OBJECTIVE: To investigate the effect of compound pattern of ceramic bovine bone (CBB) and hydrogel(HG) on attachment, proliferation and differentiation of bone marrow stromal cell (MSC), and to find out the best way of constructing tissue engineered bone. METHODS: CBB, HG and MSC was compounded in different patterns and sequences to form CBB/HG/MSC (group A), HG/MSC/CBB (group B), CBB/MSC/HA (group C) and CBB/MSC (control group). Attachment and morphology of MSC were observed by scanning electronic microscope; the proliferation of MSC was evaluated by cell count; alkaline phosphatase(ALP) activity was examined by histochemistry and type I collagen synthesis was examined by immunohistochemistry staining 5 and 10 days later. RESULTS: In group A, MSC spread better, and ALP activity of group A was significantly higher than that of group B and control group(P lt; 0.01); but there was no significant difference between group A and group C(P gt; 0.05). There was no significant difference in type I collagen synthesis between four groups on the 5th day; but mean gray scale of type I collagen in group B was significantly higher than that in the other groups on the 10th day(P lt; 0.01). CONCLUSION: Different compound patterns of CBB, HG and MSC affect attachment, proliferation, differentiation of MSC. The compound pattern of CBB/HG/MSC is better than the others.
Objective To introduce the development of dextran-based hydrogel and its drug delivery system in drug sustained and/or controlled release, and to investigate their application in tissue engineering.Methods Related literature was extensively reviewed and comprehensively analyzed. Results In recent years, great progress was made in the studies of dextran-based hydrogels and study on dextran-based intelligent materials became an investigative hotspot especially in tissue engineering. Conclusion Dextran based hydrogel is considered to be a good potential material in field of drug delivery and tissue engineering. Endowed with new characteristics, a series of intelligent biomaterials can be derived from dextran-based hydrogels, which can be widely used in biomedicine. Further study should be done on the industrialization of its interrelated production.
Heart failure affects quality of life and life expectancy of tens of millions of individuals. There are no available economic and effective treatments for end-stage heart failure. Hydrogels are novel tissue engineering materials, which have the potential to ameliorate myocardium remodeling, increase cardiac output, improve quality of life and prolong life span by implantation into myocardium. The preclinical experiments and clinical trials have greatly explored the function of hydrogels in heart failure. In this review, we summarized the approaches of implantation, mechanism and clinical outcomes of the hydrogels.
【Abstract】 Objective To increase the viscosity of chitosan/glycerol phosphate（C/GP）and to improve its preparation technique in order to develop the appl ication range of C/GP. Methods Chitosan was treated by high-pressure vapor steril ization in order to prepare high viscous C/GP（HV-C/GP）and prepare C/GP by standard methods. The rheologic changes of HV-C/GP and C/GP were detected dynamically by the Gemini rheometer. The initial solution viscosity, gelation temperature and gelation time were evaluated after the viscosity of the materials were increased. Two gelation materials were placed into continuous flow thermostated cells under the same condition and harvest them at predetermined time intervals, 1st, 2nd, 5th, 10th and 25th days, then they were dried, weighed and the mass loss rate was calculated. Ultrastructure of the freeze-dried samples was visual ized by the scanning electron microscope. Results The initial viscosity of C/GP was 1.81 Pas and that of HV-C/GP was 17.24 Pas. The latter one increased 10 times as well as the former one. The gelation temperature of C/GP was 37°C and that of HV-C/GP was 34°C. There was no remarkable difference in gelation time between them. The mass loss rate of HV-C/GP at first day was 72.5% and at 25th days was 90.8%, while that of C/GP was 55.4% and 78.2%. Porous network structure was observed by the scanning electron microscope in both of them. The pore diameter of C/GP was 50-100 μm and that of HV-C/GP was 30-50 μm, which was obviously smaller than the former. Conclusion The viscosity of HV-C/GP prepared by improved technique obviously increases and the thermosensitivity has no significant changes. The degradation time of HV-C/GP in vitro lengthens. The micrographs show that the HV-C/GP gels are porous and the pore diameter are smaller than C/GP.
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.
ObjectiveTo review the application of silk fibroin scaffold in bone tissue engineering. MethodsThe related literature about the application of silk fibroin scaffold in bone tissue engineering was reviewed, analyzed, and summarized. ResultsSilk fibroin can be manufactured into many types, such as hydrogel, film, nano-fiber, and three-dimensional scaffold, which have superior biocompatibility, slow biodegradability, nontoxic degradation products, and excellent mechanical strength. Meanwhile these silk fibroin biomaterials can be chemically modified and can be used to carry stem cells, growth factors, and compound inorganic matter. ConclusionSilk fibroin scaffolds can be widely used in bone tissue engineering. But it still needs further study to prepare the scaffold in accordance with the requirement of tissue engineering.
