Vascular Endothelial Growth Factor Concentrations Research Articles

Pristine gelatin incorporation as a strategy to enhance the biofunctionality of poly(vinyl alcohol)-based hydrogels for tissue engineering applications.

Synthetic polymers, such as poly(vinyl alcohol) (PVA), are popular biomaterials for the fabrication of hydrogels for tissue engineering and regenerative medicine (TERM) applications, as they provide excellent control over the physico-chemical properties of the hydrogel. However, their bioinert nature is known to limit cell-biomaterial interactions by hindering cell infiltration, blood vessel recruitment and potentially limiting their integration with the host tissue. Efforts in the field have therefore focused on increasing the biofunctionality of synthetic hydrogels, without limiting the advantages associated with their tailorability and controlled release capacity. The aim of this study was to investigate the suitability of pristine gelatin to enhance the biofunctionality of tyraminated PVA (PVA-Tyr) hydrogels, by promoting cell infiltration and host blood vessel recruitment for TERM applications. Pure PVA-Tyr hydrogels and PVA-Tyr hydrogels incorporated with vascular endothelial growth factor (VEGF), a well-known pro-angiogenic stimulus, were used for comparison. Incorporating increasing concentrations of VEGF (0.01-10 μg mL-1) or gelatin (0.01-5 wt%) did not influence the physical properties of PVA-Tyr hydrogels. However, their presence within the polymer network (>0.1 μg mL-1 VEGF and >0.1 wt% gelatin) promoted endothelial cell interactions with the hydrogels. The covalent binding of unmodified gelatin or VEGF to the PVA-Tyr network did not hamper their inherent bioactivity, as they both promoted angiogenesis in a chick chorioallantoic membrane (CAM) assay, performing comparably with the unbound VEGF control. When the PVA-Tyr hydrogels were implanted subcutaneously in mice, it was observed that cell infiltration into the hydrogels was possible in the absence of gelatin or VEGF at 1- or 3-weeks post-implantation, highlighting a clear difference between in vitro an in vivo cell-biomaterial interaction. Nevertheless, the presence of gelatin or VEGF was necessary to enhance blood vessel recruitment and infiltration, although no significant difference was observed between these two biological molecules. Overall, this study highlights the potential of gelatin as a standalone pro-angiogenic cue to enhance biofunctionality of synthetic hydrogels and provides promise for their use in a variety of TERM applications.

Vascular growth factors of the placenta, apoptosis of blood neutrophils in pregnant women with post-COVID syndrome

Research objectives: to determine the activity of vascular placental growth factors, apoptosis and necrosis of neutrophils in the blood of pregnant women with post-COVID syndrome.Methods and materials. 30 pregnant women (the main group) with SARS-CoV-2, positive Ig A, M or G to SARS-CoV-2 at 30–34 weeks of pregnancy took part in the study. The control group consisted of 30 women with physiological pregnancy.Blood neutrophils were studied by flow cytofluorometry. The proportion of neutrophils that were at the stage of apoptosis and necrosis was determined. The correlation of these indicators with the uncomplicated course of the gestational process during the physiological course of pregnancy and with the development of gestational complications against the background of post-COVID syndrome was determined.In the third trimester of pregnancy, we collected blood samples to determine the effect of SARS-CoV-2 infection on placental angiogenesis. We evaluated a panel of biomarkers: vascular endothelial growth factor (VEGF), placental growth factor PlGF, and interleukin-32α (IL-32α).Results. In pregnant women of the main group with a complicated course of pregnancy accompanied by post-COVID syndrome, apoptosis was at the level of 24.30 ± 0.50% of neutrophil cells, which was significantly different from the control group (4.45 ± 0.25%) (р < 0.001). The level of late apoptosis, necrosis of neutrophils increased 4 times – from 4.20 ± 0.65 to 16.80 ± 0.54% (р < 0.001). The concentration of IL-32α in pregnant women of the control group was 67.27 ± 5.63 pg/ml. Post-COVID syndrome caused an increase in this indicator in the main group by 2.8 times compared to the control group (188.36 ± 25.22 pg/ml) (p < 0.001). In the III trimester, the concentration of VEGF reached maximum values in the main group and was 192.20 ± 10.02 pg/ml, which is 2 times higher than in the control group at the same time (95.30 ± 5.65 pg/ml), (p < 0.001). In the control group the level of PIGF at full-term pregnancy was 144.53 ± 15.55 pg/ml. In women with postpartum syndrome, PIGF significantly decreased and was 43.92 ± 4.81 pg/ml, which was only 30% of the PIGF value in women with an uncomplicated pregnancy (p < 0.001).Conclusions. The development of metabolic disorders and apoptotic changes in the placental tissue are confirmed at the morphological level in the form of destructive and necrotic changes in the microcirculatory channel of the placenta. An increase in the level of annexin-positive neutrophils and activation of the degree of neutrophil necrosis is accompanied by fetoplacental dysfunction, by violation of the balance of placental growth factors and is an important marker for predicting of fetal growth retardation in pregnant women with post-COVID syndrome.

