Intubation of non-difficult airways using video laryngoscope versus direct laryngoscope: a randomized, parallel-group study.

BACKGROUND: The video laryngoscope is recommended for intubating difficult airways. The present study aimed to determine whether the video laryngoscope can further improve intubation success rates compared with the direct laryngoscope in patients with non-difficult airways. METHODS: In total, 360 patients scheduled for elective abdominal surgeries were randomly assigned to undergo intubation using either a video laryngoscope (n = 179) or a direct laryngoscope (n = 181). The following parameters were measured: mouth opening; thyromental distance; sternomental distance; shape angle of the tracheal catheter; and glottic exposure grade. RESULTS: The percentage of patients with level I-II of total glottic exposure in the video laryngoscope group was 100% versus 63.5% in the direct laryngoscope group (P < 0.001). The one-attempt success rate of intubation was 96.1% using a video laryngoscope versus 90.1% using a direct laryngoscope (P = 0.024). The intubation success rate using a video laryngoscope was 100% versus 94.5% using a direct laryngoscope (P = 0.004). Immediate oropharyngeal injury occurred in 5.1% of patients intubated using a direct laryngoscope versus 1.1% using a video laryngoscope (P = 0.033). On postoperative day 1, obvious hoarseness was exhibited by 7.9% of patients intubated using a direct laryngoscope versus 2.8% using a video laryngoscope (P = 0.035). The grade of glottic exposure and catheter shape angle were independent risk factors for tracheal intubation failure. Thyromental distance, shape angle, glottic exposure time, and surgical position were independent risk factors for postoperative complications. Thyromental distance and glottic exposure time were independent risk factors for complications lasting > 2 days. CONCLUSIONS: Intubation using a video laryngoscope yielded significantly higher intubation success rates and significantly fewer postoperative complications than direct laryngoscopy in patients with non-difficult airways. TRIAL REGISTRATION: Chinese Clinical Trial Registry. No: ChiCTR-IOR-16009023 . Prospective registration.

Application of anteromedial thigh flap for the reconstruction of oral and maxillofacial defects.

PURPOSE: To discuss the vascular anatomy of the anteromedial thigh (AMT) flap and to evaluate the feasibility of the AMT flap for the reconstruction of oral and maxillofacial defects. PATIENTS AND METHODS: A retrospective review was performed of 18 patients who underwent reconstruction of oral and maxillofacial defects with AMT flaps from January 2009 through December 2011 in the Second Xiangya Hospital. Eleven unifoliate AMT flaps were elevated to reconstruct defects of the tongue, soft palate, and floor of the mouth and 7 chimeric anterolateral thigh (ALT) and AMT flaps were harvested to reconstruct through-and-through cheek defects. RESULTS: The flaps were 4 × 6 to 9 × 11 cm(2). All the AMT flaps were nourished by the descending branch (DB) of the lateral circumflex femoral artery. The cutaneous perforators were derived from the rectus femoris branch of the DB in 15 cases and directly from the DB in the other 3 cases. Postoperatively, all flaps survived completely, without major complications. Of the 18 donor sites, 14 were closed directly, leaving only linear scars, and 4 were closed using full-thickness skin grafts owing to larger defects. All patients were followed for approximately 6 to 30 months, and they were satisfied with the esthetic and functional results of the donor and recipient sites after the reconstruction. CONCLUSIONS: Because of easy perforator dissection, the AMT flap can be used as an alternative to the ALT flap or harvested with the ALT flap as chimeric ALT and AMT flaps for the reconstruction of oral and maxillofacial defects.

Pharmacokinetics, safety, and efficacy of Fuqi Guben Gao in the treatment of kidney-yang deficiency syndrome: a randomized, double-blind phase I trial.

