Motivated by the need for bioactive materials that can accelerate dermal wound healing, this work describes the response of keratinocytes to covalently immobilized epidermal growth factor (EGF) and how differences in the physical presentation of this growth factor impact cell function. Specifically, human keratinocytes were cultured with EGF delivered in soluble form, immobilized in a homogeneous pattern, or immobilized in a gradient pattern, followed by analysis of cellular signaling, proliferation, and migration. By changing the manner in which EGF was presented, keratinocyte behavior was dramatically altered. Keratinocytes responded to immobilized EGF patterns with high EGF receptor (EGFR) but low ERK 1/2 and Akt phosphorylation, accompanied by low proliferation, high migratory activity, and coordinated cell alignment. In contrast, keratinocytes treated with soluble EGF experienced lower EGFR but higher ERK 1/2 and Akt phosphorylation, and displayed a highly proliferative, rather than migratory, phenotype. Keratinocytes also responded to differences in immobilized EGF patterns, as migration was fastest upon immobilized gradients of EGF. Better understanding the interaction of cells with soluble vs. immobilized growth factors can help elucidate native healing events and achieve greater control over cell function, which may be useful in the development of wound repair treatments for many types of tissues.

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BackgroundImproved cancer therapeutics and enhanced cancer survivorship have emphasized the severe long-term side effects of chemotherapy. Specifically, studies have linked many chemotherapy agents with primary ovarian insufficiency, although an exact insult model has not yet been determined. To investigate and ultimately solve this problem, a novel device for extended study of mammalian ovaries in vitro was developed.MethodsA bioreactor was fabricated for bovine ovarian culture that provides intravascular delivery of media to the ovary through isolation and cannulation of a main ovarian artery branch. Whole ovaries were cultured in vitro using three methods: (1) continuously supplied fresh culture media, (2) recirculated culture media, or (3) continuously supplied fresh culture media supplemented with 500 nM doxorubicin for 24 or 48 h. TUNEL assay was used to assess apoptotic cell percentages in the three groups as compared to uncultured baseline ovaries.ResultsThe ovary culture method was shown to maintain cell viability by effectively delivering nutrient-enriched pH-balanced media at a constant flow rate. Lower apoptosis observed in ovaries cultured in continuously supplied fresh culture media illustrates that this culture device and method are the first to sustain whole bovine ovary viability for 48 h. Meanwhile, the increase in the percentage of cell apoptosis with doxorubicin treatment indicates that the device can provide an alternative model for testing chemotherapy and chemoprotection treatments to prevent primary ovarian insufficiency in cancer patients.ConclusionsAn ovarian bioreactor with consistent culture media flow through an ovarian vasculature-assisted approach maintains short-term whole bovine ovary viability.Electronic supplementary materialThe online version of this article (doi:10.1186/s13048-016-0249-4) contains supplementary material, which is available to authorized users.

Thoracocentesis, a procedure in which air or fluid is removed from the pleural space, is used to relieve respiratory distress, and as a diagnostic procedure in human and veterinary medicine. Veterinary students commonly learn and practice the procedure on canine cadavers which are in limited supply and are not amenable to long-term storage and use. Practicing thoracocentesis on a cadaveric model also provides limited feedback indicative of success and/or procedural complications. One commercial model for practicing canine thoracocentesis is available, but it costs over US$2000 and is excessively bulky. In order to improve the learning process for veterinary students, we have developed a reusable synthetic canine thorax model that accurately replicates the thoracocentesis procedure, provides immediate feedback to the students and reduces the need for canine cadavers. The low cost of our product provides an efficient alternative to cadavers for instruction in veterinary schools or hospitals.

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