Benzodiazepine receptor agonist carbacetam modulates the level of vascular endothelial growth factor in the retina of rats with streptozotocin-induced diabetes

One of the primary mechanisms of retinal neurodegeneration in diabetes mellitus is gamma-aminobutyric acid (GABA) deficiency that makes the use of GABA-benzodiazepine receptor modulators a promising option for the correction of this diabetic complication. The aim of this study was to determine the effect of the benzodiazepine receptor agonist carbacetam on the expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) in retina of rats with hyperglycemia. Experimental diabetes was modeled by a single administration of streptozotocin (50 mg/kg) to three-month-old male Wistar rats. Immunoblotting and immunohistochemical studies were performed using monoclonal antibodies against VEGF and HIF-1α. It was shown that the development of diabetic retinopathy (DR) at the early stages was accompanied by a progressive multifold increase in the retina content of VEGF on 7-28 days and HIF-1α on 28th day. Insulin and insulin+carbacetam treatment significantly alleviated diabetes-induced overexpression of both HIF-1α and VEGF. Carbacetam was shown to block the diabetogenic increase in VEGF content in retina. The introduction of insulin with carbacetam significantly reduced the expression of VEGF and the development of specific morphological manifestations of DR. Thus, restoration of GABA-ergic signaling can be used as a promising therapeutic option for the correction of DR disorders. Keywords: carbacetam, GABA-benzodia­zepine receptors, HIF-1α hyperglycemia, retinopathy, streptozotocin-induced diabetes, VEGF

10018-COT-4 COMPARATIVE VOLUMETRIC ANALYSES FOLLOWING BEVACIZUMAB THERAPY FOR A PATIENT WITH CO- INCIDENCE OF GLIOBLASTOMA, MENINGIOM

Abstract BACKGROUND Given that glioblastoma, meningioma and dural arteriovenous fistura (dAVF) represent angiogenic disease mainly caused by high expression of vascular endothelial growth factor (VEGF), bevacizumab is expected to be effective for these diseases. We experienced a patient with co-incidence of these 3 diseases was given neoadjuvant bevacizumab which provided a volume reduction of glioblastoma with improvement of clinical symptoms. CASE REPORT An eighty five year-old man has suffered from aphasia and dementia. Brain MRI showed a ring enhanced intraaxial tumor with perifocal edema in left temporal lobe, a dural-attached extraaxial tumor in the left sphenoid ridge and dAVF at left transverse-sigmoid sinus. Due to elderly with poor general condition, he was treated by administrate bevacizumab rather than the resection to confirm histological diagnosis. Three days after the administration, he began to walk and speech. RESULTS For comparison of the reactivity to bevacizumab among these three diseases, we calculated the volumetric quantitative assessment of glioblastoma and meningioma by the contrast-enhanced MRI and made a qualitative assesment for the dAVF by digital subtraction angiography (DSA) and MRA with comparison between before and afterbevacizumab administration. The volume reduction rates 1 and 5 months later after bevacizumab administration in glioblastoma and in meningioma were 0.34% and 94.5%, 13.7%, 6.8%, respectively. The volume reduction rate of glioblastoma was significantly larger than of Mg. The DSA showed the dAVF did not change even though bevacizumab therapy. DISCUSSION As previously reported, the VEGF concentration in the glioblastoma was significantly higher than that in other types of tumors including meningioma. In dAVF, other angiogenic factors would be produced in addition to VEGF. CONCLUSIONS Based on these evidences and the current rare case with co-incidence of glioblastoma, meningioma, and dAVF, it suggested that the effectiveness of bevacizumab therapy would be depend on the expression level of the VEGF concentration.

The effect of curcumin on on intravitreal proinflammatory cytokines, oxidative stress markers, and vascular endothelial growth factor in an experimental model of diabetic retinopathy.