Introduction: Fuqi Guben Gao (FQGBG) is a botanical drug formulation composed of FuZi (FZ; Aconitum carmichaelii Debeaux [Ranunculaceae; Aconiti radix cocta]), Wolfberry (Lycium barbarum L. [Solanaceae; Lycii fructus]), and Cinnamon (Neolitsea cassia (L.) Kosterm. [Lauraceae; Cinnamomi cortex]). It has been used to clinically treat nocturia caused by kidney-yang deficiency syndrome (KYDS) for over 30 years and warms kidney yang. However, the pharmacological mechanism and the safety of FQGBG in humans require further exploration and evaluation. Methods: We investigated the efficacy of FQGBG in reducing urination and improving immune organ damage in two kinds of KYDS model rats (hydrocortisone-induced model and natural aging model), and evaluated the safety of different oral FQGBG doses through pharmacokinetic (PK) parameters, metabonomics, and occurrence of adverse reactions in healthy Chinese participants in a randomized, double-blind, placebo-controlled, single ascending dose clinical trial. Forty-two participants were allocated to six cohorts with FQGBG doses of 12.5, 25, 50, 75, 100, and 125 g. The PKs of FQGBG in plasma were determined using a fully validated LC-MS/MS method. Results: FQGBG significantly and rapidly improved the symptoms of increased urination in both two KYDS model rats and significantly resisted the adrenal atrophy in hydrocortisone-induced KYDS model rats. No apparent increase in adverse events was observed with dose escalation. Major adverse drug reactions included toothache, thirst, heat sensation, gum pain, diarrhea, abdominal distension, T-wave changes, and elevated creatinine levels. The PK results showed a higher exposure level of benzoylhypaconine (BHA) than benzoylmesaconine (BMA) and a shorter half-life of BMA than BHA. Toxic diester alkaloids, aconitine, mesaconitine, and hypaconitine were below the lower quantitative limit. Drug-induced metabolite markers primarily included lysophosphatidylcholines, fatty acids, phenylalanine, and arginine metabolites; no safety-related metabolite changes were observed. Conclusion: Under the investigated dosing regimen, FQGBG was safe. The efficacy mechanism of FQGBG in treating nocturia caused by KYDS may be related to the improvement of the hypothalamus-pituitary-adrenal axis function and increased energy metabolism. Clinical Trial Registration: https://www.chictr.org.cn/showproj.html?proj=26934, identifier ChiCTR1800015840.

Sphingosine-1-Phosphate Alleviates Irradiation Induced Salivary Gland Hypofunction through Preserving Endothelial Cells and Resident Macrophages.

Radiotherapy for head-and-neck cancers frequently causes long-term hypofunction of salivary glands that severely compromises quality of life and is difficult to treat. Here, we studied effects and mechanisms of Sphingosine-1-phosphate (S1P), a versatile signaling sphingolipid, in preventing irreversible dry mouth caused by radiotherapy. Mouse submandibular glands (SMGs) were irradiated with or without intra-SMG S1P pretreatment. The saliva flow rate was measured following pilocarpine stimulation. The expression of genes related to S1P signaling and radiation damage was examined by flow cytometry, immunohistochemistry, quantitative RT-PCR, Western blotting, and/or single-cell RNA-sequencing. S1P pretreatment ameliorated irradiation-induced salivary dysfunction in mice through a decrease in irradiation-induced oxidative stress and consequent apoptosis and cellular senescence, which is related to the enhancement of Nrf2-regulated anti-oxidative response. In mouse SMGs, endothelial cells and resident macrophages are the major cells capable of producing S1P and expressing the pro-regenerative S1P receptor S1pr1. Both mouse SMGs and human endothelial cells are protected from irradiation damage by S1P pretreatment, likely through the S1pr1/Akt/eNOS axis. Moreover, intra-SMG-injected S1P did not affect the growth and radiosensitivity of head-and-neck cancer in a mouse model. These data indicate that S1P signaling pathway is a promising target for alleviating irradiation-induced salivary gland hypofunction.

Vitamin D reduces the serum levels of inflammatory cytokines in rat models of periodontitis and chronic obstructive pulmonary disease.

