growth factors in regenerating tissues during skin restoration after thermal burn has not been studied.
 AIM: To estimate the morphology dynamics of skin burn healing and its relationship with the levels of vascular endothelial growth factor and basic fibroblast growth factor growth factors in rat regenerating tissues to characterize the reparative properties of 2-ethyl-6-methyl-3-hydroxypyridinium N-acetyl-6-aminohexanoate.
 MATERIALS AND METHODS: 63 nonlinear rats were used to establish thermal burn wound model according to standard methodics. Burn wounds of the experimental group animals were treated with 2% ointment of 2-ethyl-6-methyl-3-hydroxypyridinium N-acetyl-6-aminohexanoate daily, control group 1 — the burns were not treated, control group 2 — ointment base was applied daily. Morphological examinations of regenerating tissues from the burn area were carried out on days 7, 14 and 21 of the experiment after standard sample preparation. The concentrations of growth factors in homogenates of regenerating tissues were determined by Enzyme Immunoassay.
 RESULTS: The inflammation phase is characterized by vascular endothelial growth factor active production and release from cells and morphologically accompanied by early neovasculogenesis in granulation tissue and significant differences in its thickness in rats of the experimental group. During the proliferation phase, activation of fibroblast reproduction and differentiation was associated with an increase in basic fibroblast growth factor levels and the maintenance of elevated vascular endothelial growth factor levels in all groups, especially high in experimental group rats. The epithelialization phase was accompanied by a statistically significant decrease in the content of basic fibroblast growth factor and vascular endothelial growth factor in regenerating skin tissues by 1.9 and 1.8 times, respectively, in comparison with the control groups.
 CONCLUSIONS: The obtained experimental data indicate 2% ointment with 2-ethyl-6-methyl-3-hydroxypyridinium N-acetyl-6-aminohexanoate has a reparative potential, as evidenced by the accelerated reduction both the area of burn defects and the average time for their healing in the experimental group compared to the control groups.

Anti-inflammatory potential of simvastatin and amfenac in ARPE-19 cells; insights in preventing re-detachment and proliferative vitreoretinopathy after rhegmatogenous retinal detachment surgery

PurposeRhegmatogenous retinal detachment is a severe vision-threatening complication that can result into proliferative vitreoretinopathy (PVR) and re-detachment of the retina if recovery from surgery fails. Inflammation and changes in retinal pigment epithelial (RPE) cells are important contributors to the disease. Here, we studied the effects of simvastatin and amfenac on ARPE-19 cells under inflammatory conditions.MethodsARPE-19 cells were pre-treated with simvastatin and/or amfenac for 24 h after which interleukin (IL)-1α or IL-1β was added for another 24 h. After treatments, lactate dehydrogenase release, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) processing, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activity, prostaglandin E2 (PGE2) level, and extracellular levels of IL-6, IL-8, monocytic chemoattractant protein (MCP-1), vascular endothelial growth factor (VEGF), and pigment epithelium-derived factor, as well as the production of reactive oxygen species (ROS) were determined.ResultsPre-treatment of human ARPE-19 cells with simvastatin reduced the production of IL-6, IL-8, and MCP-1 cytokines, PGE2 levels, as well as NF-κB activity upon inflammation, whereas amfenac reduced IL-8 and MCP-1 release but increased ROS production. Together, simvastatin and amfenac reduced the release of IL-6, IL-8, and MCP-1 cytokines as well as NF-κB activity but increased the VEGF release upon inflammation in ARPE-19 cells.ConclusionOur present study supports the anti-inflammatory capacity of simvastatin as pre-treatment against inflammation in human RPE cells, and the addition of amfenac complements the effect. The early modulation of local conditions in the retina can prevent inflammation induced PVR formation and subsequent retinal re-detachment.

The effect of VEGF stimulation in diabetic foot ulcers: A systematic review.

