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.

Using optical coherence tomography angiography to guide the treatment of pathological myopic patients with submacular hemorrhage.

The present study aimed to investigate whether optical coherence tomography angiography (OCTA) could be used to guide the treatment of pathological myopic patients with submacular hemorrhage. Two pathological myopia patients with submacular hemorrhage were examined. Initially, choroidal neovascularization (CNV) was not observed during fundus angiography in both patients. However, based on OCTA, the first patient was diagnosed with myopic lacquer crack-related macular hemorrhage, and the second with CNV secondary to punctate inner choroidopathy. The first patient was treated with traditional Chinese medicine administered orally, and the second with intravitreal injections of anti-vascular endothelial growth factor (VEGF). Lesions in both patients were resolved. Submacular hemorrhage in pathological myopia patients could be caused by numerous mechanisms. OCTA is useful in differentiating inflammatory CNV from inflammatory lesions, particularly if CNV is not detected using other multimodal imaging techniques.

VEGF-loaded mineral-coated microparticles improve bone repair and are associated with increased expression of epo and RUNX-2 in murine non-unions.

A poor vascular supply of the fracture gap is a key factor for the development of atrophic non-unions. Mineral-coated microparticles (MCM) represent a sophisticated carrier system for the delivery of vascular endothelial growth factor (VEGF). Hence, we investigated whether VEGF-loaded MCM improve bone repair in non-unions. For this purpose, we analyzed binding and release kinetics of MCM for VEGF in vitro. Moreover, we applied VEGF-loaded or -unloaded MCM in a murine non-union model in vivo and studied the process of bone healing by means of biomechanical, radiological, histomorphometric, and Western blot techniques. MCM-free non-unions served as controls. The binding efficiency of MCM for VEGF was 46 ± 3% and the release profile revealed an initial minor burst release followed by a sustained release over a 50-day study period, thus, mimicking the physiological expression profile of VEGF during bone healing. In vivo, bone defects treated with VEGF-loaded MCM exhibited a higher bending stiffness, a higher fraction of bone volume/tissue volume and a larger callus area on days 14 and 70 when compared to the other groups. Western blot analyses on day 14 revealed a higher expression of VEGF, erythropoietin (EPO), and runt-related transcription factor 2, but not of EPO-receptor in bone defects treated with VEGF-loaded MCM. These findings demonstrate that the use of MCM for VEGF delivery shows great potential due to the ability to maintain protein stability and functionality in vivo. Moreover, the application of VEGF-loaded MCM represent a promising strategy for the treatment of non-unions. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Vascular Endothelial Growth Factor Enhances Compensatory Lung Growth in Piglets.

BACKGROUND: Vascular endothelial growth factor has been found to accelerate compensatory lung growth after left pneumonectomy in mice. The aim of this study was to determine the natural history and the effects of vascular endothelial growth factor on compensatory lung growth in a large animal model. METHODS: To determine the natural history of compensatory lung growth, female Yorkshire piglets underwent a left pneumonectomy on days of life 10-11. Tissue harvest and volume measurement of the right lung were performed at baseline (n = 5) and on postoperative days 7 (n = 5), 14 (n = 4), and 21 (n = 5). For pharmacokinetic studies, vascular endothelial growth factor was infused via a central venous catheter, with plasma vascular endothelial growth factor levels measured at various time points. To test the effect of vascular endothelial growth factor on compensatory lung growth, 26 female Yorkshire piglets underwent a left pneumonectomy followed by daily infusion of vascular endothelial growth factor at 200 µg/kg or isovolumetric 0.9% NaCl (saline control). Lungs were harvested on postoperative day 7 for volume measurement and morphometric analyses. RESULTS: Compared with baseline, right lung volume after left pneumonectomy increased by factors of 2.1 ± 0.6, 3.3 ± 0.6, and 3.6 ± 0.4 on postoperative days 7, 14, and 21, respectively. The half-life of VEGF ranged from 89 to 144 minutes. Lesser doses of vascular endothelial growth factor resulted in better tolerance, volume of distribution, and clearance. Compared with the control group, piglets treated with vascular endothelial growth factor had greater lung volume (P < 0.0001), alveolar volume (P = 0.001), septal surface area (P = 0.007) and total alveolar count (P = 0.01). CONCLUSION: Vascular endothelial growth factor enhanced alveolar growth in neonatal piglets after unilateral pneumonectomy.

