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Clinical trials of therapeutic angiogenesis by vascular endothelial growth factor (VEGF) gene delivery failed to show efficacy. Major challenges include the need to precisely control in vivo distribution of growth factor dose and duration of expression. Recombinant VEGF protein delivery could overcome these issues, but rapid in vivo clearance prevents the stabilization of induced angiogenesis. Here, we developed an optimized fibrin platform for controlled delivery of recombinant VEGF, to robustly induce normal, stable, and functional angiogenesis. Murine VEGF164 was fused to a sequence derived from α2-plasmin inhibitor (α2-PI1-8) that is a substrate for the coagulation factor fXIIIa, to allow its covalent crosslinking into fibrin hydrogels and release only by enzymatic cleavage. An α2-PI1-8-fused variant of the fibrinolysis inhibitor aprotinin was used to control the hydrogel degradation rate, which determines both the duration and effective dose of factor release. An optimized aprotinin-α2-PI1-8 concentration ensured ideal degradation over 4 wk. Under these conditions, fibrin- α2-PI1-8-VEGF164 allowed exquisitely dose-dependent angiogenesis: concentrations =25 μg/mL caused widespread aberrant vascular structures, but a 500-fold concentration range (0.01-5.0 μg/mL) induced exclusively normal, mature, nonleaky, and perfused capillaries, which were stable after 3 mo. Optimized delivery of fibrin-α2-PI1-8-VEGF164 was therapeutically effective both in ischemic hind limb and wound-healing models, significantly improving angiogenesis, tissue perfusion, and healing rate. In conclusion, this optimized platform ensured (i) controlled and highly tunable delivery of VEGF protein in ischemic tissue and (ii) stable and functional angiogenesis without introducing genetic material and with a limited and controllable duration of treatment. These findings suggest a strategy to improve safety and efficacy of therapeutic angiogenesis. [ABSTRACT FROM AUTHOR]

Clinical trials of therapeutic angiogenesis by vascular endothelial growth factor (VEGF) gene delivery failed to show efficacy. Major challenges include the need to precisely control in vivo distribution of growth factor dose and duration of expression. Recombinant VEGF protein delivery could overcome these issues, but rapid in vivo clearance prevents the stabilization of induced angiogenesis. Here, we developed an optimized fibrin platform for controlled delivery of recombinant VEGF, to robustly induce normal, stable, and functional angiogenesis. Murine VEGF164 was fused to a sequence derived from α2-plasmin inhibitor (α2-PI1-8) that is a substrate for the coagulation factor fXIIIa, to allow its covalent crosslinking into fibrin hydrogels and release only by enzymatic cleavage. An α2-PI1-8-fused variant of the fibrinolysis inhibitor aprotinin was used to control the hydrogel degradation rate, which determines both the duration and effective dose of factor release. An optimized aprotinin-α2-PI1-8 concentration ensured ideal degradation over 4 wk. Under these conditions, fibrin- α2-PI1-8-VEGF164 allowed exquisitely dose-dependent angiogenesis: concentrations =25 μg/mL caused widespread aberrant vascular structures, but a 500-fold concentration range (0.01-5.0 μg/mL) induced exclusively normal, mature, nonleaky, and perfused capillaries, which were stable after 3 mo. Optimized delivery of fibrin-α2-PI1-8-VEGF164 was therapeutically effective both in ischemic hind limb and wound-healing models, significantly improving angiogenesis, tissue perfusion, and healing rate. In conclusion, this optimized platform ensured (i) controlled and highly tunable delivery of VEGF protein in ischemic tissue and (ii) stable and functional angiogenesis without introducing genetic material and with a limited and controllable duration of treatment. These findings suggest a strategy to improve safety and efficacy of therapeutic angiogenesis. [ABSTRACT FROM AUTHOR]