The prevalence of diabetic retinopathy (DR) is high among individuals with diabetes. Curcumin (CUR) has been suggested as a possible treatment for this condition. This study aimed to investigate the impact of CUR on pro-inflammatory cytokines, oxidative stress markers, and vascular endothelial growth factor (VEGF) in an experimental model of DR. The study used Spontaneously Diabetic Torii (SDT) rats and divided them into groups to receive various CUR doses (10, 50, 100 mg/kg/day) or distilled water for four weeks. Non-diabetic Sprague-Dawley (SD) rats were used as a control group. Pro-inflammatory cytokines (interleukin (IL)-1, IL-6, tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ)) (by ELISA), oxidative stress markers (superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GPX), catalase (CAT)), and VEGF expression (by RT-PCR) and content (by Western-blot and immunostaining) were assessed as outcome measures. The study found that diabetic rats who received varying doses of CUR showed a decrease in pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1), oxidative stress markers (SOD, MDA, GPX, CAT), and VEGF expression and content in the vitreous. The decrease in these markers was dose-dependent and significantly different from diabetic rats who did not receive CUR (p<0.01). However, there was no significant difference in the vitreous level of IL-6 between the groups (p=0.35). The study concluded that CUR has the potential to alleviate inflammation and oxidative stress induced by diabetes in the vitreous microenvironment of rats. CUR also reduced the increase in VEGF levels in the vitreous of diabetic rats. These findings suggest that CUR could be a viable therapeutic option for the treatment of DR.

Assessment of plasma soluble Tie-2 level to distinguish moyamoya disease from atherosclerotic cerebrovascular disease and predict postoperative neovascularization.

Moyamoya disease (MMD) is a chronic steno-occlusive cerebrovascular disease and features the formation of hazy collateral vessels at the base of the brain. Angiopoietin (Ang)-1 and -2, their receptor Tie-2, and vascular endothelial growth factor (VEGF) that regulate angiogenesis might be important in MMD pathophysiology and postoperative collateral formation. The goal of this study was to determine whether levels of these angiogenic factors could predict collateralization in patients with MMD. A total of 196 patients with MMD and 57 with atherosclerotic cerebrovascular disease serving as controls were enrolled. Ang-1, Ang-2, Tie-2, and VEGF mRNA levels were analyzed in middle cerebral artery (MCA) arterial wall specimens by using real-time quantitative polymerase chain reaction. MCA and peripheral plasma concentrations of Ang-1, Ang-2, soluble Tie-2 (sTie-2), and VEGF were examined by enzyme-linked immunosorbent assay. Cerebral arteriography was performed 6 months after bypass surgery to assess the postoperative collateralization. In MCA specimens, patients with MMD exhibited higher expression levels of Ang-1 and Ang-2 but lowered VEGF expression. The patients with MMD had significantly higher concentrations of Ang-1 and Ang-2 but lower levels of VEGF in MCA plasma. Peripheral plasma concentrations of these growth factors were not changed. MCA and peripheral plasma sTie-2 levels were both reduced in patients with MMD. The 6-month follow-up showed that patients with good collateral formation had lower sTie-2 levels in both MCA and peripheral plasma. Furthermore, the Suzuki stage and peripheral plasma sTie-2 level were significantly correlated with good postoperative collateral formation on multivariate analysis. Ang-1, Ang-2, Tie-2, and VEGF are involved in MMD pathogenesis. The peripheral plasma level of sTie-2 can differentiate MMD from atherosclerotic cerebrovascular disease and serve as a novel biomarker to predict postoperative collateral formation.

Efficacy and Safety of Biosimilar QL1207 vs. the Reference Aflibercept for Patients with Neovascular Age-Related Macular Degeneration: A Randomized Phase 3 Trial.

This trial aimed to compare the efficacy and safety between biosimilar QL1207 and the reference aflibercept for the treatment of neovascular age-related macular degeneration (nAMD). This randomized, double-blind, phase 3 trial was conducted at 35 centers in China. Patients aged ≥ 50years old with untreated subfoveal choroidal neovascularization secondary to nAMD and best-corrected visual acuity (BCVA) letter score of 73-34 were eligible. Patients were randomly assigned to receive intravitreous injections of QL1207 or aflibercept 2mg (0.05ml) in the study eye every 4weeks for the first 3months, followed by 2mg every 8weeks until week 48, stratified by baseline BCVA ≥ or < 45 letters. The primary endpoint was BCVA change from baseline at week 12. The equivalence margin was ± 5 letters. The safety, immunogenicity, pharmacokinetics (PK), and plasma vascular endothelial growth factor (VEGF) concentration were also evaluated. A total of 366 patients were enrolled (QL1207 group, n = 185; aflibercept group, n = 181) from Aug 2019 to Jan 2022 with comparable baseline characteristics. The least-squares mean difference in BCVA changeswas - 1.1 letters(95% confidence interval - 3.0 to 0.7; P = 0.2275) between the two groups, within the equivalence margin. The incidences of treatment-emergent adverse events (TEAE; QL1207: 71.4% [132/185] vs. aflibercept: 71.8% [130/181]) and serious TEAE (QL1207: 14.1% [26] vs. aflibercept: 12.7% [23]) appeared comparable between treatment groups, and no new safety signal was found. Anti-drug antibody, PK profiles, and VEGF concentration were similar between the two groups. QL1207 has equivalent efficacy to aflibercept for nAMD with similar safety profiles. It could be used as an alternative anti-VEGF agent for clinical practice. ClinicalTrials.gov: NCT05345236 (retrospectively registered on April 25, 2022); National Medical Products Administration of China: CTR20190937 (May 20, 2019).

