1
|
Dorcemus DL, Kim HS, Nukavarapu SP. Gradient scaffold with spatial growth factor profile for osteochondral interface engineering. Biomed Mater 2020; 16. [PMID: 33291092 DOI: 10.1088/1748-605x/abd1ba] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 12/08/2020] [Indexed: 11/11/2022]
Abstract
Osteochondral (OC) matrix design poses a significant engineering challenge due to the complexity involved with bone-cartilage interfaces. To better facilitate the regeneration of OC tissue, we developed and evaluated a biodegradable matrix with uniquely arranged bone and cartilage supporting phases: a poly(lactic-co-glycolic) acid (PLGA) template structure with a porosity gradient along its longitudinal axis uniquely integrated with hyaluronic acid hydrogel. Micro-CT scanning and imaging confirmed the formation of an inverse gradient matrix. Hydroxyapatite was added to the PLGA template which was then plasma-treated to increase hydrophilicity and growth factor affinity. An osteogenic growth factor (bone morphogenetic protein 2; BMP-2) was loaded onto the template scaffold via adsorption, while a chondrogenic growth factor (transforming growth factor beta 1; TGF-β1) was incorporated into the hydrogel phase. Confocal microscopy of the growth factor loaded matrix confirmed the spatial distribution of the two growth factors, with chondrogenic factor confined to the cartilaginous portion and osteogenic factor present throughout the scaffold. We observed spatial differentiation of human mesenchymal stem cells (hMSCs) into cartilage and bone cells in the scaffolds in vitro: cartilaginous regions were marked by increased glycosaminoglycan production, and osteogenesis was seen throughout the graft by alizarin red staining. In a dose-dependent study of BMP-2, hMSC pellet cultures with TGF-β1 and BMP-2 showed synergistic effects on chondrogenesis. These results indicate that development of an inverse gradient matrix can spatially distribute two different growth factors to facilitate chondrogenesis and osteogenesis along different portions of a scaffold, which are key steps needed for formation of an osteochondral interface.
Collapse
Affiliation(s)
- Deborah Leonie Dorcemus
- Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Unit 3247, Storrs, Connecticut, 06269, UNITED STATES
| | - Hyun Sung Kim
- Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Unit 3247, Storrs, Connecticut, 06269, UNITED STATES
| | - Syam Prasad Nukavarapu
- Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Unit 3247, Storrs, Connecticut, 06269, UNITED STATES
| |
Collapse
|
2
|
Xu TO, Kim HS, Stahl T, Nukavarapu SP. Self-neutralizing PLGA/magnesium composites as novel biomaterials for tissue engineering. Biomed Mater 2018; 13:035013. [PMID: 29362293 PMCID: PMC5884090 DOI: 10.1088/1748-605x/aaaa29] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Controlling acidic degradation of biodegradable polyesters remains a major clinical challenge. This work presents a simple and effective strategy of developing polyester composites with biodegradable magnesium metal or alloys. PLGA samples with compositions of 1, 3, 5, and 10 wt% magnesium were produced using a simple solvent-casting method, which resulted in composite films with near uniform Mg metal/alloy particle dispersion. Degradation study of the composite films showed that all compositions higher than 1 wt% magnesium were able to extend the duration of degradation, and buffer acidic pH resulting from PLGA degradation. PLGA composite with 5 wt% of magnesium showed near-neutral degradation pattern under sink conditions. Magnesium addition also showed improved mechanical characteristics in terms of the tensile modulus. In vitro experiments conducted by seeding PLGA composites with MC3T3-E1 pre-osteoblasts demonstrated increased ALP expression and cellular mineralization. The established new biodegradable polymer-metal system provides a useful biomaterial platform with a wide range of applications in biomedical device development and scaffold-based tissue engineering.
Collapse
Affiliation(s)
- Thomas O Xu
- Department of Orthopaedic Surgery, University of Connecticut Health Center, Farmington CT, United States of America. These authors contributed equally
| | | | | | | |
Collapse
|
3
|
Spencer V, Illescas E, Maltes L, Kim H, Sathe V, Nukavarapu S. Osteochondral Tissue Engineering: Translational Research and Turning Research into Products. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1058:373-390. [PMID: 29691831 DOI: 10.1007/978-3-319-76711-6_17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Osteochondral (OC) defect repair is a significant clinical challenge. Osteoarthritis results in articular cartilage/subchondral bone tissue degeneration and tissue loss, which in the long run results in cartilage/ostecochondral defect formation. OC defects are commonly approached with autografts and allografts, and both these options have found limitations. Alternatively, tissue engineered strategies with biodegradable scaffolds with and without cells and growth factors have been developed. In order to approach regeneration of complex tissues such as osteochondral, advanced tissue engineered grafts including biphasic, triphasic, and gradient configurations are considered. The graft design is motivated to promote cartilage and bone layer formation with an interdigitating transitional zone (i.e., bone-cartilage interface). Some of the engineered OC grafts with autologous cells have shown promise for OC defect repair and a few of them have advanced into clinical trials. This chapter presents synthetic osteochondral designs and the progress that has been made in terms of the clinical translation.