The purpose of this study was to investigate the effects of vitamin D in rat models of chronic obstructive pulmonary disease (COPD) and periodontitis. Animals with both periodontitis and COPD, or with periodontitis only, were established. Once the animal model was established, experimental groups received intraperitoneal injections of 25-hydroxyvitamin D3 (25-OHD3) for 8 weeks, while control groups received refined peanut oil. After sacrifice, inflammatory status was examined in terms of the serum levels of receptor activator of the nuclear factor κB ligand (RANKL), tumor necrosis factor alpha (TNF-α) and interleukins (IL-1 and IL-10), as well as alveolar bone loss, forced expiratory volume (0.20) (FEV 0.20), and the ratio of FEV0.2 to forced vital capacity. The results showed that 25-OHD3 treatment significantly alleviated inflammation by decreasing the serum levels of RANKL, TNF-α and IL-1 and increasing that of IL-10, while reducing alveolar bone loss and slightly improving lung function. These findings suggest that vitamin D supplementation could be a new clinical approach for the treatment of COPD and periodontitis.

[Characteristics of poloxamer thermosensitive in situ gel of dexamethasone sodium phosphate].

Thermosensitive in situ gel is a novel drug delivery system which can form gel in situ after injection of the polymer solution into the body and releases the drug in a controlled manner, thus provides a promising strategy for localized drug delivery. The aim of the present work is to investigate the characteristics including gelation temperature, sol-gel transition temperature (T(s-g)), gel strength, stable viscosity, erosion and drug release behavior of the thermosensitive in situ gel which are composed of different concentrations of poloxamer Pluronic F127 and F68. The gelation temperature was determined by tube-reverse method. Rheological measurements were carried out to evaluate T(s-g), stable viscosity and gel strength. Erosion of the gels and release of dexamethasone sodium phosphate (DSP) from the gels were investigated by membrane-free method and HPLC. Increased F127 concentration in gel decreased the gelation temperature, T(s-g) as well as erosion of the gel and drug release rate, while viscosity and gel strength rose accordingly. However, increased F68 in gel could lead to the opposite result. The poloxamer solution below T(s-g) is Newtonian fluid with comparatively low viscosity, but shows the characteristics of the pseudoplastic fluid when temperature rises near to T(s-g). Drug release was controlled by the erosion of the gel matrix, and both of them followed the zero-order kinetics. An optimized formation containing 22.5% F127 and 2.5% F68 showed more desirable characteristics which meet the clinical requirements and is of potential in future clinical therapy.

Quantitative proteomic analysis of deciduous molars during cap to bell transition in miniature pig.

Taking advantage of genetic manipulation tools and accessibility, almost all molecular knowledge on vertebrate tooth development was obtained from rodent models that only have one dentition in their entire lives. Whether the tooth development in other vertebrates such as swine or human follows the same rules remains elusive. Rodent dentitions differ considerably from human dentitions, therefore limiting the application of knowledge from rodent tooth to human tooth. Signal-mediated communication between cells and complex gene and protein regulatory networks are key components of tooth development. By combining isobaric tandem mass tag (TMT) labeling with liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) technology, we constructed the proteomic profile of deciduous molars at embryonic days 40 and 50 in miniature pig (Sus scrofa). During the ten days of prenatal development of the miniature pig, the morphology of the lower deciduous molar moves from the early cap to the bell stage. Thus, we identified proteins that are associated with these developing stages and identified differentially regulated proteins (DRPs) that are potential or novel drivers of tooth morphogenesis. Three candidate proteins were validated via qRT-PCR, western blotting analysis, and the location of those proteins in tooth germ were observed by immunohistochemical staining. Multiple signaling pathways and protein interaction network revealed potential mechanisms of early tooth programming in a large mammal. Bioinformatic analysis also showed that cross interaction of Wnt and Sonic hedgehog pathways may play a key role in deciduous development during cap to bell transition in miniature pig. SIGNIFICANCE: We performed the most comprehensive study of the whole tooth germ proteome in mammals to date. The high-throughput proteomic analysis identifies differentially regulated proteins and pathways that will help elucidate the mechanisms of tooth development.