Development of a potency assay for CD34+ cell-based therapy

We have previously shown that intracardiac delivery of autologous CD34+ cells after acute myocardial infarction (AMI) is safe and leads to long term improvement. We are now conducting a multicenter, randomized, controlled Phase I/IIb study in post-AMI to investigate the safety and efficacy of intramyocardial injection of expanded autologous CD34+ cells (ProtheraCytes) (NCT02669810). Here, we conducted a series of in vitro studies characterizing the growth factor secretion, exosome secretion, gene expression, cell surface markers, differentiation potential, and angiogenic potential of ProtheraCytes clinical batches to develop a potency assay. We show that ProtheraCytes secrete vascular endothelial growth factor (VEGF) and its concentration is significantly correlated with the number of CD34+ cells obtained after expansion. ProtheraCytes also secrete exosomes containing proangiogenic miRNAs (126, 130a, 378, 26a), antiapoptotic miRNAs (21 and 146a), antifibrotic miRNAs (133a, 24, 29b, 132), and miRNAs promoting myocardial regeneration (199a and 590). We also show that ProtheraCytes have in vitro angiogenic activity, express surface markers of endothelial progenitor cells, and can differentiate in vitro into endothelial cells. After the in vitro characterization of multiple ProtheraCytes clinical batches, we established that measuring the concentration of VEGF provided the most practical, reliable, and consistent potency assay.

The Clinical Relevance of Selected Cytokines in Newly Diagnosed Multiple Myeloma Patients.

Multiple myeloma (MM) is the second most common hematological neoplasm. Cytokines, chemokines, and their receptors, induced by the microenvironment of MM, participate in tumor growth, the attraction of leukocytes, cell homing, and bone destruction. This study aimed to assess the correlation between the pretreatment serum concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8), angiogenic chemokine monocyte chemoattractant protein-1 (MCP-1), and vascular endothelial growth factor (VEGF) and the clinical outcomes and survival of patients newly diagnosed with MM. The study group consisted of 82 individuals. The IL-8 concentration was significantly positively correlated with the age of onset (p = 0.007), the International Staging System (ISS) stage (p = 0.03), the Eastern Cooperative Oncology Group (ECOG) performance status (p < 0.001), the degree of anemia before treatment (p < 0.0001), the degree of kidney disease (p < 0.001), and VEGF (p = 0.0364). Chemotherapy responders had significantly lower concentrations of IL-8 (p < 0.001), IL-6 (p < 0.001), and VEGF (p = 0.04) compared with non-responders. Patients with treatment-induced polyneuropathy had significantly higher levels of IL-8 (p = 0.033). Patients with a high level of IL-6 had a 2-fold higher risk of progression-free survival (PFS) reduction (17 vs. 35 months; HR = 1.89; p = 0.0078), and a more than 2.5-fold higher risk of overall survival (OS) reduction (28 vs. 78 months; HR = 2.62; p < 0.001). High levels of IL-6, IL-8, and VEGF demonstrated significant predictive values for some clinical conditions or outcomes of newly diagnosed MM patients. Patients with an early response to chemotherapy had a significantly lower concentration of these cytokines. A high pretreatment IL-6 concentration was an independent negative prognostic marker for newly diagnosed MM patients.

Vitreous Levels of Vascular Endothelial Growth Factor and Platelet-Derived Growth Factor in Patients with Proliferative Diabetic Retinopathy: A Clinical Correlation.