Diabetic foot ulcers are a common and severe complication of diabetes mellitus, and a risk factor for amputation. Because of the vessel insufficiency in diabetic foot ulcers (DFU), vascular endothelial growth factor (VEGF) that simulates angiogenesis is of interest to promote wound healing. This systematic review evaluates the last 16 years of in-vivo studies with VEGF stimulation as a treatment for DFU, developed based on the last published systematic article. A total of 961 articles were identified through databases in two phases. 947 articles were excluded by exclusion criteria, and four articles met our inclusion criteria and were included. The effects of VEGF on wound healing were analysed in all four studies. In three studies, the VEGF-treated wounds showed statistically faster healing than those not treated with VEGF. In one study, the VEGF-treated wounds revealed a positive trend toward faster healing. Furthermore, all four studies were in favor of using VEGF, but concluded that further research is needed. These studies showed a positive trend towards faster healing and was safe when using VEGF topically on humans. Furthermore, viral particles of VEGF seem to have a systematic effect when a dose exceeding 5.0 × 109 vp pr wound. Future research in using VEGF on DFU should focus on VEGF's relevant dosage, release rate, and specific mechanism. This review inspires further research, and a consistent study design is prerequisite such that results are more homogenic and comparable. Much effort is needed to translate the results into our clinical practice.

Mussel inspired sequential protein delivery based on self-healing injectable nanocomposite hydrogel

Polysaccharide based self-healing and injectable hydrogels with reversible characteristics have widespread potential in protein drug delivery. However, it is a challenge to design the dynamic hydrogel for sequential release of protein drugs. Herein, we developed a novel mussel inspired sequential protein delivery dynamic polysaccharide hydrogel. The nanocomposite hydrogel can be fabricated through doping polydopamine nanoparticles (PDA NPs) into reversible covalent bond (imine bonds) crosslinked polymer networks of oxidized hyaluronic acid (OHA) and carboxymethyl chitosan (CEC), named PDA NPs@OHA-l-CEC. Besides multiple capabilities (i.e., injection, self-healing, and biodegradability), the nanocomposite hydrogel can achieve sustained and sequential protein delivery of vascular endothelial growth factor (VEGF) and bovine serum albumin (BSA). PDA NPs doped in hydrogel matrix serve dual roles, acting as secondary protein release structures and form dynamic non-covalent interactions (i.e., hydrogen bonds) with polysaccharides. Moreover, by adjusting the oxidation degree of OHA, the hydrogels with different crosslinking density could control overall protein release rate. Analysis of different release kinetic models revealed that Fickian diffusion drove rapid VEGF release, while the slower BSA release followed a Super Case II transport mechanism. The novel biocompatible system achieved sequential release of protein drugs has potentials in multi-stage synergistic drug deliver based on dynamic hydrogel.

Injectable microcarrier‐hydrogel composite for dental stem cell delivery and tissue regeneration

AbstractConventional methods of stem cell therapy for tissue regeneration often face challenges, such as poor cell viability and integration posttransplantation. To address this, we proposed transplanting cells within synthetic microenvironments that maintain viability, cell phenotype, support extracellular matrix (ECM) secretion, and promote differentiation to enhance the regeneration of damaged host tissue. This hypothesis was tested in dental tissue regeneration using dental pulp stem cell‐laden microcarriers (MCs) mixed in a gelatin methacrylate (GelMA) hydrogel as a delivery system. The combination of MCs and GelMA exhibited similar physical properties and favorable biological properties compared to GelMA alone. Specifically, cell‐laden MC mixed into GelMA enhanced cell proliferation and ECM secretion and maintained a normal phenotype. Notably, MC‐modified GelMA amplified odontogenic differentiation, mineralization, and vascular endothelial growth factor release. Moreover, the storage of MC‐modified GelMA showed no detrimental effects on its injection force, cell viability, and mineralization potential, which demonstrates that the composite hydrogel is a promising injectable vehicle for therapeutic stem cell delivery. This strategy may be broadly applied to various tissues and organ systems, in which the provision and instruction of a cell population to participate in regeneration may be clinically useful.