Predicting the location of mouth motor cortex in patients with brain tumors by using somatosensory evoked field measurements.

OBJECT: Before resective brain surgery, localization of the functional regions is necessary to minimize postoperative deficits. The face area has been relatively difficult to map noninvasively by using functional imaging techniques. Preoperative localization of face somatosensory cortex with magnetoencephalography (MEG) may allow the surgeon to predict the location of mouth motor areas. METHODS: The authors compared the location of face somatosensory cortex obtained with somatosensory evoked fields during preoperative MEG with the mouth motor areas identified during intraoperative electrocortical stimulation (ECS) mapping in 13 patients undergoing resection of brain tumor. RESULTS: In this group of patients, ECS mouth motor sites were usually anterior and lateral to MEG localizations of lip somatosensory cortex. The consistent quantitative relationship between results of these two mapping procedures allows the practitioner to predict the location of mouth motor cortex based on noninvasive preoperative MEG measurements. CONCLUSIONS: Based on this result, the authors suggest that somatosensory mapping using MEG can be used to guide intraoperative mapping and neurosurgical planning.

Evaluation of Parotid Salivary Glucose Level for Clinical Diagnosis and Monitoring Type 2 Diabetes Mellitus Patients.

Background. To investigate the relationships among blood glucose, mixed saliva glucose, and parotid glucose in type 2 diabetes patients and to evaluate the diagnostic and monitoring value of salivary gland glucose in patients with type 2 diabetes (type 2DM). Material and Methods. Thirty patients with type 2DM and 30 healthy age- and sex-matched individuals were included in this study. Glucose levels in unstimulated mixed saliva and in unstimulated parotid saliva were measured by the glucose oxidase peroxidase method. Results. The blood glucose and parotid salivary glucose levels in type 2DM patients were significantly higher than those in the controls (P < 0.05). The blood glucose, parotid salivary glucose, and mixed salivary glucose were 7.46 ± 1.44 mmol/L, 0.18 ± 0.19 mmol/L, and 3.17 × 10-2 ± 2.84 × 10-2 mmol/L, respectively, in the type 2DM group; the corresponding glucose levels in the control group were 5.56 ± 0.71 mmol/L, 7.70 × 10-2 ± 6.02 × 10-2 mmol/L, and 3.47 × 10-2 ± 2.79 × 10-2 mmol/L. The parotid salivary and blood glucose levels in type 2DM patients were strongly correlated; the linear regression equation for blood glucose and parotid salivary glucose was Y = 6.267X + 6.360, with r = 0.810. However, mixed salivary glucose levels were not significantly different in the type 2 diabetes group compared with the control group. Conclusion. Our results suggest that parotid salivary glucose has potential as a biomarker to monitor type 2DM and as a painless, noninvasive method for the management of type 2DM.

Decellularized Swine Dental Pulp as a Bioscaffold for Pulp Regeneration.

Endodontic regeneration shows promise in treating dental pulp diseases; however, no suitable scaffolds exist for pulp regeneration. Acellular natural extracellular matrix (ECM) is a favorable scaffold for tissue regeneration since the anatomical structure and ECM of the natural tissues or organs are well-preserved. Xenogeneic ECM is superior to autologous or allogeneic ECM in tissue engineering for its unlimited resources. This study investigated the characteristics of decellularized dental pulp ECM from swine and evaluated whether it could mediate pulp regeneration. Dental pulps were acquired from the mandible anterior teeth of swine 12 months of age and decellularized with 10% sodium dodecyl sulfate (SDS) combined with Triton X-100. Pulp regeneration was conducted by seeding human dental pulp stem cells into decellularized pulp and transplanted subcutaneously into nude mice for 8 weeks. The decellularized pulp demonstrated preserved natural shape and structure without any cellular components. Histological analysis showed excellent ECM preservation and pulp-like tissue, and newly formed mineralized tissues were regenerated after being transplanted in vivo. In conclusion, decellularized swine dental pulp maintains ECM components favoring stem cell proliferation and differentiation, thus representing a suitable scaffold for improving clinical outcomes and functions of teeth with dental pulp diseases.

