VEGF-A in Serum and Plasma Rich in Growth Factors (PRGF) Eye Drops.

BACKGROUND: Vascular endothelial growth factor (VEGF)-A, the most abundant subtype of the VEGF family in the eye, plays an important role in corneal homeostasis due to its ability to mediate corneal nerve repair. Repeated intravitreal anti-VEGF injections were shown to significantly reduce corneal nerve density, which might negatively affect corneal homeostasis and lead to a neuropathic dry eye disease. Currently, there are two effective modalities to treat dry eye while supplying VEGF to the ocular surface: serum eye drops (SED) and eye drops manufactured from plasma rich in growth factors (PRGF). The purpose of this study was to measure the VEGF-A concentration in SED and PRGF eye drops. MATERIAL AND METHODS: Ten healthy volunteers donated blood on two separate occasions, 2 - 8 days apart. Thus, a total of 20 blood samples were processed to obtain both SED and PRGF. Concentrations of VEGF-A were quantified by a Simple Plex platform run in triplicate. RESULTS: The VEGF-A concentration in SED and PRGF was very similar between the two blood samples drawn from one individual donor but showed substantial interindividual variability. However, in all 20 samples, VEGF concentrations were substantially higher in SED samples (mean 238.7 ± 146.6 pg/mL) compared to PRGF samples (mean 67.4 ± 46.3 pg/mL). Based upon the analysis of variance (ANOVA) model for the measured concentrations with fixed effects for specimen (SED vs. PRGF) and subject, the mean difference between the SED and PRGF concentration was 168.1 pg/mL (95% confidence interval: [142.4, 193.9], p < 0.001). CONCLUSION: Our study showed that the VEGF concentration was higher in SED than in PRGF. This is an important finding, particularly for potential treatment of dry eye disease in patients with neuropathic eye disease, especially in patients that received repeated anti-VEGF intravitreal injections, or in patients with Sjögren's disease, where the level of VEGF in tears might be pathologically decreased. Hypothetically, VEGF might be needed to restore ocular surface homeostasis. Although growing evidence has shown that VEGF-A plays an important role in corneal homeostasis, only a randomized prospective clinical trial will show whether supplying VEGF-A to the ocular surface might successfully restore the corneal homeostasis and overcome the problem of corneal neuropathy in these patients. For such a trial, based on our results, an undiluted SED should be preferred over a PRGF due to the higher content of VEGF-A.

Soluble Endoglin Stimulates Inflammatory and Angiogenic Responses in Microglia That Are Associated with Endothelial Dysfunction.

Increased soluble endoglin (sENG) has been observed in human brain arteriovenous malformations (bAVMs). In addition, the overexpression of sENG in concurrence with vascular endothelial growth factor (VEGF)-A has been shown to induce dysplastic vessel formation in mouse brains. However, the underlying mechanism of sENG-induced vascular malformations is not clear. The evidence suggests the role of sENG as a pro-inflammatory modulator, and increased microglial accumulation and inflammation have been observed in bAVMs. Therefore, we hypothesized that microglia mediate sENG-induced inflammation and endothelial cell (EC) dysfunction in bAVMs. In this study, we confirmed that the presence of sENG along with VEGF-A overexpression induced dysplastic vessel formation. Remarkably, we observed increased microglial activation around dysplastic vessels with the expression of NLRP3, an inflammasome marker. We found that sENG increased the gene expression of VEGF-A, pro-inflammatory cytokines/inflammasome mediators (TNF-α, IL-6, NLRP3, ASC, Caspase-1, and IL-1ß), and proteolytic enzyme (MMP-9) in BV2 microglia. The conditioned media from sENG-treated BV2 (BV2-sENG-CM) significantly increased levels of angiogenic factors (Notch-1 and TGFß) and pERK1/2 in ECs but it decreased the level of IL-17RD, an anti-angiogenic mediator. Finally, the BV2-sENG-CM significantly increased EC migration and tube formation. Together, our study demonstrates that sENG provokes microglia to express angiogenic/inflammatory molecules which may be involved in EC dysfunction. Our study corroborates the contribution of microglia to the pathology of sENG-associated vascular malformations.

VEGFA165 can rescue excess steroid secretion, inflammatory markers, and follicle arrest in the ovarian cortex of High A4 cows†.

