Bioprinting is a promising tool to fabricate well-organized cell-laden constructs for repair and regeneration of articular cartilage. The selection of a suitable bioink, in terms of composition and mechanical properties, is crucial for the development of viable cartilage substitutes. In this study, we focused on the use of one of the main cartilage components, hyaluronic acid (HA), to design and formulate a new bioink for cartilage tissue 3D bioprinting. Major characteristics required for this application such as printability, biocompatibility, and biodegradability were analyzed. To produce cartilage constructs with optimal mechanical properties, HA-based bioink was co-printed with polylactic acid (PLA). HA-based bioink was found to improve cell functionality by an increase in the expression of chondrogenic gene markers and specific matrix deposition and, therefore, tissue formation. These results indicate that it is a promising bioink candidate for cartilage tissue engineering based in 3D bioprinting. STATEMENT OF SIGNIFICANCE: The recent appearance of 3D printing technology has enabled great advances in the treatment of osteochondral disorders by fabrication of cartilage tissue constructs that restore and/or regenerate damaged tissue. In this attempt, the selection of a suitable biomaterial, in terms of composition and mechanical properties, is crucial. In this study, we describe for first time the development of a bioink based on the main component of cartilage, HA, with suitable biological and mechanical properties, without involving toxic procedure, and its application in cartilage tissue bioprinting. Hybrid constructs prepared by co-printing this bioink and thermoplastic polymer PLA provided an optimal niche for chondrocyte growth and maintenance as well as mechanical properties necessary to support load forces exerted in native tissue. We highlight the translation potential of this HA-based bioink in the clinical arena.

Intra-articular injection of platelet-rich plasma (PRP) has been established as a suitable treatment for knee osteoarthritis. Here, we present a double-blind randomized controlled clinical trial, conducted in a public Hospital of the Spanish National Health Care System, to evaluate the efficacy of injecting autologous PRP versus hyaluronic acid (HA) in knee osteoarthritis. PRP was manufactured in Malaga’s Regional Blood Center (Spain). Patients that met the eligibility criteria were randomized into a PRP group or a HA group. Pain and functional improvements were assessed pre- and post-treatment (three and six months follow-up) using the Visual Analogue Scale (VAS); the Knee and Osteoarthritis Outcome System (KOOS) scale and the European Quality of Life scale (EUROQOL). Both groups presented pain reduction at six months. The VAS scores for the PRP group improved by at least 50% from their initial value, particularly at three months following the final infiltration, with results resembling those of the HA group at six months. PRP was more effective in patients with lower osteoarthritis grades. Both treatments improved pain in knee osteoarthritis patients without statistically significant differences between them. However, PRP injection was proved to improve pain three months after the final infiltration and to be more effective in lower osteoarthritis grades.

Given the wide difference in price per vial between various presentations of hyaluronic acid, this study seeks to compare the effectiveness and treatment cost of stabilized hyaluronic acid (NASHA) in a single injection with standard preparations of hyaluronic acid (HA) in five injections in osteoarthritis (OA) of the knee. Fifty-four patients with knee osteoarthritis (Kellgren–Lawrence Grade II and III) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score greater than 7, with a homogeneous distribution of age, sex, BMI, and duration of disease, were included in this study. Patients were randomized into two groups: Group I was treated with NASHA (Durolane^®) and Group II with HA (Go-ON^®). Patient’s evolution was followed up at the 1st, 2nd, 4th, 8th, 12th, and 26th week after treatment. A statistically significant improvement in WOMAC score was observed for patients treated with NASHA versus those who received HA at Week 26. In addition, the need for analgesia was significantly reduced at Week 26 in the NASHA-treated group. Finally, the economic analysis showed an increased cost of overall treatment with HA injections. Our data support the use of the NASHA class of products in the treatment of knee OA.

Case: We describe the case of a 75-year-old patient diagnosed with high-grade epithelioid hemangioendothelioma in the left hemipelvis. She underwent an internal hemipelvectomy, followed by reconstruction with a tumor prosthesis with iliac anchorage using 3D-printed cutting and placement guides. Eighteen months postoperatively, she is pain-free and walks without appliances.Conclusions: Using 3D-printed guides could be an appropriate alternative for patients with aggressive bone tumors in the pelvic area that require hemipelvectomy and reconstruction using a prosthesis with iliac anchorage. 3D-printed cutting guides allow precise resection with appropriate margins, could reduce the risk of injuring critical structures, and facilitate proper prosthetic component positioning.