1.Stabilizers of horseradish peroxidase.
Xinhuan MAO ; Xiang LI ; Shanshan WANG ; Wenjing ZHANG ; Chengming ZENG
Chinese Journal of Biotechnology 2009;25(3):388-391
Keeping an enzyme in its native form with high catalytic activity is of great significance. In the present study, thermal stabilizers of horseradish peroxidase (HRP) were screened. The results indicated that thermal stability of HRP was enhanced by magnesium sulphate and gelatin. A synergic effect of magnesium sulphate and gelatin was observed. In the presence of the stabilizer, the enzymatic activity of HRP remained 89% after kept for 80 h at 50 degrees C and 57% for 90 days at room temperature. Thermal alterations of HRP structure in the absence and presence of the stabilizers were explored by using UV absorption spectra at 402 nm (Soret band), intrinsic fluorescence and 8-anilinonaphthalene-1-sulfonic acid (ANS) fluorescence. The results suggested that magnesium sulphate and gelatin attenuated the extent of unfolding of HRP and therefore the native enzyme structure was stabilized.
Drug Synergism
;
Enzyme Stability
;
drug effects
;
Gelatin
;
pharmacology
;
Horseradish Peroxidase
;
metabolism
;
Hot Temperature
;
Magnesium Sulfate
;
pharmacology
2.Influence of different gelatin concentration and lymphocyte isolation liquid on primary culture of umbilical cord blood derived adhesive cells.
Cheng ZHANG ; Xing-Hua CHEN ; Xi ZHANG ; Lei GAO ; Pei-Yan KONG ; Hong LIU ; Xue LIANG ; Xian-Gui PENG ; Qing-Yu WANG
Journal of Experimental Hematology 2008;16(6):1437-1441
In order to study the influence of different gelatin concentrations, and lymphocyte isolation liquid on primary culture of umbilical cord blood-derived adhesive cells (hCBACs), the red blood cells of umbilical cord blood was separated by 3% and 6 % gelatin for detecting the effectiveness of sedimentation, then the adhesion rate at 48 hours, the day of initial expansion and the rate of culture success were detected for hCBACs cultured with CD34(+) cells after the mononuclear cells were separated by 6% gelatin followed by Ficoll and Percoll, and the morphological characteristics and growth status were observed by invert microscopy. Cytochemistry stain for nonspecific esterase stain (NSE), peroxidase (POX), periodic acid Schiff reaction (PAS) and alkali phosphatase (ALP) and immunocytochemistry labeling for CD31, CD45, CD68 and fibronectin (Fn) were detected. The results showed that 6 % gelatin was better than that 3% gelatin for red blood sedimentation. The Percoll was predominant over Ficoll in adhesion rate at 48 hours, the day of initial expansion, the time of initial formation of adhesive cell colony units, the time of maximal numbers of adhesive cell colony units, the the cell fusion time and ratio of culture success. 60% fibroblast-liked cells, 36% macrophage liked cells and 4% small-round cells were observed in cells isolated by both isolated methods. The cytochemistry stain for NSE, POX, PAS and ALP was similar in two groups, the difference was not statistically significant between these two groups. The immunocytochemistry labeling for CD31, CD45, CD68 and Fn was also similar in both groups and the difference was also not statistically significant between these two groups. It is concluded that the combination of 6% gelatin with Percoll is an ideal separation method for primary culture of hCBACs, which provides basic information for clinical application.
Cell Separation
;
methods
;
Cells, Cultured
;
Fetal Blood
;
cytology
;
Gelatin
;
administration & dosage
;
pharmacology
;
Humans
;
Lymphocytes
;
cytology
3.Study of immobilization of Aspergillus oryzae mycelium aided by artificial neural network.