Effect of beta-tricalcium phosphate/poly-l-lactide composites on radial bone defects of rabbit.

OBJECTIVE: To explore the effect ofß-TCP/PLLA scaffold in repairing rabbit radial bone defects. METHODS: Thirty New Zealand rabbits were divided into ß-TCP /PLLA group (group A), pure PLLA group (group B) and contrast group (group C) randomly. The rabbits were sacrificed respectively after 4, 8, 12, 24 weeks and the X-ray film was performed at the same time to evaluate the repair effect in different groups. RESULTS: X-ray film showed there was uneven low density bone callus development in defect region after 4 weeks in group A. The defect region was filled with neonate osseous tissue completely during 12-24 weeks. X-ray score revealed that repair of bone defect results significantly better than group B and group C. CONCLUSIONS: The ß-TCP /PLLA composite is capable of repairing radial bone bone defects. ß-TCP/PLLA scaffold is significant because of rapid degradation ability, good histocompatibility and osteogenic action.

[The chimeric perforator flap pedicled with descending branch of lateral circumflex femoral artery for reconstruction of oromaxillary soft tissue defect].

OBJECTIVE: To report the application of the chimeric perforator flap pedicled with descending branch of lateral circumflex femoral artery for large and complicated oromaxillary soft tissue defect. METHODS: Based on the anatomic study of descending branches and cutaneous perforators of lateral circumflex femoral artery, the perforator vessels were found and used as flap pedicle. The perforator flap was made as chimeric flap for repairing the oromaxillary soft tissue defect in 8 cases. The chimeric perforator flaps were divided into three types as anterolateral thigh flaps and anteromedial thigh flaps, anterolateral thigh flaps and rectus femoris perforator flaps, and anterolateral thigh flaps and anterolateral thigh flaps. RESULTS: All the 16 flaps in 8 cases survived completely with no complication. The wounds in donor sites were all primarily closed with no skin graft. The patients were followed up for 1-9 months with good functional and esthetic results. There was no morbidity in donor sites. CONCLUSIONS: The chimeric perforator flap has a large tissue volume for large and complicated oromaxillary defect. There is no need for extra donor site and extra blood vessel anastomosis.

[Clinical application of free anterolateral thigh flap in the reconstruction of oromaxillo-facial defects].

OBJECTIVE: To analyze the possibility and practicality of using free anterolateral thigh flap to repair defects of oromaxillo-facial region. METHODS: One hundred and seventy-two patients underwent anterolateral thigh flap (ALP) reconstruction from Jan. 2007 to Dec. 2008. The size of the defect ranges from 4 cm x 4 cm to 10 cm x 25 cm. One hundred and six flaps were used for tongue reconstruction, 14 flaps for buccal reconstruction, 15 flaps for mouth floor reconstruction, 1 flap for lower lip and mental region reconstruction, 6 flaps for hard and soft palate reconstruction, 3 flap for maxillary part reconstruction, 18 flaps for submaxilla part reconstruction, 2 flaps for pharynx oralis reconstruction, 3 flaps for repairing large-area defect of facial, 1 flap for repairing neck and shoulder region and 3 flaps for repairing defect of Infratemporal fossa. Of these flaps, 151 were musculocutaneous flaps, 13 were fasciocutaneous flaps and 8 were chimeric flaps. RESULTS: The success rate reaches 98.3% (169 of 172). Postoperatively, 4 cases encountered vascular crisis, 1 of which survived completely with successful vessel exploration, 3 cases with partial necrosis; and 3 cases with complete necrosis. One case with bleeding after operation. Six cases with parotid fluidly and parotid fistula, 8 cases with mouth floor fistula, 6 cases with infection, 3 cases with infection and partial necrosis on the lateral thigh. All patients achieved acceptable contour, appearance and function. CONCLUSION: Free anterolateral thigh flap can repair kinds of complicated defects on oromaxillo-facial region.

