OBJECTIVE: To compare the effects of three different crosslinkers on the biocompatibility, physical and chemical properties of decellularized small intestinal submucosa (SIS) porous scaffolds. METHODS: The SIS porous scaffolds were prepared by freeze-drying method and randomly divided into three groups, then crosslinked by glutaraldehyde (GA), 1-ethyl-3-(3-dimethylaminopropyl) carbodi-imide (EDC) and procyanidine (PA) respectively. To evaluate the physicochemical property of each sample in different groups, the following experiments were conducted. Macroscopic morphologies were observed and recorded. Microscopic morphologies of the scaffolds were observed using field emission scanning electron microscope (FESEM) and representative images were selected. Computer software (ImageJ) was used to calculate the pore size and porosity. The degree of crosslinking was determined by ninhydrin experiment. Collagenase degradation experiment was performed to assess the resistance of SIS scaffolds to enzyme degradation. To evaluate the mechanical properties, universal mechanical testing machine was used to determine the stress-strain curve and compression strength was calculated. Human bone marrow mesenchymal cells (hBMSCs) were cultured on the scaffolds after which cytotoxicity and cell proliferation were assessed. RESULTS: All the scaffolds remained intact after different crosslinking treatments. The FESEM images showed uniformed interconnected micro structures of scaffolds in different groups. The pore size of EDC group[(161.90±13.44) μm] was significantly higher than GA group [(149.50±14.65) μm] and PA group[(140.10±12.06) μm] (P < 0.05). The porosity of PA group (79.62%±1.14%) was significantly lower than EDC group (85.11%±1.71%) and GA group (84.83%±1.89%) (P < 0.05). PA group showed the highest degree of crosslinking whereas the lowest swelling ratio. There was a significant difference in the swelling ratio of the three groups (P < 0.05). Regarding to the collagenase degradation experiment, the scaffolds in PA group showed a significantly lower weight loss rate than the other groups after 7 days degradation. The weight loss rates of GA group were significantly higher than those of the other groups on day 15, whereas the PA group had the lowest rate after 10 days and 15 days degradation. PA group showed better mechanical properties than the other two groups. More living cells could be seen in PA and EDC groups after live/dead cell staining. Additionally, the proliferation rate of hBMCSs was faster in PA and EDC groups than in GA group. CONCLUSION The scaffolds gained satisfying degree of crosslinking after three different crosslinking treatments. The samples after PA and EDC treatment had better physicochemical properties and biocompatibility compared with GA treatment. Crosslinking can be used as a promising and applicable method in the modification of SIS scaffolds.
Biocompatible Materials/chemistry* ; Cross-Linking Reagents/chemistry* ; Humans ; Porosity ; Tissue Engineering/methods* ; Tissue Scaffolds/chemistry* ; Weight Loss

The effect of parasitic ions on the results of ultraviolet A (UVA) cross-linking in iontophoresis was still not clear. In this work, the porcine sclera was cross-linked by riboflavin lactate Ringer's solution (group A) and riboflavin normal saline (group B)
Animals ; Collagen ; Cross-Linking Reagents ; Ions ; Iontophoresis ; Permeability ; Photosensitizing Agents/pharmacology* ; Riboflavin ; Sclera ; Swine ; Ultraviolet Rays

China is the country with high incidence of high myopia in the world. High myopia can cause severe vision impairment. So far, there is no effective treatment for high myopia in clinic. Scleral collagen cross-linking surgery has been proven to be effective in preventing animal eye axial elongation
Animals ; Collagen ; Cross-Linking Reagents ; Finite Element Analysis ; Photosensitizing Agents ; Riboflavin ; Sclera

