Objective To investigate the feasibility of fetal liver cells for liver tissue engineering, the supporting function of poly L lactic acid (PLLA) scaffold for fetal liver cells and the effects of oncostatin M (OSM), nicotinamide (NA) and dimethyl sulfoxide(DMSO) on growth and hepatic differentiation. Methods After three dimensional PLLA scaffolds having a porous structure were prepared by using NH 4HCO 3 particle, fetal liver cells obtained from E14.5 C57BL/6CrSlc murine embryos were inoculated in the scaffolds. Cells were cultured in Williams’E medium with or without OSM, NA and DMSO for 30 days. Changes in cell number, liver-specific function, and cellular morphology were observed. Results When compared with in monolayer culture, cell number and albumin secretion increased obviously in three-dimensional PLLA. Alburmin secretion increased slightly in OSM group of monolayer culture, but increased obviously in OSM groupo of PLLA culture and in OSM/NA/DMSO group of both monlayer and PLLA cultures. Conclusion The three-dimensional PLLA scaffold is a good supporting material for the cultivation of tetal liver cells. OSM, NA and DMSO remarkaly stimulated maturation of hepatic parenchymal cells in vitro in terms of morphology and liver-specific function.
ObjectiveTo investigate the preparation and osteogenic properties of poly (L-lactic acid)(PLLA)/lecithin porous scaffolds with open pore structure.MethodsPLLA/lecithin porous scaffolds with different lecithin contents (0, 5%, 10%, 20%, 30%, 40%, 50%) were prepared by thermally induced phase separation (groups A, B, C, D, E, F, and G, respectively). Scanning electron microscopy (SEM) was used to observe the surface morphology of the scaffolds. Wide-angle X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to detect the crystallinity of the scaffolds. The water uptake ability of the scaffolds was measured. The cell growth and viability of bone marrow mesenchymal stem cells (BMSCs) of mouse on each scaffold was assessed by cell counting kit 8 (CCK-8) method. The osteogenic differentiation ability of BMSCs on each scaffold was evaluated by alkaline phosphatase (ALP) activity. Finally, a critical-size rat calvarial bone defect model was used to evaluate the osteogenesis of the scaffolds in vivo. Micro-CT was used to reconstruct the three-dimensional model of the defect area, and the bone volume and bone mineral density were quantitatively analyzed.ResultsSEM results showed that the lecithin could slightly reduce the pore size; when lecithin content was 50%, platelet-like structure could be observed on the scaffolds. Wide angle XRD and DSC showed that the crystallinity of scaffolds gradually decreased with the increase of lecithin content. The water uptake ability test showed that the hydrophilicity of scaffolds increased with the increase of lecithin content. CCK-8 assay showed that cell activity gradually increased with the increase of culture time. After 7 days of culture, the absorbance (A) value of groups C, D, E, and F were significantly higher than that of groups A, B, and G (P<0.05), but no significant difference was found among groups C, D, E, and F (P>0.05). After 14 days of osteogenic induction, with the increase of lecithin content, there was a significant difference in ALP activity of each group. The ALP activity in groups D, E, F, and G were significantly higher than that in groups A, B, and C (P<0.05).In vivo, the results of Micro-CT examination and bone volume and bone mineral density showed that the scaffolds with 30% lecithin had the best repairing effect.ConclusionPrepared by thermally induced phase separation, the cytocompatibility, osteogenic differentiation, and bone repair ability of the PLLA/lecithin porous scaffold is obviously better than that of pure PLLA scaffold. PLLA/lecithin porous scaffold with suitable lecithin content is a promising scaffold material for bone tissue engineering.
Objective To investigate if lactic acid can promote the expression of vascular endothelial growth factor (VEGF) in the rat retinal explants.Methods The retinas of two-week neonatal SD rats were placed onto the culture plate inserts and incubated with Dulbeccoprime;s modified Eagleprime;s medium （DMEM） plus 2% fetal bovine serum (FBS) containing 10,20,30 mmol/L of lactic acid, respectively. Each group had 24 retinas. At 24 hours after incubation, the retinas were sectioned for light microscopy and the expression of VEGF was measured by real time PCR and Western blot. Results The cultured retinas maintained intact construction, and no cytolysis and apoptosis were observed under light microscope. RT-PCR showed the levels of VEGF mRNA were 0.74plusmn;0.06 for 10 mmol/L lactic acid group, 0.99plusmn;0.12 for 20 mmol/L group, and 1.45plusmn;0.17 for 30 mmol/L group respectively. VEGF expression was 0.34plusmn;0.15 for 10 mmol/L, 0.54plusmn;0.16 for 20 mmol/L, and 0.93plusmn;0.23 for 30 mmol/L group respectively by Western blot. Both PCR and Western blot showed 30 mmol/L of lactic acid significantly increased the levels of VEGF mRNA and VEGF expression. Conclusion The induction of retinal VEGF by lactic acid is concentration-dependent.