Background: The global epidemic status of diabetic retinopathy (DR) and its burden presents an ongoing challenge to health-care systems. It is of great interest to investigate potential prognostic biomarkers of DR. Such markers could aid in detecting early stages of DR, predicting DR progression and its response to therapeutics. Herein, we investigate the prognostic value of intravitreal concentrations of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) in a DR cohort. Materials and methods: Vitreous sample acquisition was conducted at King Abdullah University Hospital (KAUH) between December 2020 and June 2022. Samples were obtained from any patient scheduled to undergo a pars plana vitrectomy (PPV) for any indication. Included patients were categorized into a DR group or a corresponding non-diabetic (ND) control group. Demographics, clinicopathological variables, standardized laboratory tests results, and optical coherence tomography (OCT) data were obtained for each included individual. Intravitreal concentrations of VEGF and PDGF were assessed using commercial enzyme-linked immunosorbent assay (ELISA). Results: A total of 80 eyes from 80 patients (DR group: n = 42 and ND control group: n = 38) were included in the analysis. The vitreous VEGF levels were significantly higher in the DR group compared to the ND control group (DR group 5744.06 ± 761.5 pg/mL versus ND control group 817.94 ± 403.1 pg/mL, p = 0.0001). In addition, the vitreous PDGF levels were also significantly higher in the DR group than those in the ND control group (DR group 4031.51 ± 410.2 pg/mL versus ND control group 2691.46 ± 821.0 pg/mL, p = 0.001). Bassline differences between test groups and clinical factors impacting VEGF and PDGF concentrations were investigated as well. Multiple regression analysis indicated PDGF as the sole independent risk factor affecting best-corrected visual acuity (BCVA) at the last follow-up visit: the higher the PDGF vitreous levels, the worst the BCVA. Conclusions: Vitreous concentrations of VEGF and PDGF are correlated with DR severity and may exhibit a possible prognostic potential value in DR. Further clinical and experimental data are warranted to confirm the observed findings and to help incorporate them into daily practice.

Predictors of visual outcome after pars plana vitrectomy secondary to proliferative diabetic retinopathy.

Objective: Advanced proliferative diabetic retinopathy can lead to serious ophthalmological complications, including blindness. This research aimed to determine visual outcomes after pars plana vitrectomy secondary to proliferative diabetic retinopathy, as well as to identify its predictors. Methods: This prospective clinical study was performed in the Ophthalmology Clinic of the Clinical Centre University of Sarajevo. 60 subjects (eyes) with performed pars plana vitrectomy secondary to proliferative diabetic retinopathy were included in the study. Results: After univariate linear regression analysis, glucose, HbA1c, vascular endothelial growth factor, previous pan-retinal laser photocoagulation, baseline best corrected visual acuity, gas injection, vitreous haemorrhage, iris rubeosis, and glaucoma were found to be statistically significant parameters associated with postoperative visual outcome (p<0.05). Multivariate linear regression analysis was performed to evaluate the association between factors and postoperative best corrected visual acuity. Only intravitreal vascular endothelial growth factor concentration, previous pan-retinal photocoagulation, and gas injection remained statistically significant associated with postoperative best corrected visual acuity (p<0.05). Conclusion: Vitrectomy is an effective treatment for advanced proliferative diabetic retinopathy. Factors correlated with the better visual outcome are good systemic control, previous pan-retinal photocoagulation, low intravitreal vascular endothelial growth factor concentration, younger age, intraoperative internal gas tamponade, combined phacoemulsification and pars plana vitrectomy surgery, and the absence of postoperative complications. Abbreviations: PDR = proliferative diabetic retinopathy, VEGF = vascular endothelial growth factor, TDR = tractional retinal detachment, BCVA = best corrected visual acuity, DR = diabetic retinopathy, RDD = rhegmatogenous retinal detachment, NVG = neovascular glaucoma, BRVO = branch retinal vein occlusion, CBC = complete blood count, DBT = differential blood count, ESR = erythrocyte sedimentation rate, HbA1c = glycosylated hemoglobin, PHACO = phacoemulsification, ILM = internal limiting membrane, PPV = pars plana vitrectomy, IOP = intraocular pressure, PRP = pan-retinal photocoagulation, ETDRS = Early treatment diabetic retinopathy study.

Effect of a novel tyrosine kinase inhibitor nintedanib on bFGF and VEGF concentrations in a rabbit retinal vein occlusion model.