A population of cows with excess androstenedione (A4; High A4) in follicular fluid, with follicular arrest, granulosa cell dysfunction, and a 17% reduction in calving rate was previously identified. We hypothesized that excess A4 in the ovarian microenvironment caused the follicular arrest in High A4 cows and that vascular endothelial growth factor A would rescue the High A4 phenotype. In trial 1, prior to culture, High A4 ovarian cortex (n = 9) had greater numbers of early stage follicles (primordial) and fewer later-stage follicles compared to controls (n = 11). Culture for 7 days did not relieve this follicular arrest; instead, High A4 ovarian cortex had increased indicators of inflammation, anti-Mullerian hormone, and A4 secretion compared to controls. In trial 2, we tested if vascular endothelial growth factor A isoforms could rescue the High A4 phenotype. High A4 (n = 5) and control (n = 5) ovarian cortex was cultured with (1) PBS, (2) VEGFA165 (50 ng/mL), (3) VEGFA165B (50 ng/mL), or (4) VEGFA165 + VEGFA165B (50 ng/mL each) for 7 days. Follicular progression increased with VEGFA165 in High A4 cows with greater early primary, primary, and secondary follicles than controls. Similar to trial 1, High A4 ovarian cortex secreted greater concentrations of A4 and other steroids and had greater indicators of inflammation compared to controls. However, VEGFA165 rescued steroidogenesis, oxidative stress, and fibrosis. The VEGFA165 and VEGFA165b both reduced IL-13, INFα, and INFß secretion in High A4 cows to control levels. Thus, VEGFA165 may be a potential therapeutic to restore the ovarian steroidogenic microenvironment and may promote folliculogenesis.

Lenvatinib Plus Anti-PD-1 Combination Therapy for Advanced Cancers: Defining Mechanisms of Resistance in an Inducible Transgenic Model of Thyroid Cancer.

Background: Combination therapy with lenvatinib plus programmed death-1 (PD-1) immune checkpoint blockades (ICBs) is under investigation in many solid tumors, including thyroid cancer. Lenvatinib is known to reduce angiogenesis and may overturn the immunosuppressive effects of vascular endothelial growth factor in the tumor microenvironment. Previous studies investigating the effects of VEGF receptor inhibition on the immune response were performed in rapidly growing tumor models where immune equilibrium is not established before treatment. We hypothesize that physiologically relevant preclinical models are necessary to define mechanisms of resistance to immune-targeted combination therapies. Methods: We utilized the TPO-CreER/BrafV600E/wt/Trp53Δex2-10/Δex2-10 inducible transgenic model of advanced thyroid cancer to investigate lenvatinib treatment in the context of an anti-PD-1 ICB. Following tumor establishment, 3.5 months postinduction, mice were treated with high- (10 mg/kg) or low-dose (2 mg/kg) lenvatinib, anti-PD-1, or combination of lenvatinib with anti-PD-1. Tumor volume and lung metastases were assessed in each group. Immune infiltrate was characterized by flow cytometry and immunohistochemistry, and TCRß sequencing was performed to further investigate the T cell response. Results: Both low- and high-dose lenvatinib reduced tumor volume, while anti-PD-1 had no effect, alone or in combination. Although both low- and high-dose lenvatinib reduced vascular density, low-dose lenvatinib was superior in controlling tumor size. Lung metastases and survival were not improved with therapy despite the effects of lenvatinib on primary tumor size. Low-dose lenvatinib treatment led to a subtle reduction in the dominant Ly6G+CD11b+ myeloid cell population and was associated with increased CD4+ T cell infiltrate and enrichment in 4-1BB+ and granzyme B+ CD4+ T cells and FoxP3+ regulatory T cells. Polyclonal T cell expansion was evident in the majority of mice, suggesting that a tumor-specific T cell response was generated. Conclusions: The effects of lenvatinib on the immune response were most pronounced in mice treated with low-dose lenvatinib, suggesting that dose should be considered in clinical application. While the immune-modulating potential of lenvatinib is encouraging, alterations in the immune milieu and T cell activation status were insufficient to sustain durable tumor regression, even with added anti-PD-1. Additional studies are necessary to develop more effective combination approaches in low-mutation burden tumors, such as thyroid cancer.

Effects of nanoparticle-mediated Co-delivery of bFGF and VEGFA genes to deep burn wounds: An in vivo study.