Objective
To investigate the effect of a porous calcium phosphate/bone matrix gelatin (BMG) composite cement (hereinafter referred to as the " porous composite cement”) for repairing lumbar vertebral bone defect in a rabbit model.
Methods
BMG was extracted from adult New Zealand rabbits according to the Urist’s method. Poly (lactic-co-glycolic) acid (PLGA) microsphere was prepared by W/O/W double emulsion method. The porous composite cement was developed by using calcium phosphate cement (CPC) composited with BMG and PLGA microsphere. The physicochemical characterizations of the porous composite cement were assessed by anti-washout property, porosity, and biomechanical experiment, also compared with the CPC. Thirty 2-month-old New Zealand rabbits were used to construct vertebral bone defect at L3 in size of 4 mm×3 mm×3 mm. Then, the bone defect was repaired with porous composite cement (experimental group, n=15) or CPC (control group, n=15). At 4, 8, and 12 weeks after implantation, each bone specimen was assessed by X-ray films for bone fusion, micro-CT for bone mineral density (BMD), bone volume fraction (BVF), trabecular thickness (Tb. Th.), trabecular number (Tb.N.), and trabecular spacing (Tb. Sp.), and histological section with toluidine blue staining for new-born bone formation.
Results
The study demonstrated well anti-washout property in 2 groups. The porous composite cement has 55.06%±1.18% of porosity and (51.63±6.73) MPa of compressive strength. The CPC has 49.38%±1.75% of porosity and (63.34±3.27) MPa of compressive strength. There were significant differences in porosity and compressive strength between different cements (t=4.254, P=0.006; t=2.476, P=0.034). X-ray films revealed that the zone between the cement and host bone gradually blurred with the time extending. At 12 weeks after implantation, the zone was disappeared in the experimental group, but clear in the control group. There were significant differences in BMD, BVF, Tb. Th., Tb. N., and Tb. Sp. between 2 groups at each time point (P<0.05). Histological observation revealed that there was new-born bone in the cement with the time extending in 2 groups. Among them, bony connection was observed between the new-born bone and the host in the experimental group, which was prior to the control group.
Conclusion
The porous composite cement has dual bioactivity of osteoinductivity and osteoconductivity, which are effective to promote bone defect healing and reconstruction.
Objective To explore the prognostic significance of baseline clinical and pulmonary physiological variables on idiopathic pulmonary fibrosis ( IPF) . Methods Patients diagnosed with IPF according to 2011 ATS/ERS/JRS/ALAT statementwere selected from Nanjing DrumTower Hospital between January 1, 2002 and July 31, 2010. The baseline characteristics were abstracted, including age, gender, smoking history, corticosteroid, delay before diagnosis, body mass index, finger clubbing, oxygenation index ( PaO2 /FiO2 ) , C-reaction protein, erythrocyte sedimentation rate ( ESR) , serum lactate dehydrogenase ( LDH) , albumin, vital capacity ( VC) , forced vital capacity ( FVC) , total lung capacity ( TLC) , and singlebreath diffusing capacity of the lung for carbon monoxide ( DLCO) . The relationships between all factors and survival were examined with a univariate Cox proportional-hazard model. Kaplan-Meier method was used to assess the survival probabilities between groups with different baseline characteristics. Results Eighty-four patients were included in this study, with the median survival time of 34. 7 months. PaO2 /FiO2 , FVC% pred, VC% pred, TLC% pred, and DLCO% pred showed significant associations with the mortality of IPF ( hazard ratios 0. 940-0. 994, P lt; 0. 01) . The Kaplan-Meier analyses for above variables also showed significant differences ( P lt;0. 05) . Besides, the statistical difference of survival probability could be found between the patients with elevated serumLDH and those with normal LDH ( 27. 0 months vs. 43. 1 months, P =0. 014) . Conclusions Baseline oxygenation and pulmonary function parameters may indicate the prognosis of IPF patients. Serum LDH may provide clinicians with additional prognostic information.
Objective To develop a novel prediction model based on cerebrospinal fluid (CSF) lactate for early identification of high-risk central nervous system (CNS) infection patients in the emergency setting. Methods Patients diagnosed with CNS infections admitted to the Department of Emergency Medicine of West China Hospital, Sichuan University between January 1, 2020 and December 31, 2023 were retrospectively selected. Patients were classified into a survival group and a death group according to their 28-day survival status, and clinical characteristics were compared between groups. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of 28-day mortality, which were subsequently used to construct a nomogram. Results A total of 173 patients were included, comprising 135 in the survival group and 38 in the death group. Multivariate analysis identified the Acute Physiology and Chronic Health Evaluation Ⅳ (APACHE Ⅳ) score [odds ratio (OR)=1.027, 95% confidence interval (CI) (1.002, 1.055), P=0.034], CSF lactate [OR=1.147, 95%CI (1.025, 1.286), P=0.018], and interleukin-6 [OR=1.002, 95%CI (1.001, 1.004), P=0.002] as independent predictors of 28-day mortality. The integrated model combining APACHE Ⅳ score, CSF lactate, and interleukin-6, demonstrated superior predictive performance compared with the APACHE Ⅳ score alone (P=0.020), and showed good calibration (Hosmer-Lemeshow P=0.50). Conclusions This tool may provide a useful instrument for emergency physicians to assess the 28-day mortality risk in patients with CNS infections, potentially facilitating early and targeted interventions for high-risk individuals. However, as the findings of this study are derived from a single-center retrospective dataset, the clinical applicability of this model requires further external validation through large-scale, prospective, multicenter studies to evaluate its generalizability.
