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find Keyword "delivery" 42 results
  • The distribution of nerve growth factor in rabbits′ eyes after intraocular injection in two different means

    Objective To observe the distribution and concentration of 125I-nerve growth factor (NGF) in rabbitsprime; eyes after intravitreal injection and posterior juxtascleral injection.Methods Intravitreal injection(group A) and posterior juxtascleral injection (group B) were performed with the dosage of 30mu;g/100mu;l 125I-NGF on left and right eyes in 45 white rabbits respectively. The gamma;-counts and the concentration of 125I-NGF (%ID/g) of each ocular tissue was determined 15 and 30 minutes, and 1,3,6,12,24,and 48 hours after injection. Results The 125I-NGF diffusion in group A was faster in ocular content and ocular inner wall. The vitreous content of 125I-NGF decreased gradually in group A, the curve changes in other eye tissues were normal. The concentration of 125I-NGF reached the peak 3 hours after injection in aqueous humor, iris and ciliary body, retina, and choroids, but 6 hours after injection in sclera and 8 hours in cornea. The changes of concentration of 125I-NGF in group B showed normal curve change. The peak time in group B were all 6 hours in all the tissues except aqueous humor (3 hours). Except the high concentration in vitreous body caused by intravitreal injection, the concentration of 125I-NGF in retina was the highest in group A. Conclusion Intravitreal injection of 125I-NGF can gain higher concentration in each ocular tissue than posterior juxtascleral injection, especially in retina. So intravitreal injection of NGF is a better ocular delivery method to treat the ocular fundus diseases.

    Release date:2016-09-02 05:43 Export PDF Favorites Scan
  • STUDY ON IN VIRO DRUG DELIVERY AND REPAIRING LARGE SEGMENTAL INFECTEDBONY DEFECT WITH MASSIVE RECONSTITUTED BOVINE XENOGRAFT AIDED BY CALCIUM PHOSPHATE CEMENT DRUG CORE

    Objective To find out an effective technique torepair large segmental infected bony defect.Methods Calcium phosphate cement(CPC) incorporated with bone morphogenetic protein and gentamycin was embedded in the massive reconstituted bovine xenograft(MRBX), then CPC-MRBX was obtained after CPC’s solidification. In vivo test was applied to test the drug delivery capability of CPC-MRBX, in which it was implanted in the dorsal muscle pouch of 18 rabbits. The drug concentration of animal blood and surrounding soft tissue of the CPC-MRBX in the muscle pouch was measured 1, 2, 5, 10, 15, 20, 25, 30 and 35 d after operation, 2 rabbits each time. Large segmental infected femur defect in the rabbit model was created to test the repairing capability of CPC-MRBX. External fixation was done 1.5~2.0 cm above the knee, the most adjacent nail to fracture site was 0.5~0.8 cm away, and proper pressure was applied to the graft. In experimental group(n=25), the bony defect was replaced by CPC-MRBX, while in the control group(n=15) dissected bone block was re-implanted in original position. The animal was subjected to radiographic, histological examination at 4, 8, 16 and 24 weeks. The general condition was observed after the operation.Results CPC-MRBX was easily made under normal temperature and pressure. In viro drug delivery test showed that the drug concentration of the tissue remainedabove the minimal inhibitory concentration of staphylococcus 30 d after operation and no significant increase of blood drug concentration was observed. In experimental group, no adverse influence was observed. Four weeks after operation, the animal could bear load, bony callus around the graft was observed by X-ray, and abundant chondral tissues that grew into CPC-MRBX were observed by histological method. Eight weeks after operation, progressively increasing bony callus around the graft was observed, external fixation could be removed, normal function was restored, and CPC was degenerated dramatically while new bone tissues were growing. Sixteen weeks after the operation, more new bone tissues grew and CPC was degenerated furtherly while marrow tissues were taking shape. Twenty-four weeks after the operation, femur healed completely and CPC was degenerated completely. In the control group, the autograft remained unhealedon X-ray at 4 weeks, and osteomyelitis manifestation such as inflammatory cells infiltration and osteolysis was detected at 4 weeks. All the animals in the control group died before the 8th week, 4 of which showed positive hemoculture. Conclusion CPC-MRBX is readily available and can be applied to repairing large segmental infected bony defect.30 d after operation and no significant increase of blood drug concentration was observed. In experimental group, no adverse influence was observed. Four weeks after operation, the animal could bear load, bony callus around the graft was observed by X-ray, and abundant chondral tissues that grew into CPCMRBX were observed by histological method. Eight weeks after operation, progressively increasing bony callus around the graft was observed, external fixation could be removed, normal function was restored, and CPC was degenerated dramatically while new bone tissues were growing. Sixteen weeks after the operation, more new bone tissues grew and CPC was degenerated furtherly while marrow tissues were taking shape. Twenty-four weeks after the operation, femur healed completely and CPC was degenerated completely. In the control group, the autograft remained unhealedon X-ray at 4 weeks, and osteomyelitis manifestation such as inflammatory cells infiltration and osteolysis was detected at 4 weeks. All the animals in the control group died before the 8th week, 4 of which showed positive hemoculture.Conclusion CPC-MRBX is readily available and can be applied to repairing large segmental infected bony defect.