Deep burns are a common form of trauma worldwide, and they are hard to be cured in a short time and enhance psychological pressure of the patients. How to effectively promote the healing of wounds after burns is a continuing challenge currently faced by burn physicians. Various strategies of promoting wound healing of deep burns have been developed, including gene therapy and growth factor therapy. In this study, we developed a combined therapy using PLGA nanoparticles as carriers to deliver bFGF and VEGFA genes to promote healing of burn wounds. We first inserted the bFGF and VEGFA genes into pEGFP-N1 vectors and loaded the mixed generated plasmids into PLGA nanoparticles. Next, we injected the nanoparticle/plasmid complexes into the rats intracutaneously and found that the complexes were successfully transfected in vivo one week later. Finally, we injected the nanoparticle/plasmid complexes containing bFGF and VEGFA around burn wounds. We found that the percentage of wound healing of rats treated with nanoparticles/bFGF+ VEGFA plasmid complexes was higher than that of rats in the scald control group, and the early percentage of wound complete epithelialization was also higher. Therefore, combining gene therapy with nanoparticles may be an effective biological strategy for wound repair.

Visual Outcome of Anti-vascular Endothelial Growth Factor Injections at the University College Hospital, Ibadan.

Aim: The aim of the study was to evaluate the 1-year outcome of intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy in an eye unit in sub-Saharan Africa. Methodology: This retrospective study included 182 eyes of 172 patients managed in the vitreoretinal unit between 2016 and 2019 who were treated with intravitreal anti-VEGF bevacizumab (1.25 mg/0.05 ml) with at least 1 year of follow-up. The outcome measures were change in best-corrected visual acuity (BCVA) over 1 year of follow-up, the number of injections taken, and complications. Results: The mean age was 61.1 ± 16.3 years (male-to-female ratio of 1:1.1) and about 62.1% above >60 years. A total of 330 injections were given during the period audited. The mean number of injections was 1.8 ± 0.93. Ninety-four (51.7%) eyes had only one injection, while 33 (18.1%), 50 (27.5%), and 5 (2.7%) had 2, 3, and 4 injections, respectively. About 78.5% had moderate-to-severe visual impairment at baseline and 44.5%, 16.4%, 12.6%, and 7.1% at 1, 3, 6, and 12 months post injections, respectively. The mean BCVA improved for all eyes from 1.67 ± 0.91 logarithm of minimum angle of resolution (logMAR) at baseline to 1.50 ± 1.27 logMAR at 1 year. The logMAR letters gained was 23 at 1 month and 8.25 at 1 year; the eyes that had three injections gained 10 letters, while those that had one injection gained three letters. Eyes with age-related macular degeneration and idiopathic polypoidal choroidopathy gained 7.5 and 9 letters, respectively, at 1 year after at least three injections. There was a statistically significant association between an increasing number of injections and improved visual outcome (P = 0.043). One patient each developed endophthalmitis (0.6%) and inferior retinal detachment (0.6%) post injection. Conclusion: Visual acuity gain was recorded in patients who had intravitreal anti-VEGF injections in 1 year. It is recommended that patients should have more than one injection.