Collapse
Affiliation(s)
- Victoria Spencer
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT, USA
| | - Erica Illescas
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT, USA
| | - Lorenzo Maltes
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT, USA
| | - Hyun Kim
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT, USA
| | - Vinayak Sathe
- Department of Orthopaedic Surgery, University of Connecticut Health, Storrs, CT, USA
| | - Syam Nukavarapu
- Department of Biomedical Engineering, University of Connecticut, Storrs, CT, USA. .,Department of Orthopaedic Surgery, University of Connecticut Health, Storrs, CT, USA. .,Department of Materials Science and Engineering, University of Connecticut, Storrs, CT, USA.
| |
Collapse
|
4
|
Dorcemus DL, George EO, Dealy CN, Nukavarapu SP. * Harnessing External Cues: Development and Evaluation of an In Vitro Culture System for Osteochondral Tissue Engineering. Tissue Eng Part A 2017; 23:719-737. [PMID: 28346796 PMCID: PMC5568178 DOI: 10.1089/ten.tea.2016.0439] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 02/15/2017] [Indexed: 01/14/2023] Open
Abstract
Over the last decade, engineered structures have been developed for osteochondral (OC) tissue regeneration. While the optimal structure design is yet to be determined, these scaffolds require in vitro evaluation before clinical use. However, the means by which complex scaffolds, such as OC scaffolds, can be tested are limited. Taking advantage of a mesenchymal stem cell's (MSC's) ability to respond to its surrounding we harness external cues, such as the cell's mechanical environment and delivered factors, to create an in vitro culture system for OC tissue engineering with a single cell source on a gradient yet integrated scaffold system. To do this, the effect of hydrogel stiffness on the expression of human MSCs (hMSCs) chondrogenic differentiation was studied using histological analysis. Additionally, hMSCs were also cultured in different combinations of chondrogenic and osteogenic media to develop a co-differentiation media suitable for OC lineage differentiation. A uniquely graded (density-gradient matrix) OC scaffold with a distal cartilage hydrogel phase specifically tailored to support chondrogenic differentiation was cultured using a newly developed "simulated in vivo culture method." The scaffold's culture in co-differentiation media models hMSC infiltration into the scaffold and subsequent differentiation into the distal cartilage and proximal bone layers. Cartilage and bone marker staining along with specific matrix depositions reveal the effect of external cues on the hMSC differentiation. As a result of these studies a model system was developed to study and culture OC scaffolds in vitro.
Collapse
Affiliation(s)
- Deborah L Dorcemus
- 1 Department of Biomedical Engineering, University of Connecticut , Storrs, Connecticut
- 2 Institute for Regenerative Engineering, UCONN Health , Farmington, Connecticut
| | - Eve O George
- 2 Institute for Regenerative Engineering, UCONN Health , Farmington, Connecticut
| | - Caroline N Dealy
- 3 Center for Regenerative Medicine and Skeletal Development, Department of Reconstructive Sciences, UCONN Health , Farmington, Connecticut
| | - Syam P Nukavarapu
- 1 Department of Biomedical Engineering, University of Connecticut , Storrs, Connecticut
- 2 Institute for Regenerative Engineering, UCONN Health , Farmington, Connecticut
- 4 Orthopaedic Surgery Department, UCONN Health , Farmington, Connecticut
- 5 Department of Material Science and Engineering, University of Connecticut , Storrs, Connecticut
| |
Collapse
|
5
|
Hendrikson WJ, van Blitterswijk CA, Rouwkema J, Moroni L. The Use of Finite Element Analyses to Design and Fabricate Three-Dimensional Scaffolds for Skeletal Tissue Engineering. Front Bioeng Biotechnol 2017; 5:30. [PMID: 28567371 PMCID: PMC5434139 DOI: 10.3389/fbioe.2017.00030] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 04/25/2017] [Indexed: 01/13/2023] Open
Abstract
Computational modeling has been increasingly applied to the field of tissue engineering and regenerative medicine. Where in early days computational models were used to better understand the biomechanical requirements of targeted tissues to be regenerated, recently, more and more models are formulated to combine such biomechanical requirements with cell fate predictions to aid in the design of functional three-dimensional scaffolds. In this review, we highlight how computational modeling has been used to understand the mechanisms behind tissue formation and can be used for more rational and biomimetic scaffold-based tissue regeneration strategies. With a particular focus on musculoskeletal tissues, we discuss recent models attempting to predict cell activity in relation to specific mechanical and physical stimuli that can be applied to them through porous three-dimensional scaffolds. In doing so, we review the most common scaffold fabrication methods, with a critical view on those technologies that offer better properties to be more easily combined with computational modeling. Finally, we discuss how modeling, and in particular finite element analysis, can be used to optimize the design of scaffolds for skeletal tissue regeneration.