To evaluate whether a novel tyrosine kinase inhibitor nintedanib could inhibit basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) simultaneously for retinal vascular disease in vivo. After a laser induced rabbit retinal vein occlusion (RVO) model was made, 0.5 mg of nintedanib was injected intravitreally in the left eye on the third day while the right eye was as a control. Intracameral samples were taken on the day before laser treatment and days 1, 3, 7, 14, 21, and 28 after treatment. Enzyme-linked immunosorbent assay (ELISA) was used to test the bFGF and VEGF-A concentrations in the aqueous humor. Both bFGF and VEGF-A rose significantly on the third day after laser treatment in both eyes. In the control eye the bFGF concentration peaked on the 14th day while the VEGF-A concentration dropped rapidly soon after the third day. After nintadanib injection in the study eye, both bFGF and VEGF-A showed a significant reduction on the 4th day (7th day after laser treatment) when compared to the control eye, and kept on low level in the following several weeks. Intravitreal injection of nintedanib can inhibit the expression of bFGF and VEGF in the process of RVO model to a certain extent, which is expected to become a new method for the treatment of retinal vascular diseases or fibrotic diseases.

Electrochemical determination of vascular endothelial growth factor using functional metal-polymer nanocomposites

Vascular endothelial growth factor (VEGF) is a homo-dimeric glycoprotein that plays a prominent part in the pathophysiology of angiogenesis and vasculargenesis, such as tumorigenesis, vascular permeability and metastasis. Quantification of VEGF in the body is significant for clinical diagnosis and treatment. An electrochemical sensor for the sensitive determination of VEGF was developed. Functional metal-polymer nanocomposites, gold nanoparticles@poly(o-phenylenediamine) (AuNPs@PoPD), and AuNPs@PoPD-labeled VEGF antibodies (Ab-AuNPs@PoPD) were synthesized. The glassy carbon electrode modified with graphene nanoribbons (GNRs), AuNPs and VEGF, GCE/GNRs-AuNPs/VEGF, was fabricated and it was employed to capture Ab-AuNPs@PoPD. Free VEGF proteins had an inhibitory action on the assembly of GCE/GNRs-AuNPs/VEGF/Ab-AuNPs@PoPD, leading to the decrease of the electrochemical probe, PoPD, on the modified electrode and the decline of current signal in the voltammetic measurement. Under the optimal experimental conditions, the peak current difference was proportional to the VEGF concentration in the range of 0.500–500 ng mL−1 and the limit of detection was 300 pg mL−1. The proposed sensor exhibited a good selectivity, reproducibility and stability. High-salt microenvironment induced the dysfunction of human umbilical vein endothelial cells (HUVECs). Electrochemical measurements reveal that increasing NaCl concentration in the growth medium promoted the release of VEGF from dysfunctional HUVECs.

VEGF-modified PLA/HA nanocomposite fibrous membrane for cranial defect repair in rats.

A major obstacle to bone tissue repair is the difficulty in establishing a rapid blood supply areas of bone defects. Vascular endothelial growth factor (VEGF)-infused tissue-engineered scaffolds offer a possible therapeutic option for these types of injuries. Their role is to accelerate angiogenesis and improve bone healing. In this study, we used electrostatic spinning and biofactor binding to construct polylactic acid (PLA)/hydroxyapatite (HA)-VEGF scaffold materials and clarify their pro-vascular role in bone defect areas for efficient bone defect repair. PLA/HA nanocomposite fibrous membranes were manufactured by selecting suitable electrostatic spinning parameters. Heparin and VEGF were bound sequentially, and then the VEGF binding and release curves of the fiber membranes were calculated. A rat cranial defect model was constructed, and PLA/HA fiber membranes bound with VEGF and unbound with VEGF were placed for treatment. Finally, we compared bone volume recovery and vascular recovery in different fibrous membrane sites. A VEGF concentration of 2.5µg/mL achieved the maximum binding and uniform distribution of PLA/HA fibrous membranes. Extended-release experiments showed that VEGF release essentially peaked at 14days. In vivo studies showed that PLA/HA fibrous membranes bound with VEGF significantly increased the number of vessels at the site of cranial defects, bone mineral density, bone mineral content, bone bulk density, trabecular separation, trabecular thickness, and the number of trabeculae at the site of defects in rats compared with PLA/HA fibrous membranes not bound with VEGF. VEGF-bound PLA/HA fibrous membranes demonstrate the slow release of VEGF. The VEGF binding process does not disrupt the morphology and structure of the fibrous membranes. The fibrous membranes could stimulate both osteogenesis and angiogenesis. Taken together, this research provides a new strategy for critical-sized bone defects repairing.

