Research progress in biomimetic nano formulations of biofilms / 中国药科大学学报

@#Biomimetic nano formulations of biofilms have low immunogenicity, high targeting, and good biocompatibility, and can avoid being cleared by the endothelial reticular system, thus with in longer blood circulation time in the body.This article mainly reviews the main types as well as advantages and disadvantages of biomimetic nano formulations of biofilms, including tumor cell membranes, red blood cell membranes, platelet membranes, white blood cell membranes, stem cell membranes, extracellular vesicles (exosomes, microvesicles, and apoptotic bodies), endoplasmic reticulum membranes, and composite biofilms, with also a prospect of the challenges facing biomimetic nano formulations of biofilms and their future development based on their current research status, aiming to provide some insight for further research on biomimetic nano formulations of biofilms.

Treatment of Post - traumatic Bone Defects with infection in L ong B ones

Background: Open fractures are a challenging condition to treat because they are frequently compounded by infection and nonunion. Traditional bone defect care strategies are mostly focused on fracture union rather than infection prevention. The goal of this study is t o use the Masquelet approach to examine the outcome of a post - traumatic defect with infection in long bones. This method is a two - step process. Stage I surgery includes debridement and the placement of an antibacterial spacer in the bone defect. Stage II s urgery involved removing the spacer while preserving the induced membrane that had grown on the spacer's surface and filling the bone - gap with morselized iliac crest bone - graft within the membrane sleeve. Methods: There were 22 patients in this study (18 m ales and 4 females), all of them had infected long bone fractures with a bone defect. The average length of the bone defect was 3.5 centimetres. The duration of follow - up varied from 6 to 15 months. Results: After an average of 11.5 weeks following the fir st step of surgery, radiological union was achieved. After stage 1, no patient had any remaining infection. After radiological union, all of the patients were able to mobilise with full weight bearing and a satisfactory range of motion in the adjoining joi nts. Conclusion: With favourable outcomes, this treatment can be used on infected fractures with bone loss on a regular basis. Antibiotic cement spacers, used in conjunction with complete debridement, minimise the risk of infection. The graft is revascular ized through induced biomembrane. In most circumstances, union may be predicted; nonetheless, the length of time it takes to reach an agreement is a constraint. The technique is low - cost and does not necessitate any additional training or equipment. Despit e the fact that it is a two - stage procedure, it does not necessitate several surgeries as in traditional approaches.

Study on the effect of small alcohol on lipid hydration and liposome formation / 生物医学工程学杂志

Liposomes with precisely controlled composition are usually used as membrane model systems to investigate the fundamental interactions of membrane components under well-defined conditions. Hydration method is the most common method for liposome formation which is found to be influenced by composition of the medium. In this paper, the effects of small alcohol (ethanol) on the hydration of lipid molecules and the formation of liposomes were investigated, as well as its coexistence with sodium chloride. It was found that ethanol showed the opposite effect to that of sodium chloride on the hydration of lipid molecules and the formation of liposomes. The presence of ethanol promoted the formation of liposomes within a certain range of ethanol content, but that of sodium chloride suppressed the liposome formation. By investigating the fluorescence intensity and continuity of the swelled membranes as a function of contents of ethanol and sodium chloride, it was found that sodium chloride and ethanol showed the additive effect on the hydration of lipid molecules when they coexisted in the medium. The results may provide some reference for the efficient preparation of liposomes.

Biomembrane formation after radiofrequency ablation prevents bone cement extravasation during percutaneous vertebroplasty for treating vertebral metastases with posterior margin destruction: An animal study