Abstract: Background: Low level light therapy (LLLT) is an attractive alternative to enhance wound healing. So far most studies are performed with red or infrared irradiation. However, we recently showed that blue light (470nm) can significantly influence biological systems, improving perfusion by release of nitric oxide from nitrosyl complexes with haemoglobin in a skin flap model in rats. Here, we compared the effects of blue and red low level light by light-emitting diodes (LEDs) on in vivo wound healing in an excision wound model in rats. Methods: Circular excision wounds were surgically created on the dorsum of each rat. Excisions on either the left or right side were illuminated post-OP and on five consecutive days for 10min by LED at 470nm or 630nm with an intensity of 50mW/cm2, while protecting the contralateral side from exposure. In the control group, neither side was illuminated. On day 7 post-OP, we analysed planimetric and histological parameters, as well as expression of keratin-1, keratin-10 and keratin-17 on mRNA level. Results: Illumination substantially influenced wound healing. Blue light significantly decreased wound size on day 7, which correlated with enhanced epithelialisation. Light also affected mRNA expression. Both wavelengths decreased keratin-1 mRNA on day 7 post-OP, while keratin-10 mRNA level was elevated in both light treated group compared to control. Keratin-17 mRNA was also elevated in the red light group, but was unchanged in the blue light group. Conclusion: In contrast to previous studies, we showed that also blue light significantly influences wound healing. Furthermore, our data suggest that light therapy can play an important role in normotrophic wound healing by affecting keratin expression. Illumination would provide an easily applicable, safe and cost-effective treatment of surface wounds. [Copyright &y& Elsevier]

Body temperature is a clinical parameter in vaccine quality control to detect systemic side-effects or to monitor progression of infectious diseases. Moreover, changes in body temperature are used as clinical parameters to define humane endpoints in animal experiments. However, measuring body temperature via the rectal route can be troublesome and distressing to the animal. Non-invasive measurement methods were developed in recent years. The aim of this investigation was to study and to compare rectally measured body temperature with data obtained with implanted temperature-sensitive transponders (TST) in mice, guinea pigs, rabbits and pigs under the controlled conditions of regulatory testing.

For licensing the efficacy of vaccines for veterinary use has to be demonstrated by well-controlled laboratory experiments in which vaccinated and untreated animals of the target species are challenged. Erysipelas challenge tests cause extreme suffering of the unprotected animals with high fever, apathy, large skin lesions, and even death. This paper describes a standardised procedure for the vaccination challenge test and gives due consideration to the welfare of the animals. By monitoring and using clinical signs observed during the test it is possible to minimise animal pain and distress, thus preventing unnecessary animal suffering.

The antibody-stimulating activities and side effects of commercially available adjuvants were compared in BALB/c mice immunised with the immunosuppressive (ISU) peptide of HIV I. Clinical and pathological-histological parameters as well as behavioural changes, were used to assess the distress and pain caused to the animals. Complete Freund's Adjuvant (FAk) was used as the positive control and PBS as the negative control. The oil-based adjuvants Montanide ISA 51(R) (M 51), Specol(R), and Hunter's TiterMax Gold(R) (HTMG) were used with the ISU-peptide conjugated to KLH. The water-soluble Gerbu Adjuvant(R) was administered together with the antigen KLH conjugate and also with the ISU-peptide conjugated to cholera toxin B subunit (ChTxB). The Dutch "Code of Practice" was used as a guideline for all immunisations. No changes in animal activity or behaviour was observed in any of the groups. All the oil-based adjuvants gave rise to swellings and encapsulations, which were most pronounced in the HTMG-group. Although body weight increased throughout the study, no increase was seen in any adjuvant group for a short period after each booster immunisation, nor after the first immunisation in the HTMG group. FAk induced a light fever after all immunisations. FAk, Specol and M 51 as well as Gerbu-ChTxB induced antibody titres which were detectable in the ELISA, but no detectable antibody the water-soluble adjuvants or following administration of HTMG applied with the ISU-peptide-KLH conjugate.