RésuméObjectif: Le but de l'étude était d'évaluer le résultat à 1 an d'un traitement intravitréen anti-facteur de croissance endothélial vasculaire (anti VEGF) dans une unité ophtalmologique en Afrique subsaharienne. Méthodologie: Cette étude rétrospective a inclus 182 yeux de 172 patients pris en charge dans l'unité vitréorétinienne entre 2016 et 2019 qui ont été traités par bevacizumab anti-VEGF intravitréen (1,25 mg/0,05 ml) avec au moins 1 an de suivi. Les mesures des résultats étaient le changement de la meilleure acuité visuelle corrigée (MAVC) sur 1 an de suivi, le nombre d'injections effectuées et les complications. Résultats: L'âge moyen était de 61,1 ± 16,3 ans (ratio homme/femme de 1:1,1) et d'environ 62,1 % au-dessus de > 60 ans. Au total, 330 injections ont été effectuées au cours de la période auditée. Le nombre moyen d'injections était de 1,8 ± 0,93. Quatre-vingt quatorze yeux (51,7 %) n'ont eu qu'une seule injection, tandis que 33 (18,1 %), 50 (27,5 %) et 5 (2,7 %) ont eu 2, 3 et 4 injections, respectivement. Environ 78,5% avaient une déficience visuelle modérée à sévère au départ et 44,5%, 16,4%, 12,6% et 7,1% à 1, 3, 6 et 12 mois après les injections, respectivement. La MAVC moyenne s'est améliorée pour tous les yeux, passant de 1,67 ± 0,91 logarithme de l'angle minimal de résolution (logMAR) au départ à 1,50 ± 1,27 logMAR à 1 an. Les lettres logMAR acquises étaient de 23 à 1 mois et de 8,25 à 1 an ; les yeux qui ont eu trois injections ont gagné 10 lettres, tandis que ceux qui ont eu une injection ont gagné trois lettres. Les yeux atteints de dégénérescence maculaire liée à l'âge et de choroïdopathie polypoïdale idiopathique ont gagné 7,5 et 9 lettres, respectivement, à 1 an après au moins trois injections. Il y avait une association statistiquement significative entre un nombre croissant d'injections et une amélioration des résultats visuels (P = 0,043). Un patient a développé une endophtalmie (0,6 %) et un décollement de la rétine inférieure (0,6 %) après l'injection. Conclusion: Un gain d'acuité visuelle a été enregistré chez les patients ayant eu des injections intravitréennes d'anti VEGF en 1 an. Il est recommandé que les patients aient plus d'une injection. Mots-clés: Anti facteur de croissance endothélial vasculaire, bevacizumab (Avastin), injections intravitréennes, ranibizumab (Lucentis), rétine, résultat visuel Dernière modification.

[Design of Synthetic Polymer Nanoparticles That Capture and Neutralize Target Molecules].

Protein affinity reagents that specifically and strongly bind to target molecules are widely used in disease detection, diagnosis, and therapy. Although antibodies and their fragments are the gold standard in protein-protein inhibitors (PPIs), synthetic polymers such as linear polymers, dendrimers, and nanoparticles as cost-effective PPIs have attracted great attention as alternatives to antibodies. These polymers exhibit high affinity to the target by imitating natural protein-protein interactions. However, only a few in vivo applications have been reported. Here, our recent advances in the development of synthetic polymers for in vivo application are reviewed. Poly(N-isopropylacrylamide) (pNIPAm) was used as a model of synthetic affinity reagents. Incorporation of both sulfated carbohydrate and hydrophobic monomers into lightly crosslinked pNIPAm nanoparticles (NPs) captured and neutralized vascular endothelial growth factor (VEGF) and inhibited tumor growth upon intravenous injection into tumor-bearing mice. Modification of a liposome with the pNIPAm-based linear polymer increased the polymer circulation time after intravenous injection and improved the affinity for the target. The pNIPAm-based NPs delivered by oral administration captured the target small molecules and inhibited their absorption from the intestine. Our recent findings provide useful information for the design of synthetic polymers that capture target molecules in vivo.

Enhanced Neovascularization Using Injectable and rhVEGF-Releasing Cryogel Microparticles.

Cryogels are gel networks or scaffolds with a large porous structure; they can be tailored for injectability and for possessing a shape-memory ability. Herein, a growth factor-releasing cryogel microparticle (CMP) system is fabricated, and the therapeutic efficacy of recombinant human vascular endothelial growth factor (rhVEGF)-loaded CMP (V-CMP) for neovascularization is investigated. To prepare the cryogels, both methacrylated chitosan (Chi-MA) and methacrylated chondroitin sulfate (CS-MA) are used, and crosslinking using a radical crosslinking reaction is established. The physical, mechanical, and biological properties of the cryogels are analyzed by varying the amount of CS-MA used. The cryogels are then pulverized, and microsized CMPs are fabricated. CMPs dispersed in saline demonstrate a shear-thinning property, and can thus be extruded through a 23G needle. Additionally, V-CMP exhibit a sustained release profile of rhVEGF and enhance the in vitro proliferation of endothelial cells. Finally, neovascularization and effective tissue necrosis prevention are observed when V-CMPs are injected into a hindlimb ischemia mouse model. Thus, the injectable V-CMP system developed herein demonstrates a high potential utility in various tissue regeneration applications based on cell or growth factor delivery.

Suction Cups-Inspired Adhesive Patch with Tailorable Patterns for Versatile Wound Healing.