Increased vascularization promotes functional recovery in the transected spinal cord rats by implanted vascular endothelial growth factor-targeting collagen scaffold.

Spinal cord injury (SCI) is global health concern. The effective strategies for SCI are relevant to the improvement on nerve regeneration microenvironment. Vascular endothelial growth factor (VEGF) is an important cytokine for inducing angiogenesis and accelerating nerve system function recovery from injury. We proposed that VEGF could improve nerve regeneration in SCI. However, an uncontrolled delivery system target to injury site not only decreases the therapeutic efficacy but also increases the risk of tumor information. We implanted collagen scaffold (CS) targeted with a constructed protein, collagen-binding VEGF (CBD-VEGF), to bridge transected spine cord gap in a rat transected SCI model. Functional and histological examinations were conducted to assess the repair capacity of the delivery system CS/CBD-VEGF. The results indicated that the implantation of CS/CBD-VEGF into the model rats improved the survival rate and exerted beneficial effect on functional recovery. The controlled intervention improved the microenvironment, guided axon growth, and promoted neovascularization at the injury site. Therefore, the delivery system with stable binding of VEGF potentially provides a better therapeutic option for SCI. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1024-1034, 2018.

Specific humoral and cellular immune responses in cancer patients undergoing chronic immunization with a VEGF-based therapeutic vaccine.

CIGB-247 is a cancer therapeutic vaccine, based on recombinant modified human vascular endothelial growth factor (VEGF) as antigen, in combination with the adjuvant VSSP, a bacterially-derived adjuvant. The vaccine have demonstrated efficacy in several murine malignancy models. These studies supported the rationale for a phase I clinical trial where safety, tolerance, and immunogenicity of CIGB-247 was studied in patients with advanced solid tumors at three antigen dose level. Surviving individuals of this clinical trial were eligible to receive off-trial voluntary re-immunizations. The present work is focus in the immunological follow up of these patients after approximately three years of immunizations, without additional oncological treatments. Long term vaccination was feasible and safe. Our results indicated that after sustained vaccination most of the patients conserved their seroconversion status. The specific anti-VEGF IgG titer diminished, but in all the cases keeps values up from the pre-vaccination levels. Continued vaccination was also important to produce a gradual shift in the anti-VEGF IgG response from IgG1 to Ig4. Outstanding, our results indicated that long-term off-trial vaccination could be associated with the maintaining of one reserve of antibodies able to interfere with the VEGF/Receptor interaction and the production of IFNγ secretion in CD8+ cells. The results derived from the study of this series of patients suggest that long term therapeutic vaccination is a feasible strategy, and highlight the importance of continuing the clinical development program of this novel cancer therapeutic vaccine candidate. We also highlight the future clinical applications of CIGB-247 in cancer and explain knowledge gaps that future studies may address. Registration number and name of trial registry: RPCEC00000102. Cuban Public Clinical Trial Registry (WHO accepted Primary Registry). Available from: http://registroclinico.sld.cu/.

Dual growth factor delivery from biofunctionalized allografts: Sequential VEGF and BMP-2 release to stimulate allograft remodeling.

Autografts have been shown to stimulate osteogenesis, osteoclastogenesis, and angiogenesis, and subsequent rapid graft incorporation. Large structural allografts, however, suffer from limited new bone formation and remodeling, both of which are directly associated with clinical failure due to non-unions, late graft fractures, and infections, making it a priority to improve large structural allograft healing. We have previously shown the osteogenic ability of a polymer-coated allograft that delivers bone morphogenetic protein-2 both in vitro and in vivo through both burst release and sustained release kinetics. In this study, we have demonstrated largely sequential delivery of bone morphogenetic protein-2 and vascular endothelial growth factor from the same coated allograft. Release data showed that loading both growth factors onto a polymeric coating with two different techniques resulted in short-term (95% release within 2 weeks) and long-term (95% release within 5 weeks) delivery kinetics. We have also demonstrated how released VEGF, traditionally associated with angiogenesis, can also provide a stimulus for allograft remodeling via resorption. Bone marrow derived mononuclear cells were co-cultured with VEGF released from the coated allograft and showed a statistically significant (p < 0.05) and dose dependent increase in the number of tartrate-resistant acid phosphatase-positive multinucleated osteoclasts. Functionality of these osteoclasts was assessed quantitatively and qualitatively by evaluating resorption pit area from both osteo-assay plates and harvested bone. Data indicated a statistically significant higher resorption area from the cells exposed to VEGF released from the allografts over controls (p < 0.05). These results indicate that by using different loading protocols temporal control can be achieved when delivering multiple growth factors from a polymer-coated allograft. Further, released VEGF can also stimulate osteoclastogenesis that may enhance allograft incorporation, and thus mitigate long-term clinical complications. © 2017 Orthopedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1086-1095, 2017.

