BACKGROUND: Phosphorylcholine-containing poly (L-lactide) (PLLA-PC) is a kind of novel amphiphilic copolymer with good biocompatibility and biodegradability. In the previous work, self-assembly micelles of PLLA-PC were prepared with film rehydration method. But it hardly formed micelle with film rehydretion method because the longer chains of LLA existed in the PLLA-PC copolymer. However, the mechanism of phosphotipid choline polymer with long hydrophobic chain forming micelle remains still unclear. OBJECTIVE: To prepare self-assembling nanoparticles of PLLA-PC using solvent evaporation method, and to explore the factors that affected the properties and stability of nanoparticles.METHOD: ① Nanoparticles were prepared with solvent evporation metod.PLLA-PC copolymer was dissolved into acetone, and the copolymer solution was added dropwise to distilled water with stirring to yield nanoparticles. The critical micelle concentration (CMC) was performed on the F-7000FL220-240V. The emission and excitation wavelength were 395 nm and 300 mm, respectively. Transmission electron microscopy (TEM) was carried out on a JEM-100CX electron microscope to observe the morphology of PLLA-PC nanoparticles. Dynamic light scattering measurements on nanoparticle solutions were performed on a NANOSIZE 3600 at room temperatire. ②Gel permeation chromatography(GPC)measurements were perfrmed on a Waters 717 apparatus equipped with an RI detector. THF was used as the mobile phase at a flow rate of 1.0 mlJmin. A 1 g/L solution (50 μL) was injected for each analysis. RESULTS AND CONCLUSION: TEM indicated that the PLLA-PC nanoparticles presented typical shell/core structure. The critical micelle concentration was determined by fluorescent probe method. The results showed that the CMCs were quite low ( 10~(-3) g/L) and were dependent on the LLA units in the copolymer. The size and size distribution of the nanoparticles were detected by dynamic light scattering. The results indicated that the size could be affected by the LLA units, concentration of the organic solution and the concentration of the aqueous solution of the nanoparticles. On the other hand, they hardly changed over the dilution with water, which was of great importance in venous injection. They degraded at 37℃. PLLA-PC nanoparticles with controllable sizes can be prepared with phase separation method and might serve as a novel material for drug delivery.

OBJECTIVE: To review classification and synthesis of amphiphilic polymers containing polyethylene glycol and the application as drug carriers.DATA SOURCE: A computer-based research was conducted in SCI-Expanded, El Compendex and China Journal Full-text Database for articles concerning classification and synthesis of amphiphilic polymers containing polyethylene glycol and their micelles application as drug carriers published from January 2000 to July 2009.DATA SELECTION: A total of 616 articles were primarily obtained. Following reading titles and abstract, articles addressing detail classification and synthesis of amphiphilic polymers containing polyethylene glycol and representative micellar influencing factor were included. Totally 31 English and Chinese literatures were collected for further analysis.MAIN OUTCOME MEASURES: Classification, synthesis and drug vector mechanism of amphiphilic polymers containing polyethylene glycol and the micellar application as drug carriers were measured.RESULTS: Star-shaped copolymer could elevate micellar stability, but there were many arm numbers, whicti might induced a decrease in drug carrier volume. Special group introduced in copolymer contributed to the combination of drug and carrier. To connect target group could provide target transport property. The length and density of polyethylene glycol chain in copolymer was related to micellar function. Changed the length and density of polyethylene glycol could obtain polymer micelles that circulated in vivo for a long time.CONCLUSION: Amphiphilic polymers containing polyethylene glycol has outstanding potential in medical drug carrier field and isolation technique.

Objective To investigate the gender differences of glucose metabolic network in brains of healthy adults at resting state by 18F-FDG PET.Methods A total of 204 dextromanual,healthy individuals (104 males,average age:(53.45±11.51) years;100 females,average age:(54.11±12.09) years) were enrolled from June 2011 to June 2016 to construct brain metabolic networks.The nodal and global parameters,including clustering coefficient (Cp),characteristic path length (Lp) and betweenness centrality (Cb),were analyzed by graph theory.Permutation test with 1 000 repetitions was used.Results The brain metabolic networks derived from 18F-FDG PET data were with small-world properties in both male group and female group.Compared with Cb in females,Cb in males was significantly reduced in left postcentral gyrus,right angular gyrus and left temporal pole/middle temporal gyrus (permutation test,all P<0.05);and it was increased in left amygdala,left precuneus,right temporal pole/middle temporal gyrus and left inferior temporal gyrus (permutation test,all P<0.05).Comparing with the females,the male group had higher Cp and longer absolute Lp but without significant difference (permutation test,all P>0.05).Conclusions There are gender-related differences of topological structure in whole-brain metabolic networks.Gender should be considered as a covariate while designing experiments,accounting for cerebral metabolic data from normal control and experimental patients as well as making clinical decisions.

