Mussel inspired injectable chitosan hydrogel modified with catechol for cell adhesion and cartilage defect repair

Repairing articular cartilage defect is a great challenge due to the poor self-regenerative capability of cartilage. Hydrogel-based tissue engineering has been considered as an effective strategy. In this study, inspired...

Hyaluronic acid hydrogel encapsulated BMP-14-modified ADSCs accelerate cartilage defect repair in rabbits

Background Cartilage defect has a limited capacity to heal. In this context, we hypothesized that hyaluronic acid (HA) hydrogel encapsulated BMP-14-modified adipose-derived mesenchymal stem cells (ADSCs) could accelerate cartilage defect repair in rabbits. Methods ADSCs were isolated and identified by flow cytometry. ADSCs were treated with adenovirus vector encoding BMP-14 (Ad-BMP-14) or adenovirus vector encoding control (Ad-ctrl). Real-time PCR (RT-PCR) and western blot assay was performed to verify the transfection efficacy and chondrogenic differentiation markers (ACAN, Collagen II and SOX9). Rabbit cartilage defect model was performed and randomly divided into following groups: control group, HA hydrogel + ADSCs, ADSCs, HA hydrogel + BMP-14 transfected ADSCs, HA hydrogel + BMP-14 transfected ADSCs. At 6, 9 and 12 weeks after surgery, scanning electron microscopy, hematoxylin–eosin, Safranin-O/Fast Green and immunohistochemical staining for Collagen II were performed to determine the role of HA hydrogel encapsulated BMP-14-modified ADSCs in cartilage repair in vivo. Results ADSCs were successfully isolated and positively expressed CD29, CD44 and CD90. Transfection efficacy of Ad-BMP-14 was verified by RT-PCR and western blot assay. Moreover, Ad-BMP-14 could significantly increased chondrogenic differentiation markers (ACAN, Collagen II and SOX9). The LV-BMP-14-ADSCs and HA hydrogel + LV-BMP-14-ADSCs groups revealed smoother surface cartilage repair that was level with the surrounding cartilage and almost complete border integration. Conclusions HA hydrogel encapsulated BMP-14-modified ADSCs accelerate cartilage defect repair in rabbits. We need to further validate the specific mechanism of action of HA hydrogel encapsulated LV-BMP-14-ADSCs involved in the repairing cartilage damage in vivo.

3D Bioprinting Photo-Crosslinkable Hydrogels for Bone and Cartilage Repair

Three-dimensional (3D) bioprinting has become a promising strategy for bone manufacturing, with excellent control over geometry and microarchitectures of the scaffolds. The bioprinting ink for bone and cartilage engineering has thus become the key to developing 3D constructs for bone and cartilage defect repair. Maintaining the balance of cellular viability, drugs or cytokines’ function, and mechanical integrity is critical for constructing 3D bone and/or cartilage scaffolds. Photo-crosslinkable hydrogel is one of the most promising materials in tissue engineering; it can respond to light and induce structural or morphological transition. The biocompatibility, easy fabrication, as well as controllable mechanical and degradation properties of photo-crosslinkable hydrogel can meet various requirements of the bone and cartilage scaffolds, which enable it to serve as an effective bio-ink for 3D bioprinting. Here, in this review, we first introduce commonly used photo-crosslinkable hydrogel materials and additives (such as nanomaterials, functional cells, and drugs/cytokine), and then discuss the applications of the 3D bioprinted photo-crosslinkable hydrogel scaffolds for bone and cartilage engineering. Finally, we conclude the review with future perspectives about the development of 3D bioprinting photo-crosslinkable hydrogels in bone and cartilage engineering.