Study of the Cytotoxicity of a Composite of Carboxymethylcellulose (CMC) and a BioCeramic (Biphasic Calcium Phosphate-BCP) Injection for Use in Articular Cartilage Repair

Abstract

The failure of organs and tissues caused by trauma and other injuries is one of the most costly of human health problems. It is estimated that 1.6 million people experience work limitations caused by osteoarthritis and related disorders, representing 8.3% of all main conditions. Joint injuries frequently lead to progressive joint degeneration and post-traumatic osteoarthritis. Articular cartilage has only a limited capacity for self-healing, mainly due to the fact that it is avascular; and once seriously damaged, articular cartilage lesions will not regenerate. There is strong evidence that cartilage lesions may lead to osteoarthritis when left untreated. Numerous animal experiments and clinical studies have shown that early biological reconstruction of circumscribed cartilage defects in the knee is superior to conservative or delayed surgical treatment. Tissue engineering has shown promising therapeutic strategies for repair or regeneration of damaged tissues. Currently, ceramic based and polymeric scaffolds have been developed to bring about the restoration of tissue functions. The bioceramics associated with water-soluble polymers have been developed as substitutes for various orthopedic applications. The objectives of this work are the processing and characterization of a composite of carboxymethylcellulose (CMC) and biphasic calcium phosphate (Biphasic Calcium Phosphate - BCP) in the form of a hydrogel, and a study of its cytotoxicity (in vitro), aimed at its application as an injectable biomaterial in order to repair the extracellular matrix of articular cartilage. The CMC and BCP were characterized by Fourier Transform Infrared Spectrometry (FTIR) and X-Ray Diffraction (XRD), X-ray fluorescence (XRF), respectively, and scanning electron microscopy (SEM) of powders and the composite. To evaluate the biological effect of the composite hydrogel, tests of cytotoxicity (MTT) and rheological tests under real conditions of use were performed. The composite of carboxymethylcellulose (CMC) and bioceramics (biphasic calcium phosphate-BCP) in the form of hydrogel showed an adequate injectability in the conditions studied, and a non-toxic response, presenting potential for use as fillers or to stimulate the healing of cartilage defects in the extracellular matrix of articular cartilage.