Objective To fabricate in situ crosslinking hyaluronic acid hydrogel and evaluate its biocompatibility in vitro. Methods The acrylic acid chloride and polyethylene glycol were added to prepare crosslinking agent polyethylene glycol acrylate (PEGDA), and the molecular structure of PEGDA was analyzed by Flourier transformation infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. Hyaluronic acid hydrogel was chemically modified to prepare hyaluronic acid thiolation (HA-SH). And the degree of HA-SH was analyzed qualitatively and quantitatively by Ellman method. HA-SH solution in concentrations (W/V) of 0.5%, 1.0%, and 1.5% and PEGDA solution in concentrations (W/V) of 2%, 4%, and 6% were prepared with PBS. The two solutions were mixed in different ratios, and in situ crosslinking hyaluronic acid hydrogel was obtained; the crosslinking time was recorded. The cellular toxicity of in situ crosslinking hyaluronic acid hydrogel (1.5% HA-SH and 4% PEGDA mixed) was tested by L929 cells. Meanwhile, the biocompatibility of hydrogel was tested by co-cultured with human bone mesenchymal stem cells (hBMSCs). Results Flourier transformation infrared spectroscopy showed that most hydroxyl groups were replaced by acrylate groups; 1H nuclear magnetic resonance spectroscopy showed 3 characteristic peaks of hydrogen representing acrylate and olefinic bond at 5-7 ppm. The thiolation yield of HA-SH was 65.4%. In situ crosslinking time of hyaluronic acid hydrogel was 2 to 70 minutes in the PEGDA concentrations of 2%-6% and HA-SH concentrations of 0.5%-1.5%. The hyaluronic acid hydrogel appeared to be transparent. The toxicity grade of leaching solution of hydrogel was grade 1. hBMSCs grew well and distributed evenly in hydrogel with a very high viability. Conclusion In situ crosslinking hyaluronic acid hydrogel has low cytotoxicity, good biocompatibility, and controllable crosslinking time, so it could be used as a potential tissue engineered scaffold or repairing material for tissue regeneration.
Objective To observe the efficacy of hydrogel dressings in preventing and treating vein injury of rabbits so as to provide a experimental evidence for cl inical appl ication. Methods Twenty-four healthy large-eared Japanese rabbits (48 ears) were choosen, weighing (2.15 ± 0.15) kg, and divided into 3 groups randomly. The vein injury models were made byintravenously infusing 20% mannite (2.5 mL/kg). The sites of puncture were treated with hydrogel dressings (group A, n=8) and 25%MgSO4 (group B, n=8) 5 minutes after infusion. The sites of puncture were not treated as a blank control (group C, n=8). The tissue specimens were collected from the auricular veins at 24 hours after mannite infusion for histological observation by HE staining. The injury of the vessel wall, hemorrhage around the vessels, infiltration of inflammatory cells, and disturbance of circulation were observed to evaluate the injury degree of vein. Results There existed redness and congestion in the injured veins of each group. HE staining showed that in both groups A and B, the vessel wall was sl ightly injured and hemorrhage around the vessel was mild. There existed infiltration of inflammatory cells in the vessel wall and surrounding tissues. There also existed congestion and thrombus in the vessel lumen in these two groups. While in group C, the injury of vessel wall was severe, and schistic bleeding in the surrounding tissue of the vessel was existed. The severe congestion and thrombus in the vessel lumen was observed. There was no significant difference among three groups in the extent of vein wall injury and hemorrhage around the vessel (P gt; 0.05). The degree of infiltration of inflammatory cells and circulatory disturbance in both groups A and B were significantly less than that of group C (P lt; 0.05); but there was no significant difference between groups A and B (P gt; 0.05). Conclusion Hydrogel dressing is helpful to prevent vein injury of rabbits induced by mannite.
This research aims to investigate the encapsulation and controlled release effect of the newly developed self-assembling peptide R-LIFE-1 on exosomes. The gelling ability and morphological structure of the chiral self-assembling peptide (CSAP) hydrogel were examined using advanced imaging techniques, including atomic force microscopy, transmission electron microscopy, and cryo-scanning electron microscopy. The biocompatibility of the CSAP hydrogel was assessed through optical microscopy and fluorescent staining. Exosomes were isolated via ultrafiltration, and their quality was evaluated using Western blot analysis, nanoparticle tracking analysis, and transmission electron microscopy. The controlled release effect of the CSAP hydrogel on exosomes was quantitatively analyzed using laser confocal microscopy and a BCA assay kit. The results revealed that the self-assembling peptide R-LIFE-1 exhibited spontaneous assembly in the presence of various ions, leading to the formation of nanofibers. These nanofibers were cross-linked, giving rise to a robust nanofiber network structure, which further underwent cross-linking to generate a laminated membrane structure. The nanofibers possessed a large surface area, allowing them to encapsulate a substantial number of water molecules, thereby forming a hydrogel material with high water content. This hydrogel served as a stable spatial scaffold and loading matrix for the three-dimensional culture of cells, as well as the encapsulation and controlled release of exosomes. Importantly, R-LIFE-1 demonstrated excellent biocompatibility, preserving the growth of cells and the biological activity of exosomes. It rapidly formed a three-dimensional network scaffold, enabling the stable loading of cells and exosomes, while exhibiting favorable biocompatibility and reduced cytotoxicity. In conclusion, the findings of this study support the notion that R-LIFE-1 holds significant promise as an ideal tissue engineering material for tissue repair applications.
Hydrogel is a kind of degradable hydrophilic polymer, but excessive hydrophilicity leads to larger volume, lower elastic modulus and looser structure, which further affect its use. Especially in the field of biomedical engineering, excessive swelling of the hydrogel can compress the nerves and improve degradation rate resulting in mismatch of tissue growth and released ions. Therefore, anti-swelling hydrogel has been a research hotspot in recent years. This paper reviews the recent research progress on anti-swelling hydrogel, and expounds the application mechanism and preparation method of hydrogel in biomedical engineering, aiming to provide some references for researchers in the field of anti-swelling hydrogel.