[Toxicity of cationic liposome Lipofectamine 2000 in human pancreatic cancer Capan-2 cells].

OBJECTIVE: To investigate the toxicity of cationic liposome Lipofectamine 2000 (Lipo) in human pancreatic cancer Capan-2 cells. METHODS: Capan-2 cells were cultured in the presence of Lipo at toxic concentrations, and the cell growth, apoptosis and cell cycle changes were evaluated by cell counting and flow cytometry. RESULTS: The concentrations of both Lipo and siRNA affected the transfection efficiency. In a transfection volume of 2 ml, the presence of 5 microl Lipo resulted in slowed growth of Capan-2 cells, which was especially obvious after 3 days (P<0.001). Prolonged culture of the transfected cells caused significant increases in early apoptotic cells (P<0.05) and in the damaged or necrotic cells (P<0.001), and resulted in reduced viable cells (P<0.01); these changes became obvious after a 48-hour culture, which also increased the ratio of G(0)/G(1) phase cells (P<0.05) and decreased those of G(2)/M phase cells (P<0.01), S phase cells (P<0.01), and the late apoptotic cells (P<0.05). CONCLUSION: Toxic concentrations of Lipo can affect the growth, apoptosis and cell cycles of Capan-2 cells in vitro, and this urges careful concentration selection when using Lipo for gene transfer into different cells.

[Biodistribution of (99m)Tc-labeled anti-VEGF mAb 5-FU loaded polylactic acid nanoparticles in human gastric carcinoma xenografts].

OBJECTIVE: To prepare (99m)Tc-labeled Anti-VEGF mAb 5-FU loaded polylactic acid nanoparticles ((99m)Tc-Ab-5-FU-NPs) and investigate its biodistribution in human gastric carcinoma xenografts. METHODS: (99m)Tc-Ab-5-FU-NPs were prepared by labeling Ab-5-FU-NPs with (99m)Tc using improved Schwarz method. After isolation of (99m)Tc-Ab-5-FU-NPs using SephadexG250 column, the labeling ratio and radiochemical purity were determined using chromatography. The immunocompetence of (99m)Tc- Ab-5-FU-NPs was detected by ELISA and immunohistochemistry. (99m)Tc-Ab-5-FU-NPs were then injected via the tail vein into SCID mice bearing human gastric carcinoma, and (99m)Tc labeled mice-derived monoclonal IgG loaded polylactic acid nanoparticles were used as the control, followed by radioimmunoscintigraphic imaging at 2 and 6 h. The radioactive count and radioactive ratio of the tumor and non-tumor tissue (T/NT) in the animal models were calculated using ROI technique. After imaging at 24 h, SCID mice were sacrificed and the radioactive distribution, the %ID/g, as well as the T/NT radioactive ratio were examined, respectively. The concentrations of 5-FU in the tumor and blood were also detected using HPLC method. RESULTS: The labeling ratio of (99m)Tc-Ab-5-FU-NPs was 90%-95%. (99m)Tc-Ab-5-FU-NPs were detected in the tumor tissues by radioimmunoimaging 2 h after the injection. ID%/g in the tumor tissues at 2 and 6 h were both significantly higher than that of the control group. Both the ID%/g in tumor tissues and radioactive ratio of tumor and blood at 6 h were higher than those at 2 h, and the concentration of 5-FU in experimental group increased continuously with time and was significantly higher than that in control group. CONCLUSIONS: (99m)Tc-Ab-5-FU-NPs prepared in this study can meet the demands of radioimmunoimaging, and the anti-VEGF monoclonal antibody possesses reliable immune targeting ability. Six hours after injection, (99m)Tc-Ab-5-FU-NPs can specifically accumulate in the tumor tissues in human gastric carcinoma xenografts at high concentration.