Transplantation of testicular tissue in alginate hydrogel loaded with VEGF nanoparticles improves spermatogonial recovery.

Transplantation of cryopreserved immature testicular tissue (ITT) is a promising strategy to restore fertility in young boys facing gonadotoxic treatments. However, up to now, limited spermatogonial recovery has been achieved in xenografting models used to evaluate the potential of cryopreserved tissue transplantation. When comparing avascular xenografts of cryopreserved and fresh human ITT into a mouse model, the number of spermatogonia was significantly reduced, regardless of the cryopreservation procedure used. To improve tissue engraftment, revascularization and hence spermatogonial survival, ITT was embedded in two types of hydrogel loaded with VEGF nanoparticles. Small pieces (±1mm(3)) of testicular tissue were grafted in NMRI mice as follows: grafted without encapsulation, grafted after encapsulation in fibrin, in alginate, in fibrin-VEGF-nanoparticle (NP) and in alginate-VEGF-NP. Non-grafted tissue served as control. After 5 and 21days of implantation, seminiferous tubule integrity, revascularization and spermatogonial recovery were evaluated by histology and immunohistochemistry. Seminiferous tubule integrity ranged from 13.3% to 39.6% and 42.7% to 68.7% on day 5 and day 21, respectively. Vascular density on day 5 was found to be higher in VEGF supplemented groups, regardless of the hydrogel used. Staining for phosphorylated VEGF receptor 2 and endothelial proliferation on day 5 was higher in all groups compared to non-grafted avascular controls. Spermatogonial recovery ranged between 14.8% and 27.3% on day 21 and was significantly higher in the alginate and alginate-VEGF-NP groups. The present study demonstrates the potential of alginate hydrogel loaded with nanoencapsulated growth factors to improve cryopreserved tissue engraftment.

Effects and mechanism analysis of vascular endothelial growth factor and salvianolic acid B on 125I-low density lipoprotein permeability of the rabbit aortary endothelial cells.

Atherosclerosis is the common pathological basis of cardiovascular and cerebrovascular disease. This study aimed to investigate the effects of vascular endothelial growth factor (VEGF) and salvianolic acid B (SalB) on the permeability of the rabbit aortary endothelial cells (RAECs) and to figure out the possible underlying molecular mechanisms. The extravasation of (125)I-low density lipoprotein ((125)I-LDL) through the RAECs was significantly increased by VEGF and decreased by SalB. Meanwhile, the tight junction-associated proteins occludin and claudin-5 were found downregulated by VEGF and the caveolae structure proteins caveolin-1 and caveolin-2 upregulated, which were abolished by the infusion of SalB. In addition, a marked increase in levels of cGMP and protein kinase G-1 (PKG-1) as well as activation of nuclear factor-κB (NF-κB) p65 were found after VEGF infusion, which were attenuated by SalB. This study demonstrates that VEGF and SalB can alter the LDL permeability of the RAECs by a paracellular pathway (downregulation of occludin and claudin-5) and a transcellular pathway (upregulation of caveolin-1 and caveolin-2), in which the cGMP/PKG/NF-κB signal pathway is possibly involved. The experimental results provide a new method and basic knowledge of prevention and treatment for cardiovascular and cerebrovascular disease.

Superparamagnetic iron oxide nanoparticles mediated (131)I-hVEGF siRNA inhibits hepatocellular carcinoma tumor growth in nude mice.