Aims: We aimed to investigate the feasibility, safety, and efficacy of radiofrequency ablation (RFA) combined with percutaneous vertebroplasty (PVP) for treating VX2 vertebral metastases with posterior margin destruction in a rabbit model. Materials and Methods: Sixty rabbit models of VX2 vertebral metastases with posterior margin destruction were constructed through computed tomography (CT)-guided percutaneous puncture and randomly divided into four groups of 15 rabbits each: Groups A, RFA+PVP; B, PVP; C, RFA; and D, control. Five rabbits in each group were sacrificed within 24 h of the procedure. Pathological examination and immunohistochemical staining revealed the presence of a biomembrane barrier at the tumor edge; furthermore, bone cement leakage into the spinal canal was observed. The survival time of the remaining rabbits per group was observed, and the differences were analyzed. Results: CT scans of Group A and C rabbits revealed a low-density band around the tumor ablation region. Bone cement leakage rate significantly differed between Groups A and B (20% vs. 100%; P < 0.05). The average postoperative survival times of Group A, B, C, and D rabbits were 16.72 ± 0.93, 7.26 ± 0.75, 7.80 ± 1.30, and 3.84 ± 1.24 days, respectively, showing a significant difference between Group A and the remaining groups (P < 0.05). Conclusions: The biomembrane barrier formed at the tumor edge after RFA can prevent bone cement leakage into the spinal canal, reducing spinal cord injury and prolonging the survival time

Research progress on macrophage membrane nano-biomimetic preparations on brain diseases and its inspiration on druggability of active components of traditional Chinese medicine / 中草药

Although nano preparations could improve the physicochemical properties of drugs, they are easy to be recognized and cleared by mononuclear phagocytes, which will not only reduce the half-life of drugs, but also cause immunogen reaction, thus affecting the safe and effective use of drugs. The combination of cell membrane and new nanotechnology will increase the cell compatibility with the advantages of nano preparations, further enhance the targeting effect of target organs or tissues, and improve the efficacy. At present, the existence of the brain barrier restricts the entry of all macromolecular substances and 98% small molecule drugs into the brain, becoming the main problem in the treatment of encephalopathy. Macrophages are common immune cells and play an important role in the development and prognosis of brain diseases. Therefore, the combination of macrophage membranes and nano preparations becomes the immune system's own substances to avoid recognition and clearance, and increase the circulation of drugs, then reuse the blood-brain barrier permeability of macrophages to increase the drug into brains to improve the clinical efficacy. Traditional Chinese medicine has complex components and significant curative effect, but most of them have problems in poor solubility and stability, which lead to low bioavailability in vivo and affect the application. Therefore, based on domestic and foreign literatures, this article integrates the application of macrophage membrane modified nano-preparations in encephalopathy and its effects on the medicinal properties of active ingredients of traditional Chinese medicine, in order to promote the development and utilization of traditional Chinese medicine resources.

Limb Reconstruction Using Masquelet Technique in the Treatment of Post-traumatic Compound Tibial Fractures with Bone Loss

Introduction: Traumatic segmental bone defects of leg are difficult problem to manage with significant long-term morbidity.Historically, due to difficulty in managing segmental bone defects, amputation was the preferred treatment. Later over the lasthalf-century, limb salvage was done using various techniques such as vascularized fibular grafts, acute limb shortening, externalfixator application, and filling the defect with autograft or allograft. More recently, Masquelet described the use of cement spacerapplication within this defect and staged bone grafting within the induced biomembrane formed around the spacer as a potentialtreatment strategy to manage these bone defects.Method: This study describes the clinical, radiological, and functional outcome in 20 patients with traumatic bone loss of up to5 cm managed using Masquelet technique.Results: The outcome was analyzed using Association for the study and application of methods of ilizarov (ASAMI) scorewhich showed excellent results in 10 patients, good in 5 patients, fair in 2 patients, and poor in 3 patients.Conclusion: We conclude that the induced membrane technique can be a valuable addition to the armamentarium of limbreconstruction procedures in patients with small bone defects with or without soft tissue injury.

