{'fraction_non_alphanumeric': 0.02172437202987101, 'fraction_numerical': 0.008825526137135099, 'mean_word_length': 6.2254901960784315, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Biopolymer materials for cartilage tissue engineering

BACKGROUND: Biopolymer materials have unique advantages in cartilage tissue engineering, which have become an increasing concern in cartilage repair. OBJECTIVE: To summarize the application of biopolymer materials in cartilage tissue engineering in recent years. METHODS: The first author retrieved PubMed, ScienceDirect and Medline databases for relevant articles published from January 2000 to June 2017. The key words were “cartilage defect, biopolymer” in English. Initially, 305 articles were retrieved, and finally 72 articles were included in result analysis. RESULTS AND CONCLUSION: Commonly used polymer compounds are classified into natural materials (including natural polymer proteins, polysaccharides and polynucleotides) and synthetic materials (including polylactic acid, polyethylene glycol, polyvinyl alcohol). The multilayer scaffold technology is one of the application innovations of biopolymer materials. This scaffold is consistent with the natural cartilage in the structure, on which newborn cartilage tissues develop similar biomechanical properties, mechanical strength and shear resistance to normal cartilage. Biopolymer scaffolds and hydrogels can load stem cells and cytokines and exert a synergistic repair of cartilage defects, which have achieved desired repair results. Despite limitations in clinical practice, biopolymer materials will surely become a hot issue in cartilage repair.