Medical patches play an important role in wound healing because of their tissue conformality, drug release capacity, and convenient operation. Great efforts have been devoted to developing new-generation patches with distinctive features promoting wound healing. Here, inspired by the structure of octopus suction cups and the component of natural tissue, a biocompatible wound patch with selective adhesiveness and individualized design using a combined strategy of template-replication and mask-guided lithography is presented. Such patches are based on Ecoflex film with suction-cup-mimicking microstructures to adhere to normal skin and with biocompatible gelatin methacryloyl (GelMA) hydrogel to contact wounded areas. An ultraviolet mask with a tailorable pattern is employed to shape the GelMA hydrogel into customized geometry replicating individual wound areas, and thus both adhesion and antiadhesion properties are integrated into the same patch. In addition, vascular endothelial growth factor is loaded to accelerate the healing process. Based on these advantages, the authors demonstrate that the present patches not only adhere to different skin surfaces, but also promote the treatment of a rat cutaneous wound model. Thus, it is believed that this versatile patch can break through the limitation of traditional patches and be ideal candidates for wound healing and related biomedical applications.

Accelerated and Improved Vascular Maturity after Transplantation of Testicular Tissue in Hydrogels Supplemented with VEGF- and PDGF-Loaded Nanoparticles.

Avascular transplantation of frozen-thawed testicular tissue fragments represents a potential future technique for fertility restoration in boys with cancer. A significant loss of spermatogonia was observed in xeno-transplants of human tissue most likely due to the hypoxic period before revascularization. To reduce the effect of hypoxia-reoxygenation injuries, several options have already been explored, like encapsulation in alginate hydrogel and supplementation with nanoparticles delivering a necrosis inhibitor (NECINH) or VEGF. While these approaches improved short-term (5 days) vascular surfaces in grafts, neovessels were not maintained up to 21 days; i.e., the time needed for achieving vessel stabilization. To better support tissue grafts, nanoparticles loaded with VEGF, PDGF and NECINH were developed. Testicular tissue fragments from 4-5-week-old mice were encapsulated in calcium-alginate hydrogels, either non-supplemented (control) or supplemented with drug-loaded nanoparticles (VEGF-nanoparticles; VEGF-nanoparticles + PDGF-nanoparticles; NECINH-nanoparticles; VEGF-nanoparticles + NECINH-nanoparticles; and VEGF-nanoparticles + PDGF-nanoparticles + NECINH-nanoparticles) before auto-transplantation. Grafts were recovered after 5 or 21 days for analyses of tissue integrity (hematoxylin-eosin staining), spermatogonial survival (immuno-histo-chemistry for promyelocytic leukemia zinc finger) and vascularization (immuno-histo-chemistry for α-smooth muscle actin and CD-31). Our results showed that a combination of VEGF and PDGF nanoparticles increased vascular maturity and induced a faster maturation of vascular structures in grafts.

Laser-induced choroidal neovascularization: A case report and some reflection on animal models for age-related macular degeneration.

RATIONALE: Laser induced maculopathy includes retinal photoreceptor disruption, macular hole, macular hemorrhage, and rarely choroidal neovascularization (CNV). Here we report a case of laser induced CNV that was treated by intravitreal anti-vascular endothelial growth factor (VEGF) injection and resulted in visual improvement and CNV resolution during 1-year follow up. In addition, the case of laser induced CNV treated with intravitreal anti-VEGF injections are reviewed for the first time in literature. PATIENT CONCERNS: A 7-year-old boy presented to our department with blurred vision in his right eye for 2 months. The symptom immediately happened after the boy staring at the laser beam for a few seconds. Examination of ocular fundus with slit lamp showed yellowish lesion in macula in his right eye. DIAGNOSES: CNV was confirmed by fundus examinations, including color fundus photograph, spectral domain optical coherence tomography, fluorescein angiography, and spectral domain optical coherence tomography angiography. INTERVENTIONS: After the diagnosis of laser induced CNV, intravitreal ranibizumab (LUCENTIS, NOVARTIS) injection was performed. OUTCOMES: After 1 injection of intravitreal ranibizumab, the best corrected visual acuity improved from 20/50 to 30/50 and CNV gradually regressed during 1-year follow up. LESSONS: For young patients with laser induced CNV, intravitreal anti-VEGF injections may be helpful in visual improvement and CNV regression. Moreover, age seems to be a significant factor thus we propose that old animals may be more appropriate for laser induced CNV animal models of age-related macular degeneration.

