The repair of bone tissue injuries, especially those occurring in the craniofacial region, is a significant challenge in orthopaedics. There are currently few effective treatments available for these injuries. Tissue engineering seeks to repairor replace the damaged tissue by encouraging regeneration of the host tissue through provision of the necessary biochemical, cellular, and mechanical cues. Human mesenchymal stem cells (hMSCs) are a promising cell source for bone regeneration as they are capable of differentiating into osteogenic tissue, are easily obtainable from bone marrow, and can proliferate in culture readily so that it is possible to obtain a sufficient number of cells for tissue engineering approaches. RNA interference is a powerful gene silencing mechanism that inhibits gene expression at the translational level by the targeted destruction of specific mRNA molecules, and has the potential to revolutionize disease treatment and aid in the functional repair of damaged tissue by decreasing the expression of specific proteins. Additionally, the potential for delivering short interfering RNA (siRNA) to stem cells to direct their differentiation to promote the desired tissue growth is exciting. However, effectively delivering bioactive siRNA to damaged tissue sites remains a challenge, and more research is needed to determine its effectiveness in the differentiation of hMSCs and enhancement of resultant tissue formation. Thus, this proposed work seeks to engineer novel biomaterial systems for controlled and sustained delivery of siRNA and to examine the effect of delivering siRNA against BMP antagonists on the osteogenic diferentiation of hMSCs and bone formation. The central hypothesis is that silencing the expression of BMP antagonists via controlled delivery of siRNA will promote the osteogenic response of hMSCs, and enhance bone regeneration. This will be addressed by the following specific aims: (1) engineer novel biopolymer hydrogels capable of releasing siRNA in a sustained and controllable manner over time, (2) deliver siRNA against a BMP antagonist from biopolymer hydrogels and investigate its effect on guiding encapsulated and surrounding hMSCs down the osteogenic lineage and (3) assess the ability of the system to drive bone formation in vivo upon implantation of hydrogel constructs containing siRNA and hMSCs into a critical-size bone defect. This proposal aims to demonstrate the utility of a new approach to improve the repair of bony defects, which would have great clinical benefit, in addition to creating a platform technology that could then be used for other therapeutic applications.

Public Health Relevance

Treating bone defects incurred by mililons of Americans each year, especially those occurring in the craniofacial region, remains a significant chalenge to the orthopaedics community as there are few viable options for those that exhibit problematic healing. We propose to engineer biopolymer systems for the delivery of siRNA to mesenchymal stem cells to silence the expresion of bone morphogenetic protein (BMP) antagonists and thereby increase their osteogenic response. The results from this proposal will represent a significant advance for osteogenic tissue regeneration for healing bone defects, provide an increased understanding of stem cell diferentiation decision pathways, and lead to the development of a platform technology for the effective delivery of siRNA that may hold promise for many applications in regenerative and therapeutic medicine.

National Institute of Health (NIH)
National Institute of Dental & Craniofacial Research (NIDCR)
High Priority, Short Term Project Award (R56)
Project #
Application #
Study Section
Musculoskeletal Tissue Engineering Study Section (MTE)
Program Officer
Lumelsky, Nadya L
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Case Western Reserve University
Biomedical Engineering
Schools of Engineering
United States
Zip Code
Nguyen, Minh K; Jeon, Oju; Dang, Phuong N et al. (2018) RNA interfering molecule delivery from in situ forming biodegradable hydrogels for enhancement of bone formation in rat calvarial bone defects. Acta Biomater 75:105-114
Seo, Jungmok; Shin, Jung-Youn; Leijten, Jeroen et al. (2018) High-throughput approaches for screening and analysis of cell behaviors. Biomaterials 153:85-101
Nguyen, Minh K; Jeon, Oju; Krebs, Melissa D et al. (2017) Corrigendum to ""Sustained localized presentation of RNA interfering molecules from in situ forming hydrogels to guide stem cell osteogenic differentiation"" [Biomaterials 35/24 (2014) 6278-6286]. Biomaterials 125:12
Leijten, Jeroen; Seo, Jungmok; Yue, Kan et al. (2017) Spatially and Temporally Controlled Hydrogels for Tissue Engineering. Mater Sci Eng R Rep 119:1-35
Nguyen, Minh Khanh; McMillan, Alexandra; Huynh, Cong Truc et al. (2017) Photocrosslinkable, biodegradable hydrogels with controlled cell adhesivity for prolonged siRNA delivery to hMSCs to enhance their osteogenic differentiation. J Mater Chem B 5:485-495
Huynh, Cong Truc; Nguyen, Minh Khanh; Naris, Mantas et al. (2016) Light-triggered RNA release and induction of hMSC osteogenesis via photodegradable, dual-crosslinked hydrogels. Nanomedicine (Lond) 11:1535-50
Huynh, Cong Truc; Nguyen, Minh Khanh; Tonga, Gulen Yesilbag et al. (2016) Photocleavable Hydrogels for Light-Triggered siRNA Release. Adv Healthc Mater 5:305-310
Hill, Michael C; Nguyen, Minh K; Jeon, Oju et al. (2015) Spatial control of cell gene expression by siRNA gradients in biodegradable hydrogels. Adv Healthc Mater 4:714-22
Jeon, Oju; Wolfson, David W; Alsberg, Eben (2015) In-situ formation of growth-factor-loaded coacervate microparticle-embedded hydrogels for directing encapsulated stem cell fate. Adv Mater 27:2216-23
Samorezov, Julia E; Alsberg, Eben (2015) Spatial regulation of controlled bioactive factor delivery for bone tissue engineering. Adv Drug Deliv Rev 84:45-67

Showing the most recent 10 out of 20 publications