Active ingredients screening by cell membrane chromatography and simultaneous quantitation of ginsenosides in bulk drug of secondary ginsenoside H dripping pills / 中草药

To establish a HPLC-MS/MS method for simultaneous determination and active ingredients screening of pseudoginsenoside RT5, 20(S)-ginsenoside Rh1 and 20(S)-ginsenoside Rh2 by cell membrane chromatography (CMC) in secondary ginsenoside H dripping pills (SGHDP). Methods The samples were separated on Century SIL BDS C18 column (250 mm × 4.6 mm, 5 μm) eluted with 0.2% formic acid aqueous solution-acetonitrile in a gradient mode, and the target compounds were analyzed by positive ion multiple reaction monitoring (MRM) mode, and active ingredients of SGHDP obtained in solid-phase of biomembrane by CMC technology were determined at the same time. Results The linear ranges of pseudoginsenoside RT5, 20(S)-ginsenoside Rh1, and 20(S)-ginsenoside Rh2 were 0.095-0.235, 0.042-0.168, and 0.105-0.419 mg/mL; the extraction recoveries were 99.95%, 100.12%, and 100.06%; and RSD were 1.06%, 0.96%, and 0.91%, respectively. The contents of pseudoginsenoside RT5, 20(S)-ginsenoside Rh1, and 20(S)-ginsenoside Rh2 in SGHDP were 21.24%, 21.42%, and 29.70%, respectively. 20(S)-Ginsenoside Rh2 was the active ingredient obtained by biomembrane using as a new quality control maker for SGHDP. Conclusion The developed method is accurate and reliable for the determination of three ginsenosides in SGHDP, and provides a new reference for quality control of SGHDP. 20(S)-Ginsenoside Rh2 is a immobilization component of red cell membrane, speculated to be the active ingredient of SGHDP, which is in consistent with previous studies on antitumor and antidepression.

Antimicrobial efficacy of new triple antibiotics in combination with calcium hydroxide for Enterococcus faecalis: An In vitro comparative study / 第二军医大学学报

Objective To evaluate the antibacterial effects of the combination of calcium hydroxide and new triple antibiotics against Enterococcus faecalis (E. faecalis). Methods Eighty single rooted premolar teeth (intact and normal development) were included in this study. E. faecalis infected model was established in vitro. Model teeth were divided randomly into five groups with 16 teeth in each group, and the teeth in the five groups were treated using normal saline (NS group), calcium hydroxide (CH group), conventional triple antibiotics (mixed with metronidazole, minocycline and ciprofloxacin, TAP group), new triple antibiotics (mixed with ornidazole, minocycline and ciprofloxacin, NTAP group) or new triple antibiotics in combination with calcium hydroxide (NTAPTCH group), respectively, as intracanal medicament. The colony-forming units were counted at day 3 and day 7 after operation using colony-counting method. Scanning electronmicroscope was used to confirm the bacterial counting results. Results The colony-forming units on day 3 and day 7 of post-operation in the NTAP and NTAPTCH groups were both significantly lower than those in the TAP and CH groups (both P0.05). Scanning electron microscope results showed fewer bacteria on the root canal walls in the NTAP and NTAP + CH groups than the other three groups. Conclusion Antibacterial effect of new triple antibiotic used alone or in combination with calcium hydroxide for E. Faecalis issuperior to conventional triple antibiotics and calciumhydroxide. So new triple antibiotic used alone or in combination with calcium hydroxide can be considered as an effective alternative intracanal medicament.

Screening of active components of Jitongning Tablet by liposome equilibrium dialysis and LC-MS analysis / 中草药

Objective: To explore the interaction between the effective components of Jitongning Tablet (JT) and liposome biomembrance, in order to predict in vivo absorption of the effective components. Methods: Liposome as the model of biomembrance, active components were screened by liposome equilibrium dialysis and LC-MS; And the effect of experiment conditions on the interaction of the liposome concentration, and the pH value of buffer were also investigated. Results: There were 11 compounds in JT with obvious interaction with liposome, including 4 flavonoids, 2 triterpenoid, 4 coumarins, and 1 phenylpropionic acid. The concentration of liposome and pH value of buffer remarkably affected the interaction between JT and liposome. Conclusion: The established method contributes to predicting the multiple components absorption in body, indicating the potentially active compounds and providing reference for further research of pharmacodynamic substance basis.

Casearia sylvestris Swartz Extract Release Using Natural Rubber Latex Biomembranes as Carrier.

