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Published Online: 1 September 2017

Thermosensitive Poly(N-vinylcaprolactam) Injectable Hydrogels for Cartilage Tissue Engineering

Publication: Tissue Engineering Part A
Volume 23, Issue Number 17-18


Injectable hydrogels have gained prominence in the field of tissue engineering for minimally invasive delivery of cells for tissue repair and in the filling of irregular defects. However, many injectable hydrogels exhibit long gelation times or are not stable for long periods after injection. To address these concerns, we used thermosensitive poly(N-vinylcaprolactam) (PNVCL) hydrogels due to their cytocompatibility and fast response to temperature stimuli. Changes in the PNVCL molecular weight and concentration enabled the development of hydrogels with tunable mechanical properties and fast gelation times (<60 s when the temperature was raised from room temperature to physiologic temperature). Chondrocytes (CHs) and mesenchymal stem cells were encapsulated in PNVCL hydrogels and exhibited high viability (∼90%), as monitored by Live/Dead staining and Alamar Blue assays. Three-dimensional constructs of CH-laden PNVCL hydrogels supported cartilage-specific extracellular matrix production both in vitro and after subcutaneous injection in nude rats for up to 8 weeks. Moreover, biochemical analyses of constructs demonstrated a time-dependent increase in glycosaminoglycans (GAGs) and collagen, which were significantly augmented in the implants cultured in vivo. Histological analyses also demonstrated regular distribution of synthesized cartilage components, including abundant GAGs and type II collagen. The findings from this study demonstrate thermosensitive PNVCL as a candidate injectable biomaterial to deliver cells for cartilage tissue engineering.

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Published In

cover image Tissue Engineering Part A
Tissue Engineering Part A
Volume 23Issue Number 17-18September 2017
Pages: 935 - 945
PubMed: 28384053


Published in print: September 2017
Published online: 1 September 2017
Published ahead of print: 6 April 2017
Published ahead of production: 1 March 2017
Accepted: 16 February 2017
Received: 23 October 2016


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Renata L. Sala, MSc
Interdisciplinary Laboratory of Electrochemistry and Ceramics, Department of Chemistry, Federal University of São Carlos, São Carlos, Brazil.
Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania.
Mi Y. Kwon, BS
Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania.
Minwook Kim, PhD
McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
Translational Musculoskeletal Research Center, CMC VA Medical Center, Philadelphia, Pennsylvania.
Sarah E. Gullbrand, PhD
McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
Translational Musculoskeletal Research Center, CMC VA Medical Center, Philadelphia, Pennsylvania.
Elizabeth A. Henning, PhD
McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
Translational Musculoskeletal Research Center, CMC VA Medical Center, Philadelphia, Pennsylvania.
Robert L. Mauck, PhD
Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania.
McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
Translational Musculoskeletal Research Center, CMC VA Medical Center, Philadelphia, Pennsylvania.
Emerson R. Camargo, PhD
Interdisciplinary Laboratory of Electrochemistry and Ceramics, Department of Chemistry, Federal University of São Carlos, São Carlos, Brazil.
Jason A. Burdick, PhD
Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania.


This article is part of a special focus issue on Strategic Directions in Musculoskeletal Tissue Engineering. Additional articles can be found in Tissue Engineering Part A, volume 23, numbers 15–16 and Tissue Engineering Part B, number 4.
Address correspondence to:Jason A. Burdick, PhDDepartment of BioengineeringUniversity of PennsylvaniaPhiladelphia, PA 19104E-mail: [email protected]

Disclosure Statement

No competing financial interests exist.

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