Collagen contains abundant cell binding motifs, which are conducive to adhesion, migration, and differentiation, maintain cell vitality and promote cell proliferation. However, pure collagen hydrogel has some shortcomings such as poor mechanical properties, poor thermal stability and fast degradation. Numerous studies have shown that the properties of collagen can be improved by combining it with natural polysaccharides such as alginate, chitosan, hyaluronic acid and cellulose. In this paper, the research status and biological application fields of four kinds of composite hydrogels, including collagen-alginate composite hydrogels, collagen-chitosan hydrogels, collagen-hyaluronic acid hydrogels and collagen-cellulose hydrogels, were summarized. The common preparation methods of four kinds of composite hydrogels were introduced, and the future development direction of collagen-based composite hydrogels was prospected.
Hydrogels/chemical synthesis* ; Collagen/chemistry* ; Polysaccharides/chemistry* ; Alginates/chemistry* ; Hyaluronic Acid/chemistry* ; Chitosan/chemistry* ; Biocompatible Materials/chemistry* ; Humans ; Tissue Engineering/methods* ; Cellulose/chemistry* ; Tissue Scaffolds

Objective To investigate the expressions of transforming growth factor β1 (TGF-β1) and brain natrium peptide (BNP) in patients with diastolic heart failure (DHF),and to explore the correlation between plasma levels of TGF-β1,BNP and TGF-β1/BNP with parameter of diastolic function,diastolic dysfunction and New York Heart Association (NYHA) classification of cardiac function.Methods Hospitalized patients with DHF from October 2016 to November 2017 in Beijing Chaoyang Hospital were selected as subjects.At the same time,the age-and gender-matched non-heart failure hospitalized patients were selected as the control.The diastolic function index (E/e') was measured using cardiac ultrasound spectral Doppler and tissue Doppler methods.The diastolic dysfunction classification was evaluated according to the American Society of Echocardiography guidelines.Cardiac function was evaluated with NYHA classification.The levels of plasma TGF-β1 and BNP were measured with method of enzyme linked immunosorbent assay (ELISA).The correlation between the indicators was analyzed and the receiver operating characteristic (ROC) curve was drawn.Results A total of 186 patients were enrolled,including 114 patients as DHF group [54 males and 60 females,mean age (70.75 ± 11.45) years old] and 72 cases as control group [41 males and 31 females,mean age (68.74 ± 10.86) years old].The levels of TGF-β1 [(77.68 ± 42.31) ng/L] and BNP [(1 153.84 ± 564.96) ng/L] in patients with DHF were significantly higher than those of the control group [(18.76 ± 13.70),(264.07 ± 179.43) ng/L,t =15.62,13.77,P ＜ 0.01].Pearson correlation analysis showed that level of plasma TGF-β1 had a significant liner correlation with index E/e' (r =0.582,P ＜ 0.01),level of plasma BNP had a low-degree liner correlation with index E/e' (r =0.261,P ＜ 0.01),and TGF-β1/BNP had no correlation with index E/e' (r =0.081,P ＞ 0.05).Spearman correlation analysis showed that the levels of TGF-β1 and BNP were significantly correlated with diastolic dysfunction grading (r =0.473,0.417,P ＜ 0.01),while TGF-β1/BNP had no correlation with diastolic dysfunction grading (r =0.062,P ＞ 0.05).Plasma TGF-β1 and BNP had low-degree correlation with NYHA classification of heart failure (r =0.309,0.326,P ＜ 0.01),TGF-β1/BNP had no correlation with NYHA classification of heart failure (r =0.011,P ＞ 0.05).Logistic analysis showed that both plasma TGF-β1 and BNP were independent predictors of DHF (OR =1.264,2.283,P ＜ 0.05 or ＜ 0.01).The area under ROC curve (AUC) of BNP for prediction of DHF was 0.937 ± 0.064,and TGF-β1 was 0.597 ± 0.042.AUC areas of BNP and TGF-β1 were significantly different (P ＜ 0.01).Conclusions The expressions of plasma TGF-β1 and BNP in patients with DHF are higher than those without DHF.The levels of plasma TGF-β1 and BNP are significantly correlated with index E/e',diastolic dysfunction grading and NYHA classification.Both elevated BNP and TGF-β1 levels are independent predictors of DHF.Both plasma BNP and TGF-β1 have auxiliary diagnostic value on DHF and the diagnostic value of plasma BNP is greater than plasma TGF-β1.