Yan WANG ; Feng-Bao ZHANG ; Zhi-Ming GAO ; Zheng-Xiao SONG ; Guo-Liang ZHANG ; Lin ZHAO
Chinese Journal of Biotechnology 2002;18(2):221-224
Aspergillus oryzae mycelium pellets with abundant aminoacylase were cultured by liquid fermentation. Mycelium pellets were immobilized by crosslinking method with reagent of gelatin and formaldehyde. Basing on the orthogonal design table L16 (4(5)), artificial neural network(ANN) model with back-propagation(BP) of error structured 4-10-15-1 was used to optimize the immobilization conditions. And the optimal conditions were obtained. Then the activity of the immobilized cells prepared under the optimal conditions was assayed. Compared with the free mycelium activity of 1800 u, the residual activity rate was 83%, which was in good accordance with that predicted by ANN. It illustrated that artificial neural network can be used to find optimal conditions for cell immobilization.
Amidohydrolases
;
drug effects
;
metabolism
;
Aspergillus oryzae
;
enzymology
;
Dose-Response Relationship, Drug
;
Enzymes, Immobilized
;
Formaldehyde
;
pharmacology
;
Gelatin
;
pharmacology
;
Mycelium
;
Neural Networks (Computer)
4.Bone morphogenetic protein 7 mediates stem cells migration and angiogenesis: therapeutic potential for endogenous pulp regeneration.
Cheng LIANG ; Qingqing LIANG ; Xun XU ; Xiaojing LIU ; Xin GAO ; Maojiao LI ; Jian YANG ; Xiaotao XING ; Haisen HUANG ; Qi TANG ; Li LIAO ; Weidong TIAN
International Journal of Oral Science 2022;14(1):38-38
Pulp loss is accompanied by the functional impairment of defense, sensory, and nutrition supply. The approach based on endogenous stem cells is a potential strategy for pulp regeneration. However, endogenous stem cell sources, exogenous regenerative signals, and neovascularization are major difficulties for pulp regeneration based on endogenous stem cells. Therefore, the purpose of our research is to seek an effective cytokines delivery strategy and bioactive materials to reestablish an ideal regenerative microenvironment for pulp regeneration. In in vitro study, we investigated the effects of Wnt3a, transforming growth factor-beta 1, and bone morphogenetic protein 7 (BMP7) on human dental pulp stem cells (h-DPSCs) and human umbilical vein endothelial cells. 2D and 3D culture systems based on collagen gel, matrigel, and gelatin methacryloyl were fabricated to evaluate the morphology and viability of h-DPSCs. In in vivo study, an ectopic nude mouse model and an in situ beagle dog model were established to investigate the possibility of pulp regeneration by implanting collagen gel loading BMP7. We concluded that BMP7 promoted the migration and odontogenic differentiation of h-DPSCs and vessel formation. Collagen gel maintained the cell adhesion, cell spreading, and cell viability of h-DPSCs in 2D or 3D culture. The transplantation of collagen gel loading BMP7 induced vascularized pulp-like tissue regeneration in vivo. The injectable approach based on collagen gel loading BMP7 might exert promising therapeutic application in endogenous pulp regeneration.
Animals
;
Bone Morphogenetic Protein 7/pharmacology*
;
Cell Differentiation
;
Cells, Cultured
;
Collagen/pharmacology*
;
Dental Pulp
;
Dogs
;
Endothelial Cells
;
Gelatin
;
Humans
;
Methacrylates
;
Mice
;
Regeneration
;
Stem Cells
5.Effects of methacrylic anhydride gelatin hydrogel loaded with silver and recombinant human basic fibroblast growth factor on deep partial-thickness burn wounds in rabbits.