    Release date:2016-09-01 09:29 Export PDF Favorites Scan
  • Safety and efficacy of dexamethasone intravitreal implant for treatment of macular edema secondary to retinal vein occlusionin Chinese patients: randomized, sham-controlled, multicenter study

    Objective To evaluate the safety and efficacy of dexamethasone intravitreal implant 0.7 mg (DEX) for treatment of macular edema associated with retinal vein occlusion (RVO). Methods This study was a six-month, randomized, double-masked, sham-controlled, multicenter, phase 3 clinical trial with a 2-month open-label study extension. Patients with branch or central RVO received DEX (n=129) or sham procedure (n=130) in the study eye at baseline; all patients who met re-treatment criteria received DEX at month 6. Efficacy measures included Early Treatment Diabetic Retinopathy Study (ETDRS), best-corrected visual acuity (BCVA), and central retinal thickness (CRT) on optical coherence tomography. Results Time to ≥15-letter BCVA improvement from baseline during the first 6 months (primary endpoint) was earlier with DEX than sham (P<0.001). At month 2 (peak effect), the percentage of patients with ≥15-letter BCVA improvement from baseline was DEX: 34.9%, sham: 11.5%; mean BCVA change from baseline was DEX: 10.6±10.4 letters, sham: 1.7±12.3 letters; and mean CRT change from baseline was DEX: −407±212 μm, sham: −62±224 μm (all P<0.001). Outcomes were better with DEX than sham in both branch and central RVO. The most common treatment-emergent adverse event was in-creased intraocular pressure (IOP). Increase sin IOP generally were controlled with topical medication. Mean IOP normalized by month 4, and no patient required incisional glaucoma surgery. Conclusions DEX had a favorable safety profile and provided clinically significant benefit in a Chinese patient population with RVO. Visual and anatomic outcomes were improved with DEX relative to sham for 3 - 4 months after a single implant.

    Release date:2018-05-18 06:38 Export PDF Favorites Scan
  • Correlation Analysis on Adverse Pregnancy Outcomes with Previous Bearing Status

    Objective To explore the correlation between adverse pregnancy outcomes and previous bearing status. Methods The related information of pregnant and postnatal women was extracted from 6825 hospitalized records in two general hospitals and one special hospital, which were selected by the method of cluster sampling, and the related rate and correlation analyses were calculated. Results Women who had abortion history were much easier to cause adverse pregnancy outcomes compared to those who had no abortion history, with the incidence rates of 16.83% and 13.31%, respectively; the incidence rates of adverse pregnancy outcomes of women who ever had zero, one, and two or more than twice of delivery were 14.14%, 16.34% and 22.78%, respectively; the rates of women on their third or more than third, second, first or zero pregnancy were 49.14%, 18.05%, 14.22% and 12.88%, respectively; and the rates of adverse pregnancy outcomes of women with abnormal and normal gestation history were 31.06% and 14.21%, respectively. Conclusion The previous abortion, delivery times and abnormal gestation history are highly related to adverse pregnancy outcomes. Therefore, in order to reduce adverse pregnancy outcomes, it is necessary to make an effective family planning and decrease abortion and pregnancy.