Polydopamine-Functionalized Strontium Alginate/Hydroxyapatite Composite Microhydrogel Loaded with Vascular Endothelial Growth Factor Promotes Bone Formation and Angiogenesis.

Critical-size bone defects are a common and intractable clinical problem that typically requires filling in with surgical implants to facilitate bone regeneration. Considering the limitations of autologous bone and allogeneic bone in clinical applications, such as secondary damage or immunogenicity, injectable microhydrogels with osteogenic and angiogenic effects have received considerable attention. Herein, polydopamine (PDA)-functionalized strontium alginate/nanohydroxyapatite (Sr-Alg/nHA) composite microhydrogels loaded with vascular endothelial growth factor (VEGF) were prepared using microfluidic technology. This composite microhydrogel released strontium ions stably for at least 42 days to promote bone formation. The PDA coating can release VEGF in a controlled manner, effectively promote angiogenesis around bone defects, and provide nutritional support for new bone formation. In in vitro experiments, the composite microhydrogels had good biocompatibility. The PDA coating greatly improves cell adhesion on the composite microhydrogel and provides good controlled release of VEGF. Therefore, this composite microhydrogel effectively promotes osteogenic differentiation and vascularization. In in vivo experiments, composite microhydrogels were injected into critical-size bone defects in the skull of rats, and they were shown by microcomputed tomography and tissue sections to be effective in promoting bone regeneration. These findings demonstrated that this novel microhydrogel effectively promotes bone formation and angiogenesis at the site of bone defects.

Preparation of Chitosan Nanoparticles Loaded with Vascular Endothelial Growth Factor and Its Application in the Treatment of Skin Injury

This research was aimed to explore the application of chitosan (CS) nanoparticles (NPs) loaded with vascular endothelial growth factor (VEGF) in rat skin injury. Method: the VEGF-loaded CS NPs (VEGF/CS-NPs) were prepared, and a skin injury model on the back skin of rats was established. The VEGF/CS-NPs were applied to the injury model to observe the skin changes in the wound area of each group, compare the healing rate, the number of micro-vessels, and VEGF expression in each group of rats, so as to explore the intervention effect of VEGF/CS-NPs in skin injury. Results: the prepared VEGF/CS-NPs were spherical or quasi-spherical in morphology, uniformly dispersed, with smooth surfaces and relatively uniform size. The average particle size (PS) of the blank CS-NPs was 267.5 nm± 25.3 nm, while that of the drug-loaded CS-NPs was 298.6 nm ±44.7 nm, and the PS distribution was also very concentrated. The genipin cross-linked NPs could effectively prevent the degradation of the spherical wall and achieve the slow release of VEGF. After VEGF was applied to rats in the form of NPs, its healing rate and micro-vessel count were markedly superior to those of VEGF injection alone and blank group (P < 0.05), and VEGF expression in skin injury tissues was also greatly increased (P < 0.05). Conclusion: VEGF/CS-NPs could improve the bioavailability of VEGF and promote the healing of rat skin injuries.

Monitoring Cutaneous Leishmaniasis Lesions in Mice Undergoing Topical Miltefosine Treatment

