There are limited options for reconstruction of bone defects resulting from congenital anomaalies, trauma, infection, and oncologic resection. Nearly one million bone graft procedures are performed annually, with the clinical 'gold standard'being the use of decellularized allografts. Of these allograft implantation procedures, nearly 60% fail within 10 years of implantation due to poor graft-host integration and microcrack propagation. Unlike allografts, autografts fully heal and integrate, mediated by the periosteum, a thin layer of tissue and periosteal cells (PCs) surrounding bone, where healing is coordinated by a variety of contextual cues including matrix and paracrine factors. PCs, which persist during autografts healing for only ~21 days, are phenotypically similar to bone marrow-derived mesenchymal stem cells (MSCs). Therapeutically, however, MSCs are favored compared to PCs as they are isolated from bone marrow, reducing bone tissue morbidity resulting from PC isolation. A critical knowledge gap exists in identifying the critical cues (paracrine factors, matrix interactions, etc. that orchestrate autograft healing and are absent in allografts, preventing the translation of therapies to effectively revitalize allografts. Our objective is to develop periosteum mimetics composed of synthetic hydrogels (poly(ethylene glycol), PEG) for MSC transplantation to (1) promote cell-mediated allograft healing/integration, to (2) isolate the critical factors of the periosteum in healing, and to (3) develop cell-free therapies that result in complete allograft healing and integration. Hydrogels will be used to surround allografts, taking advantage of structural integrity of allografts and improving what is insufficient in healing and integration by recreating the periosteum. We hypothesize that hydrogel nanoarchitectures can be tuned through alterations in degradation and biochemical functionalities to promote MSC-mediated allograft healing and integration. We further hypothesize that MSCs promote healing through simple release of paracrine factors, thus, cell-free revitalization approaches can be developed. The rationale for this work is to identify translatable therapies, based on critical healing factor, to improve healing and integration of the 300,000 massive allograft procedures performed annually in the US.
Three specific aims are outlined:
Aim 1 : Develop periosteum- mimetic PEG hydrogels to support MSC-mediated allograft healing in vivo.
Aim 2 : Identify critical paracrine factors produced by hydrogel-transplanted MSCs that modulate allograft healing.
Aim 3 : Develop paracrine factor-releasing hydrogels to enhance allograft revitalization in the absence of cell transplantation. Successful completion of these Aims will significantly advance our understanding of how MSCs coordinate allograft healing and integration and of how to design synthetic polymer scaffolds to promote natural bone regeneration processes. This material platform should be readily tailored for applications towards regenerating tissues beyond bone, as well as providing specific advantages for future directions in the design of cell delivery vehicles. !

Public Health Relevance

The proposed research is relevant to public health because it addresses a critical need for structurally sound, well-integrated, and successful bone grafts. Structural allografts are the gold standard for massive orthopaedic reconstruction surgery but cannot be remodeled by the host, leading to failure rates of ~60% after 10-years. Therefore, tissue-engineering approaches to recreate critical functions of the periosteum, the tissue responsible for autograft healing, will enhance allograft revitalization, creating new and innovative approaches for successful bone grafting.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
1R01AR064200-01
Application #
8476900
Study Section
Musculoskeletal Tissue Engineering Study Section (MTE)
Program Officer
Wang, Fei
Project Start
2013-03-01
Project End
2018-02-28
Budget Start
2013-03-01
Budget End
2014-02-28
Support Year
1
Fiscal Year
2013
Total Cost
$293,569
Indirect Cost
$102,319
Name
University of Rochester
Department
Biomedical Engineering
Type
Schools of Engineering
DUNS #
041294109
City
Rochester
State
NY
Country
United States
Zip Code
14627
Vella, Joseph B; Trombetta, Ryan P; Hoffman, Michael D et al. (2018) Three dimensional printed calcium phosphate and poly(caprolactone) composites with improved mechanical properties and preserved microstructure. J Biomed Mater Res A 106:663-672
Han, Songfeng; Proctor, Ashley R; Ren, Jingxuan et al. (2018) Temporal blood flow changes measured by diffuse correlation tomography predict murine femoral graft healing. PLoS One 13:e0197031
Wang, Yuchen; Zhang, Sue; Benoit, Danielle S W (2018) Degradable poly(ethylene glycol) (PEG)-based hydrogels for spatiotemporal control of siRNA/nanoparticle delivery. J Control Release 287:58-66
Wang, Yuchen; Newman, Maureen R; Benoit, Danielle S W (2018) Development of controlled drug delivery systems for bone fracture-targeted therapeutic delivery: A review. Eur J Pharm Biopharm 127:223-236
Malcolm, Dominic W; Varghese, Jomy J; Sorrells, Janet E et al. (2018) The Effects of Biological Fluids on Colloidal Stability and siRNA Delivery of a pH-Responsive Micellar Nanoparticle Delivery System. ACS Nano 12:187-197
Newman, Maureen R; Russell, Steven G; Schmitt, Christopher S et al. (2018) Multivalent Presentation of Peptide Targeting Groups Alters Polymer Biodistribution to Target Tissues. Biomacromolecules 19:71-84
Wang, Yuchen; Malcolm, Dominic W; Benoit, Danielle S W (2017) Controlled and sustained delivery of siRNA/NPs from hydrogels expedites bone fracture healing. Biomaterials 139:127-138
Malcolm, Dominic W; Freeberg, Margaret A T; Wang, Yuchen et al. (2017) Diblock Copolymer Hydrophobicity Facilitates Efficient Gene Silencing and Cytocompatible Nanoparticle-Mediated siRNA Delivery to Musculoskeletal Cell Types. Biomacromolecules 18:3753-3765
Vats, Kanika; Marsh, Graham; Harding, Kristen et al. (2017) Nanoscale physicochemical properties of chain- and step-growth polymerized PEG hydrogels affect cell-material interactions. J Biomed Mater Res A 105:1112-1122
Wang, Yuchen; Newman, Maureen R; Ackun-Farmmer, Marian et al. (2017) Fracture-Targeted Delivery of ?-Catenin Agonists via Peptide-Functionalized Nanoparticles Augments Fracture Healing. ACS Nano 11:9445-9458

Showing the most recent 10 out of 30 publications