OBJECTIVE: To investigate the effect of blocking pannexin-1 against acute kidney injury induced by cisplatin. METHODS: Twenty-six male C57BL/6 mice aged 6-8 weeks were randomly divided into control group, cisplatin model (Cis) group and cisplatin + carbenoxolone treatment group (Cis + CBX). In Cis group and Cis + CBX group, the mice were injected intraperitoneally with 20 mg/kg of cisplatin and with CBX (20 mg/kg) at 30 min before and 24 and 48 h after cisplatin inhjection, respectively. All the mice were sacrificed at 72 h after cisplatin injection, and plasma and kidney samples were collected for testing mRNA and protein expression levels of pannexin-1 in the renal tissue using RT-qPCR and Western blotting and for detecting plasma creatinine and BUN levels; the pathological changes in the renal tissues were observed using Periodic Acid-Schiff staining. The expression of kidney injury molecule 1 (KIM-1) was examined using immunohistochemistry and the mRNA expressions of KIM-1 and neutrophil gelatinase- related lipid transport protein (NGAL) were detected by RT-qPCR to evaluate the injuries of the renal tubules. The infiltration of F4/80-positive macrophages and CD4-positive T cells were observed by immunofluorescence. In the experiment, human proximal tubule epithelial cell line HK-2 was stimulated with 50 μmol/L cisplatin to establish a cell model of acute kidney injury, and the mRNA and protein expressions of pannexin-1 were detected by RT-qPCR and Western blotting at 4, 6, 12, 18 and 24 h after the stimulation. RESULTS: Compared with the control mice, the cisplatin-treated mice showed significantly up-regulated protein levels ( < 0.05) and mRNA levels ( < 0.005) of pannexin-1 in the kidney tissue. Cisplatin stimulation also caused significant increases in the protein levels ( < 0.005) and mRNA levels ( < 0.005) of pannexin-1 in cultured HK-2 cells. Compared with cisplatin-treated mice, the mice treated with both cisplatin and the pannexin-1 inhibitor CBX showed obviously lessened kidney pathologies and milder renal tubular injuries with significantly reduced plasma BUN and Scr levels ( < 0.01), expressions of KIM-1 and NGAL in the kidney ( < 0.05), and infiltration of F4/80-positive macrophages ( < 0.01) and CD4- positive T cells ( < 0.05) in the kidney tissues. CONCLUSIONS In cisplatin induced acute kidney injury mice model, Pannexin-1 expression is up-regulated in the kidneys tissue, and blocking pannexin-1 alleviates the acute kidney injury reducing renal inflammatory cell infiltration.
Acute Kidney Injury ; drug therapy ; metabolism ; Animals ; Cisplatin ; pharmacology ; Connexins ; drug effects ; metabolism ; Cross-Linking Reagents ; pharmacology ; Humans ; Kidney ; Kidney Tubules ; Male ; Mice ; Mice, Inbred C57BL ; Nerve Tissue Proteins ; drug effects ; metabolism ; Random Allocation

There is no safe and effective standard method for glans penis augmentation. Furthermore, there has been scant research on glans penis augmentation due to a poor understanding of glans anatomy, technical difficulty, and a lack of suitable substances for augmentation. Cross-linked dextran gel is a newly developed filler for soft-tissue augmentation. We evaluated the efficacy and safety of using a novel technique to inject cross-linked dextran gel for glans penis augmentation during a 24-week follow-up study. This prospective, single-arm, multicenter study enrolled twenty healthy adult men who underwent glans penis augmentation between June and August 2013. Cross-linked dextran gel was injected into the glans penis using a simple and easy technique. The sizes of the glans penis and individual satisfaction were assessed. Any adverse event was also reported. A total of 18 individuals were analyzed; two of them were lost to follow-up. The mean procedure time and injected volume were about 30 min and 6.6 ± 0.9 ml, respectively. The mean surface areas of the glans at baseline and 24 weeks were 20.0 ± 3.5 cm2 and 33.6 ± 5.4 cm2 , respectively, representing a mean increase of 68.7% ± 14.0% (P < 0.001). Sixteen individuals (88.9%) were satisfied with the outcomes, and none were dissatisfied. There were no serious adverse events during the study. Cross-linked dextran gel injection for glans penis augmentation was easy and showed a significant augmentative effect on the glans penis, good durability, and was well tolerated without serious adverse events. Therefore, cross-linked dextran gel injection may be an effective, new technique for glans penis augmentation.
Adult ; Aged ; Cross-Linking Reagents ; Dextrans/therapeutic use* ; Follow-Up Studies ; Gels ; Humans ; Injections ; Male ; Middle Aged ; Patient Satisfaction ; Penis/anatomy & histology* ; Prospective Studies ; Treatment Outcome ; Young Adult