Xing Jun CHEN ; Xing WU ; Huan Huan LIN ; Zhao Xing LIU ; Sha LIU
Chinese Journal of Burns 2022;38(7):640-649
Objective: To investigate the effects of methacrylic anhydride gelatin (GelMA) hydrogel loaded with silver and recombinant human basic fibroblast growth factor (rh-bFGF) on deep partial-thickness burn wounds in rabbits. Methods: The experimental research method was adopted. Low-concentration GelMA materials, medium-concentration GelMA materials and high-concentration GelMA materials containing different concentrations of methacrylic anhydride (MA) were prepared, after adding photoinitiator, low-concentration GelMA hydrogels, medium-concentration GelMA hydrogels, and high-concentration GelMA hydrogels were obtained, respectively. The nuclear magnetic resonance spectroscopy was performed to detect the hydrogen nuclear magnetic resonance spectra of the above-mentioned three concentrations of GelMA materials, and to calculate the degree of substitution according to the spectrum diagram. The three-dimensional microstructure and pore size of 3 types of above-mentioned GelMA hydrogels were detected by field emission scanning electron microscopy (FESEM), with 9 samples measured. According to the selected concentration of MA, ten kinds of solutions of GelMA with different concentration of silver (silver-containing GelMA) were synthesized, and the silver-containing GelMA solution of each concentration was divided into three parts, and then exposed to ultraviolet light lasting for 20, 25, and 35 s, respectively. After adding photoinitiator,the corresponding silver-containing GelMA hydrogels were obtained. The residual degradation rate of silver-containing GelMA hydrogel with different photocrosslinking times was detected by collagenase degradation method at degradation of 12, 24, 36, and 48 h; and the time required for complete degradation was detected, and the sample number was 5. The inhibition zone diameter of GelMA hydrogel under above screened photocrosslinking times containing 10 concentrations of silver against Staphylococcus aureus was measured to reflect its antibacterial ability, and the sample numbers were all 5. The silver-containing GelMA hydrogel with statistical significance compared with the antibacterial circle diameter of the silver-containing GelMA hydrogel containing the lowest concentration (no silver) was considered as having antibacterial activity. The three-dimensional microstructure and pore size of the silver-containing GelMA hydrogels with antibacterial activity and the lowest drug concentration selected were detected by FESEM, and the sample numbers were all 9. The freeze-dried alone GelMA hydrogel and the freeze-dried silver-containing GelMA hydrogel were soaked in phosphate buffer solution for 24 h, respectively, then the swelling rate of the two GelMA hydrogel were calculated and compared by weighing method, and the sample number was 5. GelMA hydrogel containing silver and rh-bFGF, namely compound hydrogel for short, was prepared according to the preliminary experiment and the above experimental results. The appearance of the composite hydrogel was observed in general, and its three-dimensional microstructure and pore size were detected by FESEM. The deep partial-thickness burn wound was made on the back of 30 rabbits (aged 4-6 months, female half and half). Meanwhile, with the rabbit head as the benchmark, the wounds on the left side of the spine were treated as composite hydrogel treatment group, and the wounds on the right side were treated as gauze control group, and which were treated accordingly. On post injury day (PID) 3, 7, 14, 21, and 28, the healing of wounds in the two groups was observed. On PID 7, 14, 21, and 28, the wound healing area was recorded and the healing rate was calculated, with a sample number of 30. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and independent sample t test. Results: The substitution degree among low-concentration GelMA materials, medium-concentration GelMA materials, and high-concentration GelMA materials was significantly different (F=1 628.00, P<0.01). The low-concentration GelMA hydrogel had a loose and irregular three-dimensional spatial network structure with a pore size of (60±17) μm; the medium-concentration GelMA hydrogel had a relatively uniform three-dimensional spatial network and pore size with a pore size of (45±13) μm; the high-concentration GelMA hydrogel had the dense and disordered three-dimensional spatial network with a pore size of (25±15) μm, the pore sizes of 3 types of