{"638473":{"#nid":"638473","#data":{"type":"news","title":"Healing Under Pressure","body":[{"value":"\u003Cp\u003EThe natural processes of wound or bone healing rely on the growth of new blood vessels, or angiogenesis. If someone breaks a bone, it is standard practice to apply a cast and immobilize the broken bone, so that healing can proceed without mechanical distortion.\u0026nbsp;\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EAfter those initial stages of healing, applying surprising amounts of pressure can encourage angiogenesis, according to a new paper in\u0026nbsp;\u003Cem\u003E\u003Ca href=\u0022https:\/\/advances.sciencemag.org\/content\/6\/34\/eabb6351\u0022\u003EScience Advances\u003C\/a\u003E \u003C\/em\u003Efrom \u003Ca href=\u0022http:\/\/www.willett-regenerative-labs.com\/\u0022\u003ENick Willett\u0026rsquo;s lab.\u0026nbsp;\u003C\/a\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026ldquo;These data have implications directly on bone healing and more broadly on wound healing,\u0026rdquo; says Willett, assistant professor in the Wallace H. Coulter Department of Biomedical Engineering (BME) at Georgia Tech and Emory University. \u0026ldquo;In bone healing or grafting scenarios, physicians are often quite conservative in how quickly patients begin to load the repair site.\u0026rdquo;\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EFormer BME graduate student Marissa Ruehle was the first author of the paper. She and her colleagues investigated how mechanical strain affects angiogenesis, when microvascular fragments are cultured in a collagen hydrogel.\u0026nbsp;\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EResearchers applied pressure to the growing blood vessels to a degree that created five, 10 or 30 percent strain. The pressure, either early (zero to five days) or late (five to 10 days), was applied rhythmically in a way that simulated walking. Willett says he and his team expected (based on previous research) that 30 percent strain would hinder healing. Instead, the highest amount of strain pushed blood vessels to grow longer and branch more \u0026ndash; but only when applied in the later stages.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026ldquo;We originally hypothesized that 30 percent strain would be inhibitory both early and delayed, because it is such a large magnitude,\u0026rdquo; says Willett, a researcher in the Petit Institute for Bioengineering and Bioscience. \u0026ldquo;This finding highlights the differences in strain sensitivity between the early stage, when vessels are still forming, and more established networks.\u0026rdquo;\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003ERuehle and the other researchers were able to discern the effects of the mechanical strain on proliferation, and on the extracellular matrix \u0026ndash; the mesh of proteins outside the cell. They also could take a peek at some of the genes whose activity was affected by high amounts of mechanical strain.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe authors say that modulating the timing of mechanical strain could be relevant for several scenarios of healing or regeneration, where rehabilitation and mechanical therapy could be used to enhance repair.\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThey write, \u0026ldquo;While we were initially motivated by bone tissue regeneration, a number of other tissues also experience ECM [extracellular matrix] forces; for example, ligaments and tends undergo tension, venous ulcers are often treated with compression bandages, and even cutaneous wounds experience tension during closure.\u0026rdquo;\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003ECONTACT:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EQuinn Eastman\u003C\/p\u003E\r\n\r\n\u003Cp\u003EScience Writer\u003C\/p\u003E\r\n\r\n\u003Cp\u003EEmory University School of Medicine\u003C\/p\u003E\r\n\r\n\u003Cp\u003EVisit the\u0026nbsp;\u003Ca href=\u0022http:\/\/www.emoryhealthsciblog.com\/\u0022 target=\u0022_blank\u0022\u003EEmory Lab Land blog\u003C\/a\u003E!\u003C\/p\u003E\r\n\r\n\u003Cp\u003ETwitter:\u0026nbsp;@Eastman, Quinn\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"From Nick Willett lab: Delayed mechanical strain promotes angiogenesis in bone\/wound healing"}],"field_summary":[{"value":"\u003Cp\u003EFrom Nick Willett lab: Delayed mechanical strain promotes angiogenesis in bone\/wound healing\u003C\/p\u003E\r\n","format":"limited_html"}],"field_summary_sentence":[{"value":"From Nick Willett lab: Delayed mechanical strain promotes angiogenesis in bone\/wound healing"}],"uid":"28153","created_gmt":"2020-08-27 01:07:32","changed_gmt":"2020-08-27 01:08:14","author":"Jerry Grillo","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2020-08-26T00:00:00-04:00","iso_date":"2020-08-26T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"638471":{"id":"638471","type":"image","title":"Nick Willett","body":null,"created":"1598490023","gmt_created":"2020-08-27 01:00:23","changed":"1598490023","gmt_changed":"2020-08-27 01:00:23","alt":"","file":{"fid":"242783","name":"Nick Willett.jpg","image_path":"\/sites\/default\/files\/images\/Nick%20Willett.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/Nick%20Willett.jpg","mime":"image\/jpeg","size":784587,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/Nick%20Willett.jpg?itok=SixxJWxc"}}},"media_ids":["638471"],"groups":[{"id":"1254","name":"Wallace H. Coulter Dept. of Biomedical Engineering"}],"categories":[],"keywords":[{"id":"126571","name":"go-PetitInstitute"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}