Impact of Lipid/Magnesium Hydroxide Hybrid Nanoparticles on the Stability of Vascular Endothelial Growth Factor-Loaded PLGA Microspheres.

The purpose of the present study is to characterize poly(d,l-lactide-co-glycolide) (PLGA) composite microcarriers for vascular endothelial growth factor (VEGF) delivery. To reduce the initial burst release and protect the bioactivity, VEGF is encapsulated in soybean l-α-phosphatidylethanolamine (PE) and l-α-phosphatidylcholine (PC) anhydrous reverse micelle (VEGF-RM) nanoparticles. Also, mesoporous nano-hexagonal Mg(OH)2 nanostructure (MNS)-loaded PE/PC anhydrous reverse micelle (MNS-RM) nanoparticles are synthesized to suppress the induced inflammation of PLGA acidic byproducts and regulate the release profile. The flow-focusing microfluidic geometry platforms are used to fabricate different combinations of PLGA composite microspheres (PLGA-CMPs) with MNSs, MNS-RM, VEGF-RM, and native VEGF. The essential parameters of each formulation, such as release profiles, encapsulation efficacy, bioactivity, inflammatory response, and cytotoxicity, are investigated by in vitro and in vivo studies. The results indicate that generated acidic byproducts during the hydrolytic degradation process of PLGA can be buffered, and pH values inside and outside microspheres can remain steady during degradation by MNSs. Furthermore, the significant improvement in the stability of the encapsulated VEGF is confirmed by the bioactivity assay. In vitro release study shows that the VEGF initial burst release is well minimized in the present microcarriers. The present monodisperse PLGA-CMPs can be widely used in various tissue engineering and therapeutic applications.

Biologics in the Treatment of Achilles Tendon.

The treatment of Achilles tendinitis from conservative to minimally invasive to surgery gives patients a wide range of treatment options for this common pathology. The use and role of biologics to augment this treatment is emerging. The use of biologics may enhance the healing potential of the Achilles tendon when conservative treatment fails. There are a handful of biologics being investigated to obtain if improved outcomes can be maximized.

Comparison of visual outcomes between therapy choices and subtypes of polypoidal choroidal vasculopathy (PCV) in Taiwan: a real-world study.

Polypoidal choroidal vasculopathy (PCV) is a distinctive type of neovascular age-related macular degeneration prevalent in many Asian countries. However, there is still some controversy in how the subtypes of PCV are classified. This post-hoc study redefined the branching vascular network (BVN) and PCV subtypes through retrospective review of indocyanine green angiography (ICGA) and fluorescein angiography images from two observational studies (RENOWNED/REAL). Of the visual outcomes for each angiographic subtype and treatment pattern investigated, BVN was identified in 56.3% of PCV patients. The proportions and features of the re-defined PCV subtypes were 43.8%, 10.4%, and 45.8% for subtype A (without distinctive features of BVN), B (with BVN but no leakage), and C (with BVN and leakage), respectively. Subtype A had better visual outcomes when compared to subtype C. This possibly resulted from a better baseline visual acuity in subtype A. Moreover, combination therapy [photodynamic therapy plus anti-vascular endothelial growth factor (VEGF)] may lead to better visual improvement than mono-anti-VEGF treatment alone. This study provides the prevalence of PCV subtypes in Taiwan and may serve as a reference for PCV treatment strategies in a real-world setting, especially for the combination therapy and patients without distinctive features of BVN.

Multifunctional Composite Inverse Opal Film with Multiactives for Wound Healing.

A film with an elaborate microstructure and multifunctions is urgently needed in wound healing. Here, we present a multiactive encapsulated inverse opal film with a monitorable delivery system for chronic wound healing. The inverse opal film is prepared by using poly(lactic-co-glycolic acid) to negatively replicate a colloidal crystal template, which presents a high specific surface area and interconnected nanopores. It could be imparted with a potent antibacterial effect and promote angiogenesis by loading the vascular endothelial growth factor into the nanopores and encapsulating by chitosan. In addition, it is demonstrated that the structure color change of the film could intuitively reflect the drug release progress from the nanopores, which made the film a real-time drug monitoring system. In the affected wound model, the properties of the multifunctional film in promoting wound healing are certified by the faster healing speed, more granulation tissue, less inflammation, and even a distribution of new blood vessels and collagen. These results indicate that the resultant multifunctional film has a practical application value in clinical wound care.

