Electrospun nanofiber blend with improved mechanical and biological performance

Abstract

Anderson Oliveira Lobo,1–4 Samson Afewerki,3,4 Mirian Michele Machado de Paula,5 Paria Ghannadian,5 Fernanda Roberta Marciano,2,5 Yu Shrike Zhang,3,4 Thomas Jay Webster,5 Ali Khademhosseini3,4,6–10 1LIMAV-Interdisciplinary Laboratory for Advanced Materials, PPGCM-Materials Science and Engineering Graduate Program, UFPI-Federal University of Piauí, Teresina, Piauí, CEP 64049-550, Brazil; 2Institute of Science and Technology, Brasil University, São Paulo, CEP 08230-030, Brazil; 3Division of Engineering in Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Cambridge, MA 02139, USA; 4Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; 5Department of Chemical Engineering, Northeastern University, Boston, MA 02115, USA; 6Department of Bioengineering, Department of Chemical and Biomolecular Engineering, Henry Samueli School of Engineering and Applied Sciences, University of California-Los Angeles, Los Angeles, CA 90095, USA; 7Department of Radiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA 90095, USA; 8Center for Minimally Invasive Therapeutics (C-MIT), University of California-Los Angeles, Los Angeles, CA 90095, USA; 9California NanoSystems Institute (CNSI), University of California-Los Angeles, Los Angeles, CA 90095, USA; 10Department of Bioindustrial Technologies, Konkuk University, Seoul 143-701, Republic of Korea Background: Here, electrospun fibers based on a blend of polycaprolactone (PCL), poly(ethylene glycol) (PEG), and gelatin methacryloyl (GelMA) were developed. The careful choice of this polymer combination allowed for the preparation of a biomaterial that preserved the mechanical strength of PCL, while at the same time improving the hydrophilicity of the blended material and human osteoblast maturation. Methods: The morphology, chemical structure, wettability, and mechanical properties before and after UV photocrosslinking were evaluated. Furthermore, human osteoblasts (hFOB) were cultivated for up to 21 days on the scaffolds, and their potential to upregulate cell proliferation, alkaline phosphatase (ALP) activity, and calcium deposition were investigated.Results: Contact angle measurement results showed that the developed scaffolds presented hydrophilic properties after PEG and GelMA incorporation before (25°) and after UV photocrosslinking (69°) compared to pure PCL (149°). PCL:PEG:GelMA-UV displayed a slight increase in mechanical strength (elastic modulus ~37 MPa) over PCL alone (~33 MPa). Normally, an increase in strength of fibers leads to a decrease in elongation at break, due to the material becoming less deformable and stiffer, thus leading to breaks at low strain. This behavior was observed by comparing PCL (elongation at break ~106%) and PCL:PEG:GelMA-UV (~50%). Moreover, increases in ALP activity (10-fold at day 14) and calcium deposition (1.3-fold at day 21) by hFOBs were detected after PEG and GelMA incorporation after UV photocrosslinking compared to pure PCL. Ultrathin and hydrophilic fibers were obtained after PEG and GelMA incorporation after UV photocrosslinking, but the strength of PCL was maintained. Interestingly, those ultrathin fiber characteristics improved hFOB functions.Conclusion: These findings appear promising for the use of these electrospun scaffolds, based on the combination of polymers used here for numerous orthopedic applications. Keywords: biomaterials, electrospinning, human osteoblasts, mechanical properties, wettability, bone regeneration

Keywords

• biomaterials
• electrospinning
• human osteoblasts
• mechanical properties
• wettability
• bone regeneration