A study was conducted on BALB/c mice infected with Leishmania (Leishmania) amazonensis to analyse the effects of 0.5% miltefosine (MTF) hydrogel treatment on cutaneous leishmaniasis (CL) lesions. The mice were treated for 25 days topically, and lesion sizes, parasite loads, histopathology, ultrastructure, cytokines including interleukin 4 (IL-4), tumour necrosis factor alfa (TNFα), interferon gamma (IFNγ), IL-10, and vascular endothelial growth factor (VEGF) profiles were evaluated on days 0, 12, 25, and 85. After 12 days of treatment, the lesion sizes and parasite numbers decreased. By day 60 post treatment, there were no lesions and only a few parasites. At day 25, there was a temporary papillomatosis reaction, an increase in mast cells, a few giant cells, and granulomas, and a decrease in diffuse inflammatory infiltrate and parasites. Transmission electron microscopy (TEM) examination showed early ultrastructural changes, including macrophages without parasites and vacuoles containing electrodense material. At the different evaluated times, the cytokine regulation indexes (ICRs) decreased for IL-4, TNFα, and VEGF. According to the study, the 0.5% MTF hydrogel was effective and showed positive results from the early stages of usage. The MTF directly targeted parasites, downregulated the release of IL-4, TNFα, and VEGF, increased mast cell production, and induced granuloma reaction during evaluation periods.

Inhibitory Effect of Heparin/Polyarginine/Hyaluronic Acid Complex on Coronary Artery Restenosis by Loading Vascular Endothelial Growth Factor

This research was aimed to investigate the inhibitory effect of heparin/polyarginine/hyaluronic acid (HPHA) complex loaded with vascular endothelial growth factor (VEGF) on coronary artery restenosis (CAR). Dopamine was grafted to obtain dopamine-hyaluronic acid (DPA) composite material, and heparin/polyarginine (HP) nanoparticles (NPs) loaded with VEGF were obtained through electrostatic binding (ESB). The HP NPs loaded with VEGF mixed with hyaluronic acid (HA) were mixed in a 10:1 volume ratio to obtain a composite solution, namely HPHA complex. Next, the sodium metaperiodate was added to form a hydrogel. The samples were characterized using a zeta potential (ZP) analyzer, transmission electron microscopy (TEM), Fourier transform infrared spectrometer (FTIR), and water contact angle (WCA). Enzyme-linked immunosorbent assay (ELISA) and toluidine blue O (TBO) staining were employed to assess the immobilization and release of VEGF and heparin. Rhodamine staining was adopted to evaluate the adhesion of platelets, fibrinogen, macrophages, and umbilical artery smooth muscle cells (UASMCs). Furthermore, CCK-8 assay was performed to evaluate the adhesion and proliferation of endothelial cells (ECs). The results revealed that compared to 0 mg/L, the particle size (PS), polydispersity index (PDI), and θ angle decreased, and the absolute value of ZP increased at 100, 200, 300, and 400 mg/L. The cumulative release (CR) of VEGF at 200 mg/L was higher to that at 0 mg/L, while that of heparin was lower (P <0.05). The platelet surface coverage rate (PSCR), relative platelet activation rate (RPAR), and fibrinogen coverage rate (FCR) at 10 and 20 days were lower and exhibited great difference to those at 0 mg/L (P <0.05). Compared to groups II and III, group I presented a markedly higher number of macrophages and UASMCs on the first and third days of culture (P <0.05). 3 days after culture, adhesion and proliferation of ECs in groups U, I, and K increased greatly (P <0.05). In conclusion, the HPHA complex prepared from HP NPs loaded with VEGF and HA in this research exhibited good stability, uniformity, hydrophilicity, and blood compatibility. It effectively blocked the adhesion of macrophages and UASMCs and promoted the proliferation of ECs, thus conforming to the mechanism of inhibiting CAR after coronary stent intervention.

Combined VEGF and bFGF loaded nanofiber membrane protects against neuronal injury and hypomyelination in a rat model of chronic cerebral hypoperfusion