GelMA hydrogels were significantly differences (F=12.20, P<0.01), and medium concentration of MA was selected for the concentration of subsequent materials. The degradability of silver-containing GelMA hydrogels with different concentrations of the same photocrosslinking time was basically same. The degradation residual rates of silver-containing GelMA hydrogels with 20, 25, and 35 s crosslinking time at 12 h were (74.2±1.7)%, (85.3±0.9)%, and (93.2±1.2)%, respectively; the residual rates of degradation at 24 h were (58.3±2.1)%, (65.2±1.8)%, and (81.4±2.6)%, respectively; the residual rates of degradation at 36 h were (22.4±1.9)%, (45.2±1.7)%, and (68.1±1.4)%, respectively; the residual rates of degradation at 48 h were (8.2±1.7)%, (32.4±1.3)%, and (54.3±2.2)%, respectively, and 20, 25, and 30 s photocrosslinking time required for complete degradation of silver-containing GelMA hydrogels were (50.2±2.4), (62.4±1.4), and (72.2±3.2) h, and the difference was statistically significant (F=182.40, P<0.01), 25 s were selected as the subsequent photocrosslinking time. The antibacterial diameters of 10 types of silver-containing GelMA hydrogels against Staphylococcus aureus from low to high concentrations were (2.6±0.4), (2.5±0.4), (3.2±0.4), (12.1±0.7), (14.8±0.7), (15.1±0.5), (16.2±0.6), (16.7±0.5), (16.7±0.4), and (16.7±0.6) mm, respectively, and which basically showed a concentration-dependent increasing trend, and the overall difference was statistically significant (F=428.70, P<0.01). Compared with the silver-containing GelMA hydrogel with the lowest concentration, the antibacterial circle diameters of other silver-containing GelMA hydrogels with antibacterial ability from low to high concentration were significantly increased (with t values of 26.35, 33.84, 43.65, 42.17, 49.24, 55.74, and 43.72, respectively, P<0.01). The silver-containing GelMA hydrogel with the antibacterial diameter of (12.1±0.7) mm had the lowest antibacterial activity against Staphylococcus aureus and the lowest drug loading concentration, and the concentration of silver was selected for the concentration of subsequent materials. The microscopic morphology of the silver-containing GelMA hydrogel containing silver element with a pore size of (45±13) μm had a regular and linear strip-like structure. After soaking for 24 h, the swelling ratio of silver-containing GelMA hydrogel was similar to that of alone GelMA hydrogel. The composite hydrogel was colorless, clear and transparent, and its three-dimensional microstructure was a regular and uniform grid, with a filament network structure inside, and the pore size of (40±21) μm. On PID 3, a large amount of necrotic tissue and exudate of rabbit wound in composite hydrogel group were observed, and scattered scabs, a small amount of necrotic tissue and exudate of rabbit wound in gauze control group were observed. On PID 7, the area of rabbit wound in composite hydrogel group was significantly reduced, and adhesion of rabbit wound and gauze in gauze control group was observed. On PID 14, In composite hydrogel group, the rabbit wound surface was ruddy, and the growth of granulation tissue was observed, and in gauze control group, the rabbit wound base was pale, and the blood supply was poor. On PID 21, the rabbit wounds in composite hydrogel group healed completely, and rabbit wound in gauze control group had healing trend. On PID 28, new hair could be seen on rabbit wound surface in composite hydrogel group; oval wound of rabbit in gauze control group still remained. On PID 7, 14, 21, and 28, the wound healing areas of rabbit in composite hydrogel group were significantly larger than those in gauze control group (with t values of 2.24, 4.43, 7.67, and 7.69, respectively, P<0.05 or P<0.01). Conclusions: The medium-concentration GelMA hydrogel has good physical and chemical properties in terms of swelling and degradability. The screened silver-containing GelMA hydrogels had the lowest antibacterial activity and the lowest drug loading concentration. Composite hydrogel can significantly shorten the healing time of deep partial-thickness burn wounds in rabbits.
Anhydrides
;
Animals
;
Anti-Bacterial Agents
;
Burns/drug therapy*
;
Female
;
Fibroblast Growth Factor 2
;
Gelatin/pharmacology*
;
Humans
;
Hydrogels/pharmacology*
;
Rabbits
;
Recombinant Proteins
;
Staphylococcal Infections
;
Staphylococcus aureus
6.Effects of in situ cross-linked graphene oxide-containing gelatin methacrylate anhydride hydrogel on wound vascularization of full-thickness skin defect in mice.
