Research group "Biomaterials for Tissue Engineering"

Group leader:


  Sahar Salehi, PhD. 0921-55 5593
  sahar.salehi(.at.)bm.uni-bayreuth.de
   

Research overview:

The group’s research interests are based on developing materials-based engineering strategies for regenerative medicine using different biomaterials and micro-engineering techniques. Our specific focus is on the in vitro interaction of cells and tissues with engineered materials, where important design variables will include different topographies and morphologies. The research output should clarify how cells sense and respond to the biomaterials and thereby further modify their environment towards building tissue-like constructs.

This group has expertise in developing and combining advanced biomaterials with microfabrication techniques to engineer complex and functional tissue constructs. We are also working on developing injectable and biodegradable materials for cell delivery, nanofibrous scaffolds from natural and synthetic polymers for tissue engineering as well as micropatterned fibers for co-culture of different cell lines.
Current efforts are focused on the following areas:

  • 3-dimensional micro- and nano-structured scaffolds with controlled architecture
  • Tissue engineering of soft and hard tissues such as cornea, skeletal muscle, tendon, bone and their interfaces
  • Co-culture of different types of cells to model and study the cell cross-talk
  • Injectable hydrogels for cell delivery
  • Determination of the biomechanics of tissues and their appropriate scaffolds in vitro
  • Using external stimulation factors to enhance in vitro tissue formation and evaluation of the engineered constructs
  • Engineered tissue for regeneration of the corneal epithelium, endothelium and stroma
  • Bioprinting of vascularized innervated tissues.

The scope of the group is to create an interdisciplinary research environment for students and collaborations with other national and international research groups to solve biomedical problems. Our motivation is to provide students a broad set of skills and knowledge in a multidisciplinary area dedicated to the growing interface between engineering, chemistry, biology and medicine. Therefore, students with different background in engineering, materials science, biochemistry and biology are welcome to join. We would like to develop solutions which are clinically translatable for human health and trying to train and integrate the next generation of scientists with broad skills in a multidisciplinary environment of science engineering and medicine.

Research Projects:

Skeletal Muscle Tissue Engineering Using Nanofibrous Scaffolds and Injectable Materials
Skeletal muscles have a high capacity of self-repair but are not able to regenerate when a significant loss of tissue occurs, resulting in severe loss of function. Cell transplantation therapy provides a potential solution for treating skeletal muscle disorders, but cell survival after transplantation is poor. This limitation could be addressed by grafting donor cells onto biomaterials to protect them against harsh environments and processing, consequently improving cell viability when injected in situ. In our recent studies, we tried to investigate different approaches to fabricate various substrates across micro- and nano-scale for cell culture. In one approach we developed ultrathin ribbons with “canal-like” structures as an injectable material from poly (lactic-co-glycolic acid) (PLGA) using a microfabrication technique to generate ribbons of aligned murine skeletal myoblasts (C2C12).

 

Fig. 1 Skeletal Muscle Tissue Engineering: Development of flexible cell loaded ultrathin PLGA-nanoribbons for minimally invasive delivery of skeletal muscle cells.

Salehi, S. et al., ACS Biomaterials Science & Engineering 2017, 3 (4), 579–589. Copyright© 2017 American Chemical Society.

 

Fabrication of Bio- and Immuno-Compatible Fibrous Scaffold for Cornea Tissue Engineering

A major challenge in corneal tissue engineering and lamellar corneal transplantation is to develop synthetic scaffolds able to simulate the optical and mechanical properties of the native cornea. In our studies, we evaluated elastomeric, biodegradable nanofibrous scaffold from poly (glycerol sebacate) (PGS)-poly (ε-caprolactone) (PCL) with respect to their cyto- and immunocompatibility. These scaffolds were semi-transparent with well-defined mechanical properties and directed positive effects on viability of human corneal endothelial cells (HCEC) and human conjunctival epithelial cells (HCjEC). Moreover, within 3 days HCEC established monolayers with the hexagonal morphology typical for this cell type. The PGS-PCL fibers did not trigger effects in granulocytes, naive and activated peripheral blood mononuclear cells (PBMCs). Scaffolds with a higher content of PGS-PCL (4:1) ratio showed the best cell organization, cyto- and immunocompatibility.

 

Fig. 2 Cornea Tissue Engineering: Poly (glycerol sebacate)-Poly (ε-caprolactone) blend nanofibrous scaffold as intrinsic bio- and immunocompatible system for corneal repair.

Salehi, S. et al., Acta Biomaterialia 2017, 50C, 370-380. Copyright© 2017 Elsevier

 
Selected publications:

R Banan Sadeghian, M. Ebrahimi, S. Salehi (2017). Electrical stimulation of microengineered skeletal muscle tissue, effect of stimulus parameters on myotube contractility and maturation. J. Tissues Eng. Regen. Med. in print. doi: 10.1002/term.2502.

S. Salehi, S. Ostrovidov, R. Banan Sadeghian, M. Ebrahimi, X. Liang, H. Bae, K. Nakajima, T. Fujie, A. Khademhosseini (2017).Development of flexible cell loaded ultrathin ribbons for minimally invasive delivery of skeletal muscle cells. ACS Biomaterials Sci. Eng. 3 (4), 579–589.

S. Salehi, M. Czugala, P. Stafiej, M.H. Fathi, T. Bahners, J.S. Gutmann, B.B. Singer, T.A. Fuchsluger (2017). Poly (glycerol sebacate)-poly (ε-caprolactone) blend nanofibrous scaffold as intrinsic bio- and immunocompatible system for corneal repair. Acta Biomater. 50C, 370-380.