Objective To investigate the relationship between activation of gliacytes , mitogen-activated protein kinase (p38MAPK) and neuronal apoptosis after microinjecting aggregated Aβ25-35 into hippocampus.Methods The model was established by using stereotaxic technique to inject 10μg aggregated Aβ25-35 into dorsal hippocampus in rats .The rats were grouped as the control , vehicle and model groups .Immunohistochemistry and Western blotting were used for detection of activation of microglia(MG), atrocytes (AS) and expression of p-p38MAPK in the hippocampus.ELISA was used to evaluate the level of TNF-αand IL-1β.The survival neurons were observed by Nissl staining and the apoptotic neurons were identified by tunnel staining .Results Expression of ox-42, GFAP, p-p38MAPK were up-regulated in hippocampus, as well as TNF-α、IL-1β, which reached a highest value on the 7th day after injection of Aβ25-35.However, the number of neuron with Nissl positive decreased gradually , and the tunnel positive neurons increased highly and reached a peak value on the 7th day.There were significant differences between the control and vehicle group ( P <0.01). Conclusion Apoptosis of the neuron caused by Aβ25-35 injection may result from activation of gliacytes , p38 MAPK and increase of TNF-αand IL-1βlevel.

Objective To study the effect of flupentioxl melitracen and pinaverium bromide treatment on the changes of anorectal motility and rectal sensation in the patients of diarrhea-predominant irritable bowel syndrome (IBS-D) accompanying with depression and/or anxiety status. Methods Forty-four patients with IBS-D accompanying with depression and/or anxiety status were divided into group A (flupentioxl melitracen and pinaverium bromide) and group B (pinaverium bromide) by random digits table,and treated for 4 weeks. Twenty-five healthy subjects were included as control group. The anorectal motility and rectal sensation before and after taking medicines were compared. Results When abdominal pressure was increased, the net increased pressure of anal sphincter was (3.0 ± 1.2 ) kPa in group A and (2.9 ± 1.2)kPa in group B. They were lower than that in control group [(3.6 ± 1.6) kPa](P＜ 0.05). The rectal lowest volume of sensory threshold, the maximal volume of tolerance and maximal compliance were (55 ± 20) ml,( 145 ± 78 ) ml, ( 21.9 ± 12.9 ) ml/kPa in group A, ( 56 ± 38 ) ml, ( 150 ± 50 ) ml, (20.8 ± 11.2) ml/kPa in group B. They were lower than those in control group [(80 ± 38 ) ml, ( 190 ± 50 ) ml, (30.8 ± 15.2 ) ml/kPa](P ＜ 0.01 ). The rectal lowest volume of sensory threshold, the maximal volume of tolerance and maximal compliance were higher than those before taking medicines. Only the rectal lowest volume of sensory threshold in group B was higher than that before taking medicines. The rectal lowest volume of sensory threshold, the maximal volume of tolerance and maximal compliance in group A after taking medicines were higher than those in group B (P ＜ 0.05 or ＜ 0.01 ). Conclusions Higher sensitivity, lower tolerance,lower compliance of rectum and weakened anal automatic control function in IBS-D may be associated with diarrhea and frequent defecation. Treatment combining flupentioxl melitracen with pinaverium bromide may preferably improve the aperception functions of rectum in the patients of IBS-D accompanying with depression and/or anxiety status.

Objective To study the changes of anorectal motility and rectal sensation in the elderly patients with ulcerative colitis (UC). Methods The anorectal motility and rectal sensation were investigated by Medtronic PC-Polygraf HR made by Sweden in 35 non-elderly patients versus 19 elderly patients with UC, and 20 non-elderly healthy subjects (HS) and 28 elderly HS were as control group. Results (1) The static pressure, pressure of anal sphincter and the maximal squeeze pressure of anal sphincter in non-elderly patients and elderly patients with UC showed no significant differences compared with those in non-elderly HS and elderly HS group (elderly patients with uc vs. ederly HA:t= 1.311,1.298,1.401;nonederly patients with uc vs. nonederly HS: t=1.294,1.299,1.322all P＞0.05). When abdominal pressure was increased, the net increased pressure of anal sphincter was (2.8±1.1) kPa in the elderly patients with UC, (2.9±1.3) kPa in the non-elderly patients with UC. The pressures were lower in two UC groups than in HS groups [elderly HS group:(3.8±1.2) kPa; non-elderly HS group:(3.9±1.2) kPa,elderly patients with uc vs. ederly HS:t=2.238,nonelderly patients with us vs. nonederly HS:t=2.243 all P＜0.05]. (2)The rectal lowest volume of sensory threshold, the maximal volume of tolerance and the maximal compliance were (85±30) ml, (180±69) ml, (26. 5±8.8) ml/kpa in elderly patients with UC and (65±15) ml, (170±58) ml, (22.6± 10. 3) ml/kPa in non-elderly patients with UC. They were lower than in each HS group [elderly HS group (95±31) ml, (205±78) ml, (32.9±12.9) ml/kPa; non-elderly HS group:(78±38) ml, (190±50) ml, (30.8± 15.2) ml/kpa, all P＜0. 01]. (3)The rectal lowest volume of sensory threshold, the maximal volume of tolerance and the maximal compliance in elderly patients with UC were higher than in non-elderly patients with UC (elderly patients with uc vs. elderly HS:t=3. 121,3. 135,3.146,nonederly patients with uc vs. non elderly HS: t= 3.162, 3.141, 3.188 elderly patients with uc vs. nonelderly patients with uc: t = 2. 246,2. 239,2. 240 all P＜ 0. 05). The rectal lowest volume of sensory threshold, the maximal volume of tolerance in elderly HS group were higher than in non-elderly HS group (ederly HS vs. t = 2. 328,2. 301 all P＜0. 05). Conclusions There are some anorectal motility disturbances in UC. Higher sensitivity, lower tolerance, lower compliance of rectum and weakened anal automatic control function in UC may be associated with diarrhea and frequent defecation. The rectal sensation threshold to volume stimulus is higher in elderly HS than in non-elderly HS group. The sensibility to volume ectasis of rectum is weakened and the survivability of rectum is increased in elderly patients with UC.