BACKGROUND: Hepatocellular carcinoma (HCC) is a primary liver tumor and is the most difficult human malignancy to treat. In this study, we sought to develop an integrative approach in which real-time tumor monitoring, gene therapy, and internal radiotherapy can be performed simultaneously. This was achieved through targeting HCC with superparamagnetic iron oxide nanoparticles (SPIOs) carrying small interfering RNA with radiolabled iodine 131 (131I) against the human vascular endothelial growth factor (hVEGF). METHODS: hVEGF siRNA was labeled with 131I by the Bolton-Hunter method and conjugated to SilenceMag, a type of SPIOs. 131I-hVEGF siRNA/SilenceMag was then subcutaneously injected into nude mice with HCC tumors exposed to an external magnetic field (EMF). The biodistribution and cytotoxicity of 131I-hVEGF siRNA/SilenceMag was assessed by SPECT (Single-Photon Emission Computed Tomography) and MRI (Magnetic Resonance Imaging) studies and blood kinetics analysis. The body weight and tumor size of nude mice bearing HCC were measured daily for the 4-week duration of the experiment. RESULTS: 131I-hVEGF siRNA/SilenceMag was successfully labeled; with a satisfactory radiochemical purity (>80%) and biological activity in vitro. External application of an EMF successfully attracted and retained more 131I-hVEGF siRNA/SilenceMag in HCC tumors as shown by SPECT, MRI and biodistribution studies. The tumors treated with 131I-hVEGF siRNA/SilenceMag grew nearly 50% slower in the presence of EMF than those without EMF and the control. Immunohistochemical assay confirmed that the tumor targeted by 131I-hVEGF siRNA/SilenceMag guided by an EMF had a lower VEGF protein level compared to that without EMF exposure and the control. CONCLUSIONS: EMF-guided 131I-hVEGF siRNA/SilenceMag exhibited an antitumor effect. The synergic therapy of 131I-hVEGF siRNA/SilenceMag might be a promising future treatment option against HCC with the dual functional properties of tumor therapy and imaging.

VEGF ameliorates cognitive impairment in in vivo and in vitro ischemia via improving neuronal viability and function.

Vascular endothelial growth factor (VEGF) has recently been proved to be a potential therapeutic drug in ischemic disorders depending on the dose, route and time of administration, especially in focal cerebral ischemia. Whether VEGF could exert protection in a long-term total cerebral ischemic model is still uncertain, and the cellular mechanism has not been clarified so far. In order to answer the above issue, an experiment was performed in non-invasively giving exogenous VEGF to a total cerebral ischemic model rats and examining their spatial cognitive function by performing Morris water maze and long-term potential test. Moreover, we performed in vitro experiment to explore the cellular mechanism of VEGF protection effect. In an in vitro ischemia model oxygen-glucose deprivation (OGD), whole-cell patch-clamp recording was employed to examine neuronal function. Additionally, hematoxylin-eosin and propidium iodide staining were applied in vivo and in vitro in the neuropathological and viability study, separately. Our results showed that intranasal administration of VEGF could improve the cognitive function, synaptic plasticity and damaged hippocampal neurons in a global cerebral ischemia model. In addition, VEGF could retain the membrane potential, neuronal excitability and spontaneous excitatory postsynaptic currents in the early stage of ischemia, which further demonstrated that there was an acute effect of VEGF in OGD-induced pyramidal neurons. Simultaneously, it was also found that the death of CA1 pyramidal neuronal was significantly reduced by VEGF, but there was no similar effect in VEGF coexists with SU5416 group. These results indicated that VEGF could ameliorate cognitive impairment and synaptic plasticity via improving neuronal viability and function through acting on VEGFR-2.

Silibinin inhibits VEGF secretion and age-related macular degeneration in a hypoxia-dependent manner through the PI-3 kinase/Akt/mTOR pathway.

BACKGROUND AND PURPOSE: Hypoxia-mediated neovascularization plays an important role in age-related macular degeneration (AMD). There are few animal models or effective treatments for AMD. Here, we investigated the effects of the flavonoid silibinin on hypoxia-induced angiogenesis in a rat AMD model. EXPERIMENTAL APPROACH: Retinal pigmented epithelial (RPE) cells were subjected to hypoxia in vitro and the effects of silibinin on activation of key hypoxia-induced pathways were examined by elucidating the hypoxia-inducible factor-1 alpha (HIF-1α) protein level by Western blot. A rat model of AMD was developed by intravitreal injection of VEGF in Brown Norway rats, with or without concomitant exposure of animals to hypoxia. Animals were treated with oral silibinin starting at day 7 post-VEGF injection and AMD changes were followed by fluorescein angiography on days 14 and 28 post-injection. KEY RESULTS: Silibinin pretreatment of RPE cells increased proline hydroxylase-2 expression, inhibited HIF-1α subunit accumulation, and inhibited VEGF secretion. Silibinin-induced HIF-1α and VEGF down-regulation required suppression of hypoxia-induced phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (mTOR) pathway. In the rat model of AMD, silibinin administration prevented VEGF- and VEGF plus hypoxia-induced retinal oedema and neovascularization. CONCLUSION AND IMPLICATIONS: The effects of silibinin, both in vitro and in vivo, support its potential as a therapeutic for the prevention of neovascular AMD.

