Enhanced chondrogenic differentiation of stem cells using an optimized electrospun nanofibrous PLLA/PEG scaffolds loaded with glucosamine.

Recently, tissue engineering has become one of the most important approaches in medical research for the treatment of injuries and lesions. In the present study, poly(l-lactide) acid (PLLA), and polyethylene glycol (PEG) with different ratios and PEG molecular weights were used in order to produce appropriate nanofibrous scaffolds using the electrospinning technique for cartilage tissue engineering applications. Glucosamine was also incorporated into the polymeric scaffolds to enhance the biological properties. Mesenchymal stem cells and chondrocytes were used to monitor the differentiation yield. Water absorption test, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, real-time reverse transcription polymerase chain reaction and mechanical properties analyses were performed to characterize the prepared scaffolds. All fabricated scaffolds had porous and nanofibrous structure with interconnected pores. The PLLA-PEG scaffolds containing PEG with the molecular weights of 3000 and 20,000 and ratio of 85:15 was selected for glucosamine incorporation and cell culture studies due to their superior mechanical properties. According to our data, it was identified that PLLA/PEG 20,000 containing glucosamine had the most capability to support protein absorption, stem cell attachment, and proliferation. Chondrogenic-related genes such as sex-determining region Y-Box 9 (SOX9) and collagen type II were shown to be expressed on these scaffolds higher than those observed on control groups. Taking together, it was demonstrated that in combination with PLLA, PEG 20,000 is a suitable substrate to improve the mechanical and physical properties of nanofibrous scaffolds. In addition, glucosamine-PLLA/PEG 20,000 was shown to support stem cell attachment, proliferation, and chondrogenic differentiation and so holds promising potential for cartilage tissue engineering applications.