A series of novel biodegradable and bionic functional polymers, PLLA-PC-PLLA, were synthesized using L-lactide ring-opening polymerization by L-a-Glycerophosphorylcholine (PC) from nature source. The hydrophilicity of the polymers was investigated. The results made known that, as PC group was brought into the backbone of PLLA, PLLA-PC-PLLA gained much better hydrophilicity than did PLLA, and polar phosphatidylcholines probably transferred to the sample surface in aqueous environment. The relative growth ratios of ECV304 cells to the lixivium of all PLLA-PC-PLLA were higher than 84% in 5 d culture. The cells adhesion of ECV304 on the films of PLLA-PC-PLLA lagged as compared to that on PLLA, but they could proliferate and cover the films in total. The difference between PLLA-PC-PLLA and PLLA was due to the existence of PC group. Thus, PLLA-PC-PLLA, the same as PLLA, are not cytotoxic, and ECV304 can attach and proliferate on them. PLLA-PC-PLLA have potential applications in the fields of tissue engineering and drug delivery system.
Cell Adhesion ; physiology ; Drug Carriers ; Endothelial Cells ; cytology ; Humans ; Hydrophobic and Hydrophilic Interactions ; Lactic Acid ; chemistry ; pharmacology ; Phosphorylcholine ; chemistry ; pharmacology ; Polyesters ; Polymers ; chemistry ; pharmacology ; Surface Properties ; Tissue Scaffolds ; Umbilical Veins ; cytology

Biocompatibility is the essential property of biomaterials, which is the essence of biomaterial evaluation as well as the foundation of the design and improvement of biomaterials. Several methods were carried out to evaluate the biocompatibility of poly(L-Lactide)-b-poly(trimethylene carbonate (PLLA-b-PTMC) and poly(D,L-Lactide)-b-poly(trimethylene carbonate) (PDLLA-b-PTMC) with poly(L-Lactide) (PLLA) and poly(trimethylene carbonate) (PTMC) as control, including extract liquid experiment, directly contact experiment of materials and cells, hemolytic ratio analysis and platelet adhesion investigation. The results revealed that all the materials exhibited an acceptable cytotoxicity, and proliferation of cells on the modified materials was less than that on the PLLA but more than that on PTMC. The results of hemocompatibility experiments showed that no significant hemolysis was detected when all the materials were in use; in addition, the numbers of platelets adhered on the surface of copolymers were smaller than that on the surface of PLLA, and the degree of platelet deformation was slighter. So, the biocompatibility of copolymers is similar to that of PLLA, the biocompatibility of PLLA is not remarkably changed by modification with PTMC, but rather is improved.
Absorbable Implants ; Biocompatible Materials ; chemistry ; metabolism ; Blood Platelets ; cytology ; Hardness ; Humans ; Lactic Acid ; chemistry ; metabolism ; Materials Testing ; Polyesters ; chemistry ; metabolism ; Polymers ; chemistry ; metabolism ; Tissue Engineering ; methods

Self-assembly of peptides is ubiquitous in the body of creatures. The molecules of peptides combine with each other to form proteins with different functions through self-assembly. The formation of a specific conformation of one type of protein is owing to the self-assembly of its compositive amino acids. So, researchers can design self-assembly of peptides at the molecular level and can control its formation and configuration. It has the potential for application in the preparation of new medicines and biomaterials. In recent years, self-assembling peptides have been increasingly high-lighted and used to simulate the function of natural biomolecules, to synthesize peptide-medicine, and to serve as the carriers of medicine.
Biocompatible Materials ; chemical synthesis ; Molecular Conformation ; Nanotechnology ; methods ; Peptides ; chemistry ; Protein Engineering ; methods

The properties of biomedical intelligent polymer materials can be changed obviously when there is a little physical or chemical change in external condition. They are in the forms of solids, solutions and polymers on the surface of carrier, including aqueous solution of hydrophilic polymers, cross-linking hydrophilic polymers (i.e. hydrogels) and the polymers on the surface of carrier. In this paper are reviewed the progress in researches and the application of biomedical intelligent polymer materials.
Biocompatible Materials ; chemistry ; Biotechnology ; Chemical Phenomena ; Chemistry, Physical ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; Polymers ; chemistry ; Surface Properties