title: Silk-based injectable biomaterial as an alternative to cervical cerclage: an in vitro study.
abstract: OBJECTIVE
  New therapies to prevent preterm birth are needed. Our objective was to study an injectable biomaterial for human cervical tissue as an alternative to cervical cerclage.
  
  
  METHODS
  Human cervical tissue specimens were obtained from premenopausal gynecological hysterectomies for benign indications. A 3-part biomaterial was formulated, consisting of silk protein solution blended with a 2-part polyethylene glycol gelation system. The solutions were injected into cervical tissue and the tissue was evaluated for mechanical properties, swelling, cytocompatibility, and histology.
  
  
  RESULTS
  The stiffness of cervical tissue more than doubled after injection (P = .02). Swelling properties of injected tissue were no different than native tissue controls. Cervical fibroblasts remained viable for at least 48 hours when cultured on the biomaterial.
  
  
  CONCLUSIONS
  We report a silk-based, biocompatible, injectable biomaterial that increased the stiffness of cervical tissue compared to uninjected controls. Animal studies are needed to assess this biomaterial in vivo.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Tufts Medical Center, Boston, MA 02111, USA.
authors.forename: Asha J
authors.initials: AJ
authors.lastname: Heard
authors.forename: Simona
authors.initials: S
authors.lastname: Socrate
authors.forename: Kelly A
authors.initials: KA
authors.lastname: Burke
authors.forename: Errol R
authors.initials: ER
authors.lastname: Norwitz
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.forename: Michael D
authors.initials: MD
authors.lastname: House
mesh_terms: D001672:Biocompatible Materials; D002470:Cell Survival; D002478:Cells, Cultured; D023802:Cerclage, Cervical; D002584:Cervix Uteri / Q000187:drug effects* / Q000473:pathology; D004548:Elasticity; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000473:pathology; D006801:Humans; D007267:Injections; D008422:Materials Testing; D011092:Polyethylene Glycols / Q000008:administration & dosage* / Q000737:chemistry / Q000633:toxicity; D047928:Premature Birth / Q000517:prevention & control*; D047011:Silk / Q000008:administration & dosage* / Q000737:chemistry / Q000633:toxicity; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D001672:Biocompatible Materials; D047011:Silk; D011092:Polyethylene Glycols