Rifampicin efficacy against doxorubicin-induced cardiotoxicity in mice

BackgroundThe toxic effect of doxorubicin on the heart limits its clinical usage in cancer therapy. This work intended to investigate, for the first time, the efficacy of rifampicin administration against doxorubicin-induction of cardiotoxicity in mice. Forty adult male albino mice were distributed into four sets: Control, Doxorubicin, Doxorubicin + Rifampicin 0.107, and Doxorubicin + Rifampicin 0.214, with n = 10 for each. Heart histopathology and biochemical assays for heart function tests [creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), cardiac troponin I (cTnI), atrial natriuretic peptide (ANP), and vascular endothelial growth factor (VEGF)], oxidative stress [malondialdehyde (MDA) and superoxide dismutase (SOD)], and minerals [phosphorus, sodium, potassium, and calcium] were done.ResultsDoxorubicin-induced cardiotoxicity using a total dose of 15 mg/kg was confirmed histologically. Cardiomyocytes showed congestion, necrosis, edema, and inflammatory cell infiltration. Biochemically, elevations in LDH, CK, and AST activities, p < 0.001, as well as increases in cTnI and ANP levels, p < 0.001, increased oxidative stress (MDA, p < 0.001), high minerals (Na, K, p < 0.001, P, p < 0.01, and Ca, p < 0.05), with reduced VEGF concentration, p < 0.001, and low antioxidant (SOD, p < 0.001) were observed in the Doxorubicin group compared to control. Co-treatment with rifampicin significantly (p < 0.001) reduced the increased oxidative stress, high Na and K, increased LDH, CK, AST, cTnI, and ANP, and elevated the low SOD toward the normal ranges. Our histological data supported our biochemical data; rifampicin dose 0.214 mg/kg showed better improvements than dose 0107.ConclusionsOur results demonstrated that rifampicin could help protect the body against doxorubicin-induced cardiotoxicity through its antioxidative effect.

Effects of advanced platelet-rich fibrin on deep partial-thickness burn wounds in nude mice

Effects of advanced platelet-rich fibrin on deep partial-thickness burn wounds in nude mice

Mathematical and numerical analyses of cellular, molecular and angiogenic parameters of a rat skin wound healing model.

The inflammatory phase is an important event in the skin wound healing process. The deposition of granulation tissue in the wound bed and the rebuilding of the vascular network occur as inflammation diminishes. An angiogenic component in the formation of granulation tissue is the secretion of vascular endothelial growth factor, which assists in the chemotaxis, proliferation, and replication of fibroblasts. In this paper, we develop a mathematical model of skin wound healing angiogenic factors based on inflammatory cells (macrophages and neutrophils) and mediators (interleukin 6 and interleukin 10). We highlight the importance of this process in vascular endothelial growth factor release and in the formation of new capillary tips. We used a mathematical model of partial differential equations based on the reaction-diffusion-advection equations. In order to calibrate the parameters, we considered an in vivo model composed by four treatments: hydroalcoholic extract and oil-resin of Copaifera langsdorffii at 10% concentration, collagenase, and Lanette cream. Using the laboratory data for the wound edge, our mathematical model estimated the values of vascular endothelial growth factor concentration, and tips density in the center of the wound with a maximum error of 2.9%, and predicted healing time required for each treatment. The region of viability for the parameters, in the proposed model, was found through numerical simulations from the Interleukin 6 and 10 dysregulation and we obtained that, among the parameters analyzed, the greatest influencer in the dynamics of the system is the one, which represents the production of Interleukin 10 during phagocytosis.

Association between clinical features and course of systemic sclerosis and serum interleukin-8, vascular endothelial growth factor, basic fibroblast growth factor, and interferon alpha.

Certain mediators, such as soluble growth factors and cytokines, among others, are implicated in the immunopathogenesis of systemic sclerosis (SSc). This study aimed to examine the association between serum levels of vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), interferon alpha (IFN-α), and basic fibroblast growth factor (bFGF) and the clinical presentation and course of SSc. This longitudinal, observational study included 43 patients with SSc and 24 healthy subjects. Serum concentrations of VEGF, IL-8, IFN-α, and bFGF were measured at baseline in patients previously treated for SSc. Medical history of patients was analyzed retrospectively at the time of cytokine measurement to infer clinical correlations, and during follow-up for a median of 5 years, assessing the incidence of death or cancer. The bFGF and IFN-α concentrations differed between SSc patients and controls (p < 0.01). In turn, organ involvement and SSc phenotypes did not impact studied cytokine concentrations, similar to systemic steroid and/or immunosuppressant use at enrollment. However, we have documented a positive correlation between the current oral steroid dose and serum levels of IL-8 and bFGF. Furthermore, patients with a VEGF level ≥95.7 pg/mL and IFN-α level ≥3.6 pg/mL required cyclophosphamide therapy more often, currently or in the past (approx. 3-fold and 4-fold, respectively). Substantially elevated VEGF and IFN-α concentrations at baseline were associated with higher cancer occurrence (n = 4) during follow-up, while elevated circulating IL-8 level was associated with an increased risk of death (n = 9). The SSc group was characterized by higher serum concentrations of bFGF and IFN-α compared to healthy controls. Patients treated with cyclophosphamide or receiving higher systemic steroid doses, thus suffering from a more severe disease type, had increased cytokine levels. Elevated circulating IFN-α and VEGF levels might be correlated with cancer, whereas raised IL-8 levels may be associated with an increased risk of death. However, further research is needed to verify our findings.