Li Ting LIANG ; Wei SONG ; Chao ZHANG ; Zhao LI ; Bin YAO ; Meng De ZHANG ; Xing Yu YUAN ; Enhe JIRIGALA ; Xiao Bing FU ; Sha HUANG ; Ping ZHU
Chinese Journal of Burns 2022;38(7):616-628
Objective: To prepare graphene oxide (GO)-containing gelatin methacrylate anhydride (GelMA) hydrogel and to investigate the effects of in situ photopolymerized GO-GelMA composite hydrogel in wound vascularization of full-thickness skin defect in mice. Methods: The experimental study method was used. The 50 μL of 0.2 mg/mL GO solution was evenly applied onto the conductive gel, and the structure and size of GO were observed under field emission scanning electron microscope after drying. Human skin fibroblasts (HSFs) were divided into 0 μg/mL GO (without GO solution, the same as below) group, 0.1 μg/mL GO group, 1.0 μg/mL GO group, 5.0 μg/mL GO group, and 10.0 μg/mL GO group treated with GO of the corresponding final mass concentration, and the absorbance value was detected using a microplate analyzer after 48 h of culture to reflect the proliferation activity of cells (n=6). HSFs and human umbilical vein vascular endothelial cells (HUVECs) were divided into 0 μg/mL GO group, 0.1 μg/mL GO group, 1.0 μg/mL GO group, and 5.0 μg/mL GO group treated with GO of the corresponding final mass concentration, and the migration rates of HSFs at 24 and 36 h after scratching (n=5) and HUVECs at 12 h after scratching (n=3) were detected by scratch test, and the level of vascular endothelial growth factor (VEGF) secreted by HSFs after 4, 6, and 8 h of culture was detected by enzyme-linked immunosorbent assay method (n=3). The prepared GO-GelMA composite hydrogels containing GO of the corresponding final mass concentration were set as 0 μg/mL GO composite hydrogel group, 0.1 μg/mL GO composite hydrogel group, 1.0 μg/mL GO composite hydrogel group, and 5.0 μg/mL GO composite hydrogel group to observe their properties before and after cross-linking, and to detect the release of GO after soaking with phosphate buffer solution for 3 and 7 d (n=3). The full-thickness skin defect wounds were made on the back of 16 6-week-old female C57BL/6 mice. The mice treated with in situ cross-linked GO-GelMA composite hydrogel containing GO of the corresponding final mass concentration were divided into 0 μg/mL GO composite hydrogel group, 0.1 μg/mL GO composite hydrogel group, 1.0 μg/mL GO composite hydrogel group, and 5.0 μg/mL GO composite hydrogel group according to the random number table, with 4 mice in each group. The general condition of wound was observed and the wound healing rate was calculated on 3, 7, and 14 d of treatment, the wound blood perfusion was detected by laser Doppler flowmetry on 3, 7, and 14 d of treatment and the mean perfusion unit (MPU) ratio was calculated, and the wound vascularization on 7 d of treatment was observed after hematoxylin-eosin staining and the vascular density was calculated (n=3). The wound tissue of mice in 0 μg/mL GO composite hydrogel group and 0.1 μg/mL GO composite hydrogel group on 7 d of treatment was collected to observe the relationship between the distribution of GO and neovascularization by hematoxylin-eosin staining (n=3) and the expression of VEGF by immunohistochemical staining. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and Tukey's method. Results: GO had a multilayered lamellar structure with the width of about 20 μm and the length of about 50 μm. The absorbance value of HSFs in 10.0 μg/mL GO group was significantly lower than that in 0 μg/mL GO group after 48 h of culture (q=7.64, P<0.01). At 24 h after scratching, the migration rates of HSFs were similar in the four groups (P>0.05); at 36 h after scratching, the migration rate of HSFs in 0.1 μg/mL GO group was significantly higher than that in 0 μg/mL GO group, 1.0 μg/mL GO group, and 5.0 μg/mL GO group (with q values of 7.48, 10.81, and 10.20, respectively, P<0.01). At 12 h after scratching, the migration rate of HUVECs in 0.1 μg/mL GO group was significantly higher than that in 0 μg/mL GO group, 1.0 μg/mL GO group, and 5.0 μg/mL GO group (with q values of 7.11, 8.99, and 14.92, respectively, P<0.01), and the migration rate of HUVECs in 5.0 μg/mL GO group was significantly lower than that in 0 μg/mL GO group and 1.0 μg/mL GO group (with q values of 7.81 and 5.33, respectively, P<0.05 or P<0.01 ). At 4 and 6 h of culture, the VEGF expressions of HSFs in the four groups were similar (P>0.05); at 8 h of culture, the VEGF expression of HSFs in 0.1 μg/mL GO group was significantly higher than that in 0 μg/mL GO group and 5.0 μg/mL GO group (with q values of 4.75 and 4.48, respectively, P<0.05). The GO-GelMA composite hydrogels in the four groups were all red liquid before cross-linking, which turned to light yellow gel after cross-linking, with no significant difference in fluidity. The GO in the GO-GelMA composite hydrogel of 0 μg/mL GO composite hydrogel group had no release of GO at all time points; the GO in the GO-GelMA composite hydrogels of the other 3 groups was partially released on 3 d of soaking, and all the GO was released on 7 d of soaking. From 3 to 14 d of treatment, the wounds of mice in the 4 groups were covered with hydrogel dressings, kept moist, and gradually healed. On 3, 7, and 14 d of treatment, the wound healing rates of mice in the four groups were similar (P>0.05). On 3 d of treatment, the MPU ratio of wound of mice in 0.1 μg/mL GO composite hydrogel group was significantly higher than that in 0 μg/mL GO composite hydrogel group, 1.0 μg/mL GO composite hydrogel group, and 5.0 μg/mL GO composite hydrogel group (with q values of 10.70, 11.83, and 10.65, respectively, P<0.05 or P<0.01). On 7 and 14 d of treatment, the MPU ratios of wound of mice in the four groups were similar (P>0.05). The MPU ratio of wound of mice in 0.1 μg/mL GO composite hydrogel group on 7 d of treatment was significantly lower than that on 3 d of treatment (q=14.38, P<0.05), and that on 14 d of treatment was significantly lower than that on 7 d of treatment (q=27.78, P<0.01). On 7 d of treatment, the neovascular density of wound of mice on 7 d of treatment was 120.7±4.1 per 200 times of visual field, which was significantly higher than 61.7±1.3, 77.7±10.2, and 99.0±7.9 per 200 times of visual field in 0 μg/mL GO composite hydrogel group, 1.0 μg/mL GO composite hydrogel group, and 5.0 μg/mL GO composite hydrogel group (with q values of 12.88, 7.79, and 6.70, respectively, P<0.01), and the neovascular density of wound of mice in 1.0 μg/mL GO composite hydrogel group and 5.0 μg/mL GO composite hydrogel group was significantly higher than that in 0 μg/mL GO composite hydrogel group (with q values of 5.10 and 6.19, respectively, P<0.05). On 7 d of treatment, cluster of new blood vessels in wound of mice in 0.1 μg/mL GO composite hydrogel group was significantly more than that in 0 μg/mL GO composite hydrogel group, and the new blood vessels were clustered near the GO; a large amount of VEGF was expressed in wound of mice in 0.1 μg/mL GO composite hydrogel group in the distribution area of GO and new blood vessels. Conclusions: GO with mass concentration lower than 10.0 μg/mL had no adverse effect on proliferation activity of HSFs, and GO of 0.1 μg/mL can promote the migration of HSFs and HUVECs, and can promote the secretion of VEGF in HSFs. In situ photopolymerized of GO-GelMA composite hydrogel dressing can promote the wound neovascularization of full-thickness skin defect in mice and increase wound blood perfusion in the early stage, with GO showing an enrichment effect on angiogenesis, and the mechanism may be related to the role of GO in promoting the secretion of VEGF by wound cells.