VEGF Modulates the Neural Dynamics of Hippocampal Subregions in Chronic Global Cerebral Ischemia Rats.

Theta and gamma rhythms in hippocampus are important to cognitive performance. The cognitive impairments following cerebral ischemia is linked with the dysfunction of theta and gamma oscillations. As the primary mechanism for learning and memory, synaptic plasticity is in connection with these neural oscillations. Although vascular endothelial growth factor (VEGF) is thought to protect synaptic function in the ischemia rats to relieve cognitive impairment, little has been done on its effect of neural dynamics with this process. The present study investigated whether the alternation of neural oscillations in the hippocampus of ischemia rats is one of the potential neuroprotective mechanisms of VEGF. Rats were treated with the intranasal administration of VEGF at 72 h following chronic global cerebral ischemia procedure. Then local field potentials (LFPs) in hippocampal CA1 and CA3 regions were recorded and analyzed. Our results showed that VEGF can improve the power of theta and gamma rhythms in CA1 region after ischemia. Chronic global cerebral ischemia reduced the theta-gamma phase-amplitude coupling (PAC) not only within CA1 area but also in the pathway from CA3 to CA1, while VEGF alleviated the decreased coupling strength. Despite these notable differences, there were no obvious changes in the PAC within CA3 region. Surprisingly, the ischemia state did not affect the phase-phase interaction of hippocampus. In conclusion, our findings demonstrated that VEGF enhanced the theta-gamma PAC strength of CA3-CA1 pathway in ischemia rats, which may futher improve the information transmission within the hippocampus. These results illustrated the potential electrophysiologic mechanism of VEGF on cognitive improvement.

THE EFFECT OF ENDOPHTHALMITIS ON RECURRENCE OF MACULAR EDEMA IN EYES RECEIVING INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR.

PURPOSE: Visual outcomes after postinjection endophthalmitis have been well-studied, but the effect of endophthalmitis on the underlying exudative disease process remains unclear. We investigate the need for continued anti-vascular endothelial growth factor injections after endophthalmitis. METHODS: Eyes that developed endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor between January 1, 2016, and May 31, 2018, at a single academic retina practice were identified. Retrospective chart review was performed to determine 1) the proportion of eyes without recurrence of macular edema or subretinal fluid after endophthalmitis and 2) the proportion achieving a 12-week or greater interval between anti-vascular endothelial growth factor injections or exudation after endophthalmitis compared with internal controls before endophthalmitis. RESULTS: Of 50 eyes with endophthalmitis, seven (14.0%) had no fluid recurrence at a mean of 98.1 week. Of 43 eyes with recurrence, 48.0% achieved a >12-week recurrence-free interval after endophthalmitis (vs. 8.3% before endophthalmitis; P < 0.0001). Eyes with compared to those without choroidal neovascularization were more likely to achieve this interval (60.5% vs. 8.3%, respectively; P = 0.002). CONCLUSION: Endophthalmitis after anti-vascular endothelial growth factor injection is associated with relative stability of the underlying exudation. Further research is necessary to elucidate the mechanism, which may be useful in developing strategies and targets for the treatment of exudative macular diseases.

Sustained delivery of vascular endothelial growth factor from mesoporous calcium-deficient hydroxyapatite microparticles promotes in vitro angiogenesis and osteogenesis.

Promoting the growth of blood vessels within engineered tissues remains one of the main challenge in bone tissue engineering. One way to improve angiogenesis is the use of vascular endothelial growth factor (VEGF) as it holds the ability to increase the formation of a vascular network. In the present study, collagen scaffolds with VEGF-releasing hydroxyapatite particles were fabricated, in order to engineer a material both capable of presenting an osteoconductive surface and delivering an angiogenic growth factor in a localized and sustained manner, in order to enhance osteogenesis as well as angiogenesis. To this end, we developed microparticles and characterize their size, chemical properties and Ca/P ratio to validate the formation of hydroxyapatite. We then evaluated the osteogenic potential of HAp when cultured with mesenchymal stem cells and compare it to commercially available hydroxyapatite (SBp). Finally, we characterized the encapsulation and release of VEGF in the HAp and assess the angiogenic potential of the VEGF-HAp when cultured with endothelial cells. We demonstrated the successful fabrication of calcium deficient hydroxyapatite microparticles (CDHAp), with biological properties closer to the bone than stoichiometric, commercially available hydroxyapatite. This CDHAp exhibited a well-defined 3D network of crystalline nanoplates forming mesoporous and hollow structures. The high specific area created by those structures enabled the loading of VEGF with high efficiency when compared to the loading efficiency of SBp. Furthermore, their biological performances were evaluated in vitro. Our results indicate that VEGF-CDHAp can be used to improve both osteogenesis and angiogenesis in vitro.