PACAP-ADNP axis prevents outer retinal barrier breakdown and choroidal neovascularization by interfering with VEGF secreted from retinal pigmented epitelium cells

During diabetic retinopathy (DR) progression, the retina undergoes various metabolic changes, including hypoxia-signalling cascade induction in the cells of retinal pigmented epithelium (RPE). The overexpression of hypoxic inducible factors causes transcription of many target genes including vascular endothelial growth factor (VEGF). The RPE cells form the outer blood retinal barrier (oBRB), a specialized structure that regulates ions and metabolites flux into the retina to maintain a suitable quality of its extracellular microenvironment. VEGF worsens retinal condition since its secretion from the basolateral compartment of RPE cells compromises the barrier’s integrity and induces choroidal neovascularization. In this work, we hypothesized that PACAP prevents the damage to oBRB and controls choroidal neovascularization through the induction of ADNP. Firstly, we demonstrated that ADNP is expressed in Streptozotocin (STZ)-induced diabetic animals. To validate our hypothesis, we cultured endothelial cells (H5V) forming vessels-like structures, in a conditioned medium (CM) derived from ARPE-19 cells exposed to hyperglycaemic/hypoxic insult, containing a known VEGF concentration. The involvement of PACAP-ADNP axis on oBRB integrity was evaluated through the measurement of trans-epithelial-electrical resistance and permeability assay performed on ARPE cell monolayer cultured in CM and by analysing the expression of two tight junction forming proteins, ZO1 and occludin. By culturing H5V in CM, we demonstrated that PACAP-ADNP axis counteracted vessels-like structures formation promoted by VEGF. In conclusion, the results suggested a primary role of PACAP/ADNP axis in preventing oBRB damage and in controlling aberrant choroidal neovascularization induced by VEGF secreted from RPE cells exposed to hyperglycaemia/hypoxic insult in DR.

Vascular Endothelial Growth Factor as Potential Biomarker for COVID-19 Severity.

COVID-19 is characterized by immunological responses to viral replication and coherent with endothelitis, microvascular disturbance of lung vasculature and coagulopathy. Vascular Endothelial Growth Factor (VEGF) is a proangiogenic mediator regulating endothelial changes. It is induced by proinflammatory signaling and hypoxia. We sought to determine whether VEGF levels differ between SARS-CoV-2-positive patients of different disease severity and whether VEGF might be useful in risk stratification. After retrospective screening of all SARS-CoV-2-positive patients treated in Unfallkrankenhaus Berlin in 2020, we included those with documented VEGF measurement. We extracted laboratory values and clinical parameters. An exploratory data analysis was performed to detect possible relations between VEGF level and clinical disease features. We included 167 SARS-CoV-2-positive patients of which 139 suffered from COVID-19. Seventy-one of the COVID-19 patients had to be treated in the intensive care unit (ICU), those patients exhibited higher VEGF levels than those being admitted to normal wards (535 vs 279 pg/L, P < .001). APACHE-2 (Acute Physiology And Chronic Health Evaluation Score) correlated with mortality and patients with high values showed higher VEGF concentrations on admission (456 vs 875 pg/L, p = 0.006). Receiver operating characteristic analytic revealed that the occurrence of organ dysfunctions like acute respiratory distress syndrome (ARDS), shock, or acute kidney injury could be predicted by VEGF. It was significantly higher in patients who later died compared to survivors (637 vs 389 pg/mL, P = 0.041) and predicted mortality with same accuracy as established markers. In our cohort, association of VEGF above 277 pg/L on admission with risk of ARDS could be confirmed in logistic regression adjusting for possible confounding factors (odds ratio 3.1, 95% confidence interval: 1.34-7.7). Even though there are several limitations to this retrospective study it revealed that in COVID-19 patients VEGF can contribute to the prediction of necessity of ICU, mortality and the prediction of ARDS, kidney injury or shock. Its use in risk stratification and potential pathogenetic involvement should be further investigated.