Objective To analyze the effectiveness and effect on pregnant outcome about living preparation of lactobacillus versus metronidazole in the treatment of bacterial vaginosis in pregnancy. Methods We searched PubMed, The Cochrane Library, VIP, CNKI, Wangfang, CBM, FMJS, and FEBMT to identify randomized controlled trials (RCT) of living preparation of lactobacillus versus metronidazole for bacterial vaginosis in pregnancy. The quality of the included trials was assessed. RevMan 5.0.24 software was used for meta-analysis. Results Eight trials involving 1 687 patients were included. The results of meta-analysis showed: no significant difference was found in the effectiveness between the two groups (RR=1.04, 95%CI 1.00 to 1.08, P=0.08); living preparation of lactobacillus had lower recurrence rate and lower premature delivery rate compared with metronidazole (RR=0.16, 95%CI 0.06 to 0.43, P=0.0004; RR=0.56, 95%CI 0.33 to 0.94, P=0.03); no significant differences were found in premature rupture of membrane, puerperal infection, infant of low-birth weight, infant infection, and infant jaundice between the two groups. Conclusion The effectiveness about living preparation of lactobacillus versus metronidazole for bacterial vaginosis in pregnancy is similar, but living preparation of lactobacillus has lower recurrence rate and lower premature delivery rate, the others of effect on pregnant outcome are similar.
Objective To establish an animal model for repairing the sciatic nerve defect with a biodegradable poly D,L-lactic acid/nerve growth factor (PDLLA/NGF) that can control the release conduit in rats and to observe an effect of the conduit on the sciatic nerve regeneration. Methods The PDLLA conduit and the PDLLA/NGF-controlled release conduit (NGF 450 U per conduit) were madewith the solvent-volatilixation method. Forty male SD rats were randomly and equally divided into 4 groups. The middle segments (10 mm) of the sciatic nerves of the rats were excised and were then repaired with the sciatic nerve autograft(Group A), with the PDLLA conduit (Group B), with the PDLLA conduit and an injection of NGF (30 U) into the conduit (Group C), and with the PDLLA/NGF controlled-release conduit (Group D), respectively, with the 10-mm nerve defect left behind. Three months after operation, the morphologic parameters of the nerve regeneration were observed and evaluated under light microscope and electron microscope, and the image analysis was also made. Results Three months after operation, porous adherence between the conduit and the surrounding tissues could be observed. The conduit presented a partial biodegradation but still remainedintact in the outline and the proximal nerve regenerated through the conduit cavity. Based on the histological observation, the quantity, uniformity, and maturity of the nerve fiber regeneration in Groups A and D were better than those in Groups B and C. The image analysis indicated that there were no significant differences in the nerve fiber diameter, axon diameter or myelin thickness between Group A and Group D (P＞0.05). However, all the parameters in Groups A and D were better than those in Groups B and C (P＜0.05). Conclusion The PDLLA/NGF-controlled release conduit can effectively promote the sciatic nerve regeneration of rats. Its morphological index is similar to that of the nerve autograft.
ObjectiveTo review the research progress and challenges of poly (L-lactic acid) (PLLA) membrane in preventing tendon adhesion. MethodsThe relevant literature at home and abroad in recent years was extensively searched, covering the mechanism of tendon adhesion formation, the adaptation challenge and balancing strategy of PLLA, the physicochemical modification of PLLA anti-adhesion membrane and its application in tendon anti-adhesion. In this paper, the research progress and modification strategies of PLLA membranes were systematically reviewed from the three dimensions of tissue adaptation, mechanical adaptation, and degradation adaptation. ResultsThe three-dimensional adaptation of PLLA membrane is optimized by combining materials (such as hydroxyapatite, polycaprolactone), structural design (multilayer/gradient membrane), and drug loading (anti-inflammatory drug). The balance between anti-adhesion and pro-healing is achieved, the mechanical adaptation significantly improve, and degradation is achieved (targeting the degradation cycle to 2-4 weeks to cover the tendon repair period). ConclusionIn the future, it is necessary to identify the optimal balance point of three-dimensional fitness, unify the evaluation criteria and solve the degradation side effects through the co-design of physicochemical modification and drug loading system to break through the bottleneck of clinical translation.