Induction of beta-cell resistance to hypoxia and technologies for oxygen delivery to transplanted pancreatic islets.

Hypoxia is believed to be a crucial factor involved in cell adaptation to environmental stress. Islet transplantation, especially with immunoisolated islets, interrupts vascular connections, resulting in the substantially decreased delivery of oxygen and nutrients to islet cells. Insulin-producing pancreatic beta cells are known to be highly susceptible to oxygen deficiency. Such susceptibility to hypoxia is believed to be one of the main causes of beta-cell death in the post-transplantation period. Different strategies have been developed for the protection of beta cells against hypoxic injury and for oxygen delivery to transplanted islets. The enhancement of beta-cell defense properties against hypoxia has been achieved using various techniques such as gene transfection, drug supplementation, co-culturing with stem cells and cell selection. Technologies for oxygen delivery to transplanted islets include local neovascularization of subcutaneous sites, electrochemical and photosynthetic oxygen generation, oxygen refuelling of bio-artificial pancreas and whole body oxygenation by using hyperbaric therapy. Progress in the field of oxygen technologies for islet transplantation requires a multidisciplinary approach to explore and optimize the interaction between components of the biological system and different technological processes. This review article focuses mainly on the recently developed strategies for oxygenation and protection from hypoxic injury - to achieve stable and long-term normoglycaemia in diabetic patients with transplanted pancreatic islets.

Captopril attenuates hypertension and renal injury induced by the vascular endothelial growth factor inhibitor sorafenib.

Vascular endothelial growth factor inhibitors (VEGFi) are known to cause hypertension and renal injury that severely limits their use as an anticancer therapy. We hypothesized that the angiotensin-converting enzyme inhibitor captopril not only prevents hypertension, but also decreases renal injury caused by the VEGFi sorafenib. Rats were administered sorafenib (20 mg/kg per day) alone or in combination with captopril (40 mg/kg per day) for 4 weeks. Sorafenib administration increased blood pressure, which plateaued by day 10. Concurrent treatment with captopril for 4 weeks resulted in a 30 mmHg decrease in blood pressure compared with sorafenib alone (155 ± 5 vs 182 ± 6 mmHg, respectively; P < 0.05). Furthermore, concurrent captopril treatment reduced albuminuria by 50% compared with sorafenib alone (20 ± 8 vs 42 ± 9 mg/day, respectively; P < 0.05) and reduced nephrinuria by eightfold (280 ± 96 vs 2305 ± 665 µg/day, respectively; P < 0.05). Glomerular injury, thrombotic microangiopathy and tubular cast formation were also decreased in captopril-treated rats administered sorafenib. Renal autoregulatory efficiency was determined by evaluating the afferent arteriolar constrictor response to ATP. Sorafenib administration attenuated the vasoconstriction to ATP, whereas concurrent captopril treatment improved ATP reactivity. In conclusion, captopril attenuated hypertension and renal injury and improved renal autoregulatory capacity in rats administered sorafenib. These findings indicate that captopril treatment, in addition to alleviating the detrimental side-effect of hypertension, decreases the renal injury associated with anticancer VEGFi therapies such as sorafenib.

Complementary therapeutic effects of dual delivery of insulin-like growth factor-1 and vascular endothelial growth factor by gelatin microspheres in experimental heart failure.