Currently, there are no effective therapeutic targets for the treatment of chronic cerebral hypoperfusion(CCH)-induced cerebral ischemic injury. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are discovered as the inducers of neurogenesis and angiogenesis. We previously made a nanofiber membrane (NFM), maintaining a long-term release of VEGF and bFGF up to 35 days, which might make VEGF and bFGF NFM as the potential protective agents against cerebral ischemic insult. In this study, the effects of VEGF and bFGF delivered by NFM into brain were investigated as well as their underlying mechanismsin a rat model of CCH. VEGF + bFGF NFM application increased the expressions of tight junction proteins, maintained BBB integrity, and alleviated vasogenic cerebral edema. Furthermore, VEGF + bFGF NFM sticking enhanced angiogenesis and elevated CBF. Besides, VEGF + bFGF NFM treatment inhibited neuronal apoptosis and decreased neuronal loss. Moreover, roofing of VEGF + bFGF NFM attenuated microglial activation and blocked the launch of NLRP3/caspase-1/IL-1β pathway. In addition, VEGF + bFGF NFM administration prevented disruption to the pre/postsynaptic membranes and loss of myelin sheath, relieving synaptic injury and demyelination. Oligodendrogenesis, neurogenesis and PI3K/AKT/mTOR pathway were involved in the treatment of VEGF + bFGF NFM against CCH-induced neuronal injury and hypomyelination. These findings supported that VEGF + bFGF NFM application constitutes a neuroprotective strategy for the treatment of CCH, which may be worth further clinical translational research as a novel neuroprotective approach, benifiting indirect surgical revascularization.

Pearl Powder Hybrid Bioactive Scaffolds from Microfluidic 3D Printing for Bone Regeneration.

The development of bioactive scaffolds by mimicking bone tissue extracellular matrix is promising for bone regeneration. Herein, inspired by the bone tissue composition, a novel pearl powder (PP) hybrid fish gelatin methacrylate (GelMa) hydrogel scaffold loaded with vascular endothelial growth factor (VEGF) for bone regeneration is presented. With the help of microfluidic-assisted 3D printing technology, the composition and structure of the hybrid scaffold can be accurately controlled to meet clinical requirements. The combination of fish skin GelMa and PP also endowed the hybrid scaffold with good biocompatibility, cell adhesion, and osteogenic differentiation ability. Moreover, the controlled release of VEGF enables the scaffold to promote angiogenesis. Thus, the bone regeneration in the proposed scaffolds could be accelerated under the synergic effect of osteogenesis and angiogenesis, which has been proved in the rat skull defect model. These features indicate that the PP hybrid scaffolds will be an ideal candidate for bone regeneration in clinical applications.

Kaempferol attenuates carbon tetrachloride (CCl4)-induced hepatic fibrosis by promoting ASIC1a degradation and suppression of the ASIC1a-mediated ERS

BackgroundKaempferol is a flavonoid derived from the herb, Kaempferia galanga L., in addition to exhibiting a wide range of pharmacological properties, kaempferol is also an anti-inflammatory, anti-lipid metabolizing, and anti-oxidative stress agent. The underlying molecular mechanisms of its effects on vascular endothelial growth factor (VEGF) secretion and activation of hepatic stellate cells (HSCs) are yet unknown. Activated HSCs induces VEGF release and extracellular matrix (ECM) accumulation which are important factors in hepatic fibrosis. PurposeOur aim is to explore how kaempferol may affect hepatic fibrosis and the mechanisms behind its effects. MethodsThe in vivo model was Sprague-Dawley rats induced with carbon tetrachloride (CCl4). Histological staining was used to observe histological features of the liver. The levels of (alanine aminotransferase) ALT and (aspartate aminotransferase) AST were detected by the corresponding kits. Platelet-derived growth factor (PDGF) was used to stimulate the HSC-T6 rat hepatic stellate cells. The mechanisms underlying this process were investigated using a variety of molecular approaches, including immunofluorescence, RT-qPCR, and western blotting. Moreover, intracellular Ca2+ were observed by laser confocal microscope. ResultsIt was found that kaempferol significantly reduced the expression of ASIC1a, VEGF, α-SMA and Collagen-I proteins in a model of CCl4-induced hepatic fibrosis in rats. In HSC-T6, kaempferol inhibits activation of HSCs by decreasing expression of ASIC1a, eIF2α, p-eIF2α and ATF-4. Laser confocal fluorescence showed that kaempferol inhibited Ca2+ influx and reduced Ca2+ concentration around the endoplasmic reticulum. Molecular docking and cellular thermal shift assay (CETSA) results further indicated that kaempferol interacted with ASIC1a. We found that kaempferol may promote the degradation of ASIC1a and inhibited ASIC1a- mediated upregulation of ERS. ConclusionThe data from our in vivo experiments demonstrate that kaempferol effectively attenuates hepatic fibrosis. In vitro studies we further propose a novel mechanism of kaempferol against hepatic fibrosis which can interact with ASIC1a and promote ASIC1a degradation while inhibiting the activation and VEGF release of HSCs by suppressing the ASIC1a-eIF2α-ATF-4 signaling pathway.