The ubiquitin-proteasome system plays a pivotal role in breast tumorigenesis by controlling transcription factors, thus promoting cell cycle growth, and degradation of tumor suppressor proteins. However, breast cancer patients have failed to benefit from proteasome inhibitor treatment partially due to proteasome heterogeneity, which is poorly understood in malignant breast neoplasm. Chemical crosslinking is an increasingly important tool for mapping protein three-dimensional structures and proteinprotein interactions. In the present study, two cross-linkers, bis (sulfosuccinimidyl) suberate (BS(3)) and its water-insoluble analog disuccinimidyl suberate (DSS), were used to map the subunit-subunit interactions in 20S proteasome core particle (CP) from MDA-MB-231 cells. Different types of gel electrophoresis technologies were used. In combination with chemical cross-linking and mass spectrometry, we applied these gel electrophoresis technologies to the study of the noncovalent interactions among 20S proteasome subunits. Firstly, the CP subunit isoforms were profiled. Subsequently, using native/SDSPAGE, it was observed that 0.5 mmol/L BS(3) was a relatively optimal cross-linking concentration for CP subunit-subunit interaction study. 2-DE analysis of the cross-linked CP revealed that α1 might preinteract with α2, and α3 might pre-interact with α4. Moreover, there were different subtypes of α1α2 and α3α4 due to proteasome heterogeneity. There was no significant difference in cross-linking pattern for CP subunits between BS(3) and DSS. Taken together, the gel-based characterization in combination with chemical cross-linking could serve as a tool for the study of subunit interactions within a multi-subunit protein complex. The heterogeneity of 20S proteasome subunit observed in breast cancer cells may provide some key information for proteasome inhibition strategy.
Amino Acid Sequence ; Breast Neoplasms ; drug therapy ; genetics ; pathology ; Cell Line, Tumor ; Cross-Linking Reagents ; administration & dosage ; Electrophoresis, Gel, Two-Dimensional ; Female ; Humans ; Mass Spectrometry ; Proteasome Endopeptidase Complex ; drug effects ; Protein Binding ; drug effects ; Protein Isoforms ; genetics ; Protein Subunits ; biosynthesis ; genetics ; Proteomics ; Succinimides ; administration & dosage

We studied the effect of calcium ion on particle size and pore structure of cross-linked enzyme aggregates (CLEAs) of glucose oxidase, with activity and stability of the enzyme as evaluation criteria. With calcium ion to prepare CLEA significantly decreased particle sizes of CLEAs whilst the pore structures of CLEAs gradually disappeared with the increase of calcium concentration. When glucose oxidase was precipitated at 0.1 mmol/L Ca²⁺, glucose oxidase in CLEA showed the definitive pore structure. Moreover, glucose oxidase activity in CLEA with Ca²⁺ was 1.69 times higher than that without Ca²⁺. Even at Ca²⁺ as high as 1.0 mmol/L, glucose oxidase activity in CLEA was 42% higher than that of CLEA without Ca²⁺. Furthermore, CLEA prepared with 0.1 mmol/L Ca²⁺ not only exhibited higher substrate conversion and operational stability, but also increased the maximum reaction speed. Therefore, calcium ion improved the performance of glucose oxidase in CLEAs.
Calcium ; chemistry ; Cross-Linking Reagents ; Enzyme Stability ; Enzymes, Immobilized ; Glucose Oxidase ; chemistry ; Oxidation-Reduction ; Particle Size

OBJECTIVETo investigate the biocompatibility and degradation rate of crosslinking sodium hyaluronate gel with different ratio of molecular weight, so as to choose the effective, safe and totally degraded hyaluronate gel for aesthetic injection.