The Natural Rubber Latex (NRL) from Hevea brasiliensis has shown promise in biomedical applications due to its low cost, easy handling, mechanical properties and biocompatibility, being used for bone regeneration and wound healing due to its natural stimulus to angiogenesis. The aim of this work was to incorporate Casearia sylvestris Sw. extract in NRL biomembranes and study its release behavior. The complex membraneextract has as object of study a new approach of using C. sylvestris extract in the treatment of wounds, for possessing antiseptic activity, anti-inflammatory and analgesic properties. The C. sylvestris species (Salicaceae), popularly known as "guaçatonga", presents great distribution and is used in folk medicine as antiulcer, wound healing, anti- snake venom, properties which have been proven and related to clerodane diterpenes (casearins A-X). The release rate of C. sylvestris compounds from extract-membrane complex was monitored and analyzed using the method of optical spectroscopy (UV-VIS). The release varied with temperature ranging from 14 to 33 days, releasing more than 90%, with an interesting and promising biomedical application, such as wound healing and burns.

Simulation study of influences of chain length on the shielding effect of PEGylated nanoparticles / 国际生物医学工程杂志

Objective To investigate the influence of surface grafting density of polyethylene glycol (PEG) molecules on the interactions of nanoparticle with the biomembrane.Methods The dynamics of polymer as well as its shielding effect on the wrap of the membrane were investigated using coarse-grained (CG) molecular dynamics simulations.A coarse grained model force field,MARTINI,was employed for its ability to reproduce experimental properties of various lipid dynamics and some kinds of polymer as well.Results As a result,structural variations and energy changes of grafted PEG molecules on the nanoparticles,adsorbing dynamics of PEGs on the membrane as well as the wrap rates of the membrane were obtained to shed light on the PEGylation-mediated shielding mechanism in the adsorption of PEGylated nanoparticles on the membrane.Conclusions The surface grafting density of PEGylated nanoparicles has been found to play a crucial role in the stealth shielding behavior of PEGylated nanocarriers.These studies are consistent with experimental observations and to some extent give a molecular level interpretation of the macroscale observations of prolonged circulation half-life of stealth nanocarriers.

Spectroscopic and thermal characterization of alternative model biomembranes from shed skins of Bothrops jararaca and Spilotis pullatus / Caracterização espectroscópica e térmica de biomembranas modelo alternativo de peles galpão de Bothrops jararaca e Spilotis pullatus

Recently, there has been an interest in the use of shed snake skin as alternative model biomembrane for human stratum corneum. This research work presented as objective the qualitative characterization of alternative model biomembranes from Bothrops jararaca and Spilotis pullatus by FT-Raman, PAS-FTIR and DSC. The employed biophysical techniques permitted the characterization of the biomembranes from shed snake skin of B. jararaca and S. pullatus by the identification of vibrational frequencies and endothermic transitions that are similar to those of the human stratum corneum.

Existe atualmente interesse no uso da muda de pele de cobra como modelos alternativos de biomembranas da pele humana. O presente trabalho apresentou como objetivo a caracterização qualitativa de modelos alternativos de biomembranas provenientes de mudas de pele de cobra da Bothrops jararaca e Spilotis pullatus por espectroscopia Raman (FT-Raman), espectroscopia fotoacústica no infravermelho (PAS-FTIR) e calorimetria exploratória diferencial (DSC). As técnicas biofísicas FT-Raman, PAS-FTIR e DSC permitiram caracterizar qualitativamente os modelos alternativos de biomembranas provenientes das mudas de pele de cobra da B. jararaca e S. pullatus e identificar freqüências vibracionais e transições endotérmicas similares ao estrato córneo humano.