R. Banan Sadeghian, S. Ostrovidov, J. Han, S. Salehi, H. Bae, M. Chen, A. Khademhosseini (2017). Macroporous mesh of nanoporous gold in electrochemical monitoring of superoxide release from cells. Biosensors and Bioelectronics 88, 41-47.

R. Banan Sadeghian, S. Ostrovidov, J. Han, S. Salehi, H. Bae, M. Chen, A. Khademhosseini (2016). Online monitoring of super oxide anion release from skeletal muscle tissue using an electrochemical biosensor based on thick-film nanoporous gold. ACS Sens. 1 (7), 921–928.

S. Ostrovidov, X. Shi, R. Banan Sadeghian, S. Salehi, T. Fujie, H. Bae, M. Ramalingam, A. Khademhosseini (2015). Review paper: Stem cell differentiation toward the myogenic lineage for muscle tissue regeneration: A focus on muscular dystrophy. J. Stem cells Rev. Rep. 11 (6), 866-84.

S. Ahadian, R. Banan Sadeghian, S. Salehi, S. Ostrovidov, H. Bae, M. Ramalingam, A. Khademhosseini (2015). Review paper: Bioconjugated hydrogels for tissue engineering and regenerative medicine, ACS Bioconjugate Chem. 26 (10), 1984-2001.

S. Altinpinar, H.  Zhao, W. Ali, R. Kappes, P. Schuchardt, S. Salehi, G. Santoro, P. Theato, S. Roth, J. Gutmann (2015). Distorsion of ultrathin photocleavable block copolymer films during photocleavage and nanopore formation, Langmuir 31 (32), 8947-52.

S. Salehi, M.H. Fathi, Sh. HaghjooyJavanmard, M. Moshayedi, F. Barneh (2015). Fabrication and characterization of biodegradable polymeric films for corneal stroma tissue engineering, J. Adv. Biomedical Res., 4:9.

S. Salehi, T. Bahners, J.S. Gutmann, E. Mäder, S.L. Gao, T.A. Fuchsluger (2014). Characterization of structural, mechanical and nano-mechanical properties of electrospun PGS/PCL fibers. RSC Advances 4, 16951.

S. Salehi, M.H. Fathi, Sh. HaghjooyJavanmard, T. Bahners, J.S. Gutmann, S. Ergün, K.P. Steuhl, T.A. Fuchsluger (2014). Generation of PGS/PCL-blend nanofibrous scaffolds mimicking corneal stroma structure. Macromol. Mater. Eng. 299, 455–69.

S. Khorsand, M.H. Fathi, S. Salehi, S. Amirkhanlou (2014). Hydroxyapatite/Alumina nanocrystalline composite powder synthesized by sol-gel process for biomedical applications. Int. J. Miner., Metall. Mater. 21 (10), 1033-36.

T. Fuchsluger, S. Salehi, C. Petsch, B. Bachmann (2014). New possibilities for ocular surface reconstruction: collagen membranes and biocompatible elastomer nanofibers. Ophthalmologie 111 (11), 1019–26.

S. Salehi, A. Grünert, T. Bahners, J.S. Gutmann, K.P. Steuhl, M. Czugala, B.B. Singer, T.A. Fuchsluger (2014). New nanofibrous scaffold for corneal tissue engineering. Klinische Monatsblätter für Augenheilkunde, 2014, 231, 626–30.

S. Salehi, M.H. Fathi (2010). Fabrication and Characterization of Sol-gel Derived Hydroxyapatite / Zirconia Composite Nanopowders with Various Contents of Yttria, Ceram. Int. 36, 1659–67 .

S. Salehi, M.H. Fathi (2011). Elaboration of sol-gel derived hydroxyapatite/yttria stabilized zirconia composite coatings obtained for biomedical application. Defect and Diffusion Forum 312-315, 894-99.

Book chapter

S. Salehi, M. Kharaziha, A. Fallahi, N. Masoumi, A. Tamayol (2017). Medical Textiles for Tissue Engineering and Biomedical Application. Book title: “Textile Finishing: Recent Developments and Future Trends” edited by K. L. Mittal & T. Bahners. Scrivener Publishing LLC (accepted).

 

Biography:

Dr. Sahar Salehi is the leader of the research group “Biomaterials for Tissue Engineering” at the Department of Biomaterials at the University of Bayreuth, Germany studying the biomedical applications of natural and synthetic materials. In particular, her projects are focused on tissue engineering of different musculoskeletal tissues such as bone, tendon, skeletal muscle, and other soft tissues such as cornea. She received her PhD. degree from Isfahan University of Technology in Iran in 2013 for her studies on development of nanofibrous scaffolds for cornea tissue engineering with previous degrees (BSc. and MSc.) in Materials Science and Engineering. During her PhD, she was a recipient of German Academic Exchange Service (DAAD) scholarship in 2011, which allowed her to broaden her PhD project as a visiting researcher at the German Textile Research Institute (DTNW) and University Hospital of Essen, Germany. Prior to the start of her current position in April, 2017 she worked in the Khademhosseini Laboratory (http://www.tissueeng.net/lab/) at Japan’s World Premier International-Advanced Institute of Materials Research (WPI-AIMR) situated within Tohoku University, Sendai, Japan. There, her research topic was injectable and biodegradable materials for skeletal muscle tissue engineering.