Growth Factors Released from Advanced Platelet-Rich Fibrin in the Presence of Calcium-Based Silicate Materials and Their Impact on the Viability and Migration of Stem Cells of Apical Papilla.

Advanced platelet-rich fibrin (A-PRF) provides the scaffold and growth factors necessary for stem cells to proliferate and differentiate in successful regenerative endodontic procedures. This study investigates the release of transforming growth factor-β1 (TGF-β1), platelet-derived growth factor (PDGF), and vascular endothelial growth factor (VEGF) from A-PRF in cell culture media in the presence and absence of mineral trioxide aggregate (MTA) or Biodentine. Additionally, this research assesses the viability and migration of stem cells of the apical papilla (SCAP) in previously conditioned media. A-PRF obtained from 14 participants were incubated for 7 days in cell culture media alone or via layering with MTA or Biodentine discs and the release of selected growth factors in the media was evaluated using ELISA. The viability of SCAP grown in conditioned media was measured using the CCK8 assay, while SCAP migration was assessed via a transwell assay by counting migrated cells. The release of TGF-β1, PDGF, and VEGF was significantly higher in media with A-PRF alone than in the presence of either calcium-based silicate material (p < 0.05), which showed no difference from the no-A-PRF control (p < 0.05). None of the tested growth factors released in the A-PRF-conditioned media correlated with clot weight. A-PRF-conditioned media, both with and without calcium-based silicate materials, did not impact SCAP viability and migration (p > 0.05). This study shows that SCAP behavior is not impacted by the decrease in growth factor released in the presence of calcium-based silicate materials and that their role in REPs warrants further investigation.

Programmed release of vascular endothelial growth factor and exosome from injectable chitosan nanofibrous microsphere-based PLGA-PEG-PLGA hydrogel for enhanced bone regeneration

The healing of large bone defects remains a significant challenge in clinical practice. Accelerating both angiogenesis and osteogenesis can promote effective bone healing. In the natural healing process, angiogenesis precedes osteogenesis, providing a blood supply that supports the subsequent progression of osteogenesis. Developing a biomimetic scaffold that mimics the in vivo environment and promotes the proper sequence of vascularization followed by ossification is crucial for successful bone regeneration. In this study, a novel injectable dual-drug programmed releasing chitosan nanofibrous microsphere-based poly(D, l-lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(D,l-lactide-co-glycolide) (PLGA-PEG-PLGA) hydrogel is fabricated by incorporating vascular endothelial growth factor (VEGF) and microspheres loaded with dental pulp stem cells-derived exosomes (DPSCs-Exo). Rapid release of VEGF promotes the swift initiation of angiogenesis, while DPSCs-Exo release ensures persistent osteogenesis. Our results demonstrate that chitosan microsphere-based PLGA-PEG-PLGA hydrogel significantly promotes angiogenesis in human umbilical vascular endothelial cells and enhances the osteogenic differentiation of pre-osteoblasts. Furthermore, in vivo transplantation of this injectable chitosan microsphere-based PLGA-PEG-PLGA hydrogel into calvarial bone defects markedly promotes bone formation. Overall, our study provides a promising approach for improving bone regeneration by temporally replicating the behavior of angiogenesis and osteogenesis.