Mechanism of Biological Effects of ELF Pulsed Electromagnetic Wave on Cells / 航天医学与医学工程

Objective To observe changes of cytosolic Ca2+ levels before and after irradiation by ELF pulsed electromagnetic waves and to study the mechanism of these changes.Methods Basing on the result from experiment,time-frequency analysis was applied to analyze the bio-effects of ELF pulsed electromagnetic field on cytosolic Ca2+ levels.Results The PHMx(t,?)isoline of cytosolic Ca2+ levels of the cells before(a)and after(b)irradiation by ELF pulsed electromagnetic field was given.Electrohydrodynamic instability and a crystalline liquid biomembrane were applied to explain the mechanism of biological effects on the cells.Conclusion The cytosolic Ca2+ concentration represents a well-defined pattern of spectrum in time-frequency domain,containing continuous and dispersive spectral components.The circs which was considered to induce bio-effects in time-frequency domain presented two unique properties:the continuous spectrum of cellular Ca2+ fluctuations in time-frequency domain was narrowed by the high-energy spectrum component restrained,and the distribution and the frequencies of the dispersive spectra were changed.Furthermore,the pulse frequencies and intensities producing the bio-effects are discrete and distant.

Expression of TNF-? in a rat model of chronic Pseudomonas aeruginosa biomembrane associated with lung infection / 中国病理生理杂志

AIM:To investigate the kinetics of tumor necrosis factor alpha(TNF-?)in an animal model of chronic P.aeruginosa biomembrane associated with lung infection.METHODS:Rats were challenged with 0.1 mL of PAO579(1012 CFU/L)in alginate beads or 0.1 mL of planktonic PAO579(1012 CFU/L).After challenging for 3,7 and 14 d,bacteriological and pathological features,and TNF-? expression in lung tissue were observed.RESULTS:(1)CFU/lung in alginate beads group was significantly higher than that in planktonic bacteria group(P

The stereomicroscopy observation for bone-defect restoration around BLB implants / 实用口腔医学杂志

Objective:To observe the bone regeneration capacity of bone defects around BLB implants covered with or without membranes.Methods:Implants were installed into femoral bone of grown-up dogs.Near implants,3 mm horizontal width,5 mm vertical depth and 1,2,3,4 mm horizontal length(along the macroaxis of femoral bone) standard gradient bone defects were made.On one side,the incisions were directly sutured by lamination,and on the other side the incisions were sutured by lamination after using collagen membrane to cover on the defects.Three months after the operation the specimens were observed by stereomicroscopy.Results:In the groups with 1,2 and 3 mm defects,the defect areas had been filled completely with new bone which was mainly compact cortex.In the group with 4 mm defects,the defect areas were filled with new bone which was mainly trabecular bone.Bigger lacunes could be observed in the groups without membranes.Conclusion:If the defect is less than 3 mm,whether bioresorbable collagen membrane is used or not,osseointegration is well in the implant-bone interface.Improving bone regeneration should be done when the bone defect extension is bigger.

THE ULTRASTRUCTURE OF THE B(?)OMEMBRANE OF THE DOG SINUS NODE CELL——BY FREEZE REPLICAS METHOD / 解剖学报

The fine structure of the biomembrane of the sinus node cells in the dog wasstudied with the replicas of freezecleaved specimens.The intramembranous particles.(IMP)in the PF and EF faces of the plasma mcmbrane of the sinus node cells,were present.The density of the IMP on the PF faces was more dense than those ofEF faces,In general,the shape of the IMP of the plasma membrane(PF and EFfaces)exhibited spherical or spheroidal.The IMP of PF faces may be divided into,three groups,i.e.the larger,medium and small size.Numerous endocytotic vesicles.found on the PF faces appeared as circular depressions and as small walled craterson EF faces.No regular array of the vesicles had been observed on both faces,TheIMP of the mitochondrial cristae were more dense than those of the depression.TheIMP of PF face of the nuclear membrane were observed.Their size and shapepresent a uniform appearance.There were many nuclear pores in the surface of thenuclear membrance.In the cytoplasm,longitudinal and transverse sections of the myofibrils werefound.On the transverse section,the myofilaments of A and I band werepresent.The intercalated disk was observed.The gap junctions present between thesinus node cells were proved by Masson-Pevet et al in the rabbits but were notfound in our specimens.