Anhydrides
;
Animals
;
Endothelial Cells
;
Eosine Yellowish-(YS)
;
Female
;
Gelatin/pharmacology*
;
Graphite
;
Hematoxylin
;
Humans
;
Hydrogels/pharmacology*
;
Methacrylates
;
Mice
;
Mice, Inbred C57BL
;
Neovascularization, Pathologic
;
Skin Abnormalities
;
Vascular Endothelial Growth Factor A
7.The study and clinical application of absorbable hemostatic agent.
Journal of Biomedical Engineering 2009;26(4):922-926
This paper reviews the mechanisms and properties of different absorbable hemostatic agents. The development tendency of absorbable hemostatic agent is forecasted. Its' qualities of being useful to surgeons are introduced and are embodied in surgeon's comprehending of the hemostatic characteristic of absorbable hemostatic agents as well as in their clinical use of such agents accurately. At the same time, the researchers in pursuit of the medical materials can work with reference to the data herein presented.
Absorption
;
Animals
;
Blood Loss, Surgical
;
prevention & control
;
Cellulose, Oxidized
;
administration & dosage
;
pharmacology
;
Chitosan
;
administration & dosage
;
pharmacology
;
Fibrin Tissue Adhesive
;
administration & dosage
;
pharmacology
;
Gelatin Sponge, Absorbable
;
administration & dosage
;
pharmacology
;
Hemostatics
;
administration & dosage
;
pharmacology
;
Humans
8.Preparation of alpha-tricalcium phosphate/HA whisker/carboxymethyl chitosan-gelatin composite porous bone cement.
Dongjuan WEI ; Xiang ZHANG ; Jianwen GU ; Ping HU ; Weizhong YANG ; Dongning CHEN ; Dali ZHOU
Journal of Biomedical Engineering 2012;29(3):491-495
In order to investigate the effects of HA whisker and carboxymethyl chitosan-gelatin(CMC-Gel) on the mechanical properties of porous calcium phosphate cement, a series of alpha-tricalcium phosphate (alpha-TCP), HA whisker and L-sodium glutamate porogen with different mass fractions were mixed, and setting liquid was added to them to prepare alpha-TCP/HA whisker composite porous bone cement. Then, the cement was immersed in a series of CMC-Gel solutions which had different weight ratios of CMC to Gel to prepare alpha-TCP/HA whisker/CMC-Gel composite porous bone cement. The compressive strengths and microstructure of cement were characterized by mechanical testing machine and SEM. The results showed that when the mass fraction of HA whisker is 4%, the compressive strength of alpha-TCP/HA whisker composite porous bone cement reaches 2.57MPa, which is 1.81 times that of alpha-TCP bone cement. When the weight ratio of CMC to Gel is 50:50, the compressive strength of alpha-TCP/HA whisker/CMC-Gel composite porous bone cement is 3. 34MPa, which is 2.35 times that of alpha-TCP bone cement, and the toughness of the composite cement is greatly improved as well.
Biocompatible Materials
;
chemistry
;
pharmacology
;
Bone Cements
;
chemical synthesis
;
Calcium Phosphates
;
chemistry
;
Chitosan
;
analogs & derivatives
;
chemical synthesis
;
chemistry
;
Compressive Strength
;
Gelatin
;
chemistry
;
Hydroxyapatites
;
chemical synthesis
;
chemistry
;
Porosity
9.Effects of Plasmid Fibroblast Growth Factor-2 Magnetic Chitosan Gelatin Microspheres on Proliferation and Differentiation of Mesenchymal Stem Cells.