[Study of the anti-tumor effect of anti-vascular endothelial growth factor McAb 5-fluorouracil loaded polylactic acid nanoparticles].

OBJECTIVE: To explore the anti-tumor efficacy of anti- vascular endothelial growth factor (VEGF) McAb 5-fluorouracil (5-FU) loaded polylactic acid (PLA) nanoparticles (NPS) in human gastric carcinoma xenografts of nude mice. METHODS: Anti-VEGF McAb 5-FU loaded PLA NPS were made by ultrasound emulsification. Nude mice model of human gastric carcinoma xenografts was established. Therapeutic effects of drugs on human gastric carcinoma xenografts and side effects concerned were observed. RESULTS: The tumor inhibition rates of control group, nanosphere without 5-FU group, 5-FU (20 mg/kg) group, anti-VEGF McAb nanosphere without 5-FU group, anti-VEGF McAb group, nanosphere with 5-FU group, 5-FU (20 mg/kg) combined with anti-VEGF McAb group, anti-VEGF McAb 5-FU loaded nanosphere group was 0, 6.61%, 24.26%, 27.94%, 35.29%, 37.50%, 39.71% and 52.21% respectively, and there were no significant differences between anti-VEGF McAb 5-FU loaded nanosphere group and nanosphere group without 5-FU in WBC count, serum alanine transferase level or creatinine level. Compared with control group and anti-VEGF McAb 5-FU loaded nanosphere group, the 5-FU group decreased by 34.43% and 37.38% respectively in WBC count (P< 0.05), and increased by 93.17% and 66.56% respectively in alanine transferase. There were significant differences between experimental groups and control group in apoptosis index, especially between anti-VEGF McAb 5-FU loaded nanosphere group and control group (P< 0.05). The microvessel density (MVD) of experimental groups containing anti-VEGF McAb was significantly lower than that of control group or groups containing 5-FU (P< 0.05). CONCLUSION: Anti-VEGF McAb 5-FU loaded nanosphere can increase the tumor inhibitory rate of 5-FU, induce apoptosis by inhibiting tumor angiogenesis with less side effect, and then enhance therapeutic effect, which indicate its potential as a novel, safe nano-tumor-targeting drug.

[Preparation and release efficiency of polylactic acid nanoparticle].

BACKGROUND & OBJECTIVE: As a new drug delivery carrier, medical nanoparticle (NP) appears to be very promising and are widely studied. Compare with microparticle, nanoparticle possesses several advantages, such as ultramicroscopic size, could be ingested by the cells after crossing the tissue matrix, and can penetrate the arterial wall and cross the blood-brain barrier. This study was to prepare polylactic acid (PLA) nanoparticle, and observe its morphology, diameter, structure, surface elements, and ability of in vitro drug release. METHODS: The biodegradable PLA was used as the carrier, and 5-fluorouracil (5-FU) was used as the model drug. 5-FU-PLA nanoparticle (5-FU-PLA-NP) was prepared by matrix and ultrasound emulsification. Morphology of 5-FU-PLA-NP was observed under scanning electron microscope; its surface elements were detected by X ray photoelectron spectroscopyû its drug loading (DL), embedding ratio (ER), and ability of in vitro drug release were assessed by ultraviolet spectroscopy. RESULTS: The nanoparticle was uniformly spherical with average diameter of (191+/-17) nm, DL of 15.2%, and ER of 45.6%. The nanoparticle showed sustained release character in the experiment of in vitro drug release: the cumulative drug release rate in analog body fluid was 94.3% at the 10th day. CONCLUSION: PLA-NP may serve as a carrier of 5-FU, and can change the pharmacokinetics of 5-FU, slower down drug release; 5-FU-PLA-NP can be prepared as intravenous injection, and may prolong the in vivo circulation time of 5-FU, so as to play more efficient antitumor effects.