AIMS: Strategies to prevent adverse left ventricular (LV) remodelling after myocardial infarction have included several traditional approaches and novel cell-based or gene therapies. Delivery of growth factors in post-infarction heart failure has emerged as a valuable alternative strategy. Our aim was to investigate the effects of sequential release of vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) from biodegradable gelatin microspheres in experimental heart failure. METHODS AND RESULTS: Gelatin hydrogel microspheres were known to guarantee a sustained release of encapsulated growth factors, characterized by an initial burst followed by a slower release. Rats with moderate myocardial infarction were randomized to receive empty microspheres (MI), microspheres loaded with IGF-1 or VEGF, or a combination thereof (DUAL). Myocardial injections of microspheres were performed at the time of surgery, and treatment lasted 4 weeks. Echocardiography, LV catheterization, morphometric histology and immunohistochemistry, and molecular assessment of downstream mediators [e.g. Akt, endothelial nitric oxide synthase (eNOS), and sarco/endoplasmic reticulum calcium ATPase-2 (SERCA-2)] were assessed at the end of the treatment period. Infarct sizes were 33 ± 2, 28 ± 4, 24 ± 3, and 16 ± 3% in the MI, IGF-1, VEGF, and DUAL groups, respectively. IGF-1 attenuated LV remodelling, improved LV systolic and diastolic function, increased myocyte size, and reduced apoptotic deaths, capillary loss, and indexes of inflammation. VEGF-treated animals displayed a marked myocardial neoangiogenesis that led to the formation of mature vessels if combined with IGF-1 delivery. Downstream effects of IGF-1 were principally mediated by the Akt-mTOR (mammalian target of rapamycin)-dependent pathway, and both growth factors, particularly VEGF, induced a robust and sustained increase of eNOS. CONCLUSION: IGF-1 and VEGF exerted complementary therapeutic effects in post-infarction heart failure. Biodegradable gelatin microspheres provide sustained and controlled growth factor release locally, exposing myocardial tissue without the side effects of systemic administration.

Bevacizumab for the first-line treatment of human epidermal growth factor receptor 2-negative advanced breast cancer.

PURPOSE OF REVIEW: Breast cancer is the most common cancer in women worldwide and its incidence is increasing as a result of the continued adoption of lifestyles associated with increased risk factors. Approximately, 75% of breast cancers do not express the human epidermal growth factor receptor 2 (HER2), including hormone receptor-positive and triple-negative tumors. HER2-negative breast cancers are resistant to, or eventually become resistant to, existing targeted treatments such as HER2-targeted agents and hormone therapies, and, as a consequence, are associated with poorer outcomes than HER2-positive breast cancer. Bevacizumab is a humanized monoclonal antibody that recognizes vascular endothelial growth factor-A, a rate-limiting step in pathological angiogenesis such as tumor growth. As angiogenic pathways become more complex as breast cancer progresses, angiogenesis inhibitors should be initiated earlier in the disease course. This review will discuss the evidence for bevacizumab as first-line therapy in metastatic breast cancer, with a particular focus on patients with HER2-negative disease. RECENT FINDINGS: Bevacizumab, when administered in combination with first-line standard chemotherapy, significantly increases progression-free survival and overall response rate in patients with metastatic breast cancer. SUMMARY: Novel targeted therapies that are appropriate to HER2-negative breast cancer, such as bevacizumab, may represent valuable therapeutic options in the clinical management of metastatic breast cancer.

Temperature-induced gel formation of core/shell nanoparticles for the regeneration of ischemic heart.

Vascular endothelial growth factor (VEGF)-loaded core/shell nanoparticles were prepared and their gelation behavior in response to temperature was characterized for the regeneration of ischemic heart. The core is composed of lecithin containing VEGF and the shell is composed of Pluronic F-127 (poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer). When Capryol 90 (propylene glycol monocaprylate) was added to an aqueous solution of the core/shell nanoparticles, a temperature-induced gel composed of core/shell nanoparticles was observed to form at body temperature. This phenomenon was utilized for the stable localization of core/shell nanoparticles at the ischemic area. For an in vivo assessment, VEGF-loaded core/shell nanoparticles with and without inducement of the gel formation were applied to a subacute myocardial infarction model in rats and functional analysis of the heart was monitored by means of a PV catheter four weeks later. The results showed that the VEGF-loaded core/shell nanoparticles and their gel improved the heart functions, particularly with regard to the ejection fraction and cardiac output.

Omental roll-up: a technique for islet engraftment in a large animal model.