Xingpo DING ; Ming LI ; Yujiang CAO ; Qiong YANG ; Tongchuan HE ; Cong LUO ; Haibing LI ; Yang BI
Journal of Biomedical Engineering 2015;32(5):1083-1089
The purpose of this study is to investigate the effect of superparamagnetic chitosan FGF-2 gelatin microspheres (SPCFGM) on the proliferation and differentiation of mouse mesenchymal stem cells. The superparamagnetic iron oxide chitosan nanoparticles (SPIOCNs) were synthesized by means of chemical co-precipitation, combined with FGF-2. Then The SPCFGM and superparamagnetic chitosan gelatin microspheres (SPCGM) were prepared by means of crosslinking-emulsion. The properties of SPCFGM and SPIONs were measured by laser diffraction particle size analyser and transmisson electron microscopy. The SPCFGM were measured for drug loading capacity, encapsulation efficiency and release pharmaceutical properties in vitro. The C3H10 cells were grouped according to the different ingredients being added to the culture medium: SPCFGM group, SPCGM group and DMEM as control group. Cell apoptosis was analyzed by DAPI staining. The protein expression level of FGF-2 was determined by Western blot. The proliferation activity and cell cycle phase of C3H10 were examined by CCK8 and flow cytometry. The results demonstrated that both of the SPIOCNs and SPCFGM were exhibited structure of spherical crystallization with a diameter of (25 ± 9) nm and (140 ± 12) μm, respectively. There were no apoptosis cells in the three group cells. Both the protein expression level of FGF-2 and cell proliferation activity increased significantly in the SPCFGM group cells (P < 0.05). The SPCFGM is successfully constructed and it can controlled-release FGF-2, remained the biological activity of FGF-2, which can promote proliferation activity of C3H10 cells, and are non-toxic to the cell.
Animals
;
Cell Differentiation
;
Cell Line
;
Cell Proliferation
;
Chitosan
;
Fibroblast Growth Factor 2
;
pharmacology
;
Gelatin
;
Magnetite Nanoparticles
;
Mesenchymal Stromal Cells
;
drug effects
;
Mice
;
Microspheres
;
Plasmids
10.Biochemical characters and antibiotic susceptibility of Staphylococcus aureus isolates.
Subhankari Prasad CHAKRABORTY ; Santanu Kar MAHAPATRA ; Somenath ROY
Asian Pacific Journal of Tropical Biomedicine 2011;1(3):212-216
OBJECTIVETo observe the biochemical characters and antibiotic susceptibility of isolated Staphylococcus aureus (S. auerus) strains against some conventional and traditional antibiotics.
METHODSThirty post operative pathogenic isolated S. aureus strains were used in this study. Bacterial culture was done in Mueller-Hinton broth at 37 °C. Characters of these strains were determined by traditional biochemical tests such as hydrolysis test of gelatin, urea, galactose, starch and protein, and fermentation of lactose and sucrose. Antibiotic susceptibility were carried out by minimum inhibitory concentration test, minium bactericidal concentration test, disc agar diffusion test and brain heart infusion oxacillin screening agar.
RESULTSFrom this study, it was observed that 100% S. aureus isolates showed positive results in gelatin, urea and galactose hydrolysis test, 50% isolates were positive in starch hydrolysis test, 35% in protein hydrolysis test, 100% isolates in lactose fermenting test, but no isolate was positive in sucrose fermenting test. Antibiotic susceptibility testing suggested that 20% of isolates were resistant to kanamycin and 46.67% were resistant to oxacillin.
CONCLUSIONSThese findings show that all these isolates have gelatin, urea, galactose hydrolysis and lactose fermenting activity. 20% of these isolates were resistant to kanamycin and 46.67% were resistant to oxacillin.
Anti-Bacterial Agents ; pharmacology ; Disk Diffusion Antimicrobial Tests ; Galactose ; metabolism ; Gelatin ; metabolism ; Hydrolysis ; Microbial Sensitivity Tests ; Staphylococcus aureus ; drug effects ; isolation & purification ; metabolism ; Starch ; metabolism ; Urea ; metabolism