METHODS(1) Compound colloid was formed by cross-linking the divinyl sulphone and sodium hyaluronate with different molecular weight (4 x 10(5), 8 x 10(5), 10 x 10(5), 12 x 10(5)). (2) Healthy level KM mice was randomly divided into two groups to receive hyaluronic acid gel or liquid injection. Each group was subdivided into three subgroup to receive hyaluronic acid with different molecular weight. The biocompatibility and degradation rate, of hyaluronate were observed at 7, 90, 180 days after injection. At the same time, different molecular weight of sodium hyaluronate gel is sealed or exposed respectively under the low temperature preservation to observe its natural degradation rate. (3) The most stable colloid was selected as aesthetic injector for volunteers to observe the aesthetic effect.

RESULTSThe sodium hyaluronate gel with molecular of 4 x 10(5) was completely degraded 90 days later. The sodium hyaluronate gel with molecular of 8 x 10(5) was completely degraded 180 days later. The sodium hyaluronate gel with molecular of 10 x 10(5) was degraded to 90.0% after 180 days. The sodium hyaluronate liquid can be degraded completely within 7 days. The colloid could be kept for at least 12 months when sealed under low temperature, but was totally degraded when exposed for I d. Sodium hyaluronate gel with molecular 10 x 10(5) was confirmed to be kept for at least 6 months in animal experiment and clinical trials.

CONCLUSIONSUnder the same condition of material ratio, the higher the molecular weight is, the lower the degradation rate is. But the liquidity of gel is not good for injection when molecular weight is too large. It suggests that Sodium hyaluronate gel with molecular 10 x 10(5) maybe the best choice in cosmetic injections.

Animals ; Cross-Linking Reagents ; administration & dosage ; chemistry ; Hyaluronic Acid ; administration & dosage ; chemistry ; Injections, Subcutaneous ; Mice ; Molecular Weight ; Random Allocation

OBJECTIVETo prepare pravastatin sodium-loaded chitosan microspheres to allow sustained drug release.

METHODSThe drug-loaded chitosan microspheres were prepared by using genipin as the cross-linker. The influences of molecular weight of chitosan, volume ratio of oil and water, reaction temperature, and stirring speed on the formation of chitosan microspheres were investigated. The morphology of the microspheres was observed using scanning electron microscopy. The encapsulation efficiency, swelling ratio under different pH conditions, and in vitro drug release were measured.

RESULTSThe in vitro release of pravastatin sodium could last for at least 31 days. The drug release rate varied with the reaction condition. The drug entrapment efficiency of the microsphere was 54.7%. The optimal processing conditions were as follows: chitosan viscosity of 200-400 mPa·s, oil-water proportion of 10:1, stirring speed of 850 r/min, and reaction temperature at 40 degrees celsius;.

CONCLUSIONThe pravastatin sodium-loaded microspheres show good sustained drug release property, and the drug release rate can be modified by controlling the cross-linking time.

Chitosan ; Cross-Linking Reagents ; Delayed-Action Preparations ; Iridoids ; Microscopy, Electron, Scanning ; Microspheres ; Pravastatin ; chemistry

The core-crosslinked polymeric micelles were used as a new drug delivery system, which can decrease the premature drug release in blood circulation, improve the stability of the micelles, and effectively transport the drug into the therapy sites. Then the drug bioavailability increased further, while the side effect reduced. Most drugs were physically entrapped or chemically covalent with the polymer in the internals of micelles. Based on the various constitutions and properties of polymeric micelles as well as the special characteristics of body microenvironment, the environment-responsive or active targeting core-crosslinked micelles were designed and prepared. As a result, the drug controlled release behavior was obtained. In the present paper, the research progress of all kinds of core-crosslinked micelles which were published in recent years is introduced. Moreover, the characteristic and application prospect of these micelles in drug delivery system are analyzed and summarized.
Animals ; Antineoplastic Agents ; administration & dosage ; chemistry ; therapeutic use ; Cross-Linking Reagents ; chemistry ; metabolism ; Drug Carriers ; chemistry ; metabolism ; Humans ; Micelles ; Molecular Structure ; Neoplasms ; drug therapy ; Particle Size ; Pharmaceutical Preparations ; administration & dosage ; Polyethylene Glycols ; chemistry ; metabolism ; Polymers ; chemistry ; metabolism