BACKGROUND: Attrition of transplanted islets is significant after hepatic embolization. This study was designed to investigate a novel surgical technique for islet transplantation into the omentum. This site allows placement of the islets in a three-dimensional (3D) matrix, with growth factors, to temporarily culture the islets in vivo while revascularization progresses. MATERIALS AND METHODS: Five female dogs (three partial and two total pancreatectomies) received an autologous islet transplant in the omentum. Islets were suspended in 1 mL of PBS containing 10 ug of vascular endothelial growth factor (VEGF). Fresh autologous plasma (10 mL) was mixed with the islet/VEGF suspension. The coagulum containing the islets and VEGF was then placed on the greater omentum. The leading edge of omentum was rolled up to secure the islet/VEGF/coagulum in position and to present the thin islet layer with two omental surfaces for implantation. Omentum was recovered at 2, 13, 21, 42, and 180 d. RESULTS: Immunohistochemical staining for synaptophysin, glucagon, and insulin confirmed the presence of transplanted islets in all omenta. Insulin and C peptide production from the omental islets was confirmed in portal venous samples, and normalization of morning glucose levels beginning on day 7 was seen in the total pancreatectomy experiment. CONCLUSIONS: Autologous islets implant in rolled-up omentum when placed as a VEGF/autologous plasma coagulum. This technique has potential benefits, including the opportunity to accelerate revascularization and to investigate local strategies for modulating the immune response.

Concomitant treatment with oral L-arginine improves the efficacy of surgical angiogenesis in patients with severe diffuse coronary artery disease: the Endothelial Modulation in Angiogenic Therapy randomized controlled trial.

OBJECTIVE: Endothelial dysfunction and decreased nitric oxide bioavailability may explain why therapeutic angiogenesis and cell therapy have mostly failed in humans. Building from previous large animal work, the Phase I Endothelial Modulation in Angiogenic Therapy trial tested the hypothesis that L-arginine, a nitric oxide donor, may be safe and effective in potentiating surgical angiogenesis in humans. METHODS: Patients with surgical triple-vessel coronary disease and a severely diffusely diseased left anterior descending artery were randomized in 2 x 2 factorial fashion to receive ten 200-microg injections of vascular endothelial growth factor-165 plasmid DNA or placebo in the anterior myocardium along the proximal and mid-left anterior descending arteries, plus oral L-arginine supplementation at a dose of 6 g per day or placebo for 3 months. The distal left anterior descending artery and other coronary arteries were grafted. End points included 3-month changes in myocardial perfusion and contractility of the anterior myocardium, using (13)N-ammonia positron emission tomography and echocardiography. Baseline scans were obtained 3 to 7 days postoperatively to delineate treatment effects from the effects of coronary artery bypass grafting. RESULTS: Patient (N = 19) characteristics were equivalent between groups. There was no perioperative or late mortality. Patients who received the combination of vascular endothelial growth factor and L-arginine had improved anterior wall perfusion on positron emission tomography (P = .02), a trend toward smaller perfusion defects (P = .10), and better anterior wall contractility (P = .02, Kruskal-Wallis) at 3 months versus baseline. This was corroborated by a trend toward better disease perception at 3 months versus baseline on the Seattle Angina Questionnaire (score improvement of 47 +/- 35, combination treatment group; P = .1, Kruskal-Wallis). CONCLUSION: To our knowledge, this is the first study to examine concomitant substrate modification in patients undergoing new biosurgical therapies by using vascular endothelial growth factor angiogenesis. The results suggest safety and efficacy. Concomitant endothelial modulation with L-arginine not only has the potential to make angiogenesis effective but also may have implications for cell therapy trials.

Intravascular magnetic resonance/radiofrequency may enhance gene therapy for prevention of in-stent neointimal hyperplasia.

RATIONALE AND OBJECTIVES: We evaluated the potential of using intravascular magnetic resonance (MR)/radiofrequency (RF) to enhance vascular endothelial growth factor (VEGF) gene therapy of in-stent neointimal hyperplasia. MATERIALS AND METHODS: By using a catheter-based approach, VEGF/lentivirus was locally transferred into 10 (five paired) bilateral femoral-iliac arteries of five hypercholesterolemic pigs, whereas the right arteries were heated up to approximately 41 degrees C by using an intravascular MR/RF system. Then, identical stents were placed immediately into the bilateral VEGF-targeted arteries to create in-stent neointimal hyperplasia. At day 60 after gene/stent interventions, the targeted arteries were harvested for histological correlation. RESULTS: X-Ray angiography-detectable in-stent stenoses were found in three of the arteries treated with VEGF genes only, whereas there were no in-stent stenoses in arteries treated by using MR/RF-heated VEGF genes. Correlative histological examination confirmed a 138% reduction in average thickness of neointimal hyperplasia in VEGF/RF-treated arteries compared with VEGF-only-treated arteries (P < .01). CONCLUSION: We report a potential method of using an intravascular MR/RF heating technique to enhance gene therapy of in-stent restenosis.