Collapse
Affiliation(s)
- Wim. J. Hendrikson
- Department of Tissue Regeneration, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, Netherlands
| | - Clemens. A. van Blitterswijk
- Department of Tissue Regeneration, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, Netherlands
- Complex Tissue Regeneration Department, MERLN Institute for Technology Inspired Regenerative Medicine, University of Maastricht, Maastricht, Netherlands
| | - Jeroen Rouwkema
- Department of Biomechanical Engineering, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, Netherlands
| | - Lorenzo Moroni
- Department of Tissue Regeneration, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, Netherlands
- Complex Tissue Regeneration Department, MERLN Institute for Technology Inspired Regenerative Medicine, University of Maastricht, Maastricht, Netherlands
| |
Collapse
|
6
|
Amini AR, Xu TO, Chidambaram RM, Nukavarapu SP. Oxygen Tension-Controlled Matrices with Osteogenic and Vasculogenic Cells for Vascularized Bone Regeneration In Vivo. Tissue Eng Part A 2016; 22:610-20. [PMID: 26914219 PMCID: PMC4841084 DOI: 10.1089/ten.tea.2015.0310] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 02/23/2016] [Indexed: 12/23/2022] Open
Abstract
Despite recent progress, segmental bone defect repair is still a significant challenge in orthopedic surgery. While bone tissue engineering approaches using biodegradable matrices along with bone/blood vessel forming cells offered improved possibilities, current regenerative strategies lack the ability to achieve vascularized bone regeneration in critical-sized/segmental bone defects. In this study, we introduced and evaluated a two-pronged approach for vascularized bone regeneration in vivo. The goal was to demonstrate vascularized bone formation using oxygen tension-controlled (OTC) matrices seeded with bone and blood vessel forming cells. OTC matrices were coimplanted with rabbit mesenchymal stem cells (MSCs) and peripheral blood-derived endothelial progenitor cells (PB-EPCs) to demonstrate the osteogenic and vasculogenic differentiation of these cells, postseeding on a matrix, especially deep inside the matrix pore structure. Matrices coimplanted with varied rabbit MSC and PB-EPC ratios (1:4, 1:1, and 4:1) were assessed in a nude mouse subcutaneous implantation model to determine a coimplantation ratio with superior osteogenic as well as vasculogenic properties. The implants were analyzed, at week 8, for endothelial (CD31 and Von Willebrand factor [vWF]) and osteogenic marker (RunX2 and Col I) staining qualitatively and collagen deposition and number of vessel formation quantitatively. Results from these experiments established MSC-to-PB-EPC ratio 1:1 as the best coimplantation ratio. OTC matrix with 1:1 coimplantation ratio was assessed for segmental bone defect repair in a rabbit critical-sized bone defect model. The group under investigation was OTC matrix, and the matrix was seeded with MSCs, EPCs, or MSCs:EPCs in a 1:1 ratio. Explants at week 12 were evaluated for bone defect repair via micro-CT and histology. Results from rabbit in vivo experiments show enhanced mineralization and vascularization for the 1:1 coimplantation group. Overall, the study establishes a two-pronged approach involving OTC matrix and effective progenitors for large-area and vascularized bone regeneration.
Collapse
Affiliation(s)
- Ami R. Amini
- Oral and Maxillofacial Surgery, Massachusetts General Hospital, Boston, Massachusetts
- Institute for Regenerative Engineering, University of Connecticut Health Center, Farmington, Connecticut
| | - Thomas O. Xu
- Institute for Regenerative Engineering, University of Connecticut Health Center, Farmington, Connecticut
- Department of Orthopedic Surgery, University of Connecticut Health Center, Farmington, Connecticut
| | - Ramaswamy M. Chidambaram
- Center for Comparative Medicine, University of Connecticut Health Center, Farmington, Connecticut
| | - Syam P. Nukavarapu
- Institute for Regenerative Engineering, University of Connecticut Health Center, Farmington, Connecticut
- Department of Orthopedic Surgery, University of Connecticut Health Center, Farmington, Connecticut
- Department of Materials Science & Engineering, University of Connecticut, Storrs, Connecticut
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut
| |
Collapse
|