Development and fabrication of novel woven meshes as bone graft substitutes for critical sized defects.

摘要

With more than ;Melt-spun poly-l-lactide (PL) and poly-l-lactide-co-epsilon-caprolactone (PLCL) fibers were studied to build variable mesh types to affect porosity, pore size, and cellular affinity. A custom bio-loom was designed and built based on dobby-loom textile technology for use with the resorbable polymer monofilaments. Fluid flow properties were characterized through the evaluation of permeability and wicking rate using a purpose-built permeameter.;Osteogenic viability was analyzed through studying cell adhesion and differentiation on the meshes. D1 murine bone marrow mesenchymal stem cells (MSCs) were used to characterize cell adhesion via integrin binding. Immunofluorescent analysis of Fibronectin (FN), Vitronectin (VTN), Type 1 Collagen (COL1), and Laminin-alpha 2 (LAMA2) adhesion was conducted. These proteins serve as ligands to osteogenic integrin subunits beta1, alpha2, alpha5, and alphaV. Expression of integrin subunits was tested via real-time polymerase chain reaction (RT-PCR). Additionally, MSC osteogenic differentiation was evaluated by colorimetric Alkaline Phosphatase (ALP) expression, Alizarin Red stain for mineralization, and ALP and Osteocalcin (OC) gene expression via RT-PCR.;Results showed effective creation of meshes with variable properties and significant differences in cell metabolic activity and DNA concentration. Changes in mesh parameters significantly effected mesh permeability. ECM protein adhesion and integrin PCR results suggest a means to control the early differentiation process by varying attachment and expression of VTN, beta1, and alphaV. Early stage differentiation was verified by the consistent expression of ALP, shown through colorimetric and PCR experiments. Mature differentiation was shown through constant adhesion rates of FN, COL1, and LAMA2 with subunits beta1, alpha2, and alpha5. Mineralization and OC gene expression results showed sparse mineralization and little expression of OC in the late stages of differentiation.;Additionally, work regarding the encouragement of Science, Technology, Engineering, and Math (STEM) career pursuit for underrepresented minority middle school students was conducted. Results showed that parental encouragement, external STEM environment, and extracurricular STEM exposure were closely related to a student's likelihood to express interest in a STEM career. Student interest in STEM careers significantly increased after participation in an interactive camp based on mesh-based modules. Further work explored the effect of early research experiences on the development of research identity for underrepresented minority science and engineering undergraduates. Results showed that students participating in this program significantly increased their research identity through increased self-recognition and competence in research activities.