Vascular endothelial growth factor alleviates mitochondrial dysfunction and suppression of mitochondrial biogenesis in models of Alzheimer's disease.

PURPOSE: Mitochondrial dysfunction is a prominent feature of Alzheimer's disease (AD). As vascular endothelial growth factor (VEGF) has been shown to be protective in AD, the aim of this study was to investigate the effects of VEGF on mitochondrial function in models of AD. MATERIALS AND METHODS: Adeno associated virus (AAV)-VEGF was injected into the hippocampus of APP/PS1 mice. Cognitive function was assessed in these mice with use of the Morris water maze (MWM) and ß-amyloid (Aß) levels in the hippocampus were also measured. Cell viability and reactive oxygen species (ROS) levels were determined in the SH-SY5Y cells treated with Aß25-35 which served as a cell model of AD. Transmission electron microscopy (TEM) was used to evaluate structural changes in mitochondria and mitochondrial DNA (mtDNA) copy number and mitochondrial membrane potential (MMP) were also recorded. Finally, we investigated the effects of VEGF upon mitochondrial biogenesis, autophagy and mitochondrial autophagy (mitophagy) as determined both in vivo and in vitro with western blots. RESULTS: VEGF treated mice showed improvements in spatial learning and memory along with reduced Aß levels. VEGF protected SH-SY5Y cells against Aß25-35 induced neurotoxicity as demonstrated by increased cell viability and decreased ROS production. Associated with these effects were improvements in mitochondrial structure and function, and increased numbers of mitochondria resulting from stimulation of mitochondrial biogenesis. CONCLUSIONS: VEGF alleviates Aß related patholoy in models of AD. In part, these beneficial effects of VEGF result from protection of mitochondria and stimulation of mitochondrial biogenesis.

A Chemotactic Functional Scaffold with VEGF-Releasing Peptide Amphiphiles Facilitates Bone Regeneration by BMP-2 in a Large-Scale Rodent Cranial Defect Model.

BACKGROUND: Current common techniques for repairing calvarial defects by autologous bone grafting and alloplastic implants have significant limitations. In this study, the authors investigated a novel alternative approach to bone repair based on peptide amphiphile nanofiber gels that are engineered to control the release of vascular endothelial growth factor (VEGF) to recruit circulating stem cells to a site of bone regeneration and facilitate bone healing by bone morphogenetic protein-2 (BMP-2). METHODS: VEGF release kinetics from peptide amphiphile gels were evaluated. Chemotactic functional scaffolds were fabricated by combining collagen sponges with peptide amphiphile gels containing VEGF. The in vitro and in vivo chemotactic activities of the scaffolds were evaluated by measuring mesenchymal stem cell migration, and angiogenic capability of the scaffolds was also evaluated. Large-scale rodent cranial bone defects were created to evaluate bone regeneration after implanting the scaffolds and other control materials. RESULTS: VEGF was released from peptide amphiphile in a controlled-release manner. In vitro migration of mesenchymal stem cells was significantly greater when exposed to chemotactic functional scaffolds compared to control scaffolds. In vivo chemotaxis was evidenced by migration of tracer-labeled mesenchymal stem cells to the chemotactic functional scaffolds. Chemotactic functional scaffolds showed significantly increased angiogenesis in vivo. Successful bone regeneration was noted in the defects treated with chemotactic functional scaffolds and BMP-2. CONCLUSIONS: The authors' observations suggest that this bioengineered construct successfully acts as a chemoattractant for circulating mesenchymal stem cells because of controlled release of VEGF from the peptide amphiphile gels. The chemotactic functional scaffolds may play a role in the future design of clinically relevant bone graft substitutes for large-scale bone defects.