    Release date:2016-09-07 11:03 Export PDF Favorites Scan
  • Association between pregnancy induced hypertension and preterm birth and population attributable risk in pregnant females in mainland China: a meta-analysis

    ObjectivesTo systematically review the association between pregnancy-induced hypertension (PIH) and preterm birth in mainland China.MethodsPubMed, The Cochrane Library, ScienceDirect, Web of Science, CBM, CNKI, WanFang Data and VIP databases were electronically searched to collect studies on the association between PIH and preterm birth in mainland China from January, 2007 to March, 2019. Two reviewers independently screened literature, extracted data and assessed risk of bias of included studies; then, meta-analysis was performed by using Stata 12.0 software.ResultsA total of 48 studies were included, involving 43 276 cases of premature birth, 527 995 cases of full-term control group, in which there were 3 446 cases of PIH in premature delivery, with a prevalence rate of 7.96%. There were 14 099 cases of PIH in the full-term control group, with a prevalence rate of 2.67%. The results of meta-analysis showed that PIH was associated with preterm birth (OR=3.27, 95%CI 2.64 to 4.05, P<0.001). The overall population attributable risk was 13.0%. Subgroup analysis was conducted for different study types, and the results were unaltered.ConclusionsThe current evidence shows that PIH is associated with preterm birth. During pregnancy, the management and intervention of pregnant females with gestational hypertension should be strengthened, and active treatment should be supervised to prevent the occurrence of premature birth.

    Release date:2020-02-04 09:06 Export PDF Favorites Scan
  • Research progress of methylcellulose-based thermosensitive hydrogels applied in biomedical field

    Methylcellulose is a semi-flexible cellulose ether derivative, whose hydrogels are thermosensitive and reversible, with good biocompatibility and adjustable function, and its application has attracted much attention in the biomedical field. In this paper, the application of methylcellulose-based thermo-sensitive hydrogels in biomedical field was reviewed. Based on the mechanism of gelation and influencing factors of methylcellulose, this paper focused on the recent advances in biomedical applications of methylcellulose-based hydrogels, including drug delivery, regenerative medicine, and other related fields. The current achievements in these fields were summarized in the form of lists in this paper to provide ideas and tendencies for future research. Finally, the future development of multifunctional methylcellulose-based hydrogel materials with improved performance was also discussed.

    Release date:2024-04-24 09:40 Export PDF Favorites Scan
  • PREPARATION OF PLASTIC NANO-HYDROXYAPATITE/POLY(3-HYDROYYBUTYRATE-HYDROXYVALE-RATE)POLYETHY LENE GLYCOL GENTAMICIN DRUG DELIVERY SYSTEM

    Objective To develop the plastic nano-hydroxyapatite (nano-HA)/poly (3-hydroxybutyrate-hydroxyvalerate)  polyethylene glycol(PHBV-PEG) gentamicin (GM) drug delivery system(DDS)(nano-HA/PHBV-PEG-GM-DDS) for treating osteomyelitis and find its releasing character in vivo. Methods The plastic nano-HA/PHBV- PEG-GM-DDS was prepared using nanoHAas the core carrier of GM, nano-HA with PHBV and PEG as coating and plastic fibrin glue(FG) as microsphere scaffold. The morphological features of nano-HA,drug loaded nano-HA and drug loaded nano-HA/PHBVPEG microsphere were examined by electron microscope.The GM concentration in blood, cortex bone and cancellousbone was detected at 12 different time points by the method of K-B after the plastic nano-HA/PHBV-PEGGM-DDS was implanted into the femora of 36 rabbits. Its GM releasing character was assayed in vivo. Results Nano-HA was similar to a blackjack, and its length was less than 60 nm. Drug loaded nano-HA appeared natural crystal condensate, of which surface adsorbed massive GM. The average grain diameter was 200.5 nm. Drug loaded nanoHA/PHBV-PEG microsphere had a shrinkable porous structure, of which surface configuration was consistent. The average grain diameter was 34.5 μm. The GM concentration and the antibacterial annulus was in the linear correlation. The correlation coefficient was 0.998. In cortex and cancellous bone tissue, the GM concentration was about 95.50±16.50 μg/ml and 80.20±13.80 μg/ml from the plastic nano-HA/PHBV-PEG-GM-DDS on the 1st day, then decreased gradually. After 56 days of operation, the GM concentration still exceeded the minimum inhibitory concentrationfor the staphylococcus aureus, but the peak level of serum GM concentration wasunder the nephrotoxicity concentration. Conclusion Plastic nano-HA/PHBV-PEG-GM-DDS was a good drug delivery system with sustained antibiotic effect in vivo. It was an effective method for the treatment of osteomyelitis.

    Release date:2016-09-01 09:26 Export PDF Favorites Scan
  • The Correlation of Amniotic Fluids Levels and Blood Serum Levels of Matrix Metalloproteinases-8 and Interleukin-6 with Preterm Delivery

    ObjectiveTo investigate the expression of amniotic fluid levels and blood serum levels of matrix metalloproteinases-8 (MMP-8) and interleukin-6 (IL-6) in women with preterm delivery. MethodsBetween January 2010 and December 2012, we collected the amniotic fluid of 102 preterm pregnant women and 98 full term pregnant women and analyzed the MMP-8 levels and IL-6 levels in amniotic fluid and blood serum. Meanwhile, we also collected the amniotic fluid to do bacterial culture. ResultsThe amniotic fluid levels of MMP-8 in preterm pregnant women were higher than those in full term pregnant women [(320.45±59.88) vs (153.72±29.12) ng/mL, P<0.05], but there was no obvious discrepancy in the blood serum levels of MMP-8 in the two groups [(9.56±2.11) vs (9.42±2.01) ng/mL, P>0.05]. Both amniotic fluid levels and blood serum levels of IL-6 in preterm pregnant women were significantly higher than the full term pregnant women [(90.5±16.3] vs (20.6±12.5) μg/L, P<0.05; (159.2±20.4) vs (22.3±11.8) μg/L, P<0.05]. The positive bacterial culture rate of preterm pregnant women was higher than the full term pregnant women (8.8% vs 1.0%, P<0.05). ConclusionInfection is the most important reason for preterm pregnancy. MMP-8 level increases in the amniotic fluid, and the level of IL-6 in amniotic fluid and blood serum is a valuable clinical index for identifying premature delivery.

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  • STUDY ON ADRIAMYCIN-POROUS TRICALCIUM PHOSPHATE CERAMIC DRUG DELIVERY SYSTEM AND ITS DRUG RELEASE TEST IN VIVO

    OBJECTIVE To manufacture adriamycin-porous tricalcium phosphate (A-PTCP) ceramic drug delivery system (DDS) as a possible method for bone defect treatment after bone tumor operation. METHODS A-PTCP DDS was made from putting adriamycin into PTCP. Thirty rabbits were divided randomly into group A(24 rabbits) and group B(6 rabbits). A-PTCP was implanted in the greater trochanter of the right femur in group A. Adriamycin were injected into veins in group B. Muscle around A-PTCP and plasma were taken out at different period. Adriamycin concentrations in muscle and plasma were measured by high performance liquid chromatography (HPLC). RESULTS A-PTCP could gradually release adriamycin over 10 weeks. Adriamycin concentrations in the muscle were higher than that in plasma. CONCLUSION A-PTCP may be a new method for repairing bone defects after bone tumor operation.

    Release date:2016-09-01 10:20 Export PDF Favorites Scan
  • Two-port subretinal injection without vitrectomy for the treatment of Bietti crystalline dystrophy

    ObjectiveTo observe the safety of 2-port non-vitrectomized subretinal injection (SRI) for the treatment of Bietti crystalline dystrophy (BCD). MethodsA exploratory clinical study. From February to May 2023, 6 BCD patients with 6 eyes who were confirmed by examination in Xiamen Eye Center of Xiamen University and were treated with SRI adeno-associated virus vector transgenic drugs were included in the study. Among them, 2 males had 2 eyes and 4 females had 4 eyes. Age were 34-60 years old. The study eye underwent adeno associated virus gene therapy via 2-port non-vitrectomized SRI. Two scleral ports were created using 25G vitrectomy trocar to place the light pipe and injection cannula. Anterior chamber paracentesis was performed to lower intraocular pressure. Under the silicone oil infusion mode of the vitrectomy machine, a 38G injection cannula penetrated the retina to reach the subretinal space. The injection speed was controlled by the foot pedal of the vitrectomy machine, and the drug was slowly injected into the subretinal space to create a subretinal bleb. if intra-ocular pressure assessed by finger palpation was high at the end of injection, drainage of the aqueous humor can be made by compressing the cornea incision until the intraocular pressure was normal. Patients were followed for 9-12 months and be examined using the same equipment and methods as before. ResultsRetinal pigment epithelium and choroidal atrophy were observed in all 6 eyes of 6 patients were graded as stage Ⅲ by the fundus examination revealing atrophy of retinal pigmented epithelium and choroid, with or without yellow-white crystals and/or complex lipid. The range were operation time 9-14 minutes. No vitreous prolapse, retinal hemorrhage, or retinal tear was observed during surgery. After 24 hours, optical coherence tomogrophy examination showed absorption of subretinal fluid and retinal reattachment. None of the six patients showed corneal keratic precipitates, anterior chamber cells, vitreous cells, inflammation, high intraocular pressure, or retinal tear within the 9-month follow-up. ConclusionSubretinal injection without vitrectomy using two ports is a safe and feasible alternative for adult gene therapy, and it shortens the surgical time.

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